A COMPREHENSIVE review has revealed significant findings about the persistence of viruses in human semen following acute infections, shedding light on its potential role in disease transmission and resurgence.
The study, which screened 29,739 articles and included 373 original studies, identified evidence of 22 viruses from 14 virus families persisting in semen. These findings have critical implications for public health, male fertility, and the development of drugs and vaccines.
Viruses with pandemic potential, such as Ebola, Zika, and Lassa fever, demonstrated notable persistence in semen. Ebola virus, for instance, was detected up to 988 days after discharge from treatment and 965 days after symptom onset. Similarly, Zika virus persisted for a maximum of 941 days, though the median persistence was 57 days. Detection rates varied widely: 5–73% for Ebola, 75% for Lassa fever, 33–100% for Zika, 46% for mpox, and 0–16% for COVID-19, based on cross-sectional studies involving over 8,387 participants.
Of the 22 viruses detected in semen, nine, including Ebola, Zika, and dengue, had evidence supporting sexual transmission. Detection methods included PCR, whole-genome sequencing, and immunohistochemistry, among others. Three viruses, including hepatitis A and vaccinia virus, were linked to sexual transmission without direct evidence of detection in semen.
The review also identified gaps in understanding viral persistence dynamics. Many studies failed to follow participants until virus clearance, leaving uncertainty about the actual duration of persistence. Additionally, immune status was often unrecorded, complicating the assessment of immunosuppression’s role in viral persistence. For instance, the longest Zika virus detection occurred in an immunosuppressed patient.
This variability emphasises the need for more systematic studies. Factors such as viral replication competency, confirmed for pathogens like adenovirus, dengue, and Marburg virus, and individual immune responses influence persistence. The study calls for prioritising research into these dynamics to guide future public health strategies.
Ada Enesco, EMJ
Reference
Pley C et al. Duration of viral persistence in human semen after acute viral infection: a systematic review. Lancet Microbe. 2024; DOI:10.1016/j.lanmic.2024.101013.
