(P204) Persistence of monkeypox virus at oral and rectal sites following resolution of cutaneous lesions.

Background



In 2022, a global mpox (previously monkeypox) virus outbreak occurred, predominantly affecting gay, bisexual, and other men who have sex with men (GBM). We aimed to ascertain the infectiousness of mpox from oral and anal sites over time, relative to the resolution of mucocutaneous mpox lesions.



Methods



This prospective cohort study recruited GBM with suspected, or contacts of, mpox, at Melbourne Sexual Health Centre, Australia, from June to October 2022. Men self-collected oral and anal swabs, and urine for mpox PCR and viral culture at first presentation (Day 0), with repeat testing weekly, when reviewed for clinical clearance, until lesion resolution.



Results



Characteristics of the 19 men, mpox PCR, culture and serology results are in Table 1, with timeline of symptoms and results in Figure 1. 14/19 (74%) men had initial oral PCR detection with 6/14 (42%) still positive by oral PCR and culture (median 14.5, IQR: 10.5-17 days) at or after resolution of mpox lesions at other sites. Of the 14, one had oral mpox lesions at the initial visit. 16/19 (84%) men had initial anal PCR detection with 9/16 (64%) still positive by anal PCR (median 11, IQR: 9-16 days) and 6/16 (43%) by anal culture (median 10.5, IQR: 9-15.5 days) at or after resolution of mpox lesions elsewhere. Of the 16, nine had anal mpox lesions. Among 16 men who underwent serology, 8 (50%) had mpox antibodies detected, including four with positive serology while culture positive, and two negative on day 15.



Conclusion



Australia had fewer mpox cases than the UK, Europe, and North America, thus our study had a limited sample size. Detection of mpox by culture suggests virus viability and potential infectiousness. Our data indicate that a proportion of men who had resolution of mpox lesions and who would be cleared by public health authorities and advised their mpox infection is no longer contagious, may still be infectious from oral and anal sites and should be advised to abstain from physical and sexual contact involving these sites for a longer period of time. Further longitudinal studies using culture are needed to define this period.