title: The changing relationship between bacterial STIs and HIV prevalence in South Africa - an ecological study.
abstract: Prevalence estimates of various bacterial sexually transmitted infections in South Africa have declined considerably since the mid-1990s. Syphilis among pregnant women, for example, declined from 10.8% in 1998 to 2.8% in 2001. We used Pearson's correlation coefficients to estimate the association between the prevalence of syphilis/male urethral discharge/male genital ulcers and the peak HIV prevalence at a district and provincial level in the early and late phases of the HIV epidemic in South Africa. Prevalence estimates of syphilis, male urethral discharge and male genital ulcers during the period preceding the peak HIV prevalence were all positively correlated with the peak HIV prevalence at a provincial level (Pearson's correlation coefficient [r] = 0.83, p = 0.006; r = 0.66, p = 0.052; r = 0.79, 0.011, respectively). These relationships all switched to a negative association later in the HIV epidemic at a provincial level (r = -0.53, p = 0.14; r = -0.73, p = 0.130; r = -0.54, p = 0.027, respectively). AIDS mortality may have played an important role in the decline of bacterial sexually transmitted infections such as syphilis in this region. Consequently, the relatively recent scale-up of antiretroviral therapy may result in a resurgence of syphilis and other sexually transmitted infections as observed in high-income countries.
authors.affiliation: HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium Division of Infectious Diseases and HIV Medicine, University of Cape Town, Cape Town, South Africa ckenyon@itg.be.
authors.forename: Chris Richard
authors.initials: CR
authors.lastname: Kenyon
authors.affiliation: HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Kara
authors.initials: K
authors.lastname: Osbak
authors.affiliation: HIV/STI Unit, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Jozefien
authors.initials: J
authors.lastname: Buyze
authors.affiliation: Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: R Matthew
authors.initials: RM
authors.lastname: Chico
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D015995:Prevalence; D015231:Sexually Transmitted Diseases, Bacterial / Q000453:epidemiology*; D013019:South Africa / Q000453:epidemiology; D013587:Syphilis / Q000453:epidemiology*; D055815:Young Adult
keywords: AIDS; Africa; HIV; ecological study; prevalence; sexual network; sexually transmitted infection; syphilis