In-hospital environmental surface and air contamination by monkeypox virus clade Ib in Germany.

Abstract

BACKGROUND: Mpox, caused by monkeypox virus (MPXV), is an acute global public health concern, driven by human-to-human transmissions. Only sporadic cases caused by the emerging MPXV clade Ib have been reported in Europe to date. AIM: To assess the potential for environmental contamination and indirect or airborne transmission, we conducted longitudinal environmental sampling during the hospitalization of the first German imported mpox clade Ib case in an airborne infection isolation room. METHODS: Over a period of eight days, six standardized sampling series were carried out in the anteroom, patient's room, and bathroom ≥6 h after cleaning. Swab samples from high- and low-touch areas and air samples (Coriolis μ impinger) were taken. Additionally, the exhaust HEPA filters and mobile air purifier filters were analysed. MPXV contamination was determined by polymerase chain reaction (PCR) and subsequently virus culture was performed. FINDINGS: Surface and air contamination with MPXV DNA was detected in high- and low-touch areas, as well as near and far from the patient (PCR positivity: 92 out of 100 surface samples and 11 of 12 air samples). Moreover, the analysed air-filters and adhered dust tested positive for MPXV DNA. However, replication-competent virus was identified only on the toilet seat surface on the first sampling day. CONCLUSION: Our data show a high degree of MPXV DNA contamination in the patient's environment and suggest potentially infectious fomites. While the relation between widespread DNA contamination and actual transmission risk remains difficult to assess and needs further investigation, our findings underscore the importance of environmental cleaning and disinfection.