Serological assays using dried blood spots from 5221 women in rural areas of eastern Zimbabwe
were used to assess the epidemiology of Trichomonas vaginalis infection, and its association with
HIV. Antibodies to T. vaginalis and to HIV were detected by enzyme immunoassays. Behavioural
and demographic data were collected by confidential questionnaires. In total, 516 (9.9%) women
were seropositive for T. vaginalis and seroprevalence increased with age among younger women.
Divorced, widowed and single women were more likely to be seropositive. After controlling for
age, seropositivity was significantly associated with being sexually active, having multiple sex
partners, having a partner who had multiple sex partners, and having a new sex partner in the
past year. Seropositivity was associated with a recent history of genital discharge. Overall, 208
(40.3%) T. vaginalis-positive samples were also positive for HIV, compared with 1106 (23.5%)
T. vaginalis-negative samples (age and sex adjusted OR 2.11, 95% CI 1.74–2.55, P<0.001). There
was increased risk for being HIV-positive amongst T. vaginalis-seropositive women regardless of
residence, employment or education. In a logistic regression controlling for common risk factors,
the association remained significant. T. vaginalis-seropositive young women with a history of
genital discharge were much more likely to be HIV-positive than women who were T. vaginalis-seronegative
and had no history of discharge (OR 6.08, 95% CI 2.95–12.53). Although a causal
relationship cannot be assumed, detection and treatment of trichomoniasis may be important in
strategies to reduce HIV transmission through sexually transmitted infection control