Human Immunodeficiency Virus and the Prevalence of Undiagnosed Tuberculosis in African Gold Miners
We hypothesized that rapid presentation may be a general feature of tuberculosis (TB) associated with human immunodeficiency virus (HIV) that limits the impact of HIV on the point prevalence of TB. To investigate this, we performed a cross-sectional HIV and TB disease survey with retrospective and prospective follow-up. HIV prevalence among 1,773 systematically recruited miners was 27%. TB incidence was much more strongly HIV associated (incidence rate ratio, 5.5; 95% confidence interval [CI], 3.5–8.6) than the point prevalence of undiagnosed TB disease (odds ratio, 1.7; 95% CI, 0.9–3.3). For smear-positive TB, 7 of 9 (78%) prevalent cases were HIV negative, and point prevalence was nonsignificantly lower in miners who were HIV positive (odds ratio, 0.8; 95% CI, 0.1–4.2). The calculated mean duration of smear positivity before diagnosis (point prevalence/incidence) was substantially shorter for HIV-positive than HIV-negative TB patients (0.17 and 1.15 years, respectively; ratio, 0.15; 95% CI, 0.00–0.73). HIV has considerably less impact on the point prevalence of TB disease than on TB incidence, probably because rapid disease progression increases presentation and case-finding rates. The difference in mean duration of smear positivity was particularly marked and, if generalizable, will have major implications for TB control prospects in high HIV prevalence areas.
Corbett, E.L.; Charalambous, S.; Moloi, V.M.; Fielding, K.; Grant, A.D.; Dye, C.; de Cock, K.M.; Hayes, R.J.; Williams, B.G.; Churchyard, G.J. Human Immunodeficiency Virus and the Prevalence of Undiagnosed Tuberculosis in African Gold Miners. American Journal of Respiratory and Critical Care Medicine (2004) 170 (6) 673-679. [DOI: 10.1164/rccm.200405-590OC]