The vaginal microbiome in Madagascar
The vaginal microbiome (VM) plays an important role for women's health. Changes in the VM 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 their influence on the VM is still scarce. Additionally, the majority of data on VMs originate from the Global North, generating a biased understanding of a “healthy” VM across different geographical and social contexts. The objective of our study was thus to characterize for the very first time the VM of adult women of reproductive age in Madagascar and to describe differences and variability of the vaginal environment in presence of HPV, Sh, and FGS. We characterized the VMs of 443 women, identifying the five community state types (CSTs I–V) with CST IV (highly diverse) and CST III (L. iners-dominated) as the most prevalent. CSTs were associated with antibiotics usage, while variability in the alpha and beta diversity was associated with diet behaviour and antibiotics usage. Differential abundance analysis showed variations among specific taxa in HPV-positive, Sh-infected, and FGS-positive women. This first study of the VM in Madagascar showed no Lactobacillus dominance in the Malagasy population, contributing to understanding vaginal health and opening new perspectives for the characterization of the role of the VM for high burden gynaecological disorders among the most neglected populations.