Epidemiology, the Basis for Public Health

Marcia Stanhope, PhD, RN, FAAN

Public Health Surveillance and Outbreak Investigation

Dr. Marcia Stanhope is currently an Associate of t he Tufts and Associates Search Firm, Ch icago, Ill. She is also a consultant for the nursing program at Berea College, Kentucky. She has practiced comm unity and home health nu rsin g, ha s served as an administrator and consultant in home health, and has been involved in the development of t wo nurse-managed centers. At one time in her career, she held a publ ic policy fel- lowsh ip and worked in the office of a U.S. Senator. She has taught community health, public hea lth, epide- miology, policy, primary ca re nursing, and administration courses. Dr. Stanhope forme rl y directed t he Div ision of Community Health Nursing and Admi nistrat ion and served as Associate Dean of the College of Nurs ing at the Univers ity of Kentucky. She has been respons ible for both undergraduate and graduate cou rses in population-centered nursing . She has also taught at the University of Virginia and the University of Alabama , Birm in gham. During her career at the University of Kentucky she appointed t o the Good Samaritan Founda- tion Cha ir and Professorsh ip in Community Health Nu rsing, and was honored with the University Provost's Public Scholar award. Her presentations and publications have been in the areas of home health, community health and commun ity-focused nursing practice, as well as primary care nursing .

ADDITIONAL RESOURCES . -

@ Evolve Website http://evolve.elsevier.com/Stanhope • Healthy People 2020

WebLinks-Of special note, see the link for these sites: • National Notifiable Disease Surveillance System • Enhanced Surveillance Project

• Quiz • Case Studies

OBJECTIVES After reading this chapter, the student should be able to do the fo llowing: 1. Define public health surveillance. 2. Analyze types of surveillance systems. 3. Identify steps in planning, analyzing, interviewing, and

evaluating surveillance.

KEY TERMS

• Glossary • Answers to Practice Application

Appendix D.3: Prevention and Control of Pandemic Influenza: Individuals and Families

4. Recognize sources of data used when investigating a disease/ condition outbreak.

5. Relate the role of the nurse in surveillance and outbreak investigation to the national core competencies for public health nurses.

----- ~-" - -- - - ·--- ~ ' - --- --- - --- - algorithms, p. 532 biological terrorism, p. 531 BioNet, p. 537 case definition, p. 533 chemical terrorism, p. 531 clusters of illness, p. 530 common source, p. 538 disease surveillance, p. 530 endemic, p. 538 Enhanced Surveillance Project, p. 537 epidemic, p. 538

event, p. 531 holoendemic, p. 538 hyperendemic, p. 538 infectivity, p. 538 intermittent or continuous source, p . 538 Laboratory Response Network, p. 537 mixed outbreak, p. 538 National Notifiable Disease Surveillance System, p. 536 outbreak, p. 538 outbreak detection, p. 538 outcome data, p. 531

529

PART 4 Issues and Approaches in Population-Centered Nursing

KEY TERMS-cont'd ~ - - - - - -·--- - - - - -- - - - - ·- - - pandemic, p. 538 pathogenicity, p. 538 point source, p. 538 process data, p. 531 propagated outbreak, p. 538 public health protection, p. 530 PulseNet, p. 537

CHAPTER OUTLINE -~-- -~ ---~~----~------- Disease Surveillance

Definitions and Importance Uses of Public Health Surveillance Purposes of Surveillance Collaboration among Partners Nurse Competencies Data Sources for Surveillance

Notifiable Diseases National Notifiable Diseases State Notifiable Diseases

Case Definitions Criteria Case Definition Examples

Disease surveillance has been a part of public health protection

since the 1200s, during the investigations of the bubonic plague

in Europe. During the 1600s John Graunt developed the fun-

damental principles of public health including surveillance and

outbreak investigation, and in the 1700s Rhode Island passed

the first public health laws to provide for the protection of

health and care of the population of the state. In the eighteenth

century, William Farr introduced the modern version of sur-

veillance and, along with the United States, Italy, and Great

Britain, began required reporting systems for infectious dis-

eases. In 1901, the United States began the requirement for

reporting cases of cholera, smallpox, and tuberculosis. By 1925

the United States began national reporting of morbidity causes.

By 1935 the first national health survey had been conducted,

and in 1949 the National Office of Vital Statistics published

weekly mortality and morbidity statistics in the journal Public

Health Reports. This activity was later transferred to the Centers

for Disease Control and Prevention, who began publishing the

Morbidity and Mortality Weekly Report in 1961. Laws, regula-

tions, reporting mechanisms, and data collections are all essen-

tial to surveillance and disease outbreak investigations (Thacker

et al, 2012). The Constitution of the United States provides for "police

powers" necessary to preserve health safety as well as in other

events (see Chapter 8). These powers include public health

surveillance. State and local "police powers" also provide for

surveillance activities. Health departments usually have legal

person under investigation, p. 536 sentinel, p. 534 sporadic, p. 538 syndromic surveillance systems, p. 537

virulence, p. 538 - See Glossary for definitions

- -· ~---- - -- ------ - - - -- Types of Surveillance Systems

Passive System Active System Sentinel System Special Systems

The Investigation Investigation Objectives Patterns of Occurrence When to Investigate Steps in an Investigation Displaying of Data

authority to investigate unusual clusters of illness as well

(Gostin, 2010). Florence Nightingale first demonstrated the nurse's role in

responding to disasters. Public health nurses bring specific skills

to events that require emergency responses. They are prepared

to focus on the population that is affected in order to develop

policies and comprehensive plans for conducting and evaluat-

ing disaster response drills, exercises, and trainings. Public

health nurses are first responders in emergency situations in the

community, they can lead and manage in the field and in the

incident command center, and they are able to collaborate with

others to sustain the emergency infrastructure (Association of

Public Health Nurses [APHN], 2013) . It is important for nurses

to be prepared to lead and be a team member if an unusual

occurrence or event strikes a community (see Chapters 3 and

46 about the public health response to the Ebola virus outbreak

in the United States in 2014).

DISEASE SURVEILLANCE ----------- Definitions and Importance Disease surveillance is the ongoing systematic collection, anal-

ysis, interpretation and dissemination of specific health data

for use in public health (Lee et al, 2010; Webster's New World

Medical Dictionary, 2014). Surveillance provides a means for

nurses to monitor disease trends in order to reduce morbidity

and mortality and to improve health (Veenema, 2013).

CHAPTER 24 Public Health Surveillance and Outbreak Investigation

Surveillance is a critical role function for nurses practicing in the community. A comprehensive understanding and knowl- edge of the surveillance systems and how they work will help nurses improve the quality and the usefulness of the data collected for making decisions about needed community ser- vices, community actions, and public health programming (Chapter 23 provides additional information). The surveillance features indicate it:

Is organized and planned • Is the principal means by which a population's health status

is assessed • Involves ongoing collection of specific data • Involves analyzing data on a regular basis

Requires sharing the results with others Requires broad and repeated contact with the public about personal health issues Motivates public health action as a result of data analyses to:

Reduce morbidity • Reduce mortality • Improve health Surveillance is important because it generates knowledge

of a disease or event outbreak patterns (including timing, geographic distribution, and susceptible populations). The knowledge can be used to intervene to reduce risk or prevent an occurrence at the most appropriate points in time and in the most effective ways. Surveillance is built on understanding of epidemiologic principles of agent, host, and environmental relationships and on the natural history of disease or condi- tions (see Chapter 12). Surveillance systems make it possible to engage in effective continuous quality improvement activi- ties within organizations and to improve quality of care (Veenema, 2013).

Surveillance focuses on the collection of process and outcome data. Process data focus on what is done (i.e., services provided or protocols for health care delivery). Outcome data focus on changes in health status. The activities generated by analyses of these data aim to improve public health response systems. An example of process data is collection of data about the propor- tion of the eligible population vaccinated against influenza in any one year. Outcome data in this case are the incidence rates (new cases) of influenza among the same population in the same year.

