HIV-1 infection associated with abnormal vaginal flora morphology and bacterial vaginosis

Recurrent bacterial vaginosis

Bacterial vaginosis (BV) is a common condition causing an offensive fishy smelling vaginal discharge. Some women have frequent symptomatic recurrences. Our lack of understanding of the trigger factors for the onset and resolution of BV limits our ability to manage these women effectively. Current approaches involve repeated treatment with antibiotics, with or without antifungal agents. Current studies are investigating the value of replacing the vaginal flora with cultured Lactobacillus strains. Control of BV may reduce the incidence of complications including preterm birth and possibly the acquisition of HIV infection.

HIV infected women and genital health

The clinical benefits of the recent developments in antiretroviral therapy for HIV infected patients are changing both the presentation and prognosis of individuals with HIV infection, predominantly in the developed world. The genital health of women with HIV infection is an important area for study because of the unusual presentation with which undiagnosed HIV infected women might present to clinicians, and also the evidence that inflammatory and ulcerative conditions of the genital tract of HIV infected individuals have an impact on the risk of transmission to sexual partners.

Bacterial vaginosis and disturbances of vaginal flora: association with increased acquisition of HIV

BACKGROUND

Cross-sectional studies suggest an association between bacterial vaginosis (BV) and HIV-1 infection. However, an assessment of a temporal effect was not possible.

OBJECTIVES

To determine the association of BV and other disturbances of vaginal flora with HIV seroconversion among pregnant and postnatal women in Malawi, Africa.

DESIGN

Longitudinal follow-up of pregnant and postpartum women.

METHODS

Women attending their first antenatal care visit were screened for HIV after counselling and obtaining informed consent. HIV-seronegative women were enrolled and followed during pregnancy and after delivery. These women were again tested for HIV at delivery and at 6-monthly visits postnatally. Clinical examinations and collection of laboratory specimens (for BV and sexually transmitted diseases) were conducted at screening and at the postnatal 6-monthly visits. The diagnosis of BV was based on clinical criteria. Associations of BV and other risk factors with HIV seroconversion, were examined using contingency tables and multiple logistic regression analyses on antenatal data, and Kaplan-Meier proportional hazards analyses on postnatal data.

RESULTS

Among 1196 HIV-seronegative women who were followed antenatally for a median of 3.4 months, 27 women seroconverted by time of delivery. Postnatally, 97 seroconversions occurred among 1169 seronegative women who were followed for a median of 2.5 years. Bacterial vaginosis was significantly associated with antenatal HIV seroconversion (adjusted odds ratio = 3.7) and postnatal HIV seroconversion (adjusted rate ratio = 2.3). There was a significant trend of increased risk of HIV seroconversion with increasing severity of vaginal disturbance among both antenatal and postnatal women. The approximate attributable risk of BV alone was 23% for antenatal HIV seroconversions and 14% for postnatal seroconversions.

CONCLUSIONS

This prospective study suggests that progressively greater disturbances of vaginal flora, increase HIV acquisition during pregnancy and postnatally. The screening and treating of women with BV could restore normal flora and reduce their susceptibility to HIV.

Nutritional and antimicrobial interventions to prevent preterm birth: an overview of randomized controlled trials

