BACKGROUND:In 2021, an adult with mpox clade IIb infection was admitted to a UK teaching hospital within the High Consequence Infectious Diseases (HCID) network 14 days after travelling from Nigeria and 12 days after onset of symptoms. Subsequently, two household contacts (one adult and one child) developed confirmed symptomatic mpox infection, and were admitted to the same HCID ward for management. METHODS:Environmental swabs of high-touch and low-touch surfaces were collected, including sampling before and after terminal decontamination. RESULTS:In total, monkeypox virus was detected in 72 of 222 (32.4%) samples collected by quantitative polymerase chain reaction (qPCR). Of samples collected from rooms occupied by cases with active infection, where both pre- and post-decontamination results were available, 65% of samples were positive pre-decontamination and 5% were positive post-decontamination. Environmental sampling was also conducted in a suite occupied by asymptomatic contacts and a recovered case; nine of 43 (20.9%) samples were positive during occupation and pre-decontamination, and one of 27 (3.7%) samples was positive post-decontamination. There was variation in the proportion of positive environmental swabs pre-decontamination (14-100%) and post-decontamination (0-15%) between cases. Post-decontamination, there was a reduction in qPCR-positive samples, and where samples remained positive, the level of nucleic acid detected decreased. Viral isolation was attempted in 13 of 72 qPCR-positive samples, and viable virus was identified in two samples. One of these samples was collected from a suite not occupied by any person with active infection. CONCLUSION:This study establishes the utility of environmental sampling around mpox cases to measure infection prevention and control measures, including the efficacy of cleaning protocols used.

The management of patients with acute infectious diseases can present significant challenges, especially if the causative agent has a propensity for personto- person transmission. In such cases, effective patient management is dependent on both rapid identification of disease and the provision of necessary medical care while adhering to suitable infection prevention and control measures to reduce the potential for onwards transmission. The UK has operated a defined system for managing patients with high consequence infectious diseases (HCIDs) since the 1970s, when protocols were first implemented following the first descriptions of several viral haemorrhagic fever diseases, including Marburg virus disease, Lassa fever and Ebola virus disease (EVD). While more than 200 people with HCIDs have been treated in UK hospitals since the 1970s, most of these patients had COVID-19 or mpox during the early phases of new public health emergencies of international concern (PHEICs), prior to their removal from the UK HCID list in March 2020 and June 2022, respectively. Excluding PHEICs, 26 patients have been treated in HCID treatment centres between 1962 and 2023: 10 patients with Lassa fever, 7 with mpox prior to the 2022 PHEIC, 4 with Middle East respiratory syndrome (MERS), 4 with EVD and 1 with Crimean- Congo haemorrhagic fever (CCHF). In total, 15 additional HCID patients were identified where treatment in a specialist centre did not occur due to retrospective diagnosis (4 patients with Lassa fever), mild or moderate illness [5 patients with avian influenza A(H5N1), 1 with MERS and 1 with CCHF] or death prior to transfer (2 patients with Lassa fever, 1 with CCHF and 1 with pneumonic plague). Here we summarize the UK HCID experience, including details about their detection, patient management and outcomes.

Air and surface sampling was performed in isolation rooms of seven patients with clade Ib mpox admitted to high consequence infectious disease centres in the United Kingdom. We detected monkeypox virus (MPXV) DNA in 66/90 surfaces samples and 1/14 air samples; replication competent MPXV was identified in 4/21 surface samples selected for viral isolation. These findings demonstrate that viable clade Ib MPXV contamination can occur during treatment of clade Ib mpox patients reinforcing the importance of infection prevention and control measures.

