A systematic review published in The Lancet Microbe identified 22 viruses persisting in human semen following acute infection. The analysis included 373 studies with 8,387 participants, spanning research from 1962 to 2023.

The review identified viruses from 14 viral families, including several pathogens with pandemic potential, primarily vector-borne or transmitted through bodily fluids. Twelve viruses demonstrated replication competency in semen.

Ebola virus showed persistence up to 988 days after discharge from treatment facilities, while Zika virus persisted for 941 days in an immunosuppressed patient. Median persistence times were considerably shorter: Ebola virus persisted for a median of 210 days after discharge, and Zika virus for 57 days. Kyasanur Forest disease virus showed the shortest detection period at 8 days.

Nine viruses had evidence supporting sexual transmission, with molecular and epidemiological evidence for dengue virus, Ebola virus, and Zika virus. Other viruses lacked such evidence despite being detected in semen.

The research team, led by Caitlin Pley, MB, from the Center for Global Health at Charité University Berlin, screened 29,739 articles from five databases. The study documented cases where Ebola virus transmission from survivors sparked outbreaks in Guinea in 2016 and 2021.

Findings emphasized implications for barrier contraception recommendations, semen clearance testing, and the limitations of some therapeutic agents in crossing the blood-testis barrier. Gaps remain regarding the viability of certain viruses for sexual transmission and the role of host immune status in viral persistence.

Limitations included potential publication bias, heterogeneity in study designs, and incomplete follow-up of subjects. Despite these challenges, the study expanded the count of acute-infection viruses persisting in semen from 9 to 22, offering critical insights into public health and clinical guidelines.

The study authors declared no competing interests.