Tuberculosis incidence in developing countries with high prevalence of HIV infection.

OBJECTIVE

To study the impact of the HIV epidemic on tuberculosis (TB) incidence in developing countries.

DESIGN

A simple mathematical model is constructed using figures from published reports to estimate the rise of TB incidence as the HIV epidemic expands.

METHOD: Two groups with different risk of developing TB are identified: individuals with dual infection of HIV and Mycobacterium tuberculosis and the rest of the population. The model is based on a combination of the incidence and the percentage of TB in these two groups. The expected rise in TB incidence and the percentage of TB cases that will be HIV-positive are plotted against the prevalence of HIV.

CONCLUSIONS

Unless appropriate action is taken, TB incidence in developing countries will double as the prevalence of HIV infection reaches 13 per hundred adults.