Tick-borne encephalitis virus (TBEV) is the most prevalent tick-borne viral disease in Europe and Asia. There are three main subtypes of the virus: European, Siberian, and Far Eastern, each of which having distinctive ecology, clinical presentation, and geographic distribution. In recent years, other TBEV subtypes have been described, namely the Himalayan and Baikalian subtypes. Differences in virulence between TBEV subtypes have been described, with the Far Eastern subtype causing the most severe disease in humans. Considering the emergence of new TBEV foci, the genetic characterisation of the virus in endemic regions is crucial to not only better understand its epidemiology, but also to identify possible genetic determinants of virulence, as well as develop accurate diagnostics and therapeutics. In our previous study, we identified TBEV in six localities of the Kyrgyz Republic (Kyrgyzstan), and Ala-Archa National Nature Park as a focus of TBEV transmission. Whilst we were able to retrieve the first partial TBEV sequence from Kyrgyzstan from Ixodes persulcatus ticks, we were unable to retrieve a complete genome sequence at that time. In this study, we have utilised a sequence-independent single-primer amplification (SISPA) protocol and retrieved the complete genome sequence of our previous 2009 TBEV tick sample (strain KY09) producing the third complete TBEV genome from Kyrgyzstan, and the first genome from the region clustering within the Vasilchenko lineage, suggesting a wider distribution for the lineage than was previously thought. We have also developed a tiling amplicon scheme for Siberian TBEV (TBEV-Sib) which produced > 90 % reference coverage at 100x sequencing depths for samples with as little as 1.13×104 RNA copies/ml. Since high viral loads are rare in TBEV clinical samples, the developed protocol adds value to TBEV-Sib endemic regions by offering a novel set of primers to further amplify the viral genome prior to sequencing.

An outbreak of SARS-CoV-2 (1 March to 10 May 2021) with an attack rate of 26.5% among approximately 1150 workers at a storage and distribution centre in England prompted a multidisciplinary outbreak investigation (5 May to 6 August 2021), with the aim of better understanding worker- and workplace-related risk factors for viral transmission in the warehousing sector. Overall, environmental factors (e.g., ventilation, humidity and temperature) were assessed to be appropriate at the facility. Nevertheless, 39 (51.3%) surface samples from across the site tested positive for low/ very low levels of SARS-CoV-2 RNA (Ct value ≥ 32.0 for all). Among the study participants, of whom 35.6% were confirmed or suspected cases, 95.5% reported having received COVID-19 prevention training, 100.0% reported handwashing, and 80.0% reported use of face coverings at work. Notably, 43.9% and 19.0% reported working with a symptomatic and a positive contact respectively. Furthermore, 80.5% and 46.3% had concerns regarding reduction in their income and future unemployment, respectively, due to self-isolation. The findings of this study suggest that, in addition to targeted workplace infection control measures and tailored work area specific risk assessments, an enhanced and equitable sick leave policy may help limit presenteeism and viral transmission in large workplaces.

BACKGROUND:The public order and safety (POS) sector remains susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks, as workplace attendance is typically compulsory and close physical contact is often needed. Here, we report on a SARS-CoV-2 outbreak with an attack rate of 39% (9/23), which occurred between 19 and 29 June 2021 among a cohort of new POS recruits participating in a mandatory 18-week training programme in England. METHODS:The COVID-OUT (COVID-19 Outbreak investigation to Understand Transmission) study team undertook a multidisciplinary outbreak investigation, including viral surface sampling, workplace environmental assessment, participant viral and antibody testing, and questionnaires, at the two associated training facilities between 5 July and 24 August 2021. RESULTS:Environmental factors, such as ventilation, were deemed inadequate in some areas of the workplace, with carbon dioxide (CO2) levels exceeding 1,500 ppm on multiple occasions within naturally ventilated classrooms. Activities during safety training required close contact, with some necessitating physical contact, physical exertion, and shouting. Furthermore, most participants reported having physical contact with colleagues (67%) and more than one close work contact daily (97%). CONCLUSIONS:Our investigation suggests that site- and activity-specific factors likely contributed to the transmission risks within the POS trainee cohort. Potential interventions for mitigating SARS-CoV-2 transmission in this POS training context could include implementing regular rapid lateral flow testing, optimizing natural ventilation, using portable air cleaning devices in classrooms, and expanding use of well-fitted FFP2/FFP3 respirators during activities where prolonged close physical contact is required.

Mpox, a zoonotic disease resulting from infection with monkeypox virus (MPXV), was previously considered endemic to central- and west Africa. However, an ongoing global outbreak of clade IIb (previously known as West African clade) MPXV associated with human-to-human transmission primarily through sexual contact has occurred since May 2022, with introduction of MPXV to regions and countries that had previously only reported sporadic imported cases [ 1 Thornhill J.P. et al. Monkeypox Virus Infection in Humans across 16 Countries - April-June 2022. N. Engl. J. Med. Jul. 2022; Crossref Scopus (1114) Google Scholar ], [ 2 Laurenson-Schafer H. et al. Description of the first global outbreak of mpox: an analysis of global surveillance data. Lancet Glob. Health. Jul. 2023; 11: e1012-e1023 Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar ].

