Direct detection of Trichomonas vaginalis virus in Trichomonas vaginalis positive clinical samples from the Netherlands.

Trichomonas vaginalis is the most common sexually transmitted parasitical infection worldwide. T. vaginalis can carry a virus: Trichomonas vaginalis virus (TVV). To date, four TVV species have been described. Few studies have investigated TVV prevalence and its clinical importance. We have developed a nested reverse-transcriptase PCR, with novel, type specific primers to directly detect TVV RNA in T. vaginalis positive clinical samples. A total of 119T. vaginalis positive clinical samples were collected in Amsterdam and "s-Hertogenbosch, the Netherlands, from 2012 to 2016. For all samples T. vaginalis was genotyped using multi-locus sequence typing. The T. vaginalis positive samples segregated into a two-genotype population: type I (n=64) and type II (n=55). All were tested for TVV with the new TVV PCR. We detected 3 of the 4 TVV species. Sequencing of the amplified products showed high homology with published TVV genomes (82-100%). Half of the T. vaginalis clinical samples (n=60, 50.4%) were infected with one or more TVV species, with a preponderance for TVV infections in T. vaginalis type I (n=44, 73.3%). Clinical data was available for a subset of samples (n=34) and we observed an association between testing positive for (any) TVV and reporting urogenital symptoms (p=0.023). The nested RT-PCR allowed for direct detection of TVV in T. vaginalis positive clinical samples. This may be helpful in studies and clinical settings, since T. vaginalis disease and/or treatment outcome may be influenced by the protozoa"s virus.