Gonococcal infection and human fertility in sub-Saharan Africa

An analysis is presented of the influence of Neisseria gonorrhoeae on human population growth in regions of sub-Saharan Africa where gonococcal infections are prevalent in sexually active adults. Combining epidemiological and demographic data within the framework of a mathematical model, we show that gonorrhoea has a major impact on fertility and, concomitantly, on net population growth in areas with a high prevalence of untreated infections. Specifically, a 20% prevalence in sexually active adults is predicted to induce a 50% reduction in net population growth. Model predictions are in good agreement with observed data from Uganda, and the sensitivity of the prediction to various complications, such as heterogeneity in sexual behaviour, is assessed. The analysis suggests that the predicted increase in fertility arising from expanded sexually transmitted disease (STD) control programmes in Africa to help combat the spread of human immunodeficiency viruses (HIV-1 and HIV-2) will help to offset the predicted demographic impact of AIDS in the worst afflicted areas. In other areas the rise in fertility associated with effective STD control will need to be countered by the linkage of STD control programmes with family planning initiatives.