Although surveillance was initially devoted to monitoring and reducing the spread of infectious diseases, it is now used to monitor and reduce chronic diseases and injuries, and environ - mental and occupational exposures ( Centers for Disease Control and Prevention [CDC), 2014e; Veenema, 2013) as well as per- sonal health behaviors. Surveillance systems help nurses and other professionals monitor emerging infections and bioterror- ist outbreaks (Pryor and Milligan, 2013). Bioterrorism is one example of an event creating a critical public health concern that involves environmental exposures that must be monitored. This event also requires serious planning in order to be able to respond quickly and effectively. Biological terrorism is defined as "the deliberate release of viruses, bacteria, or other germs (agents) used to cause illness or death in people, animals, or plants" (http://www.bt.cdc.gov/bioterrorism) (CDC, 2014a).

Chemical terrorism is the intentional release of hazardous chemicals into the environment for the purpose of harming or killing (CDC, 2013a). In the event of a bioterrorist attack, imagine how difficult it would be to control the spread of bio- logical agents such as botulism or anthrax or chemical agents such as sarin or ricin if no data were available about these agents, their resulting diseases or symptoms, and their usual incidence (new cases) patterns (new cases) in the community. The United States spent approximately $60 billion by 2012 to assist states in preparing for bioterrorist incidents. Roughly one half of that money has funded detection systems; dramati- cally expanded research on bioweapon agents; and the develop- ment, procurement, and stockpiling of vaccines and other medical countermeasures against these agents.

Uses of Public Health Surveillance Public health surveillance can be used to facilitate the following (CDC, 2010a):

Estimate the magnitude of a problem ( disease or event) • Determine geographic distribution of an illness or

symptoms Portray the natural history of a disease

• Detect epidemics; define a problem Generate hypotheses; stimulate research

• Evaluate control measures • Monitor changes in infectious agents

Detect changes in health practices • Facilitate planning (Koo 2010)

Purposes of Surveillance The overall purposes of surveillance are as follows: • Assess public health status • Define public health priorities • Evaluate programs

Stimulate research Surveillance helps public health departments identify trends

and unusual disease patterns, set priorities for using scarce resources, and develop and evaluate programs for commonly occurring and universally occurring diseases or events. Surveil- lance activities can be related to the core functions of public health: assessment, policy development, and assurance. Disease surveillance helps establish baseline (endemic) rates of disease occurrence and patterns of spread. Surveillance makes it pos - sible to initiate a rapid response to an outbreak of a disease or event that can cause a health problem. For example, surveillance made it possible to respond quickly to the anthrax outbreak that occurred shortly after the September 11, 2001, attack on the World Trade Centers. Surveillance also made it possible to respond early to the HlNl outbreak that initially began in Mexico in 2009 (CDC, 2012).

Surveillance data are analyzed, and interpretations of these data analyses are used to develop policies that better protect the public from problems such as emerging infections, bioterrorist biological and chemical threats, and injuries from problems such as motor vehicle accidents. In 2006 a great deal of empha- sis was placed on developing disaster management policies in health care organizations, industries, and homes so that the U.S.

PART 4 Issues and Approaches in Population-Centered Nursing

population could be prepared in the event of an emergency.

Surveillance within individual organizations, such as infection

control systems in hospitals, can be used to establish policies

related to clinical practice that are designed to improve quality

of care processes and outcomes. An example is documented by

Ergaz and colleagues (20 10), where a policy of weekly fecal

cultures for vancomycin-resistant enterococci (VRE) was insti-

tuted after the investigation of an outbreak of VRE in the neo-

natal intensive care unit. Surveillance makes it possible to have ongoing monitoring

in place to ensure that disease and event patterns improve rather

than deteriorate. They can also make it possible to study whether

the clinical protocols and public health policies that are in

place can be enhanced, based on current science, so that disease

rates actually decline (World Health Organization [WH O],

2014a). For example, the ongoing monitoring of obesity in

children in a community may show that new clinical and effec-

tive protocols need to be developed to be used in school-based

clinics to reduce the prevalence of obesity among the school

populations. Surveillance data are very helpful in determining whether a

program is effective. Such data make it possible to determine

whether public health interventions are effective in reducing the

spread of disease or the incidence of injuries. By determining

the change in the number of cases at the beginning of a program

(baseline) with the number of cases after program implementa-

tion, it is possible to estimate the effectiveness of a program.

One could then compare the effectiveness of different approaches

to reducing the problem or to improving health. Johns and col-

leagues (2010) investigated whether prior seasonal influenza

vaccination was effective against the pandemic strain of HlNl

(pHlNl) virus among military personnel. Their findings indi-

cated that with the seasonal influenza vaccines of 2004 to 2009,

moderate protection against HlNl was associated with the vac-

cines of these years. The protection seemed to have a greater

association with severe disease rather than a mild case regard-

less of age of the ill person.

Collaboration among Partners A quality surveillance system requires collaboration among a

number of agencies and individuals: federal agencies, state and

local public health agencies, hospitals, health care providers,

medical examiners, veterinarians, agriculture, pharmaceutical

agencies, emergency management, and law enforcement agen-

cies, as well as 911 systems, ambulance services, urgent care and

emergency departments, poison control centers, nurse hotlines,

schools, and industry. Such collaboration promotes the devel-

opment of a comprehensive plan and a directory of emergency

responses and contacts for effective communication and infor-

mation sharing. It is sometimes essential to include collabora-

tion with international agencies as well. The type of information

to be shared includes the following:

• How to use algorithms to identify which events should be investigated (i.e., this means using a precise step-by-step plan

outlining a procedure that in a finite number of steps helps

to identify the appropriate event) How to investigate

• Whom to contact • How and to whom information is to be disseminated

Who is responsible for appropriate action Nurses are often in the forefront of responses to be made in

the surveillance process whether working in a small rural agency

or a large urban agency; within the health department, school,

or urgent care center; or on the telephone performing triage

services during a disaster. It is the nurse who sees the event first

(APHN, 2013).

EVIDENCE-BASED PRACTICE

An analysis was conducted to identify uses of spatial ana lysis in cancer

screening interventions . Researchers used a spatial analysis tool ca ll ed

cluster detection to identify geographic areas with populations at high risk for

colorecta l cancer. Specifically, the investigators used the free cluster detec-

tion software application Sa TScan to map the at-risk population. The research-

ers sought to identify which spatial analysis method was most successful in

identifying at-risk popu lations. Various methods were used to detect areas in

Florida where the population was at high ris k. Although no single method

emerg ed as being able to detect all significant clusters, all methods did detect

one area as high ri sk. This area could be seen as a priority area to implement

a screening intervention to improve ea rl y identification of disease and early

treatment.

Nurse Use Cluster detection is a surveil lance too l that pub lic health nurses can use to

determine geographic priority areas for health promotion and disease preven-

tion interventions. Being able to focus on a specific area would enable the

nurse to use public health resources in an efficient manner and provide out-

reach to the populations at highest risk for disease.

From Sherman RL, Henry KA, Tan nen baum SL, et al: Applying spatial

ana lys is too ls in public health: an example using SaTSca n to detect geograph ic targets for colore cta l cancer sc reening interventions. Prev Chronic Dis 11 :130264, 2014. DO I: http//dx.doi.org/10.5888/ pcd11.130264.

Nurse Competencies The national core competencies for public health nurses were

developed from the Core Competencies for Public Health Pro-

fessionals ( Council on Linkages between Academia and Public

Health Practice, 2014) and by the Quad Council of Public

Health Nursing Organizations (2011). These competencies are

divided into eight practice domains: analytical assessment skills,

policy development/program planning, communication, cul-

tural competency, community dimensions of practice, basic

public health sciences, financial planning/management, and

leadership and systems thinking.

