Risk factors for Incident Trichomonas vaginalis among Women Recruited in RESPECT-2, an HIV Prevention Trial

D Helms 1, D Mosure 1, T Peterman 1, C Metcalf 1,2, J Douglas, Jr.1,3, CK Malotte 4, S Paul 5

1 Centers for Disease Control and Prevention, Division of STD Prevention, Atlanta, GA 2 Aurum Institute for Health Research, Johannesburg, South Africa

3 Denver Health, Denver Colorado4 California State University, Long Beach, CA

5 New Jersey Department of Health and Senior Services, Trenton, NJ

Trichomonas vaginalis

Most common non-viral STD

5 million new infections occurring in the US annually

50% of infected females are asymptomatic

Associated with adverse birth outcomes: premature rupture of the membranes, pre-term delivery, and low birth weight

May increase susceptibility to,

or transmissibility of, HIV

Treatment cures 90-95% of infections

Epidemiology of T. vaginalis

Prevalence typically ranges from 5-10% in women in the general population

Risk factors for prevalent trichomonas infection include: black race, history of previous STDs, sex workers, pregnancy, multiple partners, and drug use

One incidence study has been conducted*

One county in China

In women aged >25 years

Incidence rate of 1.1 per 100 person-years

*Sex Trans Dis 1996; 415-424.

Objective

To determine risk factors associated with prevalent and incident trichomonas infection

Methods

Data from an HIV-prevention counseling trial (RESPECT-2)

3 STD clinics in Long Beach, CA; Denver, CO; and Newark, NJ; 1999-2001

1507 women aged 15-39 years

Screened for STDs (chlamydia, gonorrhea, trichomonas) at baseline, 3, 6, 9, and 12 months

Wet mount or culture was used to test for trichomonas infection

Analysis Prevalent trichomonas infection

Stratified by demographic, behavioral, and clinical risk factors

Incident trichomonas infection New Infection –

Negative test at baseline and positive test at follow-up or

Positive test at least 14 days after treatment for a baseline infection

Stratified by demographic, behavioral, and clinical risk factors

Logistic regression was used to identify risk factors

Results

1507 women

1462 tested by wet mount or culture

for T. vaginalis at baseline

1269 tested at least once in follow-up*

*Average duration of follow-up = 364 days

190 (13%) prevalent infections

168 (13%) incident infections

New and Repeat Infections

190 positive

1462 women

62 repeat

1272 negative

108 new infections

121 (72%) asymptomatic

Baseline

Follow-up

Total Incident

Asymptomatic

168 total incident infections

Risk Factors for Prevalent and Incident Trichomonas Infection

Characteristics Prevalent % (N) Incident % (N) Age (years)

15-19 7.2 (359) 10.6 (303)

20-24 13.9 (461) 11.1 (395)

25-29 13.3 (278) 11.3 (240)

30-34 6.9 (195) 16.9 (178)

35-39 17.8 (169) 22.9 (153)

Race/Ethnicity

White 5.9 (307) 4.9 (268)

Hispanic 6.5 (260) 6.1 (228)

Other 7.6 (170) 6.5 (154)

Black 19.6 (725) 21.2 (619)

Education< 12 years 16.2 (413) 17.6 (358)

> 12 years 14.4 (992) 14.6 (856)

Risk Factors for Prevalent and Incident Trichomonas Infection

Characteristics Prevalent % (N) Incident % (N) Partners Past 3 Months

0 ▬ 10.7 (224)

1 11.4 (747) 10.1 (751)

2 13.7 (387) 18.9 (180)

>3 15.9 (320) 23.6 (89)

Sex for drugs/money1

Yes 26.3 (95) 40.0 (30)

No 12.1 (1359) 12.0 (990)

Symptoms of Trich2

Yes 7.5 (752) 22.1 (213)

No 5.5 (710) 11.5 (1056)

Chlamydia2

Yes 21.5 (181) 36.8 (38)

No 11.8 (1268) 12.3 (1169)

Gonorrhea2

Yes 22.7 (97) 38.5 (26)

No 12.3 (1355) 12.4 (1187) 1Ever exchanged sex for money or drugs2At time of trichomonas infection or at the last study interval

Multivariate analysis Trichomonas Infection

Prevalent IncidentRisk Factors AOR 95% C.I. AOR 95% C.I.

Age (years)15-19 1.0 - 1.0 -20-24 2.2 (1.3-3.6) 1.1 (0.6-2.0) 25-29 2.3 (1.3-4.0) 1.3 (0.7-2.7)30-34 2.4 (1.3-4.4) 1.8 (0.9-3.6) 35-39 2.6 (1.4-4.7) 2.9 (1.4-6.0)

Black 3.0 (2.0-4.5) 3.9 (2.3-6.7)

>12 years of education 1.6 (1.1-2.3) 1.9 (1.2-3.0)

Sex for drugs/money1 2.0 (1.1-3.3) 2.6 (1.1-6.2)

Partners past 3 months ▬ 2.4 (1.5-3.7)

Symptoms2 ▬ 2.4 (1.9-8.9)

Chlamydia2 3.7 (1.6-8.3) 4.1 (1.6-8.3)

1Ever exchanged sex for money or drugs2At time of incident trichomonas infection or at the last study interval

Limitations Results reflect women in STD clinics

RESPECT-2 was not designed to evaluate risk factors associated with trichomonas infection

Possible misclassification of incident infections Due to low sensitivity of wet mount or culture Due to drug resistant infection

Conclusions (1)

Trichomonas infection is a common infection 13% of women had a prevalent infection 13% of women had an incident infection

• High percentage of asymptomatic incident infection

Similar risk factors for prevalent and incident infection: Older age (>35 years), Black race, concurrent

chlamydial infection, and sex for drugs/money

Multiple partners and symptoms of trichomonas are risk factors for incident infection

Conclusions (2)

Future studies might consider additional information regarding, contraceptive method and whether the women douched

Unlike other STDs (gonorrhea and chlamydia), T. vaginalis was associated with older age in women

Further investigation should be done to determine if routine screening in STD clinics would be beneficial

The findings and conclusions in this presentation are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention