OBJECTIVE: The impact of a multicomponent intervention programme on the sexual health of adolescents was assessed in rural Tanzania. DESIGN: A community-randomized trial. METHODS: Twenty communities were randomly allocated to receive either a specially designed programme of interventions (intervention group) or standard activities (comparison group). The intervention had four components: community activities; teacher-led, peer-assisted sexual health education in years 5-7 of primary school; training and supervision of health workers to provide 'youth-friendly' sexual health services; and peer condom social marketing. Impacts on HIV incidence, herpes simplex virus 2 (HSV2) and other sexual health outcomes were evaluated over approximately 3 years in 9645 adolescents recruited in late 1998 before entering years 5, 6 or 7 of primary school. RESULTS: The intervention had a significant impact on knowledge and reported attitudes, reported sexually transmitted infection symptoms, and several behavioural outcomes. Only five HIV seroconversions occurred in boys, whereas in girls the adjusted rate ratio (intervention versus comparison) was 0.75 [95% confidence interval (CI) 0.34, 1.66]. Overall HSV2 prevalences at follow-up were 11.9% in male and 21.1% in female participants, with adjusted prevalence ratios of 0.92 (CI 0.69, 1.22) and 1.05 (CI 0.83, 1.32), respectively. There was no consistent beneficial or adverse impact on other biological outcomes. The beneficial impact on knowledge and reported attitudes was confirmed by results of a school examination in a separate group of students in mid-2002. CONCLUSION: The intervention substantially improved knowledge, reported attitudes and some reported sexual behaviours, especially in boys, but had no consistent impact on biological outcomes within the 3-year trial period.

Biological and behavioural impact of an adolescent sexual health intervention in Tanzania: a community-randomized trial.

Trichomonas vaginalis was originally considered a commensal organism until the 1950s when the understanding of its role as a sexually transmitted infection (STI) began to evolve. Trichomoniasis has been associated with vaginitis, cervicitis, urethritis, pelvic inflammatory disease (PID), and adverse birth outcomes. Infection with T vaginalis could have an important role in transmission and acquisition of HIV. T vaginalis is site specific for the genitourinary tract and has been isolated from virtually all genitourinary structures. Asymptomatic disease is common in both men and women, thus screening for disease is important. Various sociodemographic factors have been correlated with presence of T vaginalis, and may be used to predict infection. Diagnosis is usually made from wet mount microscopy and direct visualisation, which are insensitive. DNA amplification techniques perform with good sensitivity, but are not yet approved for diagnostic purposes. In areas where diagnostic methods are limited, management of trichomoniasis is usually as part of a clinical syndrome; vaginal discharge for women and urethral discharge for men. A single dose of metronidazole is effective in the majority of cases. Outside of the United States, other nitroimidazoles may be used and are as effective as metronidazole. Metronidazole resistance is an emerging problem, but its clinical importance is not yet clear. Concomitant treatment of sexual partners is recommended.

https://sti.bmj.com/content/sextrans/80/2/91.full.pdf

Trichomoniasis: clinical manifestations, diagnosis and management

Background and Objectives: The prevalence of trichomoniasis in the general population of the United States is unknown. This study provides the first population-based prevalence estimates of trichomoniasis among young adults in the United States. Methods: The National Longitudinal Study of Adolescent Health (Add Health) is an ongoing prospective cohort study. In a cross-sectional analysis of Wave III of Add Health (N = 12,449), we determined the prevalence of trichomoniasis using a polymerase chain reaction assay. Results: The estimated overall prevalence of trichomoniasis in U.S. young adults was 2.3% (95% confidence interval [CI], 1.8–2.7%). The prevalence was slightly higher among women (2.8%; 95% CI, 2.2–3.6%) than men (1.7%; 95% CI, 1.3–2.2%). The prevalence increased with age and varied by region, with the south having the highest prevalence (2.8%; 95% CI, 2.2–3.5%). The prevalence was highest among black women (10.5%; 95% CI, 8.3–13.3%) and lowest among white women (1.1%; 95% CI, 0.8–1.6%). Among men, the prevalence was highest among Native Americans (4.1%; 95% CI, 0.4–29.3%) and blacks (3.3%; 95% CI, 2.2–4.9%), and lowest among white men (1.3%; 95% CI, 0.9–1.8%). Conclusions: Trichomoniasis is moderately prevalent among the general U.S. population of young adults and disturbingly high among certain racial/ethnic groups.

