Leave Your Vaginal Part Alone: Why Douching Increases Women’s Risk of STDs

Published By The Statesman For The Statesman Digital
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Does Douching Increase Risk for Sexually Transmitted Infections? A Prospective Study in High-Risk Adolescents.

What is Douching?: The word ''douche'' is French for ''wash'' or ''soak.'' Vaginal douching is the practice of cleansing the vagina with a liquid solution for perceived hygienic reasons and/or therapeutic purposes. Many women douche in order to cleanse the vagina after menses or before or after sexual intercourse, prevent odor, alleviate vaginal symptoms, or to prevent pregnancy or sexually transmitted infections (STIs).

While many women douche for perceived hygienic benefits, douching is potentially harmful. Douching has been linked to several adverse reproductive health consequences such as pelvic inflammatory disease, reduced fertility,ectopic pregnancy, low birth weight,preterm delivery, cervical cancer, and other gynecologic health problems. Douching may also increase the risk for bacterial vaginosis and STIs though very few prospective studies are published.

Many factors and mechanisms are involved with STIs. Douching can disrupt the vaginal ecosystem. Oonderdonk et al report that douching caused partial elimination of the normal vaginal microflora with the transient reduction of bacterial counts. Ness et al. report elimination of beneficial peroxidase-producing lactobacilli after douching.

Douching also can cause invisible micro-cuts that make the vaginal membrane more permeable. This significantly increases the risk of contracting STDs, and it can also double the risk of pelvic inflammatory disease.

In a healthy vagina, hydrogen peroxide-producing lactobacilli protect against endogenous and exogenous pathogens by producing bacteriocins. Since douching causes the hydrogen peroxide-producing lactobacilli to decrease in concentration, an overgrowth of anaerobic and facultative aerobic bacteria may ensue. Bacterial vaginosis is associated with a higher prevalence of STIs and HIV-1.

Prospective studies are better able to assess whether douching is a causal factor for STIs or, in contrast, if douching is initiated because of STI symptoms. Epidemiologic studies have suggested an association between douching and adverse outcomes, but a causal relationship is not yet established. Ness et al. conducted a prospective observational study of women at high risk for acquiring sexually transmitted infections, but did not find douching to be associated with acquiring gonococcal or chlamydial genital tract infections.

Two prospective studies looked at douching and incidence of HIV-1 infection in African women, but had conflicting results. Myer et al. found no association between douching and incident HIV in an older populationwhile McClelland et al. found a statistically significant association with various types of douching methods and incident HIV in younger women.Blythe et al. suggest that douching is more common among adolescents who are at an increased susceptibility for STIs. No prospective studies on douching and the incidence of STIs in adolescents have been published.

We studied a cohort of HIV-infected and HIV-uninfected female adolescents with high-risk behavior to assess if douching was a risk factor for incident STIs. Our hypothesis was that douching increases the incidence of STIs in high-risk youth.

MATERIALS AND METHODS

Study Participants

This study included all adolescent females ages 12–19 years at baseline from an observational study called The Reaching for Excellence in Adolescent Care and Health (REACH) Project of the Adolescent Medicine HIV/AIDS Research Network. Investigators recruited both HIV-infected and HIV-uninfected adolescents at 16 locations in 13 U.S. cities from March 1996 through November 1999.

The study cohort enlisted youth who were infected with HIV through sex or drug-taking behaviors, i.e., perinatally-acquired seropositive adolescents were excluded. The control group (HIV-uninfected) was frequency-matched on several sexual-risk and age characteristics with the HIV-infected adolescents. The HIV-infected adolescents were enrolled in an approximate 2:1 ratio compared to HIV-uninfected adolescents (the ratio for females was 1.8 at the end of study recruitment).

Participants were eligible if they were enrolled in a comprehensive, adolescent-specific medical care center, enabling the management of any medical or social issues uncovered during the study. Detailed characteristics of participants, eligibility, methods, and study design have been reported elsewhere.

Procedures

The study design was an observational, prospective cohort. REACH investigators obtained data for analysis from direct face-to-face interviews, Audio Computer-Assisted Self-Administered Interviews (ACASI) for sensitive questions such as sexual activity and drug use, and laboratory tests for STIs.

The questions measured through face-to-face interviews and ACASI have been described in detail elsewhere. In the REACH study, participants came every three (HIV-infected) or six (HIV-uninfected) months for study visits and questionnaires, while laboratory assessments were completed approximately every six months.

Cervical, anal, and urine specimens were analyzed for the presence of the following STIs: Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, and Herpes simplex virus type 2 (HSV-2). We tested first void urine, anal swab, and endocervical samples for Chlamydia trachomatis and Neisseria gonorrhoeae using the ligase chain reaction technique (LCX STD system^™; Abbott Laboratories, Abbott Park, Illinois) at a central laboratory.