To be a participant in surveillance and investigation activi-

ties, the staff nurse must have the following knowledge related

to the core competencies:

1. Analytical assessment skills

• Defining the problem

• Determining a cause

• Identifying relevant data and information sources

• Partnering with others to give meaning to the data

collected Identifying risks

CHAPTER 24 Public Health Surveillance and Outbreak Investigation 533

2. Communication • Providing effective oral and written reports • Soliciting input from others and effectively presenting

accurate demographic, statistical, and scientific informa- tion to other professionals and the community at large

3. Community dimensions of practice • Establishing and maintaining links during the investigation • Collaborating with partners • Developing, implementing, and evaluating an assessment

to define the problem 4. Basic public health science skills

• Identifying individual and organizational responsibilities • Identifying and retrieving current relevant scientific

evidence 5. Leadership and systems thinking

Identifying internal and external issues that have an effect on the investigation Promoting team and organizational efforts

• Contributing to developing, implementing, and monitor- ing of the investigation

While the staff nurse participates in these activities, the nurse clinical specialist should be proficient in applying these compe- tencies. In addition, the nurse applies the nursing process in preparedness as illustrated in Table 24-1.

The Minnesota Model of Public Health Interventions: Appli- cations for Public Health Nursing Practice (2001, pp. 15-16; also see Chapters 9 and 23) suggests that surveillance is one of the interventions related to public health nursing practice. The model gives seven basic steps of surveillance for nurses to follow: 1. Consider whether surveillance as an intervention is appro-

priate for the situation. 2. Organize the knowledge of the problem, its natural course

of history, and its aftermath. 3. Establish clear criteria for what constitutes a case. 4. Collect sufficient data from multiple valid sources. 5. Analyze data. 6. Interpret data and disseminate to decision-makers. 7. Evaluate the impact of the surveillance system.

Data Sources for Surveillance Clinicians, health care agencies, and laboratories report cases to state health departments. Data also come from death certificates and administrative data such as discharge reports and billing

records (Pryor and Milligan, 2013). The following are select sources of mortality and morbidity data: 1. Mortality data are often the only source of health-related

data available for small geographic areas. Examples include the following: • Vital statistics reports ( e.g., death certificates, medical

examiner reports, birth certificates) • Mortality data can be obtained from the National Vital

Statistics System. These data are available and one of the few sources of health-related data that are available for a long time period for small geographic areas ( CDC, 2014g)

2. Morbidity data include the following: • Notifiable disease reports • Laboratory reports

Hospital discharge reports • Billing data • Outpatient health care data • Specialized disease registries • Injury surveillance systems

Environmental surveys • Sentinel surveillance systems A good example of a process in place to collect morbidity

data is the National Program of Cancer Registries ( CDC, 2014f). This program provides for monitoring of the types of cancers found in a state and the locations of the cancer risks and health problems in the state.

Each of the data sources has the potential for underreporting or incomplete reporting. However, if there is consistency in the use of surveillance methods, the data collected will show trends in events or disease patterns that may indicate a change n eeded in a program or a needed prevention intervention to reduce morbidity or mortality. Underreporting or incomplete report- ing may occur for the following reasons: social stigma attached to a disease (such as human immunodeficiency virus [HIV]/ acquired immunodeficiency syndrome [AIDS]) ; ignorance of required reporting system; lack of knowledge about the case definition, procedural changes in reporting, or changes in a database; limited diagnostic abilities; or low priority given to reporting (CDC, 2010a).

Mortality data assist in identifying differences in health status among groups, populations, occupations, and communi- ties, and in monitoring preventable deaths; they also help in examining cause-and-effect factors in diseases (CDC, 2014g). Vital statistics can be used to plan programs and to monitor

TABLE 24-1 Phases of Nursing Process Linked to Preparedness

Preparedness

Assure ca pacity to respond effectively to disasters and emergencies

Assessment

Assess the populations at risk for special needs during a disaster

DEFINITION OF:

Planning

Develop plans to care for special needs populations during a disaster

Implementation

Conduct training, drills, and exercises related to care of special needs person s

Evaluation

Evaluate plans for serving populations with special needs

Excerpted from Association of Public Health Nurses (APHN): The Role of Public Health Nurses in Emergency Preparedness and Response: Position Paper [Table 1: The Phases of Disaster Li nked to t he Nursing Process]. 2013. Retrieved Jan uary 2015 from https://www.resource nter . net/images/ AC H NE/Files/ APH N Roleof PH Nin DisasterP R R_30 May 13. pdf

534 PART 4 Issues and Approaches in Population-Centered Nursing

programs to meet Healthy People 2020 goals (see the Healthy People 2020 box for objectives related to surveillance).

The National Notifiable Disease Laboratory (NNDSS) as well as local public health laboratories, hospital discharge data, and billing data provide mechanisms for classifying diseases and events and calculating rates of diseases within and across groups, populations, and communities (CDC, 2013).

The sentinel surveillance system provides for the monitor- ing of key health events when information is not otherwise available for vulnerable populations in order to calculate or estimate disease morbidity. Registrations monitor chronic disease in a systematic manner, linking information from a variety of sources (health department, clinics, hospitals) to identify disease control and prevention strategies. Surveys then provide data from individuals about prevalence of health condi- tions and health risks. Such surveys allow for monitoring changes over time and assessing the individual's knowledge, attitudes, and beliefs (see QSEN box). This information can be used for health education and other planned interventions (Gostin, 2010).

~ FOCUS ON QUALITY AND SAFETY EDUCATION FOR NURSES

Targeted Competency: Safety Minimizes risk for harm to clients and providers through both system effective- ness and individual performance. • Knowledge: Discuss potential and actual impact of national client safety

resources, initiatives, and regulations. • Skill: Use national resources for own development and to focus attention

on safety in the community. • Attitude: Value relationships between national safety campaigns and

implementation in locales, times and settings.

Safety Question The Quad Council competency for communication skills indicates that the public health nurse uses a variety of methods to disseminate public health information to populations within a community and provides a presentation of targeted health information to multiple audiences at a local level: groups, professionals, and agency peers.

How would the nurse use the national sentinel surveillance system to identify health conditions and risks in the community? What types of data sources in this system would the nurse collect? After careful analysis of the data sources, what would the nurse include in a presentation to multiple audiences?

NOTIFIABLE DISEASES

Before 1990 state and local health departments used many dif- ferent criteria for identifying cases of reportable diseases. Using different criteria made the data less useful than it could have been because it could not be compared across health depart- ments or states, For this reason some diseases may have been under-reported and others may have been over-reported. In 1990 the CDC and the Council of State and Territorial Epide- miologists assembled the first list of standard case definitions. This list was revised in 1997, and more information may be

~ HEALTHY PEOPLE 2020 Surveillance Objectives

• EH-5: Reduce waterborne disease outbreaks arising from water intended for drinking among persons served by community water systems.

• FS-1: Reduce outbreaks of infections caused by key foodborne bacteria. • FS-2: Reduce infections associated with foodborne outbreaks due to patho-

gens commonly transmitted through food. • GH-1: Reduce the number of cases of malaria reported in the United

States. • IID-16: (Developmental) Increase the scientific knowledge on vaccine

safety and adverse events. • PHl-2: Increase the proportion of tribal, state, and local public health

agencies that incorporate core competencies for public health profession- als into the job.

• PHl-7: Increase the proportion of population-based Healthy People 2020 objectives for which national data are available for all population groups identified for the objective.

From USDHHS Healthy People 2020: A Roadmap to improve all Americans' health. Wash, DC, 2010 US Govt Printing Office

found at the CDC Division of Public Health Surveillance and Informatics website (CDC, 1997). This site contains informa- tion about the National Notifiable Disease Surveillance System (CDC-NNDSS, 2013), and the standard case definitions are updated on a case-by-case basis or otherwise remain the same. For example, the definition of anthrax was updated in 2010. New case definitions are added as new diseases are identified.

