Friday, March 14, 2008

Worlds Apart

“I know the color of that blood; it is arterial blood. I cannot be deceived in that color. That drop of blood is my death warrant. I must die.”

The British poet, John Keats, trained as a physician, gave himself this accurate prognosis in 1820 after an episode of hemoptysis (coughing blood). He realized he had contracted tuberculosis. He died soon afterward at the age of 25.

The New England Journal of Medicine, March 13, 2008, has two lead articles regarding tuberculosis. The articles are about tuberculosis in Africa and India. Below are key comments and figures from these articles mixed in with statistics regarding Haiti’s current epidemic of tuberculosis.

Tuberculosis is a terrible disease. Who ever called it “consumption” was right. People get trapped in their tiny little bodies and are unable to provide for themselves or their families. They are indeed consumed by their illness.

Tuberculosis is also highly contagious and can be spread just by talking with someone with active tuberculosis. Children are very susceptible to this disease.

Tuberculosis ruins people, families, and society.

The bottom line that needs to be stated early is that tuberculosis is preventable, treatable, and a disease of poverty. And their have been curative medications available for over 50 years.

So here is the depressing news regarding tuberculosis:

1. Africa is facing the worst tuberculosis epidemic since the advent of the antibiotic era. Africa, home to 11% of the world’s population, carries 29% of the global burden of tuberculosis cases and 34% of related deaths. More than half a million people die each year from tuberculosis in Africa.

2. During the 1990’s tuberculosis killed more people worldwide than in any other decade in history. Tuberculosis medications have been available since the 1950’s.

3. The average incidence (all new cases per 100,000 population) of tuberculosis in African counties more than doubled between 1990 and 2005, from 149 to 343. This is in contrast to the stable or declining rates in most other regions of the world.

4. The estimated incidence of tuberculosis in Haiti in 2004 was 306. And I don’t really believe this number. My guess is that tuberculosis is vastly underreported in Haiti.

5. The estimated incidence of tuberculosis in India in 2008 is 200/100,000 population. The rate of confirmed infection in India is startling. Researchers at a medical school in northern India found an incidence of about 17 new cases of active tuberculosis per 1000 medical residents per year (as compared with about 2 cases per 1000 in the general population and 0.05 in the general U.S. population.) Thus, one take home message from these horrible statistics regarding young Indian physicians is the compelling evidence of nosocomial transmission…tuberculosis is very contagious.

6. The estimated incidence of tuberculosis in the United States in 2006 was 3.4 cases. This was the lowest TB incidence ever recorded in the United States. The TB rate among foreign born persons in the United States was 9.5 times that of U.S.-born persons. The TB rates among blacks were 8.4 times higher than rates among whites.

7. Yes, you read these numbers correctly. How can one compare “rates of tuberculosis” of 300 in Haiti to 3 in the United States? Haiti is 90 minutes by air from Miami.

8. The growth of the tuberculosis epidemic in Africa and Haiti is attributable to several factors, the most important being the HIV epidemic. Autopsy studies have shown that 30-40% of HIV-infected adults die from tuberculosis.

9. South African gold miners who have one of the highest incidence rates of tuberculosis in the world, but rates remained stable in the 90’s among HIV-negative miners, while rates among HIV-positive miners increased by a factor of 10. (The cellular immunocompetence of this population became impaired, and thus susceptibility to tuberculosis increased.)

10. By the way, the incidence of tuberculosis in Haiti is higher than in South Africa. Incidence rates of tuberculosis in Yemen, Ukraine, Kazakhstan, Guyana, Thailand, Russia, Romania, North Korea, Iraq, Vietnam, Mongolia, Nepal, China, Gabon, Bolivia, Botswana, India, Sudan, Laos, Ghana, Guinea, Pakistan, Niger, and Chad are all LESS than Haiti.

11. The ability of African, Indian, and Haitian health care systems to respond to, manage, and contain the growing number of cases of tuberculosis is constrained by limitations of funding facilities, personnel, drug supplies, and laboratory capacity. Bad infrastructures yield bad tuberculosis statistics.

12. Another critical factor concerns early diagnosis and treatment of tuberculosis, which limits the spread of the disease and reduces deaths. Again, the infrastructure and the public health capabilities of the that society dictate how quickly tuberculosis is diagnosed and treated.

13. Sensitive tests for diagnosis of a disease need to be present to diagnose efficiently. Throughout Africa, diagnosis rests on the microscopical detection of acid-fast bacilli (the TB germ) in sputum, an insensitive technique that is particularly ill suited to the detection of tuberculosis in HIV-infected patients, who have fewer bacilli in their sputum and have more extrapulmonary tuberculosis than HIV-negative patients. WHO estimates that only half of all persons with smear-positive tuberculosis are identified. Modern culture and nucleic acid-amplification systems are rarely available.

14. As a result, many people remain ill and contagious with tuberculosis for prolonged periods before the disease is detected, and thousands die without ever having received a diagnosis of tuberculosis. Even with diagnosis, the average rate of successful treatment is less than 70%, which makes both relapse and the emergence of drug resistance common.

15. The availability of point-of-care diagnostic tests could substantially reduce the incidence of and mortality from tuberculosis and prompt earlier treatment, thus limiting transmission. (Point-of-care tests are tests that can be done quickly and easily at the site, rather than waiting weeks for culture results to return.) And rapid detection of drug resistant strains would facilitate earlier access to appropriate therapy. Better use of existing, highly sensitive culture techniques could reduce mortality rates associated with tuberculosis by 20% or more.

16. A new tuberculosis vaccine could protect future generations.

17. Interventions directed at people with the highest risk, including families of patients with tuberculosis or HIV infection could be extremely effective. But this would entail giving the "preferential medical option" to the poor. Who wants to do that?

18. For patients with HIV, preventative therapy with isoniazid can reduce tuberculosis incidence, yet less than 1% of all HIV-infected people worldwide who could benefit from this intervention receive it. Antiretroviral therapy alone is insufficient to control tuberculosis, but analyses suggest that isoniazid significantly augments the effect of HIV drugs.

Since the resurgence of TB in the United States during 1985-1992, the annual TB rate has decreased steadily. The TB rate in 2006 was the lowest recorded since national reporting began in 1953. The US public health system responded.

Tuberculosis is a disease of poor people around the world. And as we all know, diseases of the poor are frequently ignored. Maybe, due to the fact that people travel and tuberculosis is so highly contagious, the people that have will take more interest in eradicating tuberculosis.

In Haiti, Africa, India and many other developing countries, increased investments in research, health care systems, diagnostic laboratories, human resources, and public health services needs to occur to control the disease, death, and destruction caused by tuberculosis.


New England Journal of Medicine-- March 13, 2008
Journal of the American Medical Association-- April 25, 2007
Global Health

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