June 8, 1999
Swelling HIV infection rates continue driving a tuberculosis epidemic in sub-Saharan Africa, and world health policy makers need to better account for the intertwining of the two diseases, say Johns Hopkins researchers in a new report. Tuberculosis in the HIV-infected presents a challenge much different than tuberculosis among the HIV-negative, they add, but current efforts by the World Health Organization and by individual countries do not address these differences.
"If decision-makers ignore the clear trends in sub-Saharan Africa and continue with current approaches, the tuberculosis situation in countries with high rates of HIV is likely to worsen," says Richard E. Chaisson, M.D., an author of the report in the June International Journal of Tuberculosis and Lung Disease.
Chaisson and co-author Kevin De Cock of the Centers for Disease Control and Prevention point to the examples of New York City and Baltimore, which in recent years implemented policies that decreased the incidence of tuberculosis among high-risk groups, including those with high rates of HIV infection. Similar measures could reduce the rate of tuberculosis transmission among the large HIV-infected population of Africa as well, Chaisson says. According to the World Health Organization, two-thirds of the world's HIV-positive population, or more than 20 million people, live in sub-Saharan countries like Kenya and Zimbabwe. An estimated one-quarter to one-half of them are co-infected with tuberculosis.
An infection caused by mycobacterium, tuberculosis is transmitted through the air and kill more people worldwide than any other infectious disease. Because HIV weakens the immune system and leaves patients susceptible to the tuberculosis bug, the wet, persistent coughing and cold night sweats tuberculosis brings on are often the first clinical signs of AIDS. Moreover, tuberculosis in much more deadly in people with HIV and is the leading cause of death in that population.
Specific recommendations from the report:
- All identified HIV-positive patients (except those with symptomatic tuberculosis) should be treated with the tuberculosis-preventing drug isoniazid. "Preventive therapy for tuberculosis needs to be standard care for HIV-infected persons in developing countries," says Chaisson.
- Screening for tuberculosis in hospitals and clinics, HIV testing and counseling centers, and prisons will help identify the large, hidden number of people with both active (symptomatic) and latent tuberculosis. (Most people colonized by Mycobacterium tuberculosis never develop active infections, but are nonetheless routinely treated with prophylactic medication in the West). Screening of house mates and family members of symptomatic tuberculosis patients, and of households with HIV-positive members, is also needed.
- Because hospital-acquired strains of tuberculosis tend to be more virulent and drug resistant, special care should be taken to separate HIV-positive patients from tuberculosis patients. Also, HIV-infected hospital staff should avoid contact with tuberculosis patients. Tuberculosis wards should be well-ventilated and sunlit, if possible -- two simple ways to reduce transmission.
- To more efficiently target resources, tuberculosis outbreaks among HIV-positive patients need to be better tracked.
- Tuberculosis and HIV care need to be integrated. Managing both diseases concurrently will yield better control of tuberculosis transmission.
Relevant Web sites:
An abstract of the report is available at http://www.iuatld.org
Tuberculosis summary and statistics, compiled by Chaisson -- http://www.hopkins-id.edu/diseases/tb/index_tb.html
World Health Organization tuberculosis fact sheet -- http://www.who.int/gtb/publications/factsheet/index.htm