Air and surface sampling for monkeypox virus in UK hospitals

Background An unprecedented outbreak of monkeypox virus (MPXV) infections in non-endemic countries has been recognised since 12 May 2022. More than 6000 cases have been identified globally with more than 1500 in the UK by July 2022. Transmission of MPXV is believed to be predominantly through direct contact with lesions or infected body fluids, with possible involvement of fomites and large respiratory droplets. Importantly, a case of monkeypox in a UK healthcare worker in 2018 was suspected to be due to virus exposure while changing bedding. Methods We investigated environmental contamination with MPXV from infected patients admitted to isolation rooms in the UK, to inform infection prevention and control measures. Surface swabs of high-touch areas in isolation rooms, of healthcare worker personal protective equipment (PPE) in doffing areas, and from air samples collected before and during bedding change were analysed using MPXV qPCR to assess contamination levels. Virus isolation was performed to confirm presence of infectious virus in key positive samples. Findings We identified widespread surface contamination (66 positive out of 73 samples) in occupied patient rooms (MPXV DNA Ct values 24{middle dot}7-38{middle dot}6), on healthcare worker personal protective equipment after use, and in doffing areas (Ct 26{middle dot}3-34{middle dot}3). Five out of fifteen air samples taken were positive. Significantly, three of four air samples collected during a bed linen change in one patient's room were positive (Ct 32{middle dot}7-35{middle dot}8). Replication-competent virus was identified in two of four samples selected for viral isolation, including from air samples collected during the bed linen change. Interpretation These data demonstrate significant contamination in isolation facilities and potential for aerosolisation of MPXV during specific activities. PPE contamination was observed after clinical contact and changing of bed linen. Additionally, contamination of hard surfaces in doffing areas supports the importance of cleaning protocols, PPE use and doffing procedures.