Clinical trials of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) therapeutics often include virological secondary endpoints to compare viral clearance and viral load reduction between treatment and placebo arms. This is typically achieved using quantitative reverse-transcriptase PCR (RT-qPCR), which cannot differentiate replicant competent virus from non-viable virus or free RNA, limiting its utility as an endpoint. Culture-based methods for SARS-CoV-2 exist; however, these are often insensitive and poorly standardized for use as clinical trial endpoints. We report optimization of a culture-based approach evaluating three cell lines, three detection methods, and key culture parameters. We show that Vero-angiotensin-converting enzyme 2-transmembrane serine protease 2 cells in combination with RT-qPCR of culture supernatants from the first passage provides the greatest overall detection of Delta viral replication (22 of 32, 68.8%), being able to identify viable virus in 83.3% (20 of 24) of clinical samples with initial Ct values of <30. Likewise, we demonstrate that RT-qPCR using culture supernatants from the first passage of Vero human signaling lymphocytic activation molecule cells provides the highest overall detection of Omicron viral replication (9 of 31, 29%), detecting live virus in 39.1% (9 of 23) of clinical samples with initial Ct values of <25. This assessment demonstrates that combining RT-qPCR with virological endpoint analysis has utility in clinical trials of therapeutics for SARS-CoV-2; however, techniques may require optimization based on dominant circulating strain. IMPORTANCERT-qPCR is commonly used for virological endpoints during clinical trials for antiviral therapy to determine the quantity and presence of virus in a sample. However, RT-qPCR identifies viral RNA and cannot determine if viable virus is present. Existing culture-based techniques for SARS-CoV-2 are insensitive and not sufficiently standardized to be employed as clinical study endpoints. The use of a culture system to monitor replicating viruses could mitigate the possibility of molecular techniques identifying viral RNA from inactive or lysed viral particles. The methodology optimized in this study for detecting infectious viruses may have application as a secondary virological endpoint in clinical trials of therapeutics for SARS-CoV-2 in addition to numerous research processes.

BACKGROUND:A SARS-CoV-2 outbreak with an attack rate of 14.3% was reported at a plastics manufacturing plant in England.METHODS:Between 23rd March and 13th May 2021, the COVID-OUT team undertook a comprehensive outbreak investigation, including environmental assessment, surface sampling, molecular and serological testing, and detailed questionnaires, to identify potential SARS-CoV-2 transmission routes, and workplace- and worker-related risk factors.RESULTS:While ventilation, indicated using real-time CO2 proxy measures, was generally adequate on-site, the technical office with the highest localized attack rate (21.4%) frequently reached peaks in CO2 of 2100ppm. SARS-CoV-2 RNA was found in low levels (Ct ≥35) in surface samples collected across the site. High noise levels (79dB) were recorded in the main production area, and study participants reported having close work contacts (73.1%) and sharing tools (75.5%). Only 20.0% of participants reported using a surgical mask and/or FFP2/FFP3 respirator at least half the time and 71.0% expressed concerns regarding potential pay decreases and/or unemployment due to self-isolation or workplace closure.CONCLUSIONS:The findings reinforce the importance of enhanced infection control measures in manufacturing sectors, including improved ventilation with possible consideration of CO2 monitoring, utilising air cleaning interventions in enclosed environments, and provision of good-quality face masks (i.e., surgical masks or FFP2/FFP3 respirators) especially when social distancing cannot be maintained. Further research on the impacts of job security-related concerns is warranted.