National Notifiable Diseases Box 24-1 shows the national notifiable infectious diseases, Reporting of disease data by health care providers, laboratories, and public health workers to state and local health departments is essential if trends are to be accurately monitored. "The data provide the basis for detecting disease outbreaks, for identifying person characteristics, and for calculating incidence, geographic distribution, and temporal trends. They are used to initiate prevention programs, evaluate established prevention and control practices, suggest new intervention strategies, identify areas for research, document the need for disease control funds, and help answer questions from the community" (CDC, 2014b). The CDC and the Council of State and Territo- rial Epidemiologists have a policy that requires state health departments to report selected diseases to the CDC-NNDSS, The data for nationally notifiable diseases from 50 states, the U.S. territories, New York City, and the District of Columbia are published weekly in the Morbidity and Mortality Weekly Report (MMWR). Data collection about these diseases is ongoing and revision of statistics is ongoing. Annual updated final reports are published in the CDC Summary of Notifiable Diseases- United States (CDC, 2014b).

State Notifiable Diseases Requirements for reporting diseases are mandated by law or regulation. Although each state differs in the list of reportable diseases, the usefulness of the data depends on "uniformity,

CHAPTER 24 Public Health Surveillance and Outbreak Investigation

BOX 24-1 Infectious Diseases Designated as Notifiable at the National Level during 2014* • Anthrax • Meningococcal disease • Arboviral diseases, neuroinvasive and non-neuroinvasive • Mumps • Babesiosis • Novel influenza A virus infections • Botulism • Pertussis • Chancroid • Plague • Chlamydia trachomatis infection • Poliomyelitis, para lytic • Cholera • Poliovirus infection, nonparalytic • Coccidioidomycosis • Psittacosis • Congenital syphilis • Q fever • Cryptosporidiosis • Rabies, animal • Cyclosporiasis • Rabies, human • Dengue virus infections • Rubella • Diphtheria • Rube ll a, congenital syndrome • Ehrlichiosis and anaplasmosis • Salmonellosis • Giardiasis • Severe acute respiratory syndrome-associated coronavirus disease • Gonorrhea • Shiga toxin-producing Escherichia coli • Haemophilus influenzae, invasive disease • Shigellosis • Hansen's disease • Smallpox • Hantavirus pulmonary syndrome • Spotted feve r rickettsiosis • Hemolytic uremic syndrome, postdiarrheal • Streptococcal toxic-shock syndrome • Hepatitis A acute • Syphilis • Hepatitis B, acute • Tetanus • Hepatitis B, chronic • Toxic shock syndrome (other than streptococcal) • Hepatitis B, perinatal infection • Trichinellosis • Hepatitis C, acute • Tuberculosis • Hepatitis C, past or present • Tularemia • HIV infection (AIDS has been reclassified as HIV stage Ill) • Typhoid fever • Influenza-associated pediatric mortality • Vancomycin-interme diate Staphylococcus aureus and vancomycin-resistant • Invasive pneumococcal disease Staphylococcus aureus • Legionellosis • Varicel la • Leptospirosis • Varicella deaths • Listeriosis • Vibriosis • Lyme disease • Viral hemorrhagic fever • Malaria • Yellow feve r • Measles

From Centers for Disease Cont rol and Prevention (CDC): Summary of notifiable diseases in the United States, 2014. Retrieved January 2015 from www. CDC.gov

simplicity, and timeliness." Because state requirements differ, not all nationally notifiable diseases are legally mandated for reporting in a state. For legally reportable diseases, states compile disease incidence data (new cases) and transmit the data electronically (weekly) to the CDC through the National Electronic Telecommunications System for Surveillance (CDC- NETSS, 2013) (www.cdc.gov/surveillance).

Ongoing analysis of this extensive database has led to better diagnosis and treatment methods, national vaccine schedule recommendations, changes in vaccine formulation, and the rec- ognition of new or resurgent diseases (CDC-NEISS, 2013d). Selected data are also reported in documents such as Epidemio- logic Notes and Reports located weekly in the CDC MMWR report (www.CDC.gov). Adverse health data for the calendar year are documented on the reportable disease form, entitled EPID, to the local health department or the state department for public health. Local health department surveillance person- nel investigate case reports and proceed with recommended

public health measures, requesting assistance from the state's department assigned to monitor the reports when needed. Reports are forwarded by mail or fax or, in urgent circum- stances, by telephone 24 hours a day, 7 days a week. When reports are received, they are scrutinized carefully and, when appropriate, additional steps are initiated to assist local health departments in planning interventions.

To determine which of the national notifiable diseases are reportable in your state, go to your state health department website.

CASE DEFINITIONS Criteria Criteria for defining cases of different diseases are essential for having a uniform, standardized method of reporting and moni- toring diseases. A case definition provides understanding of the data that are being collected and reduces the likelihood that

536 ·. PART 4 Issues and Approaches in Population-Centered Nursing

different criteria will be used for reporting similar cases of a disease. Case definitions may include clinical symptoms, labo- ratory values, and epidemiologic criteria (e.g., exposure to a known or suspected case). Each disease has its own unique set of criteria based on what is known scientifically about that particular disease. Cases may be classified as suspected, probable, or confirmed, depending on the strength of the evidence sup- porting the case criteria.

Although some diseases require laboratory confirmation, even though clinical symptoms may be present, other diseases do not have laboratory tests to confirm the diagnosis. Other cases are diagnosed on the basis of epidemiologic data alone, such as exposure to contaminated food. If a case definition has been established by the CDC or another official source, it should be used for reporting purposes. The case definition should not be used as the only criterion for clinical diagnosis, quality assur- ance, standards for reimbursement, or taking public health action. Action to control a disease should be taken as soon as a problem is identified, although there may not be enough infor- mation to meet the case definition. For example, following the September 11, 2001, terrorist attacks and subsequent crises, when white powder substances were found in the offices of Congress and select post offices, the offices were shut down and evacuated for safety until the final determination of the pres- ence or absence of anthrax (Wright et al, 2010).

Case Definition Examples Many examples of case definitions exist in the literature and in

government documents. The case definition for a confirmed case of anthrax was given by the CDC (2010b) as "(l) a clini-

cally compatible case of cutaneous, inhalational, or gastrointes- tinal illness that is labo ratory confirmed by isolation of B. anthracis from an affected tissue or site, or (2) other laboratory evidence of B. anthracis infection based on at least two sup- portive laboratory tests." A suspected case was defined as "an illness suggestive of one of the known anthrax clinical forms.

No definitive, presumptive, or suggestive laboratory evidence of

B. anthracis, or epidemiologic evidence relating it to anthrax" (http://www.cdc.gov).

Kuo and colleagues (2009) reported on the first Shigella sonnei outbreak in Austria in July 2008. They provided case definitions for confirmed cases as follows: a cluster of 22 laboratory-confirmed cases of infection with S. sonnei, which was restricted to public health district X in the province of Salzburg. All cases had attended a youth group trip to a small

village in the province of Tyrol from July 7 to July 9. An out-

break case among the trip participants was a person who (1) attended the trip, and (2) fell ill with diarrhea in the period

between July 8 and July 12. Among the 61 trip participants, 42 fit the outbreak case definition, including 31 culture-confirmed cases. A household outbreak case was a person who ( 1) did not

participate in the trip, (2) fell ill with diarrhea not before July 10, and (3) had household contact with an outbreak case between 1 and 3 days before the onset of illness.

Although at this time there are limited data on the clinical presentation, the CDC (2014c) encourages health care provid- ers to be familiar with the case definitions for Middle East

respiratory syndrome coronavirus (MERS-Co V) infections. The case definition of a person under investigation (PUI) includes "fever and pneumonia or acute respiratory distress syndrome and either ( 1) a history of travel from countries in or near the Arabian Peninsula within 14 days before symptom onset, or (2) close contact with a symptomatic traveler who developed fever and acute respiratory illness (not necessarily pneumonia) within 14 days after traveling from countries in or near the Arabian Peninsula, or (3) a member of a cluster of persons with severe acute respiratory illness of unknown etiol- ogy in which MERS-CoV is being evaluated" (CDC, 2014c). This case definition relies on clinical presentation of the patient, clinical judgment of the provider, and the geographic location (epidemiologic place) of the person to confirm possible expo- sure to the disease.

