Chlamydia trachomatis, infertility, and population growth in sub-Saharan Africa

In sub-Saharan Africa, Neisseria gonorrhoeae and Chlamydia trachomatis are common infections. These pathogens are also the major causes of post-salpingitis tubal infertility, and infertility is a frequent problem in this region. A mathematical model, recently devised to estimate the effect of gonococcal infection on population growth, was used to estimate the potential effect of chlamydial infection on population growth. The model predictions for chlamydial infection were compared with those previously reported for gonococcal infection. The model predicts that both infections may be exerting severe effects on population growth at realistic prevalence rates of infection. The model also predicts that N. gonorrhoeae produces a steeper reduction in population growth than does C. trachomatis because its transmission dynamics result in a higher force of infection (incidence rate) at any given prevalence of infection. Large scale changes in the epidemiology of these infections can be expected to occur in sub-Saharan Africa because of improved sexually transmitted disease (STD) diagnosis and treatment services as a component of AIDS prevention. Changes in the epidemiology of gonococcal and chlamydial infection are predicted to result in accelerated population growth unless STD control programs are linked to effective contraception programs.