Treating Sexually Transmitted Infections (STIs)

1. STI counseling, diagnosis and treatment represent an important access point for women at high risk of HIV. [See also Antenatal Care - Testing and Counseling]

A systematic review and meta-analysis of 1,064 reports between 1998 and 2000 found that genital ulcerative disease appears to have a greater impact than nonulcerative disease on the susceptibility to HIV. Men were more affected than women by the effects of STIs Untreated concurrent STIs in an HIV-positive individual increases the rate of progression towards AIDS. “A better and more quantitative understanding of the interactions between HIV infection and classic STDs is needed ...Sexual behavior is the common risk factor for contracting both HIV and STDs” (Rottingen et al., 2001: 592).

A 2004 to 2006 cross-sectional survey study of female sex workers in India found that of the 976 women who had symptoms of an STI, more than 78% sought medical treatment; behavior that was protective for both HIV and STIs. HIV infection was strongly associated with lifetime and active syphilis.

In a study where 109,500 samples were tested during a nine-month period from patients in STI clinics in the US, Malawi and South Africa, 1 to 2 percent had acute HIV infection, which greatly increases the risk for transmission of HIV.

Ulcerative STIs, particularly chancroid, herpes simplex virus type 2 and syphilis are the most important STI cofactors for HIV transmission. Control of curative genital ulcers – chancroid and syphilis – is highly feasible and correlates well with stabilization of HIV epidemics. Effective antibiotic treatment of gonorrheal or chlyamydial infection reduces HIV viral load to normal levels. “Evidence supporting the role of STIs as HIV cofactors is extensive and indisputable” (Steen et al., 2009: 862).

The prevalence of genital shedding of herpes simplex virus (HSV)-2 and related risk factors was evaluated in a prospective population of 355 women attending the Maternity Joséphine Bongo, in Libreville, Gabon. Researchers found a high prevalence (66%) of HSV-2 seropositivity, with a high proportion, 14%, of women harboring HSV-2 DNA shedding in their genital secretions. HSV-2 genital shedding was positively associated with previous episodes of genital blisters, current genital ulcer, current genital blister, HIV seropositivity and HSV-2 seropositivity.

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2. Screening for and treating STIs syndromically on a continuous, accessible basis improves overall health, and has been associated in one study with reducing the risks of HIV acquisition in a setting with high STI prevalence.

A randomized trial was conducted over two years in rural Tanzania. STI treatment was provided in the intervention communities to assess the impact on HIV transmission. Strong evidence indicates that the STI intervention program had a substantial effect on HIV incidence in this rural African population. Six communities received the intervention immediately following the baseline survey, while six comparison communities received the intervention after the follow-up survey two years later. HIV incidence was consistently lower in the intervention community than the comparison community in all six matched pairs. After two years of the intervention, there were 48 seroconversions (1.2%) in the intervention group and 82 (1.9%) in the comparison group. HIV incidence was approximately 42% lower in the intervention group. Prevalence and incidence of STIs was measured in a random cohort consisting of 1,000 adults in each community. STI services were based on syndromic algorithms recommended by WHO (WHO, 1991). The intervention program had five components: 1) Establishment of an STI reference clinic and laboratory to monitor the effectiveness of treatment algorithms; 2) Existing staff from health centers received one week of classroom training and two weeks of practical training at the STI clinic. Staff also were trained to provide patients with health education and to offer free condoms; 3) A special delivery system of drugs was established to supplement the national essential drugs program supplies; 4) Regular supervisory visits by a program officer were conducted to provide in-service training and to check drug supplies and patient records; 5) Periodic visits by health educators to villagers were conducted to provide information on STIs, inform villagers of available treatment, and encourage prompt attendance for treatment of symptomatic STIs. Men with a positive LED test and those reporting or found to have urethral discharge were asked to provide a urethral swab. Urethral swabs were tested for Neisseria gonorrhoeae by pram stain and for Chlamydia trachomatis by antigen capture immunoassay. HIV was tested by ELISA assay. Positive samples received a second ELISA assay, and in case of discrepant or indeterminate ELISA results, a western blot test. Serological tests for syphilis were conducted using RPR and TPHA. Evaluation of the impact of the intervention on the prevalence of STIs was based on the seroprevalence of active syphilis and on the prevalence of confirmed urethritis, N. gonorrhoeae and C. trachomatis infection in men. Surveys indicated that condom use did not increase nor did sexual behavior change during the course of the intervention.

A study done in Eastern and Southern Africa showed that HIV transmission per coital act among serodiscordant couples is similar between sexes while sexually transmitted illnesses increased the risk of transmission. A total of 3,297 serodiscordant couples were included in the prospective study. The HIV-positive partner was also infected with HSV-2. After the initial examination, HIV-negative sexual partners had a quarterly visit consisting of a genital examination and an HIV test. Clients received risk-reduction counseling, quarterly syndromic STI treatment and free condoms. Plasma viral level of the HIV-positive partner was measured at enrollment, 3, 6, 12 months and at 24 months. The HIV-positive clients were interviewed every month on the number of coital acts with or without condoms, confirmed by their HIV-negative sexual partners. HIV transmission was confirmed by Western blot if a rapid test was positive. Timing of infection was determined by PCR before seroconversion. The time of HIV infection was defined as the earlier positive PCR. Each confirmed transmission between the study partners was classified as “linked”. Transmission was classified as “unlinked” if HIV was acquired from another person other than the study partner through genetic sequencing of plasma samples. Analysis was done only for linked transmissions. Sixty seven percent of the HIV-positive sexual partners were women. Thirty-four percent of the HIV-positive and 55% of the HIV-negative males were circumcised. Eighty-six linked transmissions occurred during the 24 months. In cases of unprotected sex the risk of male-to-female transmission was 1.95 times greater than female-to-male transmission. However, the increased male-to-female transmission was explained by higher viral loads in male partners and seropositivity for HSV-2 in the HIV-negative partners. The study found that the per-act risk of HIV transmission between the sexes in unprotected sex was equal. HIV-negative partners who tested positive for HSV-2 at enrollment were 2.14 times more likely to acquire HIV and those with genitourinary diseases were 2.65 times more likely to acquire HIV. The presence of trichomonal vaginalis at enrollment in the female HIV-negative sexual partner increased the risk of per-act transmission by a factor of 2.57.The presence of cervicitis or vaginitis (damaged lining of the female genitalia) was associated with a 3.63 fold increase in risk of per-act transmission. For each 10 fold increase in plasma viral RNA, increased transmission by 2.9 fold was observed. 

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3. Providing HIV testing and counseling together with STI services can reach women at high risk for HIV. [See HIV Testing and Counseling for Women]


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