T vaginalis screening goes global
A large study in Africa could help to control the HIV epidemic there, through routine screening for Trichomonas vaginalis, which can predispose to HIV infection. The study concluded that a latex agglutination test, by virtue of its simplicity, is a realistic prospect for screening in poor countries.
Sensitivity of the test was higher than for “wet preparation”—microscopic examination of a vaginal swab sample (98.8 v 81.5)—and equivalent to culture (98.2)—the definitive test for T vaginalis. Specificity, at 92.1, was satisfactory. Agreement between latex agglutination and the other tests was good (0.93 agglutination/culture; 0.88 agglutination/wet preparation). The test requires minimal equipment and training; results are available within two minutes.
Vaginal swab samples were taken by a nurse from all 206 women positive for T vaginalis by latex agglutination of initial samples obtained themselves and 412 selected women with negative initial samples out of 3807 consecutive women attending antenatal clinics in Ghana between September 2002 and May 2003. Wet preparation and culture were performed by experienced staff, and all results were read independently and blind.
A simple, rapid test is needed in developing countries, where T vaginalis infection is most prevalent. Infection increases HIV transmission, but its treatment reduces viral load in vaginal and seminal fluid. Therefore identifying and treating T vaginalis—whose rate of new infections is an estimated 170 million/year—should curb spread of HIV. “It is time to evolve routine screening and treatment for T vaginalis infection in reproductive health settings,”say the authors.
