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Cholera and Other Waterborne Diseases

Cholera

Cholera is transmitted by water or food that has been contaminated with infective feces.

The risk for transmission can be greatly reduced by disinfecting drinking water, separating human sewage from water supplies, and preventing food contamination.

Cholera

Untreated cholera is fatal in ≈25% of cases, but with aggressive volume and electrolyte replacement, the number of persons who die of cholera is limited to <1%.

Cholera

Agent: Vibrio cholerae

Distributed worldwide, particularly in tropics

Symptoms: 1-2 day incubation, exotoxin of V. cholerae causes disease

Severe cases require rapid and extensive rehydration

Estimated 1,000,000 cases per year

Watery diarrhea and dehydration

Cholera is an acute bacterial enteric disease characterized in its severe form by sudden onset, profuse watery stools, nausea, and vomiting early in the course of illness. In untreated cases, rapid dehydration, acidosis, circulatory collapse, and renal failure can occur. Diagnosis is confirmed by isolating Vibrio cholerae of the serogroup O1 or O139 from feces. Numerous pandemics of cholera occurred, primarily in the 1800s in India, Russia, Europe, Mecca, Asia, and Africa. For the first half of the 20th century, much of cholera was confined to Asia, except for a severe epidemic in Egypt in 1947. During the second half of the 20th century, three major observations have occurred regarding cholera: 1. the global spread of the seventh pandemic of cholera caused by V. cholerae O1 El Tor, 2. the recognition that environmental reservoirs of cholera exist and include one along the Gulf of Mexico coast of the U.S., and 3. the appearance for the first time of large explosive epidemics of cholera gravis caused by other serogroups (O139).

Morris gives an excellent account of the four Cholera epidemics which spread across Europe in the 19th century. Originally confined to the Bengal region of India (and thus known as Asiatic cholera) where it periodically ravaged the region; it somehow, in 1817, underwent a change. Morris attributes this to two factors - more overseas trade which encouraged its spread across to Persia (Iran) and thence on to Europe and the British Army's regular rotation of troops which allowed it to escape out of its confined region. The disease was thus familiar to Army doctors and to troops (it is estimated that it killed some 3000 of Hastings' 10,000 strong army). By 1823 it had reached Russian Astrakhan and for a period stopped. In 1826 it re-occurred at a great religious pilgrimage at Hurdwar and was carried back by pilgrims along trade routes. Unfortunately it reached Russian Nijni-Novogorod in time to infect the autumn trade fair - again trade routes saw it spread quickly to Moscow in 1830 and from then on it was merely a matter of time before it spread to all of Europe. In September 1831 it had reached Hamburg which had many trade links with Britain - the first British death occurred in October at Sunderland.

The arrival of the Cholera was long heralded in the Manx Press which from 1831 tracked its progress across Europe; on 25th May 1832 it reported Cholera in Liverpool and the first case in Douglas (Thomas Woods) was reported 17 July 1832 (see also account by George Head). This outbreak lasted until September 1832, a second outbreak occurred in August-September 1833. Some of the social attitudes have already been mentioned above.

Cholera

Treatment: Oral rehydration

Transmission: Drinking of contaminated water, consumption of infected fish, shellfish

Dormancy in aquatic environments, maintenance on zooplankton

Prevention and Control: HYGIENE! Sewage treatment, cook foods properly.

Humans are the reservoir for cholera and cholera is transmitted through ingestion of food or water contaminated directly or indirectly with feces or vomitus of infected persons. The main serogroups of cholera (O1 and O139 can persist in water for long periods. When traveling to countries with suspect water supplies, it is advised not to consume beverages produced in those countries, as the water may very well be contaminated. Vegetables and fruit may also be suspect as they could have been grown or treated with this water during or after the planting and growing process. The incubation period of cholera is usually 2-3 days long and as long as stools are positive for cholera, it is communicable.

The key to preventing cholera is to ensure a safe water supply. Chlorination of public water is a must, even if the source water appears to be uncontaminated. Careful preparation of food and beverages and after cooking or boiling, protect against contamination by flies and unsanitary handling, leftover foods should be thoroughly reheated before ingestion. Persons with diarrhea should not prepare food or haul water for others.