Zika virus (ZIKV) is a recently re-emerged flavivirus transmitted primarily through the bite of an infected mosquito, Aedes aegypti being the main vector. ZIKV infection is associated with a range of adverse effects; infection during pregnancy can lead to foetal abnormalities, including microcephaly. Lacking a licensed vaccine, or specific therapeutics, control of ZIKV transmission focuses on vector control. However, in most transmission settings, current methods are insufficient to successfully control ZIKV, or other similarly-transmitted arboviruses such as dengue and chikungunya viruses. This has stimulated interest in genetics-based methods, either to reduce the number of mosquitoes (population suppression), or to make mosquitoes less able to transmit (population modification). Here, we describe a method to selectively eliminate infected mosquitoes, using a virus sensor inserted into the mosquito genome and coupled to a quorum-counting lethal effector. In mosquitoes, ZIKV normally establishes persistent, lifelong infection; survival of these infected mosquitoes is crucial to transmission potential. Correspondingly, removal of infected mosquitoes can reduce vectorial capacity of a mosquito population, i.e. ability to transmit. Since relatively few mosquitoes become infected, typically <2%, engineered hypersensitivity to ZIKV would have only a modest population-level fitness cost, and lower still if transmission were successfully reduced by such means.

AIMS:To utilize environmental surface sampling to evaluate areas of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contamination within workplaces to identify trends and improve local coronavirus disease 2019 (COVID-19) control measures.METHODS AND RESULTS:Surface sampling was undertaken at 12 workplaces that experienced a cluster of COVID-19 cases in the workforce between March 2021 and March 2022. A total of 7.4% (61/829) samples collected were positive for SARS-CoV-2 RNA by the quantitative PCR (qPCR) with only 1.8% (15/829) of samples identified with crossing threshold (Ct) values <35.0. No sample returned whole-genome sequence inferring RNA detected was degraded.CONCLUSIONS:Few workplace surface samples were positive for SARS-CoV-2 RNA and positive samples typically contained low levels of nucleic acid. Although these data may infer a low probability of fomite transmission within the workplace, Ct values may have been lower at the time of contamination. Workplace environmental sampling identified lapses in COVID-19 control measures within individual sites and showed trends throughout the pandemic.

Mellon and colleagues reported mpox virus (MPXV) DNA in air samples from a hospital room dedicated to mpox-infected patients. 1However, longitudinal analysis of serial self-taken samples, collected contemporaneously from the same patient with mpox, have not been well described.Such data would help clinicians and policymakers to understand how long infected patients may continue to emit virus following infection, and through which route.We therefore performed a prospective longitudinal analysis of patients with mpox, with differing clinical severities of infection.

Surfaces contaminated with infectious SARS-CoV-2 particles have the potential to cause human infection and any increase in surface survivability of a SARS-CoV-2 variant may increase its prevalence over other variants. This study investigated whether there were differences in surface persistence between Delta and Omicron variants leading to Omicron's dominance globally. Stainless steel coupons were inoculated with suspensions of either Delta or Omicron variant and exposed to typical environmental conditions within a containment level 3 laboratory. Coupons were recovered at different timepoints and enumerated using plaque assay. Both variants were recoverable for >48 h on the coupons. Omicron showed a greater reduction of viability after 48 h compared to Delta with a 20-fold decrease versus 15-fold respectively, but this difference was not statistically significant (p = 0.424). These results indicate that Omicron's surface persistence is unlikely to contribute to it becoming the dominant variant over Delta.

Background An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an attack rate of 55% (22/40 workers) occurred at a public-facing office in England from August to September 2021. Published evidence regarding outbreaks in office workplaces remains limited.Aims To describe an investigation of workplace- and worker-related risk factors following an outbreak of SARS-CoV-2 in a public-facing office.Methods The COVID-19 (coronavirus disease 2019) Outbreak Investigation to Understand Transmission (COVID-OUT) study undertook an investigation of the outbreak. This included surface sampling, occupational environmental assessment, molecular and serological testing of workers, and detailed questionnaires.Results Despite existing COVID-19 control measures, surface sampling conducted during a self-imposed 2-week temporary office closure identified viral contamination (10/60 samples, 17% positive), particularly in a small, shared security office (6/9, 67% positive) and on a window handle in one open-plan office. Targeted enhanced cleaning was, therefore, undertaken before the office reopened. Repeat surface sampling after this identified only one positive (2%) sample. Ventilation was deemed adequate using carbon dioxide monitoring (typically <= 1000 ppm). Twelve workers (30%) responded to the COVID-OUT questionnaire, and all had been vaccinated with two doses. One-third of respondents (4/12) reported direct physical or close contact with members of the public; of these, 75% (3/4) reported a divider/screen between themselves and members of the public.Conclusions The results highlight the potential utility of surface sampling to identify SARS-CoV-2 control deficiencies and the importance of evolving, site-specific risk assessments with layered COVID-19 mitigation strategies. Between August and September 2021, an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with an attack rate of 55% (22/40 workers), occurred in a public-facing office in England. To identify workplace- and worker-related risk factors, an investigation involving surface sampling, occupational environmental assessment, molecular and serological testing of workers, and questionnaires was undertaken. The results highlight the potential utility of surface sampling to identify SARS-CoV-2 control deficiencies and the importance of evolving, site-specific risk assessments with layered coronavirus disease 2019 mitigation strategies.

