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 (Sh). In Madagascar, gynaecological conditions such as chronic manifestations of Sh infections (female genital schistosomiasis, FGS), HPV infections, and cervical cancer are highly prevalent; however, data on the interplay between these conditions and the vaginal microbiota (VM) is still scarce. Additionally, the majority of data originates from the Global North, generating a biased understanding of "healthy" VM across different geographical 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 presence of three conditions affecting the urogenital tract. METHODS AND RESULTS: We characterized the VM of 443 participants, identifying the five 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 behaviour and previous antibiotics usage. Differential abundance analysis showed variations among specific taxa in HPV- and FGS-positive participants. CONCLUSION: 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.