TYPES OF SURVEILLANCE SYSTEMS

Informatics is essential to the mission of protecting the public's health . Surveillance systems are designed to assist public health professionals in the early detection of disease/event outbreaks in order to intervene and reduce the potential for morbidity or mortality, or to improve the public's health status (CDC, 2012; Koo, 2010). Surveillance systems in use today are defined as

passive, active, sentinel, and special.

Passive System In the passive system, case reports are sent to local health

departments by health care providers (e.g., physicians, public health nurses), or laboratory reports of disease occurrence are

sent to the local health department. The case reports are sum- marized and forwarded to the state health department, national

government, or organizations responsible for monitoring the

problem, such as the CDC or an international organization such as the World Health Organization (WHO).

The National Notifiable Disease Surveillance System (NNDSS) is a voluntary system monitored by the CDC and includes a total of 68 infectious diseases or conditions with case

definitions that are considered important to the public's health.

In the list of 68 reportable conditions, 10 critical biological agents have potential use in a terrorist attack (CDC, 2014b). Each state determines for itself which of the diseases and conditions are of importance to the state's health and legally requires the reporting of those diseases to the state health department by health care providers, health care agencies, and

laboratories. The passive system may not provide an accurate

picture of the problem because of delayed reporting by provid-

ers and laboratories and incomplete reporting across providers

and laboratories. This system, however, has the ability to provide disease-specific demographic, geographic, and seasonal trends over time for reported events. An example is a cancer registry system in which cases are required to be reported to the state on the basis of the type of cancer, the demographics of the client, and the geographic location. Because the system has limits, a disease outbreak may be occurring before all reports are received by the state health department (Veenema, 2013; CDC-NNDSS, 2013c).

CHAPTER 24 Public Health Surveillance and Outbreak Investigation

Active System In the active system, the public health nurse, as an employee of the health department, may begin a search for cases through contacts with local health providers and health care agencies. In this system, the nurse names the disease/event and gathers data about existing cases to try to determine the magnitude of the problem (how widespread it is).

A recent example would be a search for existing cases of severe acute respiratory syndrome (SARS) within a geographic area or a foodborne outbreak of gastroenteritis, or HlNl at the local school. An ongoing tracking system within an occupa- tional setting to monitor work-related injuries/illnesses and symptoms is a process that includes occupational health and infection control personnel in interviewing workers, collecting laboratory data and demographics of workers, and seeking potential agents of exposure (Utterback and Schnorr, 2010). The active system is costly and requires numerous personnel. Because the nurse is actively looking for a case, this system offers a more complete picture of the number of existing cases. Because of limits, the active system is often used on a limited basis for investigation after a disease outbreak has been recog- nized (Gordis, 2008; Veenema, 2013).

Sentinel System In the sentinel system, trends in commonly occurring diseases or key health indicators are monitored (Healthy People 2020 [U.S. Department of Health and Human Services (USDHHS), 2010]; WHO, 2014a). A disease/event may be the sentinel, or a population may be the sentinel. In this system a sample of health providers or agencies is asked to report the problem. Some of the questions that may be asked include the following: What really happened? What are the consequences? What was different in this event? What was the outcome? Could the occur- rence have been prevented? Did providers follow procedures? Did providers know what to do? Has this happened before? If so, how was it fixed? Who reported the event? What might prevent it from happening again? (WHO, 2014b) .

For example, certain providers/agencies in a community may be asked to report the number of cases of influenza seen during a given time period in order to make projections about the severity of the "flu season." Another example would be monitoring the population of children in the local elementary school to determine the rate of obesity among school-age chil- dren. Although much may be learned about diseases and condi- tions using the sentinel system, because the system data are based on a sample of a problem or a specific population, they cannot be used to monitor specific clients, or to initiate preven- tion and control interventions for individuals. The system is useful because it helps monitor trends in commonly occurring diseases/ events.

Special Systems Special systems are developed for collecting particular types of data and may be a combination of active, passive, and/or sen- tinel systems. An example of a special system is the PulseNet system developed by the CDC, the Association of Public Health

Laboratories, and federal food regulatory agencies to "finger- print" foodborne bacteria. This system is designed to provide data for early recognition and investigation of foodborne out- breaks in all 50 states. Similarly, BioNet is a system developed by the PulseNet Partners and the Laboratory Response Network (LRN) to detect and determine links between disease agents during terrorist attacks. As a result of bioterrorism, newer systems called syndromic surveillance systems are being devel- oped to monitor illness syndromes or events. For example, data showing increased medication purchases, physician or emer- gency department visits, or culture orders as well as increased school or work absenteeism may indicate that an epidemic is developing hours or days before disease clusters are recognized or specific diagnoses are made and reported to public health agencies (Goodman et al, 2012). This approach requires the use of automated data systems to report continued (real time) or daily (near real time) disease outbreaks (Tokars et al, 2010) (Box 24-2).

Another example of a special system designed to help assess unusual patterns of diseases or conditions is the CDC's Enhanced Surveillance Project (CDC, 2013c). The ESP moni- tors emergency department data to detect unusual patterns (or aberrations) so that quick epidemiologic case confirmation and follow-up can be initiated. More information on this system can be found at the WebLinks website. Although useful, these systems are designed to be used for disease case detection, case management, and outbreak management; they require good timing. False alarms occur. The systems provide national data to detect, diagnose, and handle disease and the effects of bio- logical and chemical agents resulting from bioterrorism. The systems are intended to be used with more traditional systems. In epidemics or terrorist attacks, there is a network of links for foodborne (PulseNet), chemical (LRN), and biological genetic patterns of disease (BioNet). New systems are being developed and tested to predict epidemics, as in bioterrorism, before they have occurred (CDC, 2013c; Veenema, 2013). The new syn - dromic systems may also predict naturally occurring epidemics

BOX 24- 2 Bioterrorism and Response Networks

Integrating of training and response preparedness can be supported by the following networks: • Health Alert Network • Emergency Preparedness Information Exchange (EPIX) • Emerging Infections program • Epidemiology and Laboratory Capacity program • Assessment initiatives • Hazardous substances • Emergency events surveillance • Influenza surveillance • Local metropolitan medical response systems

From Koo D: Overview of Public Health Surveillance, 2010, Epidemiology Program Office, Centers fo r Disease Control and Prevention. Available at http ://www.cdc.govncphidisssnndssp hs overview.htm. Accessed September 27, 2010.

PART 4 Issues and Approaches in Population-Centered Nursing

(see Box 24-2 for a list of special systems available to assess data

in the case of a terrorist event).

Although all of the systems are important, the public health

nurse is most likely to use the active or passive systems. An

example of when one might use a passive system is the use of

the state reportable disease system to complete a community

assessment or MAPP (Mobilizing for Action through Planning

and Partnerships; see Chapters 18 and 25). The active system is

used when several school children become ill after eating lunch

in the cafeteria or at the local hot dog stand, to investigate the

possibility of food poisoning, or following up on contacts of a

newly diagnosed tuberculosis or sexually transmitted disease

(STD) client at the local homeless shelter (CDC, 2012). The

most recent use of the active system occurred in 2012, when a

Liberian citizen in Dallas, Texas, was found to be infected with

Ebola virus (see Chapter 46).