The study was conducted to assess the effectiveness of interventions for the prevention or treatment of nutritional and infectious disorders during pregnancy on preterm birth rates. Cochrane systematic reviews or any other more up-to-date systematic review of antimicrobial and nutritional interventions were sought. Electronic searches of the Cochrane Controlled Trials Register were carried out to identify any trials published since the most recent update of the systematic review. Also, authors of Cochrane systematic reviews, which have not been updated recently, were contacted regarding new information. Systematic reviews of nutritional and antimicrobial interventions during pregnancy, reporting preterm delivery rates (delivery before 37 weeks) and "prematurity" (including low birth weight) either as primary or secondary outcomes, were included. General interventions without a specific nutritional supplementation or antimicrobial component were not considered for inclusion. Interventions to stop labor or prolong pregnancy after a diagnosis of preterm labor were excluded. For each systematic review, data on preterm delivery rate by intervention group was obtained. The total number of trials in the review, number of trials reporting preterm birth as an outcome, number of participants and events have been systematically extracted. Eighteen systematic reviews (10 nutritional and 8 antimicrobial) were considered. Our results indicated that, overall, the treatment of asymptomatic bacteriuria reduces the incidence of preterm birth or low birth weight (< 2500 gm) (typical relative risk (RR): 0.67; 95 percent confidence interval (CI): 0.52-0.85). The protective effect of treating asymptomatic bacteriuria for preterm delivery persisted when only the three trials reporting preterm delivery (< 37 weeks) were included in the meta-analysis (typical RR: 0.53, 95 percent CI: 0.33-0.86). Routine iron supplementation prevents maternal anemia and one trial comparing routine versus selective iron supplementation showed a statistically nonsignificant reduction in preterm birth. Zinc, magnesium, and fish oil supplementations show promising results in reducing preterm birth, but the evidence is not strong. Calcium supplementation remains controversial, although there was a statistically significant reduction in preterm delivery in the subgroup of women at high risk of developing hypertension during pregnancy. Two trials with use of metronidazole (alone or with erythromycin) showed a reduction in preterm delivery in women who were at a high risk of preterm delivery and had bacterial vaginosis at screening. We have concluded that asymptomatic bacteriuria should be screened and treated in all settings that offer antenatal care. Single dose treatment seems to be as effective as longer (4-7 days) treatment, although this needs to be confirmed by a large, methodologically rigorous trial. There are a number of promising interventions such as calcium supplementation in women with low calcium intake, iron, zinc, magnesium, and fish oil supplementation, and treatment of bacterial vaginosis in women at high risk of preterm delivery that need additional research to determine a possible role for prevention of preterm delivery.

A randomized, community trial of intensive sexually transmitted disease control for AIDS prevention, Rakai, Uganda

OBJECTIVE

To describe the design and first-round survey results of a trial of intensive sexually transmitted disease (STD) control to reduce HIV-1 incidence.

STUDY DESIGN

Randomized, controlled, community-based trial in Rakai District, Uganda.

METHODS

In this ongoing study, 56 communities were grouped into 10 clusters designed to encompass social/sexual networks; clusters within blocks were randomly assigned to the intervention or control arm. Every 10 months, all consenting resident adults aged 15-59 years are visited in the home for interview and sample collection (serological sample, urine, and, in the case of women, self-administered vaginal swabs). Sera are tested for HIV-1, syphilis, gonorrhea, chlamydia, trichomonas and bacterial vaginosis. Following interview, all consenting adults are offered directly observed, single oral dose treatment (STD treatment in the intervention arm, anthelminthic and iron-folate in the control arm). Treatment is administered irrespective of symptoms or laboratory testing (mass treatment strategy). Both arms receive identical health education, condom and serological counseling services.

RESULTS

In the first home visit round, the study enrolled 5834 intervention and 5784 control arm subjects. Compliance with interview, sample collection and treatment was high in both arms (over 90%). Study arm populations were comparable with respect to sociodemographic and behavioral characteristics, and baseline HIV and STD rates. The latter were high: 16.9% of all subjects were HIV-positive, 10.0% had syphilis, and 23.8% of women had trichomonas and 50.9% had bacterial vaginosis.

CONCLUSIONS

Testing the effects of STD control on AIDS prevention is feasible in this Ugandan setting.

Sexually transmitted diseases and human immunodeficiency virus infection: cause, effect, or both?

The infectiousness of the index case and the susceptibility of the exposed host mediate the sexual transmission of human immunodeficiency virus (HIV). Infectiousness of the index case is determined by the inoculum of HIV and viral factors that favor transmission. Persons with primary infection, late stage disease, or low CD4 counts appear to transmit HIV with greater efficiency, presumably through increased viral burden in genital secretions. Susceptibility to HIV infection is determined by hereditary resistance factors, acquired immunity, site of exposure to the virus, and integrity of local barriers (e.g., vaginal epithelium). Hereditary resistance factors, such as cell surface receptors required for transmission of some viral variants, have been identified in studies of exposed, but uninfected persons. Acquired immunity, including protective cytotoxic T lymphocyte or antibody responses, may be important in persons repeatedly exposed to HIV who do not become infected. Sexual practices also affect susceptibility, with receptive anal intercourse having the highest risk, followed by vaginal intercourse and fellatio. Similarly, women are more susceptible to infection than men, through vaginal intercourse. In general, any factor affecting excretion of HIV or the number of receptive cells can be expected to affect the efficiency of transmission.