The Incidence of TB Is On the Rise in Southern Mozambique

A study led by the Manhiça Health Research Center (CISM) and ISGlobal provides for the first time data on trends in cases and other indicators of tuberculosis over 16 years in Manhiça district, in Southern Mozambique. The results are not encouraging: the number of new cases has almost triplicated between 1997 and 2012, while the rate of treatment success remains low. These results will help better understand the current TB epidemic in Mozambique, one of the few countries where incidence rates have not improved in the last years.

Tuberculosis (TB) remains a major public health concern and one of the leading causes of death worldwide. In Mozambique, the number of new cases each year remains high (552 per 100,000 inhabitants) despite the low detection rate (around 39%). To date, there is barely data on disease indicator trends in the country, although recent studies show an extremely high burden of TB/HIV coinfections.

In this study, the authors analysed data on incidence and other key disease indicators (including treatment and outcome) obtained between 1997 and 2012 in Manhiça, a highly endemic area for the disease. Over the 16 year period, 9,575 TB cases were registered. Between 1997 and 2012, the incidence (i.e. the number of new cases per year) increase three-fold and was consistently higher in males than females, regardless of age. From 2007 (when HIV testing was implemented at the national level) onwards, 70% of TB cases were also HIV positive. On average, 15% of patients died during treatment (with a higher rate for HIV-positive patients).

The increase in the number of TB cases since 1997 could be explained by the HIV epidemic, as has been the case in other countries. However, the increase in the most recent years could also reflect increased access to health services and better diagnosis. The reasons underlying the differences in TB incidence rate between females and males remain unclear but could be associated to migration of male workers to highly endemic areas in South Africa.

“The south of Mozambique is probably one of the hotspots for TB and HIV in the world” saysAlberto García Basteiro, first author of the study, “We need to reinforce control activities in the area and understand why mortality is so high despite using the correct treatment for TB and HIV”. The authors point out that the estimated rates probably underestimate the real number of cases, but they conclude that this type of studies will contribute to achieve a better understanding of the current TB epidemic in Mozambique and will help guide public health policies in the country.

Reference

García-Basteiro AL, Miranda Ribeiro R, Brew J, et al. Tuberculosis on the rise in southern Mozambique (1997-2012). Eur Respir J. 2017; 49: 160683