We read with interest the report from Mellon et al. regarding air sampling for mpox (formerly monkeypox) virus (MPXV) in an outpatient setting and the need for additional data to assess the risk to healthcare workers (HCWs) [[1]Mellon G. Rubenstein E. Antoine M. Ferré V.M. Gabassi A. Molina J.-M. et al.Air detection of monkeypox virus in a dedicated outpatient clinic room for monkeypox infection diagnosis.J Infect. 2022; (22)00750-2: S0163-S4453Google Scholar]. In August 2022, we performed longitudinal surface sampling at a large sexual health clinic in London, UK, to investigate environmental contamination of a typical outpatient setting where patients with mpox are assessed. During the four-week period of observation at the clinic, 85 patients were seen and subsequently diagnosed with mpox based on samples collected during their visit (number of patients confirmed positive seen in 7 days' prior sampling: week 1: 31 cases; week 2: 26 cases; week 3: 22 cases; week 4: 6 cases). Weekly sampling was performed in the same observation room using Copan UTM swabs (Copan, Brescia, Italy) with quantitative polymerase chain reaction (qPCR) analysis performed as previously described [[2]Gould S. Atkinson B. Onianwa O. Spencer A. Furneaux J. Grieves J. et al.Air and surface sampling for monkeypox virus in a UK hospital: an observational study.Lancet Microbe. 2022; 3: e904-e911Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar]. Samples were collected from the same eight locations each week: HCW desk, HCW keyboard, patient chair armrest, floor beneath patient chair, desk between patient and HCW, wall next to examination table (approximately where the patient head will be facing during examination), floor beneath examination table, and the door handle to exit the examination room. qPCR analysis of the 32 samples collected (eight samples collected weekly for four weeks) resulted in only three MPXV-positive samples all with crossing threshold (CT) values near the limit of detection for the assay, indicating occasional low-level contamination of the sampled environment. All three positive samples were collected from the floor of the examination room (Figure 1); viral isolation using previously described methods detected replicating virus in one sample collected from the floor beneath the examination table (week 2), confirming the presence of infection-competent MPXV in this sample [[2]Gould S. Atkinson B. Onianwa O. Spencer A. Furneaux J. Grieves J. et al.Air and surface sampling for monkeypox virus in a UK hospital: an observational study.Lancet Microbe. 2022; 3: e904-e911Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar]. Two of the three positive samples were identified in the same location on consecutive weeks, raising the possibility of duplicate identification. Though our data cannot exclude this possibility, surfaces were thoroughly cleaned using disinfectant wipes (Spill Wipes, Clinell; GAMA Healthcare, Hemel Hempstead, UK) and the floor cleaned with chlorine solution (Chlor-clean; Guest Medical, Edenbridge, UK) after each examination of a suspected mpox case, in addition to routine cleaning performed at the end of every working day. Despite a significant potential for mpox transmission in healthcare settings, few cases of mpox have been reported in HCWs, with just five cases recorded by the World Health Organization as occupational exposures in Europe through January 2023 [[3]World Health Organization/European Centre for Disease Prevention and ControlJoint ECDC–WHO Regional Office for Europe Mpox Surveillance Bulletin: 4. January 2023; (Available at:) ([last accessed January 2023])https://www.who.int/europe/publications/m/item/joint-ecdc-who-regional-office-for-europe-mpox-surveillance-bulletin–04-january-2023Google Scholar]. Infection prevention and control (IPC) measures including the use of personal protective equipment (PPE) may explain, in part, the very small number of occupationally associated infections reported. The PPE recommended for typical UK outpatient consultations (gloves, fluid-repellent surgical mask, apron, and eye protection if splash risk) is simpler than the recommended PPE for UK HCWs caring for patients with mpox admitted to hospital (gloves, fit-tested FFP3 respirator, long-sleeved fluid-repellent gown, eye protection) [[4]UK Health Security Agency. Principles for mpox control in the UK: 4 nations consensus statement. 2022. Available at: https://www.gov.uk/government/publications/principles-for-monkeypox-control-in-the-uk-4-nations-consensus-statement/principles-for-monkeypox-control-in-the-uk-4-nations-consensus-statement [last accessed January 2023].Google Scholar]. However, the amount of environmental contamination and opportunities for exposure to virus are expected to be greater and more cumulative for inpatient settings compared to outpatient settings [[1]Mellon G. Rubenstein E. Antoine M. Ferré V.M. Gabassi A. Molina J.