Without treatment Cholera kills around 40-60% of those infected. The disease causes constant vomiting and purging of the bowels - often as much as several pints in a few minutes. Descriptions abound of sodden bedclothes (highly infectious) and floors awash - such dehydration causes cramps, the body shrivels so much so that the sufferer is said to look like a monkey and the blood becomes too thick to be easily circulated thus turning the extremities black or blue. However this acute stage only lasts some 24 hours, at the end of which the victim is either dead or on their way to a slow recovery. As mentioned in the introduction, infection is by polluted water in which the excreta of an infected person enter into drinking water. The microbe is however killed by heat or by acid, some people can drink polluted water and avoid infection due to their stomach acid. Nurses would use vinegar to remove the smell of vomit from their hands, by doing so they would also kill the microbe.

Giardiasis

Protozoan infection often of upper small intestine, associated with chronic diarrhea, steatorrhea, abdominal cramps, bloating, fatigue, and weight loss.

Infectious agent: Giardia lamblia

Occurrence: Worldwide, mostly children

Diagnosis is traditionally made by identification of cysts or trophozoites in feces or of trophozoites in duodenal fluid or in mucosa obtained by small intestine biopsy. Children are infected more frequently than adults. Prevalence is higher in areas of poor sanitation and in institutions with children not toilet trained, including day care centers. Endemic infection in the U.S. UK, and Mexico most commonly occurs in July-October among children less than 3 years of age and adults 25-39 years old. It is associated with drinking water from unfiltered surface water sources or shallow wells, swimming in bodies of freshwater and having a young family member in day care.

Person to person transmission occurs by hand to mouth transfer of cysts from the feces of an infected individual, especially in institutions and day care centers, this is probably the mode of spread. Anal intercourse also facilitates transmission. The agent is communicable during the entire period of infection, which could be months. The way to prevent giardiasis is to educate families, those in day care centers, etc., in proper hygiene and handwashing. Filter public water and sanitary disposal of feces is required.

From Giardia: A Common Waterborne Disease

Surface water is especially vulnerable to Giardia contamination, and this explains why it is often called "beaver fever" or backpacker disease. "Many years ago, what we now know as giaridiasis was called beaver fever, because people who drank creek water downstream from a beaver dam often got sick," Hairston says. "Likewise, hikers and nature lovers who sample what they believe is "pure" water from a stream often end up sick because the water contains Gardia oocysts from grazing cattle or game animals."

Giardiasis

Reservoir: Humans

Mode of Transmission: person to person, fecal-oral from contaminated water

Incubation period: 3-25 days

From Giardia: A Common Waterborne Disease

Leptospirosis

Zoonotic bacterial disease with features of fever, headache, chills, myalgia, and conjunctival suffusion

Infectious agent: leptospires

Occurrence: Worldwide

Reservoir: Wild and domestic animals

Mode of Transmission: Contact of the skin or mucous membranes with contaminated water

Incubation Period: usually 10 days

Outbreaks of leptospirosis are usually caused by exposure to water contaminated with the urine of infected animals. Many different kinds of animals carry the bacterium; they may become sick but sometimes have no symptoms. Leptospira organisms have been found in cattle, pigs, horses, dogs, rodents, and wild animals. Humans become infected through contact with water, food, or soil containing urine from these infected animals. This may happen by swallowing contaminated food or water or through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin. The disease is not known to be spread from person to person. Leptospirosis occurs worldwide but is most common in temperate or tropical climates. It is an occupational hazard for many people who work outdoors or with animals, for example, farmers, sewer workers, veterinarians, fish workers, dairy farmers, or military personnel. It is a recreational hazard for campers or those who participate in outdoor sports in contaminated areas and has been associated with swimming, wading, and whitewater rafting in contaminated lakes and rivers. The incidence is also increasing among urban children.

Other manifestations that may be present are diphasic fever, meningitis, rash, hemolytic anemia, hemorrhage into skin and mucous membranes, hepatorenal failure, jaundice. Cases are often misdiagnosed with meningitis, encephalitis, or influenza. Clinical illness lasts from a few days to 3 weeks or longer. Generally, there are two phases in the illness; the leptospiremic or febrile stage, followed by the convalescent or immune phase.

The disease is an occupational hazard for rice and sugarcane fieldworkers, farmers, sewer workers, miners, veterinarians, animal husbnadrymen, dairymen, fish workers, and military troops. Outbreaks occur among those exposed to fresh river, stream, canal, and lake water contaminated by urine of domestic and wild animals, and to urine and tissues of infected animals. The disease is a recreational hazard to bathers, campers, and sportsmen in infected areas. Notable reservoirs are rats, swine, cattle, dogs, and raccoons. Direct transmission from person to person is rare. Leptospires may be excreted in the urine.

The public must be educated on the modes of transmission and to avoid swimming or wading in potentially contaminated waters. Those in occupations requiring contact with this water need to wear protections such as boots, gloves, aprons, etc.