Warm saline wet mount samples, culture (In Pouch TV^™, Biomed Diagnostics, San Jose, California), and cytologic diagnosis were used to diagnosis Trichomonas vaginalis (a clear diagnosis on any of the three was considered an infection). Serologic testing specific for HSV-2 was done by the Centers for Disease Control and Prevention using a validated in-house enzyme linked immunoassay. REACH study investigators have published details of specimen processing, transport, and laboratory techniques previously.

We excluded syphilis from the analysis as it was rare for participants to have active syphilis. Curable STIs were treated when diagnosed and follow-up exams were performed to confirm the clearing of infections. Although bacterial vaginosis was studied in these youth,we excluded this as an endpoint since it would have eliminated our ability to test our hypothesis that douching increases risk for STIs. While bacterial vaginosis is considered an STI by some, it is exceedingly common and therefore would have overwhelmed the aggregate STI endpoint (see below).

Study Variables

The principal outcome variable was any incident STI (T. vaginalis, C. trachomatis, N. gonorrhoeae, and/or HSV-2). The exposure variable was level of douching. Other douching-related variables examined in the study included age at baseline, race/ethnicity, HIV status at baseline, and self-reported sexual activity in the last 3 months at baseline.

Statistical Analysis

We used two types of analysis in this study. The first analysis type examined the association between douching behavior and time from study entry (if STI-free) or first STI-free visit (if STI noted at study entry) until advent of an incident STI. We also performed sensitivity analyses using only participants who were STI-free at baseline. We classified the female adolescents to the douching categories in two ways. The first method classified participants as never douching, intermittent douching, or always douching based on their ACASI responses at baseline and all subsequent visits.

A participant was considered to never douche if she never reported “yes” to douching, to intermittently douche if she reported “yes” to douching at some of the visits, and to always douche if she reported “yes” to douching at every visit. We only included douching information from visits with laboratory assessments. The second method of classifying the adolescents allowed prospective analysis of the data: Because having a STI may alter douching behavior, we also classified adolescents as never, intermittent, or always douching based only on reported douching behavior during the interval of time during which the adolescent was STI-free.

For example, if a participant had been STI-free from visits 1 to 4, but had a STI at visit 5, then in this second analysis, her douching status would only be based on reported douching behavior during visits 1–4. We computed Kaplan-Meier estimates of the probability of remaining STI-free as a function of time from baseline and compared douching categories using Cox proportional hazards.

The second type of analysis looked at the association between reported douching at the STI-free current visit and a positive or negative STI assessment at the next visit (up to 6 months after the current visit). Multiple outcomes were included for each subject. For example, if a subject had 3 visits, then the association between douching reported during visit 1 was assessed with STI at visit 2 and association between douching reported during visit 2 was assessed with STI at visit 3, and so on. Analyses were performed using generalized estimating equations with a logit link, adjusting for STI at current visit (yes/no), and assuming an exchangeable correlation structure.

Such an approach permits the computation of odds ratios while accounting for correlation between multiple measurements taken on the same participant. Serial correlation was accounted for by including STI at current visit, representing a first-order Markov model as we are modeling STI in future (Y_i) using STI at current visit (Y_i-1). This model therefore accounts for serial correlation and then assumes that the residual correlation is constant within an individual over time by using an exchangeable correlation structure. Confidence intervals and p-values were computed using robust standard errors.

RESULTS

Demographic Characteristics

The original REACH cohort contained 411 non-virginal female adolescents, of whom 262 (63.7%) were HIV-positive and 147 were HIV-negative as per the selection criteria of the parent cohort study. The annual retention rate for HIV-infected youth in this cohort was 95%. The female annual retention rate for HIV-uninfected adolescents was 88%, with older HIV-uninfected female adolescents having the lowest retention rates. In our douching sub-study, 43 of the 411 participants were not eligible because they had no STI-free follow-up time.

Of the 368 participants with STI-free follow-up time, the average age was 16.9 years, 73.2% were black, 64.8% were HIV-infected, and 74.9% reported being sexually active within the three months prior to baseline. The median follow-up time was 3 years (interquartile range: 1.7 to 3.8 years). Over the entire follow-up period, 88 (23.9%) never reported douching and 50 (13.6%) reported douching at every visit. Only considering STI-free follow-up time, 125 (34.2%) never reported douching whereas 99 (27.0%) reported douching at each visit. Douching information was missing for 2 individuals (0.5%) over their STI-free follow-up time. Demographic characteristics according to douching classifications are shown in Black/non-Hispanic race and infection with HIV tended to be associated with higher levels of douching (Chi-square P = 0.004 and P = 0.005, respectively, when defining douching categories based on all follow-up time; P = 0.02 and P = 0.06, respectively, when defining douching categories based on STI-free follow-up time).