-M. et al.Air detection of monkeypox virus in a dedicated outpatient clinic room for monkeypox infection diagnosis.J Infect. 2022; (22)00750-2: S0163-S4453Google Scholar,[2]Gould S. Atkinson B. Onianwa O. Spencer A. Furneaux J. Grieves J. et al.Air and surface sampling for monkeypox virus in a UK hospital: an observational study.Lancet Microbe. 2022; 3: e904-e911Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar,[5]Nörz D. Brehm T.T. Tang H.T. Grewe I. Hermanussen L. Matthews H. et al.Clinical characteristics and comparison of longitudinal qPCR results from different specimen types in a cohort of ambulatory and hospitalized patients infected with monkeypox virus.J Clin Virol. 2022; 155: 105254Crossref PubMed Scopus (31) Google Scholar,[6]Hernaez B. Muñoz-Gómez A. Sanchiz A. Orviz E. Valls-Carbo A. Sagastagoitia I. et al.Monitoring monkeypox virus in saliva and air samples in Spain: a cross-sectional study.Lancet Microbe. 2023; 4: e21-e28Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar]. The two previous studies in outpatient settings both focused on air sampling and both studies identified positive qPCR samples, although neither identified infectious virus. Our data confirm that environmental contamination of surfaces occurs in outpatient settings and can contain infectious virus. This contamination may occur due to several mechanisms including from respiratory droplets or via dislodgement of viral particles on patient clothing which are removed for patient examination. It is likely that the contact PPE recommended in outpatient settings (in combination with frequent room cleaning) is proportionate to mitigate the risk from fomite transmission within the environment; however, the detection of MPXV in air samples from previous studies does raise concerns. At present, infectious virus has not been detected in air samples and the risk of establishing human mpox infection via the respiratory route is unknown. The absence of numerous cases in HCWs working in outpatient settings suggests that either (i) infectious virus in respiratory secretions is rarely present at sufficient titre to establish infection, (ii) respiratory transmission of Clade IIb MPXV is not an optimal route of transmission, or (iii) that surgical/FFP2 masks are sufficient to mitigate the residual risks of (i) and (ii). We have shown that surface contamination occurs in an outpatient setting and, although it was minimal in the environment sampled, infection-competent MPXV could be detected. It is likely that several factors contribute to the low level of contamination observed, including minimal time spent in this locality and the frequency of cleaning. Such focused surface deposition of virus would not be expected if there had been aerosolization of virus. Thus in future studies, and where feasible, combined surface and air sampling may provide additional insights. It is feasible that the contamination observed could present an infection risk in specific situations; however, UK PPE recommendations combined with frequent standard cleaning procedures appear sufficient to mitigate onward transmission risk in outpatient settings. IPC recommendations should be kept under review as more data emerge regarding infectious virus in respiratory secretions and the risk of respiratory transmission of MPXV. The investigations performed were a component of the urgent public health investigation performed as part of UKHSA's public health incident response to cases of a high-consequence infectious disease in the UK. UKHSA is the national health security agency for England and an executive agency of the UK Government's Department of Health and Social Care. The study protocol was subject to internal review by the Research Ethics and Governance Group, which is the UKHSA Research Ethics Committee, and was granted full approval. The authors wish to acknowledge the support of S. Summers, K. Emery, and R. Davies for assistance with cell culture. Conceptualization and methodology: B.A., S.G., T.F., A.M.B., J.D., D.A., G.W.; investigation: B.A., S.P., G.W; formal analysis: B.A., A.S., O.O., J.F., I.N., J.G.; writing – original draft: B.A., A.M.B., J.D., G.W.; writing – review and editing: all authors. This report contains work supported by UKHSA Grant-in-Aid. The contents of this paper, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect UK Health Security Agency policy. This work was funded by UKHSA Grant in Aid funding and the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections. The funding source had no involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the article for publication. J.D. is supported by the Moh Foundation.