Leptospirosis

Risk factors include:

Occupational exposure -- farmers, ranchers, slaughterhouse workers, trappers, veterinarians, loggers, sewer workers, rice field workers, and military personnel

Recreational activities -- fresh water swimming, canoeing, kayaking, and trail biking in warm areas

Household exposure -- pet dogs, domesticated livestock, rainwater catchment systems, and infected rodents

Leptospirosis is rare in the continental United States. Hawaii has the highest number of cases in the United States.

Schistosomiasis

Blood fluke infection (trematode) with worms living within mesenteric or vesical veins of the host over a life span of many years

Results of chronic infection include liver fibrosis, portal hypertension, urinary manifestations including bladder cancer

Infectious Agent: Schistosoma mansomi

Occurrence: Africa, South America

Reservoir: Humans

Schistosomiasis, also known as bilharzia (bill-HAR-zi-a), is a disease caused by parasitic worms. Infection with Schistosoma mansoni, S. haematobium, and S. japonicum causes illness in humans. Although schistosomiasis is not found in the United States, 200 million people are infected worldwide.

People, dogs, cats, pigs, cattle, water buffalo, horses, and wild rodents are potential hosts of some of the other species (japonicum and heamatobium). Definitive diagnosis of schistosomiasis depends on demonstration of eggs in the stool microscopically by direct smear or on a Kato thick smear. Infection is acquired from water containing free swimming larval forms (cercariae) that have developed in snails. The eggs hatch in water and the liberated larvae penetrate into suitable freshwater snail hosts. After several weeks, the cercariae emerge from the snail and penetrate human skin, usually while the person is working, swimming, or wading in water; they enter the bloodstream and are carried to blood vessels of the lungs, migrate to the liver, develop to maturity and then migrate to veins of the abdominal cavity.

The incubation period is about 2-6 weeks. It is not communicable from person to person. The way to prevent schistosomiasis is to improve irrigation and agriculture practice. Dispose of feces and urine so that viable eggs will not reach fresh bodies of water that have snail hosts. Avoid swimming or working in contaminated water. Provide drinking and bathing water from uncontaminated source.

Naegleria

Naegleria fowleri

Microscopic, free-living amoeba that can cause rare, but severe infections of the brain

Commonly found in the environment in water and soil

Infects people by entering the body through the nose, often from swimming and diving in freshwater lakes and rivers

Naegleria fowleri is a microscopic, free-living amoeba (single-celled living organism) that can cause rare, but severe infections of the brain. The free-living ameba is commonly found in the environment in water and soil. Naegleria fowleri infects people by entering the body through the nose. This typically occurs when people go swimming or diving in warm freshwater places, like lakes and rivers. Once the ameba enters the brain it causes a severe and usually fatal infection called primary amebic meningoencephalitis (PAM). The risk for infection from Naegleria fowleri might be reduced by measures that minimize opportunities for water to enter the nose when using warm freshwater lakes or rivers.

Naegleria fowleri

Once the amoeba enters the brain it causes a severe and usually fatal infection called primary amebic meningoencephalitis (PAM)

Naegleria fowleri has three stages, cysts , trophozoites , and flagellated forms , in its life cycle. The trophozoites replicate by promitosis (nuclear membrane remains intact) . N. fowleri is found in fresh water, soil, thermal discharges of power plants, heated swimming pools, hydrotherapy and medicinal pools, aquariums, and sewage. Trophozoites can turn into temporary non-feeding flagellated forms which usually revert back to the trophozoite stage. Trophozoites infect humans or animals by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves causing primary amebic meningoencephalitis (PAM). N. fowleri trophozoites are found in cerebrospinal fluid (CSF) and tissue, while flagellated forms are occasionally found in CSF. Cysts are not seen in brain tissue.

Where is Naegleria fowleri found?

Worldwide, primarily Southern U.S. in:

Bodies of warm freshwater, lakes and rivers

Geothermal (naturally hot) water, hot springs

Geothermal (naturally hot) drinking water sources

Warm water discharge from industrial plants

Swimming pools that are poorly maintained, minimally-chlorinated, and/or un-chlorinated

Soil

found around the world. In the United States, the majority of infections have been caused by Naegleria fowleri from freshwater located in southern-tier states. The ameba is most commonly found in:

Bodies of warm freshwater, such as lakes and rivers

Geothermal (naturally hot) water, such as hot springs

Geothermal (naturally hot) drinking water sources

Warm water discharge from industrial plants

Swimming pools that are poorly maintained, minimally-chlorinated, and/or un-chlorinated

Soil

Naegleria fowleri is not found in salt water.

