To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: Vaginal Bacteria Play Role in HIV Susceptibility URL: http://www.pslgroup.com/dg/A4E52.htm Doctor's Guide August 19, 1998
BALTIMORE, MD -- Aug. 19, 1998 -- Pregnant women in one part of Africa were up to 3.7 times more likely to become infected with HIV if their vaginal bacteria became disrupted by hostile strains, according to researchers at the Johns Hopkins School of Public Health. The study also established for the first time that a woman's risk of acquiring HIV rose in direct proportion to the severity of bacterial disturbance. The findings appear in the September issue of the journal AIDS. Previous studies had often suggested an association between HIV and bacterial vaginosis (BV), the most severe disturbance of vaginal flora, but in those studies participants were examined only once and the individual results then pooled and compared. The present study was the first in which all participants were followed over several years so that BV's effect on HIV acquisition could be assessed over time. "Bacterial vaginosis is common among women of both developed and developing countries," said lead author Taha Taha, PhD, MPH, assistant scientist of epidemiology. The study recruited 1,196 HIV-negative pregnant women in Malawi, in south-east Africa, and followed them for a median of 3.4 months before their babies were born and then as for a median of 2.5 years after they had given birth. During the study, the women were tested periodically for any disturbance to the vaginal flora and for the presence of HIV. To measure the severity of the disturbance to vaginal flora, the investigators used four easily detectable symptoms that can be easily detected by healthcare workers to assess the spectrum of vaginal disturbance, from mild to severe, using only routine laboratory tests. The symptoms were elevated vaginal pH, increased vaginal discharge, microscopic detection of clue cells (epithelial cells in the vagina covered with bacteria); and a positive amine test, which detects vaginal malodour. Women with none of the four clinical criteria were said to have normal vaginal flora. Those with one or two criteria were classified as having a disturbance of vaginal flora and those with three or more were classified as having BV. As the severity of vaginal disturbance increased, the risk of HIV seroconversion increased among all women in statistically significant steps, both before and after they gave birth. Thus, compared to participants with normal flora, the risk of pregnant women becoming infected with HIV was 50 percent greater for those with one of the criteria, 2.4-fold greater for those with two and 3.7-fold greater for those with BV (three or more criteria). Similarly, postpartum HIV acquisition was 1.5 times higher among women with a single criterion than among women with normal vaginal flora; 1.7 times higher for women with two; and 3.5 times higher for women with BV. Bacteria normally present in the vagina produce hydrogen peroxide, creating an acidic (low-pH) environment that is hostile to disease bacteria and HIV. However, if pathogenic bacteria establish a foothold, they can raise vaginal pH, which destroys the normal flora and makes the vaginal environment more friendly to organisms that cause sexually transmitted diseases (STDs) like gonorrhea, syphilis and HIV. BV has been implicated in several serious obstetric and gynecological problems such as preterm delivery, premature rupture of membranes, amniotic fluid infection and pelvic inflammatory disease. Sexual transmission of BV is unlikely, since several studies have shown that treatment of male partners of women with BV did not reduce the rate of recurrence of BV in the women. --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.