A clinical evaluation of trichomoniasis in San Jose, Costa Rica using the InPouch TV test

Baseline STD prevalence in a community intervention trial of the female condom in Kenya

OBJECTIVE

We present baseline sexually transmitted disease (STD) prevalence rates from an ongoing intervention trial at Kenyan agricultural sites.

METHODS

After gaining the cooperation of management, we identified six matched pairs of tea, coffee, and flower plantations and enrolled approximately 160 women at each site. Six intervention sites received an information programme and distributed female and male condoms, while six control sites received male condoms only and similar information about them. At clinic visits, we tested participants for cervical gonorrhoea (GC) and Chlamydia trachomatis (CT) by ligase chain reaction on urine specimens, and Trichomonas vaginalis (TV) by culture. The study has 80% power to detect a 10% prevalence difference during follow up, assuming a combined STD prevalence of 20%, 25% loss to follow up and intracluster correlation coefficient (ICC) of 0.03.

RESULTS

Participants at intervention and control sites (total 1929) were similar at baseline. Mean age was 33 years, the majority were married, more than half currently used family planning, 78% had never used male condoms, and 9% reported more than one sexual partner in the 3 months before the study. Prevalences of GC, CT, and TV were 2.6%, 3.2%, and 20.4% respectively (23.9% overall), and were similar at intervention and control sites. The ICC for STD prevalence was 0.0011. Baseline STD was associated with unmarried status, non-use of family planning, alcohol use, and more than one recent sexual partner, but the highest odds ratio was 1.5.

CONCLUSIONS

Baseline results confirm a high prevalence of trichomoniasis and bacterial STD at these Kenyan rural sites. Improved STD management is urgently needed there. Our ongoing female condom intervention trial is feasible as designed.

High prevalence of trichomoniasis in rural men in Mwanza, Tanzania: results from a population based study

OBJECTIVES

To measure the prevalence of urethral infections including trichomoniasis in rural Tanzanian men, to assess the prevalence of symptoms and signs among men with Trichomonas vaginalis, and to analyse the risk factors for trichomoniasis.

DESIGN

A cross sectional study of 1004 men aged 15-54 years in a rural community in north west Tanzania.

METHODS

Participants were interviewed about sexual behaviour and symptoms of sexually transmitted diseases. First fraction urine samples and urethral swabs were collected and used to test for T vaginalis by wet preparation and culture, Neisseria gonorrhoeae by culture, Chlamydia trachomatis by ligase chain reaction and non-specific urethritis by Gram stain. Urine was also tested for the presence of leucocytes using a leucocyte esterase dipstick. Men were re-interviewed 2 weeks later to document new symptoms and signs of urethritis.

RESULTS

Complete laboratory results were available on 980 men. One in four men had laboratory evidence of urethritis. T vaginalis was found in 109 individuals (11%), gonorrhoea in eight (0.8%), and chlamydial infection in 15 (1.5%). Over 50% of men with urethritis were asymptomatic. The prevalence of signs and symptoms was similar among men with T vaginalis alone compared with men with other urethral infections. The sensitivity and specificity of the leucocyte esterase dipstick (LED) test for detecting T vaginalis were 80% and 48% respectively in symptomatic men and 60% and 68% in asymptomatic men. Factors associated with trichomoniasis included religion, type of employment, and marital status.

CONCLUSIONS

A high prevalence of urethritis was found in men in this community based study. More than half of the urethral infections detected were asymptomatic. The most prevalent pathogen was T vaginalis. Studies are needed on the prevalence of trichomoniasis in men presenting to health services with complaints suggestive of urethritis since treatment for T vaginalis is not included in the syndromic management of urethritis in most countries. The performance of the LED test as a screening test for trichomoniasis was unsatisfactory in both symptomatic and asymptomatic men. Improved screening tests are urgently needed to identify urethral infections that are asymptomatic and which are not covered by current syndromic management algorithms.

Cytopathogenic effect of Trichomonas vaginalis on human vaginal epithelial cells cultured in vitro

In this study we established human vaginal epithelial cells (hVECs) in culture and evaluated their interaction with Trichomonas vaginalis parasites to complement previous studies using other cell types. Primary cultures of hVECs were established. Contaminating fibroblasts were separated from epithelial cells by differential trypsinization. Specific antibody staining revealed that over 92% of cells in hVEC monolayers were epithelial cells. T. vaginalis adhered to hVECs and produced severe cytotoxic effects resulting in obliteration of the monolayer within 24 h. Adherence and cytotoxicity were not observed when T. vaginalis was exposed to human vaginal fibroblasts or bovine vaginal epithelial cells. Likewise, the bovine parasite Tritrichomonas foetus had no cytotoxic effects on hVECs. We concluded that the interaction between T. vaginalis and hVECs is both cell specific (limited to epithelial cells and not vaginal fibroblasts) and species specific (limited to human vaginal cells and not bovine cells). Pretreatment of T. vaginalis with metronidazole or periodate abolished the adhesion of parasites to cell monolayers and the cytotoxic effect, suggesting involvement of carbohydrate-containing molecules in these processes. Different clinical isolates of T. vaginalis caused damage to cultured cells at different rates. Parasites separated from the vaginal cell monolayer by a permeable membrane did not produce a cytopathic effect, suggesting contact-dependent cytotoxicity.

A comparison of the sensitivity of the InPouch TV, Diamond's and Trichosel media for detection of Trichomonas vaginalis

OBJECTIVE

This study compared the ability of three culture media (InPouch TV, Diamond's, and Trichosel) to support the growth of clinical isolates of Trichomonas vaginalis and their relative sensitivity for detection of the organism.

METHODS

The majority of the clinical isolates were obtained from two San Francisco Bay Area clinics. T vaginalis was subcultured in 4 ml of one of the InPouch, Diamond's, or Trichosel media for 24-48 hours before evaluation. Twenty isolates were initially cultured in the InPouch test, 13 with Diamond's, and 10 with Trichosel. A haemocytometer was used to measure the initial concentrations of the organisms. Then serial dilutions were made in saline to yield approximately 2.0 x 10(4), 2.0 x 10(3), and 2.0 x 10(2) motile T vaginalis per ml. A 30 microliter inoculum from each dilution was transferred into 4 ml aliquots of the three media (387 individual tests, 43 x 3 dilutions x 3 media). Microscopic examinations for viable trichomonads were made at 24, 48, and 96 hours. Microscopy was through the pouch wall for the InPouch medium, and through a cover slipped slide with one drop of Diamond's and Trichosel media.

RESULTS

At 24 hours, the InPouch demonstrated 84/129 positive, Diamond's 23/129, and Trichosel 18/129. At 48 hours, an accumulative positive rate for the InPouch was 98/129, for Diamond's 55/129, and Trichosel 47/129. At 96 hours the total positives for each test were 112/129 for the InPouch, 78/129 for Diamond's, and 74/129 for Trichosel.

CONCLUSIONS

The InPouch TV test was significantly more sensitive than either Diamond's or Trichosel (at 0.01 level of significance, pInPouch > pDiamond's; pInPouch > pTrichosel on all three dilutions at 24, 48, and 96 hours). This increased sensitivity was the result of either a reduced generation time or the larger volume of media examined microscopically.