The prevalence of trichomoniasis in young adults in the United States.

Background Trichomonas vaginalis infection is a sexually transmitted infection (STI) linked with reproductive health complications. However, few data exist concerning the epidemiologic profile of this pathogen in adolescent women, a group at high risk for other STIs. Methods Our objective was to describe the prevalence, incidence, natural history, and response to treatment of T. vaginalis infection in adolescent women. Women 14-17 years old were followed for up to 27 months. Vaginal swab samples were obtained during quarterly clinic visits and were self-obtained weekly during 12-week diary collection periods. The weekly samples were tested quarterly. Infections were identified by polymerase chain reaction and were treated with 2.0 g of oral metronidazole. Analysis was performed on the subset of participants who returned for at least 1 quarterly clinic visit. Results T. vaginalis infection was identified in 6.0% (16/268) of the participants at enrollment. Overall, 23.2% (57/245) of the participants with at least 3 months of follow-up had at least 1 infection episode; 31.6% (18/57) experienced multiple episodes. Seventy-two incident infection episodes were diagnosed. When treatment was not documented, weekly samples from participants were positive for up to 12 consecutive weeks. After treatment, T. vaginalis DNA was undetectable within 2 weeks in all but 3 participants. Conclusions The incidence of T. vaginalis infection is high among adolescent women; untreated infections may last undetected for 3 months or longer. Reinfection is common. Treatment with oral metronidazole is effective, and T. vaginalis DNA disappears rapidly after treatment.

Prevalence, Incidence, Natural History, and Response to Treatment of Trichomonas vaginalis Infection among Adolescent Women

This study was conducted to determine the prevalence of trichomoniasis in Malawian men to evaluate a polymerase chain reaction (PCR) detection assay for T. vaginalis in urethral swab samples and to examine the effect of T. vaginalis infection on HIV excretion in the semen. There were 206 men with symptomatic urethritis in STD clinic and 127 asymptomatic men in the Dermatology Clinic who were enrolled from January to March 1996. Results according to a wet-mount microscopy and urethral swabs culture combination showed that of 293 men only 38 (13%) men were positive for T. vaginalis. The estimated prevalence among symptomatic and asymptomatic cases was 15.7% and 8.7% respectively. The PCR yielded a sensitivity of 0.82 (95% CI: 0.66-0.92) and specificity of 0.95 (95% CI: 0.91-0.97); these were compared to the wet-mount microscopy and culture combination. Overall HIV seroprevalence of men was 51% because gonococcal urethritis was shown to significantly increase seminal HIV RNA levels. The median HIV RNA concentration in seminal plasma from men with symptomatic urethritis plus T. vaginalis infection was significantly higher than in seminal plasma from HIV-positive men with symptomatic urethritis only. Since this study has several important limitations a randomized clinical trial would be useful for determining whether urethritis cure rates can be significantly improved.

Trichomonas vaginalis as a cause of urethritis in Malawian men.

Trichomoniasis is recognised as a major sexually transmitted disease (STD) in the world and may act as an acquired immunodeficiency syndromes (AIDS) co-factor by enhancing the transmission of human immunodeficiency virus (HIV). Diagnosis of Trichomonas vaginalis can be achieved by several methods, but sensitive detection means are still lacking. In this study a 2000-bp repeated DNA fragment of T. vaginalis was cloned. Part of a conserved region of this insert was sequenced, two primers (TVK3 and TVK4) were chosen and a highly sensitive detection by polymerase chain reaction (PCR) was then developed for T. vaginalis. All strains of T. vaginalis analysed with these primers gave the expected 350-bp fragment and a 450-bp additional fragment. Sequence analysis of these PCR amplification products revealed that the 450-bp fragment contained the 350-bp with a 100-bp insertion characterised by a TGG microsatellite. A second primer set, namely TVK3 and TVK7 (determined at the border of the insertion), yielded PCR products of expected sizes. After amplification we were able to detect a single parasite. We also detected T. vaginalis in vaginal fluids of patients with STD. There was no reaction with human DNA or other infectious agents. It appears that the two set primers are highly specific of T. vaginalis and provide a useful tool for PCR diagnosis in asymptomatic and symptomatic patients especially among the HIV at risk individuals.

J L Rey

Papers

Trichomonas vaginalis: repeated DNA target for highly sensitive and specific polymerase chain reaction diagnosis.