COH320. PLEASE ANSWER THE QUESTIONS FOR EACH DISCUSSION POSTS. EACH POST SHOULD BE 200 WORDS OR MORE

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COH 320 Week 2 Session 2

Chapter 5 Stroke

Global Impact of Stroke- Mortality, DALY, Incidence, Case Fatality)

Types of Stroke

Ischemic strokes are caused by interruption of the cerebral blood supply without bleeding.

Hemorrhagic strokes involve rupture of a cerebral blood vessel and leakage of blood into the brain.

Approximately 85% of strokes are classified as ischemic and the remainder (about 15%) are hemorrhagic.

Global Mortality: Stroke

Strokes afflict more than 15 million people annually.

Approximately one third (5.5 million) are fatal.

Stroke ranks second in global mortality and is the leading cause of death in some developing countries (Hungary, Belgium and Russia).

Annual mortality rates vary widely:

< 50 deaths per 100,000 in nations of North America, Western Europe and Australia versus…

> 250 deaths per 100,000 in nations of Northern and Central Asia, Eastern Europe, Middle Africa and the South Pacific.

Approximately 85% of the annual deaths from stroke (4.7 million) occur in developing nations.

International trends in mortality from stroke are similar to that for coronary heart disease and cardiovascular disease.

Global Mortality from Stroke, 2002

Disability Adjusted Life Years (DALY) Stroke

Strokes cause both death and disability thus creating a dual health burden.

The global DALY pattern is similar to that for stroke mortality.

Annual DALYs vary widely: < 250 years of life lost per 100,000 in certain high income nations (North America, Western Europe, Australia) versus > 2,000 in some middle and low income nations (Eastern Europe, Russia, and Central Africa).

High income nations have lower DALYs and middle and low income nations have higher DALYs.

National per capita income is the strongest predictor of stroke mortality and DALY even after adjustment for other stroke risk factors.

This association reflects earlier onset of both fatal and nonfatal debilitating strokes in nations with inadequate resources to support effective preventive and therapeutic health services (Johnston et al., 2009).

Disability Adjusted Life Years for Cerebrovascular Disease, 2004

Declining Stroke Mortality in Developed Countries

In developed nations, e.g., North America, Japan and Western Europe, mortality rates from stroke have declined markedly in the past half century

This is due to primary prevention (avoidance of smoking and maintaining blood pressure, serum cholesterol and blood glucose within normal limits) plus secondary prevention (treatment of hypertension, hyperlipidemia and hyperglycemia and use of anti-thrombotic/anti-platelet therapy, e.g., low dose aspirin, for individuals with atrial fibrillation).

Decline in CVD Mortality, USA, 1970-2005

Racial Differences in Stroke Mortality

Racial disparities in stroke mortality and incidence are similar to that for coronary (ischemic) heart disease.

US Rates are markedly higher among African Americans compared to Caucasian Americans.

The high prevalence and inadequate management of hypertension account for much of the excess in stroke mortality among African Americans (Kittner et al., 1990; Gillum, 1999).

Stroke Mortality in African- and Caucasian-Americans: USA, 1980-2005

Stroke Belt, USA

The US Stroke Belt includes Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia and northern Florida.

These states have age-adjusted stroke mortality rates more than 10% above the national average.

The Stroke Belt reflects a web of causative factors such as hypertension, obesity, smoking, lack of exercise, diets high in fat and fried foods and poor access to emergency medical services.

Stroke Belt, USA (2014)

Studies have found that those born and raised in this wide swath of the United States are 34 percent more likely to die of stroke than their peers in other states.

Researchers believe that greater than average rates of obesity, cigarette smoking and high blood pressure account for the increased risk of death from stroke for those living in the Stroke Belt.

Risk Factors associated with Stroke

Stroke- Alcohol and Smoking

Smoking doubles the risk of stroke when compared to a nonsmoker. Smoking increases clot formation, thickens blood, and increases the amount of plaque buildup in the arteries.

Alcohol use has been linked to stroke in many studies. Drinking too much alcohol can increase blood pressure and the risk of stroke. Aim to drink in moderation – no more than two drinks a day for men and one drink a day for women.