THE INVESTIGATION

Investigation Objectives Any unusual increase in disease incidence (new cases) or an

unusual event in the community should be investigated. The

system used for investigation depends on the intensity of the

event, the severity of the disease, the number of people/

communities affected, the potential for harm to the community

or the spread of disease, and the effectiveness of available inter-

ventions (CDC, 2013b). The objectives of an investigation are

as follows: • To control and prevent disease or death

• To identify factors that contribute to the disease outbreak/

event occurrence

• To implement measures to prevent occurrences

Defining the Magnitude of a Problem/Event

The following definitions provide a way to describe the level of

occurrence of a disease/event for purposes of communicating

the magnitude of the problem. A disease/event that is found to

be present ( occurring) in a population is defined as endemic if

there is a persistent ( usual) presence with low to moderate

disease/event cases. The endemic levels of a disease/event in a

population provide the baseline for establishing a public health

problem. For example, foodborne botulism is endemic to

Alaska. One would need to know the baseline to determine the

existence of a change or increase in the number of cases from

the baseline. If a problem is considered hyperendemic, there is

a persistently ( usually) high number of cases. An example is the

high cholera incidence rate among Asians/Pacific Islanders.

Sporadic problems are those with an irregular pattern, with

occasional cases found at irregular intervals. Holoendemic

implies a highly prevalent problem found in a population and

commonly acquired early in life. The prevalence of this problem

decreases as age increases (Mosby's Medical Dictionary, 2013).

Epidemic means that the occurrence of a disease within an area

is clearly in excess of expected levels (endemic) for a given time

period. This is often called the outbreak. Pandemic refers to

the epidemic spread of the problem over several countries or

continents (such as the SARS and most recently the HlNl

influenza outbreak). Outbreak detection, or identifying an

increase in frequency of disease above the usual occurrence of

the disease, is the function of the investigator (Tokars et al,

2010).

Patterns of Occurrence Patterns of occurrence can be identified when investigating a

disease or event. These patterns are used to define the boundar-

ies of a problem to help investigate possible causes or sources

of the problem. A common source outbreak refers to a group

exposed to a common noxious influence such as the release of

noxious gases (e.g., ricin in the Japanese subway system several

years ago and in a water system in the United States) (Sobel and

Watson, 2009). A point source outbreak involves all persons

exposed becoming ill at the same time, during one incubation

period. A mixed outbreak ( which was described by Kuo and

colleagues (2009] while investigating a foodborne gastroenteri-

tis caused by a Shigella sonnei virus) is a common source fol -

lowed by secondary exposures related to person-to-person

contact, as in the spreading of influenza. Intermittent or con-

tinuous source cases may be exposed over a period of days or

weeks, as in the recent food poisonings at restaurants through-

out the United States as a result of the purchase of contaminated

sprouts. A propagated outbreak does not have a common

source and spreads gradually from person to person over more

than one incubation period, such as the spread of tuberculosis

from one person to another.

Causal Factors from Epidemiologic Triangle

Factors that must be considered as causes of outbreak are cat-

egorized as agents, hosts, and environmental factors (see

Chapter 12). The belief is that these factors may interact to

cause the outbreak and therefore the potential interactions

must be examined. The following presents definitions used to

classify agents in an attack:

· Infectivity: Refers to the capacity of an agent to enter a

susceptible host and produce infection or disease

· Pathogenicity: Measures the proportion of infected people

who develop the disease

• Virulence: Refers to the proportion of people with clinical

disease who become severely ill or die

Box 24-3 lists the types of agent factors that may be present.

The host factors associated with cases may be age, sex, race,

socioeconomic status, genetics, and lifestyle choices ( e.g., ciga-

rette smoking, sexual practices, contraception, eating habits).

The environmental factors that may be related to a case are

physical ( e.g., weather, temperature, humidity, physical sur-

roundings) or biological (such as insects that transmit the

agent). Some of the socioeconomic factors that might affect

development of a disease/event are behavior ( e.g., terrorist

behaviors), personality, cultural characteristics of group, crowd-

ing, sanitation, and availability of health services.

When to Investigate

An unusual increase in disease incidence should be investigated.

The amount of effort that goes into an investigation depends

on the severity or magnitude of the problem, the numbers in

CHAPTER 24 Public Health Surveillance and Outbreak Investigation 539

BOX 24-3 Types of Agent Factors

1. Biological • Bacteria (e.g., tuberculosis, sa lmonellosis. streptococcal infections) • Viru ses (e.g., hepatitis A, herpes) • Fungi (e.g., tinea capitis, blastomycosis) • Parasites (protozoa causing malaria, giardiasis; helminths [roundworms,

pinworms]; arthropods [mosquitoes, ticks, flies. mites]) 2. Physical

• Heat • Trauma

3. Chemicals • Pollutants • Medications/drugs

4. Nutrients • Absence • Excess

5. Psychological • Stress • Isolation • Social support

the population who are affected, the potential for spreading the disease, and the availability and effectiveness of intervention measures to resolve the problems. Most of the outbreaks of diseases ( or increased incidence rates) occur naturally and/or are predictable when compared with the consistent patterns of previous outbreaks of a disease, such as influenza, tuberculosis, or common infectious diseases. When a disease/event outbreak occurs as a result of purposeful introduction of an agent into the population, the predictable patterns may not exist. Clues are provided to be used when trying to determine the existence of bioterrorism. These clues are simplified and appear in the How To box entitled "Recognize the Epidemiologic Clues" (Khan and Pesik, 2011).

Steps in an Investigation First confirm whether a real disease/condition outbreak exists or if there has been a false alarm. Review the information avail- able about the situation. Determine the nature, location, and severity of the problem. Verify the diagnosis and develop a case definition to estimate the magnitude of the problem; this may change as new information is made available. Compare current incidence (number of new cases) with usual or baseline inci- dence. Use local data if available and compare them with the literature, or call the state health department. Assess the need for outside consultation. Report the situation to state public health authorities if required. Check the state reportable disease list. Early and continually changing control measures should be used on the basis of the magnitude and nature of the condition (infectious disease, chronic disease, injuries, personal behaviors, environmental exposure). Control measures may include elimi- nating a contaminated product, modifying procedures, treating carriers, or immunizing those who might contract the infec- tious disease. A request should be made that laboratory speci- mens be saved until the investigation is completed (if applicable to the case definition).

I HOW TO Recognize the Epidemiologic Clues That May Signal a Covert Bioterrorism Attack • Large number of ill persons with similar disease or syndrome • Large number of unexplained disease, syndrome, or deaths • Unusual illness in a population • Higher morbidity and mortality than expected with a common

disease or syndrome • Failure of a common disease to respond to usual therapy • Single case of disease caused by an uncommon agent • Multiple unusual or unexplained disease entities coexisting in the

same person without other explanation • Disease with an unusual geographic or seasonal distribution • Multiple atypical presentations of disease agents • Similar genetic type among agents isolated from temporally or

spatially distinct sources • Unusual, atypical, genetically engineered, or antiquated strain of

agent • Endemic disease with unexplained increase in incidence • Simultaneous clusters of similar illness in noncontiguous areas,

domestic or foreign • Atypical aerosol, food, or water transmission • Ill people presenting at about the same time • Death or illness among animals that precedes or accompanies

illness or death in humans • No illness in people not exposed to common ventilation systems,

but illness among those people in proximity to the systems

I HOW TO Conduct an Investigation • Identify investigation team and resources. • Confirm the existence of an outbreak. • Verify the diagnosis/define a case. • Estimate the number of cases. • Orient the data collected to person, place, and time. • Develop and evaluate a hypothesis. • Institute control measures and communicate findings. • Maintain surveillance (CDC, 2014h).

