Presence of Protozoan Viruses in Vaginal Samples from Pregnant Women and Their Association with Trichomoniasis

This study was conducted in Armenia and included 32 pregnant women with TV infection and 30 healthy controls. The vaginal virome includes viruses that infect human cells and unicellular eukaryotes such as <i>Trichomonas vaginalis</i> (TV). Among these are <i>Trichomonas vaginalis</i> viruses (TVVs), double-stranded RNA viruses from the <i>Totiviridae</i> family, and giant DNA viruses that replicate in protozoa. This study investigated the presence of TVVs and giant protozoan viruses in pregnant women with trichomoniasis in Armenia and explored their potential associations with adverse pregnancy outcomes. Vaginal and urethral samples were collected from 32 pregnant women with confirmed TV infection and 30 healthy pregnant controls. TVVs and giant viruses (<i>Marseilleviridae</i>, <i>Mimiviridae</i>, <i>Phycodnaviridae</i>) were detected using qRT-PCR. Viral RNA and DNA were extracted from clinical samples and TV cultures, followed by quantification and gene expression analysis. Selected TVVs were visualized via scanning electron microscopy. All TV-positive women carried at least one TVV strain, with 94% harboring multiple TVV types and TVV4 being the most common. TV infection was significantly associated with preterm birth and premature rupture of membranes (PPROM). Giant viruses were identified in all TV-positive cases but in only 40% of controls. <i>Marseilleviridae</i> gene expression was observed in TV cultures, suggesting possible interactions. These findings highlight a potential role for protozoan viruses in reproductive complications and warrant further investigation.