One drink is equal to:

12 ounces of beer

5 ounces of wine (1 glass)

1 ¼ to 1 ½ ounces of liquor

Stroke and Diabetes

Diabetes increases your risk of stroke because high levels of glucose in the blood can damage your arteries, making them harder and narrower (called atherosclerosis).

Diabetes also increases the risk of the build-up of fatty deposits in your arteries, which increases the chances of these blood vessels becoming blocked. If this happens in an artery leading to the brain, it could cause a stroke.

Prevention of Stroke

Similar to myocardial infarction, stroke is the culminating event of chronic disease processes that interact in a complex web of causation.

Pathogenic mechanisms include hypertension, inflammation, atherogenesis, tobacco addiction, insulin resistance, alcohol abuse, obesity and atrial fibrillation.

All of these risk factors are potentially modifiable through appropriate life style choices and/or therapeutic modalities.

Chapter 6-

HYPERTENSION

Hypertension

“High blood pressure is one of the most important modifiable risk factors for cardiovascular disease. It is an extremely common finding in the community and a risk factor for myocardial infarction, stroke, congestive heart failure, end-stage renal disease, and peripheral vascular disease.”

NHLBI, Consensus Statement, 1995

Global Epidemiology of Hypertension

Approximately one quarter of the world’s adult population (more than one billion people) were afflicted with hypertension at the turn of the 20th century.

If current trends continue, the prevalence is projected to increase to about 29% (more than two billion people) by 2025 (Kearney et al., 2005).

Gender Differences in Hypertension

There are differences in the age-specific prevalence patterns of hypertension in men and women

Men have higher prevalence until age 50, after which the prevalence for women is greater.

Potential reasons for the age differential in the prevalence of hypertension between men and women include (1) a protective effect of endogenous estrogens in women during the premenopausal years and (2) the effect of increased longevity and survivorship among women in the later decades of life (Kearney et al., 2005).

Age-Specific Prevalence of Hypertension

Hypertension on a Global Scale

Hypertension Europe Versus USA & Canada

Prevalence rates of hypertension differ among populations, even those of highly developed nations.

European populations consistently show higher rates than North American populations.

Recent surveys suggest the prevalence of hypertension in European populations ranges from 38% to 55% compared to 28% in the USA and Canada.

Such differences may reflect divergence in the pharmacologic management of high blood pressure (Wolf-Maier et al., 2003).

The Prevalence of Hypertension in Europe versus North America

Hypertension in the home front

Hypertension in the US Stroke Belt

The Stroke Belt in the United States is comprised of Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia and northern Florida.

These states have age-adjusted stroke mortality rates more than 10% above the national average.

These same states also have the highest prevalence rates of hypertension (Centers for Disease Control, 2007).

Obviously, there is significant overlap in the distributions of hypertension and stroke.

Percentage of Adults Aged 20 Years and Older Who Have Been Told They Have High Blood Pressure, 2007

Trends in the Prevalence of Hypertension in the USA, 1988 -2008.

Types of Hypertension

Essential Hypertension constitutes 90-95% of cases. No specific cause is identifiable in essential hypertension.

Secondary Hypertension constitutes 5-10% of cases. A definitive specific cause (usually a hormonal disorder) is readily identifiable in secondary hypertension.

Essential Hypertension

Essential hypertension develops due to the interaction of multiple factors in a web of causation.

While exact causes are difficult to establish in the majority of patients, the evidence confirming the multifactorial nature of essential hypertension is overwhelming.

Three major risk factors stand out: obesity, smoking and chronic alcohol abuse.

Many other factors doubtless contribute to the pathogenesis of essential hypertension, including:

excess dietary sodium (salt),

low dietary potassium,

Vitamin D deficiency,

excess of certain dietary fats,

sedentary life style,

psychological factors (stress or depression) and

genetic predisposition.

Secondary Hypertension

Hypertension that develops from a known cause (often a hormonal disorder) is called secondary hypertension.

Secondary hypertension accounts for only 5-10% of all cases of hypertension.

Some known causes of secondary hypertension include hyperthyroidism (elevated thyroid hormone), Cushing’s syndrome (elevated cortisol), and Conn’s syndrome (elevated aldosterone)

Risk Factors for Hypertension Obesity (BMI > 30)

Many other epidemiologic studies have revealed a strong graded relationship between obesity and hypertension.