Centers for Disease Control and Prevention (CDC): Steps to Investigation, 2014h. Retrieved January 2015 from www.CDC.gov

As the investigation continues, seek additional cases and collect critical data and specimens. Encourage immediate reporting of new cases from laboratory reports (e.g., radiology in cases of pneumonia) and physicians/other health care pro- viders, including public health nurses, health care agencies, and others in the community as appropriate. In addition, search for other cases that may have occurred in the past or are now occur- ring by reviewing laboratory reports, medical records, and client charts and questioning physicians, other health providers and agencies, and others in the community. Use a specific data collection form such as a questionnaire or a data abstract summary form. Characterize the cases by person, place, and time. Evaluate the client characteristics (i.e., age, sex, underlying disease, geographic location) and possible exposure sites. The place where the outbreak occurs provides clues to the popula- tion at risk. Did the problem occur in a community, school, or homes? Drawing tables or spot maps helps to visualize the clusters of the disease condition in specific areas of the

PART 4 Issues and Approaches in Population-Centered Nursing

TABLE 24-2 Potential Epidemiologic Factors That Call for Increased Investigation or Monitoring

Factors Reason

Disease located in one geographic area Severe symptoms/diagnoses such as encephalitis or death

Rapid rise to very high numbers of illness two to three times

Might indicate a po int source of a disease agent that can be discovered and controlled

Indicates disease process that needs rapid investigation because of severity

Potential for continuing rapid rise in numbers; requires immediate investigation to

normal baseline with steep epidemic curve institute control measures

Outbreak detected and confirmed by multiple data sources

Outbreak occurring at an unusual time or place (e .g.,

respiratory/influenza-like symptoms in summer) Outbreak confined to one age or gender group

Unlikely to be attributable to error; possibly widespread

Might indicate targeted population or early signs in a susceptible population (e .g., very

young or very old)

Number of cases continuing to rise over time Might indicate targeted population or early signs Indicates sustained outbreak that might continue to grow

From Andersson T, Bjelkmar P, Hu Ith A, et al: Syndromic surveillance for outbreak detection and investigation. Online J of Public Health Inform

5:e78, 2013.

community. The exact time period of the outbreak/occurrence is important (be sure to go back to the first case or first indica-

tion of outbreak/occurrence activity). Given the diagnosis, describe what appears to be the period of exposure. Record the

date of onset of morbidity/mortality cases and draw an epi- demic curve. Determine whether the outbreak/condition origi-

nates from a common source or is propagated. Table 24-2

suggests factors to monitor and explains the reasons for their

use. It provides clues to the use of time, place, and person.

As the investigation continues, develop a tentative hypoth-

esis (the best guess about what is happening). Do a quick evalu-

ation of the outbreak by assessing previous findings. Record,

tabulate, and review data collected from the previously described

activities to summarize common agent, environment, host

factors, and exposures. On the basis of this analysis ( and litera-

ture review if necessary), develop a hypothesis (best guess) on

(1) the likely cause, (2) the source(s), and (3) the mode of

transmission of the disease. The hypothesis should explain the

majority of cases. Frequently, there will be concurrent cases not

explained by the hypothesis that may be related to endemic or

sporadic cases, a different disease or condition (similar symp-

tomatology), or a different source or mode of transmission.

Test your hypothesis with other public health team members

(e.g., epidemiologists). Many investigations do not reach this

stage because of lack of available personnel, lack of severity of

the problem, and lack of resources available. Situations that

should be studied include disease/events associated with a com-

mercial product, disease/events associated with considerable

morbidity and/or mortality, and disease/events associated with

environmental exposures ( e.g., terrorist attack). Analyze data

collected to determine sources of transmission and risk factors

associated with disease/condition. Determine how this problem

differs in incidence or exposure for other population groups.

Refine the hypothesis (best guess) and carry out additional studies if necessary.

Evaluate the effects of control measures. Cases may cease to

occur or return to endemic (normal) level. If the control inter- ventions do not produce change, return to the beginning and

start the investigation over or reevaluate cases. Use the

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0PR ~VI

c::::::J 0-2.4 c::::::J 2.5-4.9 c::::::J 5.0-9.9 c::::::J 10.0-19.9 - 2:20

FIG 24-1 Hepatitis A cases reported in the United States and U.S. territories in 1 year.

opportunity of an outbreak to review and correct practices

related to the current situation that may contribute to an out- break in the future.

Communicate findings to those who should be notified.

Communication of findings may take two forms: an oral brief-

ing for local authorities or a written report. Describe the

problem, the data collected, the case definition with verification

of the diagnosis, data sources, the hypothesis, and testing of the

hypothesis. Present only the facts of the situation, the data analysis, and the conclusions.

Displaying of Data Reporting of data in an investigation needs to be valid: Does

the event reported reflect the true event as it occurs? It must

also be reliable: Is the same event reported consistently by dif-

ferent observers? A number of tools can be used to display data

according to time, place, or person. The spatial map shows

where the event is occurring and allows prevention resources to

be targeted, Figure 24-1 provides a map of the location of

reported cases of hepatitis A in the United States. From looking

at this map, priority prevention target areas appear to be

CHAPTER 24 Public Health Surveillance and Outbreak Investigation

TABLE 24-3 Example of Ways to Display Data * Number of Clients with Hepatitis A, by Month, for 4 Years

Year 1 Year 2 Year 3 Year 4 January 12 20 21 16 February 14 19 26 19 March 7 21 8 27 April 12 10 11 13 May 5 0 11 0 June 4 11 1 6 July 5 5 9 8 August 5 9 12 7 September 6 7 13 B October 15 B 10 70 November 8 11 0 December 0 11 20 0 Total 75 129 153 174

*This table shows the number of persons who match a case definition of a select infectious disease ove r a 4-year period. Note that for Year 4, there we re ove rall more cases, especially in March and October, with a serious outbreak in October. Modified from Centers for Disease Contro l and Preve ntion (CDC): Notifiable diseases and mortality tables. MMWR 63(28):ND-382-ND-395, July 18, 2014d. Retrieved January 2015 from http://www.cdc .gov/mmwr/preview/mmwrhtml/mm6328md. htm 7s_cid=mm6328md_ w

~ I LINKING CONTENT TO PRACTICE Remember that disease and event surveillance systems exist to help improve the health of the public through the systematic and ongoing collection, distri- bution, and use of health-related data. A nurse can contribute to such systems and best use the data collected through such systems to help manage endemic health problems and those that are emerging, such as evolving infec- tious diseases and bioterrorist (human-made) health problems. Functions of surveillance and investigati on are detecting cases, estimating the impact of disease or injury, showing the national history of a health condition , determin- ing the distribution and spread of illness. generating hypotheses. evaluating prevention and control measures. and facilitating planning (CDC. 2012) Response to bioterrorism or large-scale infectious disease outbreak may require the use of emergency pub lic health measures such as quarantine, iso- lation, closing public places. seizing property, mandatory vaccination, travel restrictions, and disposal of the deceased. In 2008 in preparation for a pro- jected H1 N1 flu epidemic, information was distributed about the use of several of these interventions. including isolation and closure of public places (see Appendix 0-3)

Suggestions for protecting health care providers from exposure include use of standard precautions when coming in contact with broken skin or body fluids. use of dispos able nonsterile gowns and gloves followed by adequate hand washing alter remova l. and use of a face shield (CDC. 2012).

The Robert Wood Johnson Foundation (RWJF) funded a project initiative focusing on the development of competencies and re sources to enhance the ability of nursing professionals to deliver high-quality and safe nursing care. The Quality Safety Education for Nurses (OSEN) collaboration identified and defined six quality and safety competencies for nursing. In addition, the

Georgia, the District of Columbia, California, New Mexico, Kansas, and Florida. Table 24-3 shows the number of cases of an infectious disease compared by month and year over 4 years. In this table, cases have increased by year with a serious out- break in October of Year 4. When cases are reported by person, they are usually reported by a person's characteristics. Data displays are a step in analysis that shows graphically what is happening. It reduces the assumptions made about the event and provides a means for describing the event using quantita- tive data. Data help in stating your hypothesis or your best guess about what is happening (refer to the CDC website for addi- tional information on outbreak investigations).

II LEVELS OF PREVENTION Surveillance Activities

Primary Prevention Develop an approach for mass immunizations of citizens to prevent the occur- rence of H1 N1 in the community.

Secondary Prevention Investigate an outbreak of flulike illness in a loca l school.

