E-DRUG: Risk of Tuberculosis Doubles in 1st Year of HIV Infection
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[Cross posted from AFRO-NETS. Of relevance to anyone involved in an HIV or a TB drug supply program. Maybe we need to combine HIV & TB in treatment in one program? LL]
Risk of Tuberculosis Doubles in First Year of HIV Infection
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The risk of tuberculosis infection doubles within one year of
HIV infection, according to a study published in the Jan. 15 is-
sue of The Journal of Infectious Diseases, now available online.
Scientists previously assumed that there was no increase in tu-
berculosis risk within the first few years of HIV infection. Pam
Sonnenberg of the London School of Hygiene and Tropical Medicine
and colleagues were therefore surprised by the results of their
research on the two infections, which they conducted in South
African gold miners.
The study was large, involving 23,874 miners from four mines,
and retrospective in design, drawing its results from the medi-
cal records available for each miner. All subjects were black
men between 18 and 65 years of age. They were divided into three
groups: those who were HIV-negative throughout the study, those
who were HIV-positive on study entry, and those whose infection
status changed from negative to positive during the study. Min-
ers were followed until they developed pulmonary tuberculosis,
left the mines, or died. Tuberculosis incidence not only doubled
within the first year of HIV infection but also increased four-
fold after two years, with a further slight increase in those
infected for longer periods of up to seven years.
Sonnenberg and colleagues explained that several characteristics
of the gold mines greatly facilitated their research: a very
high incidence of tuberculosis among the miners, due to crowded
conditions and other work-related factors; the fact that the
miners lived on-site at the mines, making their external envi-
ronments relatively uniform; and the mines' provision of free,
high-quality health care to the miners, including a voluntary
HIV testing program and tuberculosis screening and treatment
programs. The unique setting of the gold mines also provides a
caveat: because the study population was not diverse and was
characterized by unusually high rates of tuberculosis, the re-
sults may not be applicable to all individuals with HIV infec-
tion.
In an editorial accompanying the study, Diane V. Havlir and col-
leagues from the University of California San Francisco said
that this research suggests a level of immunodeficiency in HIV
infection that has not been readily appreciated. They speculated
that the risk for developing tuberculosis may increase early in
HIV infection because of profound immune dysregulation. Another
possible explanation, they noted, is that those who develop tu-
berculosis within the first year of HIV infection have a rapidly
progressing form of HIV disease.
Both the study authors and the editorialists suggested that the
results of this research may have major implications for plan-
ning public health interventions for the two diseases. "Tubercu-
losis is a leading cause of death among people infected with HIV
worldwide," said Havlir. "Perhaps the most immediate and univer-
sal implication of these data is the need to expand reliable and
affordable HIV testing in tuberculosis-endemic areas like the
South African gold mines."