The Vaginal Microbiota of Adult Malagasy Women of Reproductive Age in the Marovoay District: First Characterization and Exploration of Associations With Human Papillomavirus and Schistosoma haematobium Infections

BACKGROUND: The vaginal microbiome plays an important role for women's health. Changes in its composition have been associated with several sexually transmitted infections, including human papillomavirus (HPV) or parasitic infections such as Schistosoma haematobium. In Madagascar, gynecological conditions such as chronic manifestations of S. haematobium infections (female genital schistosomiasis), HPV infections, and cervical cancer are highly prevalent; however, data on the interplay between these conditions and the vaginal microbiota (VM) are still scarce. In addition, the majority of data originates from the Global North, generating a biased understanding of "healthy" VM across different geographic and social contexts. The objective of our study was to characterize for the first time the VM of adult women of reproductive age in Madagascar and to describe the variability of the vaginal environment in the presence of 3 conditions affecting the urogenital tract. METHODS AND RESULTS: We characterized the VM of 443 participants, identifying the 5 community state types (CSTs I-V), with CST IV (57.1%, diverse) and CST III (34.1%, Lactobacillus iners dominated) as the most prevalent. CSTs were associated with previous antibiotics usage, while variability in the alpha and beta diversity was associated with dietary behavior and previous antibiotic usage. Differential abundance analysis showed variations among specific taxa in HPV-positive and female genital schistosomiasis-positive participants. CONCLUSIONS: With this first study of the VM in Madagascar we contribute to a broader understanding of vaginal health, as well as narrowing the gap of VM research in sub-Saharan Africa by enriching microbiota databases.