Tertiary Prevention Provide health care and treatment for those infected by H1 N1.

project allowed for the development of proposed targets for the knowledge, skills, and attitudes of students for each of the six competencies that were identified by the Institute of Medicine as client-centered care. teamwork and collaboration, evidence-based practice. quality improvement, safety, and informatics. The overall goal for the OSEN project is to meet the challenge of preparing future nurses who will have the knowledge, skills, and attitudes (KSAs) necessary to continuously improve the quality and safety of the health care systems wi thin which they work. This chapter focuses on the importance of using informatics to identify, monitor, and intervene in unusual occurrences and events to protect the public and to keep communities safe (see Chapter 26 for further discussion). Informatics in the OSEN project is defined as the use of information and technology to communicate, manage knowledge, mitigate error. and support decision making. The knowledge requirement for the public health nurse and student is to explain why infor- mation and technology skills are essential for safety. The skill to be devel- oped is the seeking of education about how information is managed in the setting before providing an intervention. This chapter applies this by looking at trends of occurrences and events before investigating the situation and deciding on an intervention. It is also important to be able to use the data- bases and the tools of investigation to ensure sale processes of care. The attitude of engaging in continuous learning and the development of new technology skills is essential. In the case of an influenza pandemic and to assist clients in being safe during such an outbreak. the How To box entitled "Plan tor Pandemic Flu . Using a Planning Checklist for Individua ls and Fami- lies" provides steps tor assisting individuals and families in preparation for such an occurrence.

From Centers for Disease Control and Prevention: Nationa l Electronic Telecommu nications System for Surveillance, 2011. Avai lable at http://www.cdc .gov/surveillance. Accessed June 1, 2011.

PART 4 Issues and Approaches in Population-Centered Nursing

I HOW TO Plan for Pandemic Flu, Using a Planning Checklist for Individuals and Families Nurses are responsible for assisting clients by providing them the • Teach children to stay away from others as much as possible

means for safety. One of the roles of the nurse, to assure safety, if they are sick.

is to assist clients in being prepared for an occurrence or an event • Encourage family members to stay home from work and

in emergency and urgent situations that could compromise their school if sick.

health status or health outcomes. Following is a checklist to assist 3. Items to have on hand for an extended stay at home:

individual and family clients to prepare for a pandemic. Although • Examples of food and nonperishables

this presents a process in preparation for pandemic flu, this process • Ready-to-eat canned meats, fish, fruits, vegetables, beans,

may be used in other communicable disease outbreaks that may and soups

reach pandemic proportions. • Protein or fruit bars

Use this as a guide to educate clients if an epidemic or pandemic • Dry cereal or granola

is forecast: • Peanut butter or nuts

Prepare for an influenza pandemic as soon as it is forecast.

Prepare clients with the knowledge of both the magnitude of what

can happen during a pandemic outbreak and what actions can be

taken to help lessen the impact of an influenza pandemic on the

client(s). This checklist helps to gather the information and resources

needed in case of a flu pandemic. 1. To plan for a pandemic: the client(s) will want to:

• Store a 2-week supply of water and food.

• During a pandemic, if clients cannot get to a store, or if stores

are out of supplies, it will be important to have extra supplies

on hand. • This can be useful in other types of emergencies, such as

power outages and disasters.

• Periodically check regular prescription drugs to ensure a con-

tinuous supply at home.

• Have nonprescription drugs and other health supplies on hand,

including pain relievers, stomach remedies, cough and cold

medicines, fluids with electrolytes, and vitamins.

2. To limit the spread of germs and prevent infection: • Teach children to wash hands frequently with soap and water,

and suggest that family members model the current behavior.

• Teach children to cover coughs and sneezes with tissues, and

be sure to model that behavior in families.

• Dried fruit • Crackers • Canned juices • Bottled water • Canned or jarred baby food and formula

• Pet food • Examples of medical, health, and emergency supplies

• Prescribed medical supplies such as glucose and blood

pressure-monitoring equipment

• Soap and water, or alcohol-based (60% to 95%) hand wash

• Medicines for fever, such as acetaminophen or ibuprofen

• Thermometer • Antidiarrheal medication

• Vitamins • Fluids with electrolytes

• Cleansing agent/soap

• Flashlight

• Batteries

• Portable radio

• Manual can opener

• Garbage bags

• Tissues, toilet paper, disposable diapers

Excerpted and adapted from the U.S. Department of Health and Human Services: Plan for pandemic flu using a planning checklist for individuals

and families, 2006. Available at www.flu.gov. Accessed October 28, 2010.

I PRACTICE APPLICATION As a clinical project, the health department asked the public

health nursing class at the university to develop a community

service message to air on local radio about the potential of a

I KEY POINTS • Disease surveillance has been a part of public health protec-

tion since the 1200s, during the investigations of the bubonic

plague in Europe. • By 1925 the United States began national reporting of mor-

bidity causes. • Surveillance provides a means for nurses to monitor disease

trends in order to reduce morbidity and mortality and to

improve health. Surveillance is a critical role function for nurses practicing

in the community.

pandemic flu HlNl outbreak in 2014. What does the message

need to contain to help the community prepare?

Answers can be found on the Evolve site.

• Surveillance is important because it generates knowledge of

a disease or event outbreak patterns.

• Surveillance focuses on the collection of process and outcome

data. • Although surveillance was initially devoted to monitoring

and reducing the spread of infectious diseases, it is now used

to monitor and reduce chronic diseases and injuries, and

environmental and occupational exposures.

CHAPTER 24 Public Health Surveillance and Outbreak Investigation

I KEY PO I NTS-cont'd • Surveillance activities can be related to the core functions of

public health of assessment, policy development, and assurance.

• A quality surveillance system requires collaboration among a number of agencies and individuals. The Minnesota Model of Public Health Interventions: Appli- cations for Public Health Nursing Practice (2001) suggests that surveillance is one of the interventions related to public health nursing practice.

• Clinicians, health care agencies, and laboratories report cases to state health departments. Data also come from death cer- tificates and administrative data such as discharge reports and billing records.

• Each of the data sources has the potential for under-reporting or incomplete reporting. However, if there is consistency in the use of surveillance methods, the data collected will show trends in events or disease patterns that m ay indicate a change needed in a program or a needed prevention inter- vention to reduce morbidity or mortality. The National Notifiable Disease Laboratory, hospital dis- charge data, and billing data provide mechanisms for clas- sifying diseases and events and calculating rates of diseases within and across groups, populations, and communities. The sentinel surveillance system provides for the monitoring of key health events when information is not otherwise avail- able or in vulnerable populations to calculate or estimate disease morbidity. In 1990 the CDC and the Council of State and Territorial Epidemiologists assembled the first list of standard case definitions.

• Reporting of disease data by health care providers, laborato- ries, and public health workers to state and local health departments is essential if trends are to be accurately monitored. Requirements for reporting diseases are mandated by law or regulation. Criteria for defining cases of different diseases are essential for having a uniform, standardized method of reporting and monitoring diseases. A case definition provides understand- ing of the data that are being collected and reduces the likeli- hood that different criteria will be used for reporting similar cases of a disease.

• Surveillance systems in use today are defined as passive, active, sentinel, and special.

• Any unusual increase in disease incidence (new cases) or an unusual event in the community should be investigated.

• Patterns of occurrence can be identified when investigating a disease or event. These patterns are used to define the boundaries of a problem to help investigate possible causes or sources of the problem. Factors that must be considered as causes of outbreak are categorized as agents, hosts, and environmental factors .

• An unusual increase in disease incidence should be investigated.

• Functions of surveillance and investigation are detecting cases, estimating the impact of disease or injury, showing the national history of a health condition, determining the dis- tribution and spread of illness, generating hypotheses, evalu- ating prevention and control measures, and facilitating planning.

I CLINICAL DECISION-MAKING ACTIVITIES 1. Call the local health department and attend an emergency

response team planning meeting. How many agencies are involved? Determine the roles of each agency. Does the nurse have a role on the team? Explain.

2. Go to the Health Hazard Evaluation program website (see WebLinks). What is the purpose of this program? How

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