Human-to-Human Transmission of Monkeypox Virus, United Kingdom, October 2018

Abstract

M onkeypox is a reemerging zoonosis caused by Monkeypox virus (MPXV), a member of the genus Orthopoxvirus. MPXV is related to Variola virus, the causative agent of smallpox. Although infections with these 2 viruses share many clinical features, monkeypox is generally less severe than smallpox (1). Among unvaccinated persons, the monkeypox case-fatality rate can be up to 10%, although casefatality rates are lower for infection with the West African than the Central African clade of MPXV (2). In recent years, the number of cases and geographic spread of monkeypox have been increasing, possibly because of waning immunity to smallpox (3-5). Before 2018, the only human cases of monkeypox outside Africa occurred in the United States in 2003; that outbreak was associated with rodents imported from Ghana, and human-to-human transmission did not occur (6). In September 2018, Public Health England (PHE) was notified of 2 unrelated cases of monkeypox affecting travelers who had recently returned from Nigeria (7). We describe transmission of monkeypox virus from the second of these cases to a healthcare worker (HCW) and the public health measures implemented to prevent further cases. The Cases On September 6, 2018, a man with a maculopapular rash, fever, lymphadenopathy, and a 1-week history of feeling generally unwell (patient 2) sought care at a hospital in England (7). He was admitted to a singleoccupancy room in the acute medical unit. The staff attending the patient wore standard personal protective equipment (PPE), consisting of disposable aprons and gloves. Because a travel-associated infection was considered possible, patient 2 was transferred to an isolation room on September 7, 2018. Three days later, a clinical diagnosis of suspected monkeypox was made, and infection prevention and control precautions for a high-consequence infectious disease (HCID) were implemented (e.g., enhanced PPE consisting of disposable gown, disposable gloves, filtering facepiece 3 respirator, and face shield or goggles). The patient was transferred to an Airborne HCID Treatment Centre, and monkeypox was confirmed by laboratory testing at PHE (7). Although the risk to the public was considered to be very low, a precautionary approach was adopted. Possible hospital and community contacts of patient 2 were identified and assessed for risk (Table).

Combating SARS-CoV-2: leveraging microbicidal experiences with other emerging/re-emerging viruses

“…It can be assumed as a starting point, therefore, that the enveloped emerging/re-emerging viruses listed in Table 1 should be readily inactivated by a variety of formulated microbicidal actives. This assumption has, in fact, been verified by extensive empirical data ( Klein & Deforest, 1983 ; Sattar et al, 1989 ; McDonnell & Russell, 1999 ; Rabenau et al, 2005 ; Sattar, 2007 ; Ijaz & Rubino, 2008 ; Geller, Varbanov & Duval, 2012 ; Cook et al, 2015 , 2016 ; Cutts et al, 2018 , 2019 , 2020 ; Weber et al, 2019 ; Chin et al, 2020 ; Ijaz et al, 2020 ; Kampf et al, 2020 ; O’Donnell et al, 2020 ; Vaughan et al, 2020 ; Yu et al, 2020 ; Castaño et al, 2020 ), and has been embraced by the U.S. Environmental Protection Agency ( United States Environmental Protection Agency, 2016 ). The data for various members of the Coronaviridae family, reviewed recently by Kampf et al (2020) , Cimolai (2020) , and Golin, Choi & Ghahary (2020) support the expectation that SARS-CoV-2 and other coronaviruses of concern (e.g., MERS-CoV, SARS-CoV, mouse hepatitis virus, porcine epidemic diarrhea virus, etc.)…”

“…Small, non-enveloped viruses are considered to be less susceptible to microbicides, although these viruses display increased susceptibility to high pH, oxidizers such as sodium hypochlorite, activated hydrogen peroxide, alcohols, and a variety of microbicidal actives, relative to spores and protozoan cysts/oocysts. Mycobacteria, fungi, vegetative bacteria, and enveloped viruses appear to be more susceptible to certain formulated microbicides, such as alcohols, oxidizers, quaternary ammonium compounds (QAC), and phenolics (e.g., p -chloro- m -xylenol (PCMX)) ( Klein & Deforest, 1983 ; Sattar et al, 1989 ; McDonnell & Russell, 1999 ; Rabenau et al, 2005 ; Sattar, 2007 ; Ijaz & Rubino, 2008 ; Geller, Varbanov & Duval, 2012 ; Maillard, Sattar & Pinto, 2013 ; Cook et al, 2015 , 2016 ; Cutts et al, 2018 , 2019 , 2020 ; Rutala et al, 2019 ; Weber et al, 2019 ; Chin et al, 2020 ; Kampf et al, 2020 ; O’Donnell et al, 2020 ; Senghore et al, 2020 ; Vaughan et al, 2020 ; Yu et al, 2020 ). A number of commercially available formulated microbicides (antiseptic liquid, hand sanitizers, liquid hand wash, bar soap, surface cleanser, disinfectant wipe, and disinfectant spray) have been evaluated for virucidal efficacy against SARS-CoV-2 ( Ijaz et al, 2020 ), and as expected, were found to cause complete inactivation (3.0–4.7 log 10 ) within the 1–5 min contact times tested.…”

Exportation of Monkeypox Virus From the African Continent

“…Table 1 presents demographic and epidemiological data for Nigerian nationals who traveled to the United Kingdom (UK1 and UK2) and Singapore (SING), as well as an Israeli national who returned to Israel (ISR) after living in Nigeria, and a UK healthcare worker (UK3) who was exposed to UK2 [20]. Methods of diagnostic confirmation for these cases were reported previously [13][14][15]20], and those of Nigerian cases herein followed methods outlined previously [12].…”

Imported Monkeypox, Singapore

“…The patient's clinical manifestations of a vesiculopustular rash and uncomplicated illness was similar to monkeypox cases in the United Kingdom and Israel, which were also linked to travel from Nigeria (3,4,12). All exported cases were of the West African clade, which is thought to be milder and less transmissible than the Congo Basin clade (13).…”