The impact of HIV/AIDS on the control of tuberculosis in India

Abstract

Epidemics of HIV͞AIDS have increased the tuberculosis (TB) caseload by five or more times in East Africa and southern Africa. As HIV continues to spread, warnings have been issued of disastrous AIDS and TB epidemics in ''new-wave'' countries, including India, which accounts for 20% of all new TB cases arising in the world each year. Here we investigate whether, in the face of the HIV epidemic, India's Revised National TB Control Program (RNTCP) could halve TB prevalence and death rates in the period 1990 -2015, as specified by the United Nations Millennium Development Goals. Using a mathematical model to capture the spatial and temporal variation in TB and HIV in India, we predict that, without the RNTCP, HIV would increase TB prevalence (by 1%), incidence (by 12%), and mortality rates (by 33%) between 1990 and 2015. With the RNTCP, however, we expect substantial reductions in prevalence (by 68%), incidence (by 41%), and mortality (by 39%) between 1990 and 2015. In India, 29% of adults but 72% of HIV-positive adults live in four large states in the south where, even with the RNTCP, mortality is expected to fall by only 15% between 1990 and 2015. Nationally, the RNTCP should be able to reverse the increases in TB burden due to HIV but, to ensure that TB mortality is reduced by 50% or more by 2015, HIV-infected TB patients should be provided with antiretroviral therapy in addition to the recommended treatment for TB. millenium development ͉ goals ͉ infectious disease control ͉ dynamical simulation model I n many countries of East and southern Africa, tuberculosis (TB) notification rates have increased by five or more times as a result of the HIV epidemic (1-3). If this were to happen in India, which accounts for 20% of the global burden of TB (1), the total number of TB cases in the world would more than double. At present, Ͻ1% of Indian adults are infected with HIV, but that is about five million people (4), second only in number to South Africa (5, 6). It has been suggested that the prevalence of HIV infection in Indian adults could reach 5%, or Ϸ25 million people (7-9), and an HIV epidemic on this scale would have severe consequences for the burden not only of AIDS but also of TB.In 1993, the Government of India launched a pilot project to explore the implementation of the World Health Organization's DOTS strategy for TB control, based on combination chemotherapy (10, 11). In 1998, the Revised National TB Control Program (RNTCP) began to expand DOTS services across India. By the end of 2003, 740 million people had access to DOTS, and a further 10 million were gaining access each month. In DOTS areas in 2003, an estimated 69% of new smear-positive TB cases were detected, and 87% were successfully treated (1). Without the HIV epidemic, the RNTCP might have been expected to reduce TB incidence, prevalence, and mortality rates by Ϸ5% per year (12)(13)(14).In this paper, we use a dynamical simulation model to investigate the impact of the HIV epidemic and the RNTCP DOTS program on TB in India from 1990 to 2015. In p...

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