In the Journals

Bacterial species in vaginal microbiota may increase risk for T. vaginalis

Olamide D. Jarrett, MD, MPH
Olamide D. Jarrett

The presence of Prevotella amnii and Sneathia sanguinegens in the vaginal microbiota is significantly associated with the acquisition of Trichomonas vaginalis, according to findings published in Clinical Infectious Diseases.

“This study provides evidence that specific bacterial species within the vaginal microbiota may influence a woman’s risk of STI acquisition,” Olamide D. Jarrett, MD, MPH, associate director of academic programs at the University of Illinois at Chicago Center for Global Health, told Infectious Disease News. “If a causal pathway exists between key bacterial species and a woman’s risk of T. vaginalis acquisition, then we could potentially develop novel STI prevention strategies aimed at reducing or eliminating these high-risk bacterial species from the vaginal microbiota.”

Prior studies have shown an association between a baseline presence of intermediate vaginal microbiota or bacterial vaginosis and an increased risk for T. vaginalis, the researchers noted.

Jarrett and colleagues conducted a nested case-control study comparing the pre-T. vaginalis infection vaginal microbiota of 25 unique episodes of T. vaginalis in 18 women with 50 uninfected controls. The women included in the study were HIV-1-seronegative and enrolled in the Mombasa cohort, a prospective open cohort study of women who “exchange sex for cash or in kind payment,” the researchers explained.

According to the study, there was a greater than twofold increased risk for acquisition of T. vaginalis when P. amnii (risk ratio [RR] = 2.21; 95% CI, 1.12-4.38) and S. sanguinegens (RR = 2.58; 95% CI, 1.00-6.62) were present. When the analysis was adjusted for menstruation phases, the associated between P. amnii and acquisition of T. vaginalis remained similar (adjusted RR [aRR] = 2.11; 95% CI, 1.03-4.33), but the association between S. sanguinegens and T. vaginalis was attenuated (aRR = 2.31; 95% CI, 0.86-6.23), the researchers reported.

They recommended further studies to determine how specific bacterial species increase the risk for T. vaginalis.

“Larger studies are needed to confirm the associations seen in this study, determine if other vaginal bacterial species also increase a woman’s risk of T. vaginalis acquisition and elucidate the mechanism by which these key bacterial species increase a woman’s risk of trichomoniasis,” Jarrett said.

“If future studies confirm the presence of an association between key vaginal bacterial species and T. vaginalis acquisition, then randomized trials of vaginal health interventions aimed at altering the vaginal microbiota or reducing/eliminating these high risk species could help provide evidence of a causal association, while at the same time evaluating the efficacy of strategies aimed at reducing women’s risk of T. vaginalis infection.” – by Marley Ghizzone

Disclosures: Jarrett reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

Olamide D. Jarrett, MD, MPH
Olamide D. Jarrett

The presence of Prevotella amnii and Sneathia sanguinegens in the vaginal microbiota is significantly associated with the acquisition of Trichomonas vaginalis, according to findings published in Clinical Infectious Diseases.

“This study provides evidence that specific bacterial species within the vaginal microbiota may influence a woman’s risk of STI acquisition,” Olamide D. Jarrett, MD, MPH, associate director of academic programs at the University of Illinois at Chicago Center for Global Health, told Infectious Disease News. “If a causal pathway exists between key bacterial species and a woman’s risk of T. vaginalis acquisition, then we could potentially develop novel STI prevention strategies aimed at reducing or eliminating these high-risk bacterial species from the vaginal microbiota.”

Prior studies have shown an association between a baseline presence of intermediate vaginal microbiota or bacterial vaginosis and an increased risk for T. vaginalis, the researchers noted.

Jarrett and colleagues conducted a nested case-control study comparing the pre-T. vaginalis infection vaginal microbiota of 25 unique episodes of T. vaginalis in 18 women with 50 uninfected controls. The women included in the study were HIV-1-seronegative and enrolled in the Mombasa cohort, a prospective open cohort study of women who “exchange sex for cash or in kind payment,” the researchers explained.

According to the study, there was a greater than twofold increased risk for acquisition of T. vaginalis when P. amnii (risk ratio [RR] = 2.21; 95% CI, 1.12-4.38) and S. sanguinegens (RR = 2.58; 95% CI, 1.00-6.62) were present. When the analysis was adjusted for menstruation phases, the associated between P. amnii and acquisition of T. vaginalis remained similar (adjusted RR [aRR] = 2.11; 95% CI, 1.03-4.33), but the association between S. sanguinegens and T. vaginalis was attenuated (aRR = 2.31; 95% CI, 0.86-6.23), the researchers reported.

They recommended further studies to determine how specific bacterial species increase the risk for T. vaginalis.

“Larger studies are needed to confirm the associations seen in this study, determine if other vaginal bacterial species also increase a woman’s risk of T. vaginalis acquisition and elucidate the mechanism by which these key bacterial species increase a woman’s risk of trichomoniasis,” Jarrett said.

“If future studies confirm the presence of an association between key vaginal bacterial species and T. vaginalis acquisition, then randomized trials of vaginal health interventions aimed at altering the vaginal microbiota or reducing/eliminating these high risk species could help provide evidence of a causal association, while at the same time evaluating the efficacy of strategies aimed at reducing women’s risk of T. vaginalis infection.” – by Marley Ghizzone

Disclosures: Jarrett reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.