Number of Case-reports of Primary Amebic Meningoencephalitis Caused by Naegleria fowleri (N=143) by State of Exposure*— United States, 1962–2017

https://www.cdc.gov/parasites/naegleria/state-map.html

Most cases in Texas and SE, SW United States.

When do infections occur?

Infections usually occur when it is hot for prolonged periods of time, which causes higher water temperatures and lower water levels. Infections can increase during heat wave years.

Statistics – United States

Naegleria fowleri infections are very rare. In the 10 years from 2000 to 2009, 30 infections were reported in the U.S.

Of those cases, 28 people were infected by contaminated recreational water and 2 people were infected by water from a geothermal (naturally hot) water supply.

Infections typically occur in July, August, and September.

Symptoms

Naegleria fowleri can cause the disease primary amoebic meningoencephalitis (PAM), a brain infection that leads to the destruction of brain tissue.

In its early stages, symptoms of PAM may be similar to symptoms of bacterial meningitis.

Symptoms

Initial symptoms include headache, fever, nausea, vomiting, and stiff neck.

Later symptoms include confusion, lack of attention to people and surroundings, loss of balance, seizures, and hallucinations.

After the start of symptoms, the disease progresses rapidly and usually causes death within 1 to 12 days.

Treatment?

Several drugs are effective against Naegleria fowleri in the laboratory. However, their effectiveness is unclear since almost all infections have been fatal, even when people were treated.

How common is Naegleria fowleri in the environment?

Naegleria fowleri is commonly found in lakes in southern-tier states during the summer.

This means that recreational water users should be aware that there will always be a low level risk of infection when entering these waters.

Is it possible to test for Naegleria fowleri in the water?

No. It can take weeks to identify the ameba, but new detection tests are under development. Previous water testing has shown that Naegleria fowleri is very common in freshwater venues.

Therefore, recreational water users should assume that there is a low level of risk when entering all warm freshwater, particularly in southern-tier states.

What is the risk of infection?

The risk of Naegleria fowleri infection is very low.

There have been 30 reported infections in the U.S. in the 10 years from 2000 to 2009, despite millions of recreational water exposures each year.

By comparison, in the ten years from 1996 to 2005, there were over 36,000 drowning deaths in the U.S.

You cannot be infected with Naegleria fowleri by drinking contaminated water and the amoeba is not found in salt water.

What is the risk of infection?

It is likely that a low risk of Naegleria fowleri infection will always exist with recreational use of warm freshwater lakes, rivers, and hot springs.

The low number of infections makes it difficult to know why a few people have been infected compared to the millions of other people using the same or similar waters across the U.S.

The only certain way to prevent a Naegleria fowleri infection is to refrain from water-related activities in warm, untreated, or poorly-treated water.

June 19, 2016 – Ohio teen dies

Exposed to water (suspected source) at U.S. National Whitewater Center in Charlotte, NC

http://www.cnn.com/2016/06/22/health/brain-eating-amoeba-killed-ohio-teenager/

Rare but Fatal

Kline noted that Naegleria fowleri infections are rare. The CDC reported 37 infections in the 10 years from 2006 to 2015. But the fatality rate of the infection is as high as 97%.

"Only 3 out of the 138 known infected individuals in the United States from 1962 to 2015 have survived," the CDC said.

Prevention Methods

Avoid water-related activities in warm freshwater during periods of high water temperature and low water levels.

Hold the nose shut or use nose clips when taking part in water-related activities in bodies of warm freshwater.

Avoid digging in or stirring up the sediment while taking part in water-related activities in shallow, warm freshwater areas.

Waterborne Disease and Outbreak Surveillance System

National Outbreak Reporting System (NORS) http://www.cdc.gov/healthywater/statistics/wbdoss/nors/index.html

Outbreak Response Guides http://www.cdc.gov/healthywater/emergency/toolkit/index.html#guides

Cryptosporidium and Norovirus guides

NORS launched in 2009 following a four year commitment by CDC to the planning, development, and launch phases of the project. CDC developed NORS for waterborne disease outbreak reporting in collaboration with the Council for State and Territorial Epidemiologists (CSTE) and the Environmental Protection Agency (EPA) to improve the quality, quantity, and availability of data submitted to the Waterborne Disease and Outbreak Reporting System (WBDOSS).

The launch of NORS represents an important shift in national waterborne disease outbreak reporting—a transition from paper-based reporting to electronic reporting of outbreak data.

