The prevalence of bacterial vaginosis in KwaZulu-Natal and its association with the vaginal immune response and shedding of HIV and HSV-2.

Abstract

Introduction: South Africa has a high burden of sexually transmitted infections (STIs) and HIV. The role of Gardnerella vaginalis in the development of BV has been disputed after the recovery of G. vaginalis from healthy patients and the discovery of new bacteria using molecular identification. Infection with HSV has been associated with increased vaginal HIV RNA copies and bacterial vaginosis has been implicated as a risk factor for the transmission of HIV. Methodology: Consenting patients of > 18 years were recruited from two different primary health clinics. Microscopy was used to diagnose BV and serology for HIV, HSV-2 and syphilis testing. Chlamydia trachomatis and Neisseria gonorrhoeae were detected by BD Probetec, and conventional PCR was used for the diagnosis of Trichomonas vaginalis and recognised ulcer pathogens. Quantitative bacteriology and HIV viral loads were done using the Applied biosystems ABI 7500 Real Time instrument. Immune cells from vaginal tampon specimens were analysed using flow cytometry. Results: In both clinics, of the discharge pathogens T. vaginalis had the highest prevalence. The prevalence of both T. vaginalis and N. gonorrhoeae was significantly higher in Boomstreet clinic (p<0.05). The Umlazi D clinic had significantly more patients with BV (p<0.0001) and HSV-2 (p<0.05). Of the patients with ulcers, HSV-2 was detected in a one third of the specimens in each of the clinics. One patient was diagnosed with lymphogranuloma venereum (LGV). The Nugent score group 0-3 was dominated by Lactobacillus spp. while the Nugent score group 7-10 was dominated by Gardnerella vaginalis. The group with Nugent score 7-10 was shown to have significantly higher levels of immune cells that are proposed HIV targets. Lactobacillus spp. was associated with the group that was HIV antibody negative and Prevotella spp. with the HIV antibody positive group (p < 0.05). Prevotella spp. was not associated with shedding of HIV. The number of bacterial copies of G. vaginalis was significantly higher in patients shedding HIV (p < 0.05). In those shedding HSV-2 the number of copies of G. vaginalis was also higher but this did not reach statistical significance. Conclusion: The trend in STI prevalence was similar to that described previously. We report circulating LGV and there is a possible increase in gonorrhoeae which needs to be confirmed. The potential pathogenic role of G. vaginalis in BV as well as the increased risk of HIV transmission is emphasized.