Data from the National Health and Nutrition Examination Survey (NHANES) show the striking linear relationship between body mass index and rising blood pressure in the American adult population.

Alcohol & Hypertension

Heavy consumption (> 2 drinks per day) increases the risk 1.5 to 2-fold.

Lighter consumption may slightly decrease the risk.

Alcohol-induced hypoglycemia may be partially responsible for the observed increased in blood pressure and hypertension among heavy drinkers

Sommerfeld et al., 2007; Feldman-Billard et al., 2010

Smoking & Hypertension

Smoking has been proven to raise your blood pressure during and after (up to fifteen minutes).

This leads to the damaging of the lining of the blood vessels by creating a reduced opening which in turn increase the force needed to keep the blood flowing.

Secondhand smoke also can increase your blood pressure.

Genetics & Hypertension

African Americans have higher rates of hypertension than Caucasians which has been attributed to their heightened retention of sodium (salt).

The influence of genes that regulate the renin angiotensin system (RAS) as well as vasoactive substances may play a role in elevating the susceptibility to hypertension among African Americans.

Universal Healthcare

Universal healthcare

The map on the previous slide depicts the countries who are considered to have some sort of universal health care plans that support the population in that country. The majority are government-led programs such as the National Health Service or NHS in the UK. A group that is not considered in this count include those who may have some sort of health care plan but it is not universally applied include low socioeconomic countries in Africa and Latin America.

Some developing countries such as Costa Rica and Cuba are a few of the success stories for areas considered poor by global standards.

Tuberculosis 101

Tuberculosis

Tuberculosis (TB) is a common infectious disease caused by Mycobacterium tuberculosis.

The infection typically attacks the lungs but can also spread to other organs including the meninges, lymph nodes, skeletal system and genitourinary tract.

Tuberculosis is a communicable disease that is disseminated by coughing and sneezing.

Most infections in humans are asymptomatic and become latent, but about 10% of latent infections eventually progress to active disease.

Tuberculosis

Without treatment, active tuberculosis has a case fatality rate exceeding 50% (Jasmer, Nahid & Hopewell, 2002).

Classic symptoms of active tuberculosis are chronic cough with blood-tinged sputum, fever, night sweats and profound weight loss.

The definitive diagnosis of tuberculosis relies on chest X-rays, a tuberculin skin test (Mantoux test), blood serology and microscopic examination of cultures of biological specimens (Konstantinos, 2010)

Tuberculosis in the early years

Tuberculosis TB in the 19th & 20th Centuries

Tuberculosis was one of the leading causes of death in the United States, Europe and many other countries throughout the 19th century and the early 20th century.

Those infected with tuberculosis were isolated from society and placed in sanatoriums to prevent dissemination of the disease. (Doc Holiday)

Tuberculosis TB in the 19th & 20th Centuries

Therapies for the“white plague” were of little benefit until the development of an effective vaccine (Bacille Calmette-Guérin vaccine) in France and the subsequent discovery of streptomycin in the US (Waksman, 1952; Comstock, 1994; Bonah, 2005).

Due to the effective use of antibiotics for patients with latent and active disease during the last half of the 20th century, the death rates from tuberculosis plummeted in the United States and other developed countries.

Tuberculosis TB in the 19th & 20th Centuries

Nevertheless, with the emergence of multi-drug resistant strains of Mycobacterium tuberculosis (MDR-TB) and co-infections with HIV, there has been a resurgence of tuberculosis that has become a global public health emergency in many regions of the world (WHO, 2007).

Tuberculosis in the modern era

Tuberculosis Global Burden of TB

Based upon recent global surveys of member nations and territories, the World Health Organization reports that approximately one third of the world population is infected with Mycobacterium tuberculosis.

Most of the more than 2 billion individuals who are seropositive for Mycobacterium tuberculosis (~80%) are found in 22 developing countries, most of which are located in Asia and sub-Saharan Africa (WHO, 2007; WHO, 2009; WHO, 2010).

