Long-term persistence of human papillomavirus in environments

The possibility of its indirect transmission of human papillomavirus (HPV) via formites has been widely raised but with no biological proof. This study explored the durability of HPV16 pseudoviruses and native viruses in different environmental contamination scenarios.

Pseudoviruses were mixed with PBS, cervico-vaginal secretion (CVS), or serum to simulate contamination by genital warts, vaginal discharge or menstruation, respectively, and subjected to in-vitro cell infection assay. The integrity of native HPV16 from CVS of infected women was detected by conformation-specific antibody.

In viruses exposed to PBS, a persistent infectivity of 30% was noted for at least 7 days. A similar persistence but lower (18%) infectivity was noted in those exposed to CVS. In serum-containing medium, the infection ratio rose initially, remained stable for three more days then rapidly decreased thereafter. Upon desiccation, infectivity was persistently low (10%). Finally, intact native HPV was detectable after 5 days of environmental exposure.

This study demonstrated the high environmental survivability of HPV. However, survivability was lower in viruses exposed to CVS or desiccation.