Cryptosporidiosis

Caused by a protozoa, Cryptosporidium hominis or Cryptosporidium parvum.

Incubation Period: 1-12 days. Average of 7 days.

Outbreaks often reported in day care centers.

Cryptosporidiosis

The most common symptom of cryptosporidiosis is watery diarrhea. Other symptoms include

Dehydration

Weight loss

Stomach cramps or pain

Fever

Nausea

Vomiting

Cryptosporidiosis

Crypto has become recognized as one of the most common causes of waterborne disease (recreational water and drinking water) in humans in the United States.

The parasite is found in every region of the United States and throughout the world.

Cryptosporidiosis

Shedding of Crypto in the stool begins when the symptoms begin and can last for weeks after the symptoms (e.g., diarrhea) stop.

You can become infected after accidentally swallowing the parasite. Cryptosporidium may be found in soil, food, water, or surfaces that have been contaminated with the feces from infected humans or animals.

Spread of Cryptosporidiosis

By putting something in your mouth or accidentally swallowing something that has come into contact with stool of an infected person or animal

Swallowing contaminated recreational water

Drinking contaminated beverages

Eating uncooked, contaminated food

Touching your mouth with contaminated hands

Exposure to feces via sexual contact

Symptoms

Stomach cramps or pain

Dehydration

Nausea

Vomiting

Fever

Weight loss

Small intestine typically affected

Symptoms

Incubation period is 2-10 days, average is 7 days.

In persons with healthy immune systems, symptoms usually last about 1 to 2 weeks. The symptoms may go in cycles in which you may seem to get better for a few days, then feel worse again before the illness ends.

At-risk Populations: Swimmers

Cryptosporidium now causes over half of the reported waterborne disease outbreaks associated with swimming in chlorinated public swimming pools.

Cryptosporidium’s chlorine resistance and documented excretion for weeks after resolution of symptoms has led CDC and The American Academy of Pediatrics to recommend that all persons refrain from swimming until 2 weeks after resolution of symptoms.

Diagnosis and Treatment

Diagnosed by stool sample and subsequent analysis

Nitazoxanide has been FDA-approved for treatment of diarrhea caused by Cryptosporidium in people with healthy immune systems and is available by prescription.

Diarrhea can be managed by drinking plenty of fluids to prevent dehydration. Young children and pregnant women may be more susceptible to dehydration. Rapid loss of fluids from diarrhea may be especially life threatening to babies. Therefore, parents should talk to their health care provider about fluid replacement therapy options for infants. Anti-diarrheal medicine may help slow down diarrhea, but a health care provider should be consulted before such medicine is taken.

People who are in poor health or who have weakened immune systems are at higher risk for more severe and more prolonged illness. The effectiveness of nitazoxanide in immunosuppressed individuals is unclear. HIV-positive individuals who suspect they have Crypto should contact their health care provider. For persons with AIDS, anti-retroviral therapy that improves immune status will also decrease or eliminate symptoms of Crypto. However, even if symptoms disappear, cryptosporidiosis is often not curable and the symptoms may return if the immune status worsens.

Treatment

In 2004, the FDA licensed nitazoxanide (Alinia) for all persons ≥ 1 year of age.

Adult dosage (immune competent)

500 mg BID x 3 days

Pediatric dosage (immune competent)

1-3 years: 100 mg BID x 3 days

4-11 years: 200 mg BID x 3 days

Treatment

Nitazoxanide oral suspension (100 mg/5ml; patients ≥ 1 year of age) and Nitazoxanide tablets (500 mg; patients ≥ 12 years of age) are indicated for the treatment of diarrhea caused by Cryptosporidium.

Clinical cure (resolution of diarrhea) rates range from 72-88%

It may take up to 5 days for diarrhea to resolve in approximately 80% of patients

Cryptosporidium Outbreak in Childcare Setting

Cryptosporidium is resistant to chlorine disinfection so it is tougher to kill than most disease-causing germs.

The usual disinfectants, including most commonly used bleach solutions, have little effect on the parasite.

An application of hydrogen peroxide works best.

Cryptosporidium Outbreak in Childcare Setting

Educate staff and parents

Inform all staff about the ongoing outbreak, the symptoms of Crypto, how infection is spread, control measures to be followed, outbreak control policies, and needed changes in hygiene and cleanliness.

Notify parents of children who have been in direct contact with a child or an adult caregiver with diarrhea. Parents should contact the child's healthcare provider if their child develops diarrhea.