Individuals Seropositive for Mycobacterium tuberculosis in 22 Countries

Tuberculosis Global Burden of TB

The prevalence of seropositive individuals varies by location and also by age.

In developing countries such as the United States, Canada, European and Australasian nations, the rates remain low (less than 1%) throughout the lifespan.

In contrast, rates in endemic areas, such as sub-Saharan Africa, India, China and Russia rise dramatically with age approaching nearly 100% in some populations (Wood et al., 2010).

Tuberculosis Incidence & Prevalence of TB

Globally, there were an estimated 9.27 million incident cases of active TB detected in 2007.

This is an increase from 9.24 million cases in 2006, 8.3 million cases in 2000 and 6.6 million cases in 1990.

Most of the new cases were diagnosed in Asia (55%) and Africa (31%), with small proportions of cases in the Eastern Mediterranean Region (6%), the European Region (5%) and the Region of the Americas (3%).

Tuberculosis Incidence & Prevalence of TB

The five countries that ranked first to fifth in total numbers of cases in 2007 were India (2.0 million), China (1.3 million), Indonesia (0.53 million), Nigeria (0.46 million) and South Africa (0.46 million) (WHO, 2009; WHO, 2010).

Among the 9.27 million incident TB cases detected in 2007, an estimated 1.37 million (15%) were HIV-positive.

Of the HIV-positive cases, 79% were in the African Region and 11% were in the South-East Asia Region.

Tuberculosis Incidence & Prevalence of TB

Rates were also high in Indonesia (530,000 new cases), Nigeria (460,000 new cases) and South Africa (460,000 new cases).

Brazil had the highest incidence in South America (48 per 100,000).

Portugal and Spain had the highest incidence rates among western European nations (30 per 100,000).

Rates were comparatively low in the UK (15 per 100,000) and the USA (4 per 100,000) (WHO, 2009; WHO, 2010).

Tuberculosis Disability Adjusted Life Years (DALY)

The pattern of Disability Adjusted Life Years (DALY) lost due to premature death and disability from tuberculosis reflects high rates in sub-Saharan Africa, Southeast Asia, the Russian Federation, and some countries in South America.

Childhood deaths from tuberculosis contribute heavily to the DALY.

Disability Adjusted Life Years: Tuberculosis, 2004

Rates of Tuberculosis in the USA, 1993-2009

Tuberculosis of the Future and the Need for a Solution

Tuberculosis MDR-TB & XDR-TB

By definition, multi-drug resistant tuberculosis (MDR-TB) does not respond to first line drugs (isoniazid and rifampicin).

Extensively drug-resistant tuberculosis (XDR-TB) is also resistant to three or more of the six classes of second-line drugs (and often does not respond to any drug).

Tuberculosis MDR-TB & XDR-TB

Drug resistant tuberculosis is rapidly disseminating throughout the world.

In a recent survey of 109 member nations conducted by the World Health Organization, cases of MDR-TB were found in all participating countries and cases of XDR-TB were found in 55 (50%) of countries sampled (WHO, 2010).

http://www.pbs.org/wgbh/pages/frontline/tb-silent-killer /

Tuberculosis Prevention

The WHO strategy has six principal components:

(1) Pursue high-quality DOTS (Directly Observed Treatment Short-course) expansion and enhancement.

(2) Address TB/HIV, MDR-TB, XDR-TB and other special challenges.

(3) Contribute to health system strengthening.

(4) Engage all care providers.

(5) Empower people with TB and communities through partnership.

(6) Enable and promote TB research.

Tuberculosis Incidence & Prevalence of TB

There were an estimated 13.7 million prevalent cases of TB in 2007 (206 per 100 000 population), a slight decrease from 13.9 million cases (210 per 100 000 population) in 2006 (WHO, 2009; WHO, 2010).

The 9.27 million incident (new) cases of tuberculosis observed in 2007 converts to an annual global incidence rate of 139 per 100,000, slightly less than the incidence observed in 2004 (142 per 100,000).

The basics of Zika

Zika virus, a member of the virus family Falviviridae, can be passed from a pregnant women to her fetus.

It can cause a serious birth defect called microcephaly.

Specific defects include a smaller head for the baby than is usually expected. This can lead to varying degrees of brain damage for the baby.