Changes in key vaginal bacteria among postpartum African women initiating intramuscular depot-medroxyprogesterone acetate

Abstract

Background The ECHO trial has relieved apprehension about intramuscular depot medroxyprogesterone acetate (DMPA-IM), however it is still important to understand how DMPA-IM affects the vaginal environment. We sought to describe how DMPA-IM initiation influences vaginal bacteria associated with HIV acquisition in postpartum women. Methods Vaginal swabs were collected for Nugent score determination and taxon-specific quantitative PCR of eight bacteria. Enrollment occurred at contraceptive initiation (DMPA-IM or nonhormonal contraception (non-HC)) and repeat vaginal swabs were collected after three months. Generalized estimating equations were used to estimate changes in Nugent score, total bacterial load, and taxa concentrations among contraceptive groups. Results Women who chose DMPA-IM (n = 33) were more likely to be married (97%vs.67%) and have resumed intercourse since delivery (52%vs.29%) compared to women who chose non-HC (n = 21). After three months, significant decreases in the concentrations of Sneathia species, Mycoplasma hominis, and Parvimonas species Type 1 were seen among non-HC users, however concentrations remained stable among DMPA-IM users; contraceptive method was associated with significantly different changes in M. hominis concentration between groups (p = 0.010).

Vaginal microbiome-hormonal contraceptive interactions associate with the mucosal proteome and HIV acquisition

“…In most cases, use of progestin-based hormonal contraception has been associated with a reduction in incidence of BV [ 32 , 58 , 59 ], and higher levels of vaginal Lactobacillus spp. [ 29 ]; however, others have reported a decrease the levels of vaginal H 2 O 2 -producing lactobacilli [ 43 , 60 , 61 ], increases in microbial diversity [ 51 ], or no effect on microbiome composition [ 62 ]. We observed only minor differences in microbiome composition and no changes to microbiome-derived functional pathways.…”

The Vaginal Microbiota, Bacterial Biofilms and Polymeric Drug-Releasing Vaginal Rings

“…What can be considered a disease-causing pathogen is dependent not only on the type of microorganism and its intrinsic virulence, but also its relative dominance. Microorganisms that are normal constituents of the vaginal flora also have the potential to cause symptoms of disease, but require some alteration of the microenvironment in order to do so [41]. Candida albicans, group B Streptococcus, Gardnerella vaginalis, and Escherichia coli are common examples of microorganisms isolated from the lower female genital tract [41].…”

“…Microorganisms that are normal constituents of the vaginal flora also have the potential to cause symptoms of disease, but require some alteration of the microenvironment in order to do so [41]. Candida albicans, group B Streptococcus, Gardnerella vaginalis, and Escherichia coli are common examples of microorganisms isolated from the lower female genital tract [41]. Under normal circumstances, these organisms do not produce symptoms of infection, but have the potential to cause disease depending on the vaginal environment [41].…”

“…Candida albicans, group B Streptococcus, Gardnerella vaginalis, and Escherichia coli are common examples of microorganisms isolated from the lower female genital tract [41]. Under normal circumstances, these organisms do not produce symptoms of infection, but have the potential to cause disease depending on the vaginal environment [41]. This contrasts with putative pathogens not ordinarily part of the vaginal microbiota, whose presence is strongly associated with disease.…”

“…Prevalence of microorganisms reported in asymptomatic vaginal or cervical specimens (adapted from[40], Infectious Diseases: Research and Treatment, 2010 and[41], Clinical Infectious Diseases, 2001). + < 30%; ++ < 60%; +++ > 60%.…”