Environmental sampling played an important role in evaluating levels of environmental contamination present in hospitals and outpatient settings during the mpox 2022 outbreak This allowed validation of infection prevention and control (IPC) measures and identification of potential routes of transmission when caring for infected patients. Investigations typically focussed on sampling in high-risk settings, using quantitative polymerase chain reaction (qPCR) to identify the presence of mpox virus (MPXV) DNA ( 1 Marimuthu K. Wong J.C.C. Lim P.L. Octavia S. Huan X. Ng Y.K. et al. Viable mpox virus in the environment of a patient room. International Journal of Infectious Diseases. 2023; 131: 40-45 Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar , 2 Atkinson B. Spencer A. Onianwa O. Furneaux J. Grieves J. Nicholls I. et al. Longitudinal mpox virus surface sampling in an outpatient setting. Journal of Hospital Infection. 2023; Abstract Full Text Full Text PDF Scopus (1) Google Scholar , 3 Nörz D. Pfefferle S. Brehm T.T. Franke G. Grewe I. Knobling B. et al. Evidence of surface contamination in hospital rooms occupied by patients infected with monkeypox, Germany, June 2022. Eurosurveillance. 2022; 272200477 Crossref Scopus (40) Google Scholar , 4 Gould S. Atkinson B. Onianwa O. Spencer A. Furneaux J. Grieves J. et al. Air and surface sampling for monkeypox virus in a UK hospital: an observational study. Lancet Microbe. 2022; 3: e904-e911 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar ). On occasion, MPXV DNA contamination was detected outside controlled areas such as corridors outside of isolation rooms. However, these occurrences usually identified extremely low levels of DNA ( [4] Gould S. Atkinson B. Onianwa O. Spencer A. Furneaux J. Grieves J. et al. Air and surface sampling for monkeypox virus in a UK hospital: an observational study. Lancet Microbe. 2022; 3: e904-e911 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar ). While such findings may reflect ineffective IPC measures, other explanations for detection of low levels of DNA in 'clean' areas include qPCR false-positivity and DNA deposition from autoclaved, reusable personal protective equipment (PPE). While most PPE is typically single-use, items such as autoclavable rubber clogs can be reused if suitably sterilised, thereby offering robust foot protection in addition to other benefits such as a reduction of waste and pollution, predictable availability, and economic viability ( [5] Mantelakis A. Spiers H.V.M. Lee C.W. Chambers A. Joshi A. Availability of Personal Protective Equipment in NHS Hospitals During COVID-19: A National Survey. Ann Work Expo Health. 2021; 65: 136-140 Crossref PubMed Scopus (20) Google Scholar , [6] Khan M.T. Shah I.A. Hossain M.F. Akther N. Zhou Y. Khan M.S. et al. Personal protective equipment (PPE) disposal during COVID-19: An emerging source of microplastic and microfiber pollution in the environment. Sci Total Environ. 2023; 860160322 Crossref PubMed Scopus (8) Google Scholar ).

Multiple viruses, including pathogenic viruses, bacteriophages, and even plant viruses, cause a phenomenon termed superinfection exclusion whereby a currently infected cell is resistant to secondary infection by the same or a closely related virus. In alphaviruses, this process is thought to be mediated, at least in part, by the viral protease (nsP2) which is responsible for processing the nonstructural polyproteins (P123 and P1234) into individual proteins (nsP1-nsP4), forming the viral replication complex. Taking a synthetic biology approach, we mimicked this naturally occurring phenomenon by generating a superinfection exclusion-like state in Aedes aegypti mosquitoes, rendering them refractory to alphavirus infection. By artificially expressing Sindbis virus (SINV) and chikungunya virus (CHIKV) nsP2 in mosquito cells and transgenic mosquitoes, we demonstrated a reduction in both SINV and CHIKV viral replication rates in cells following viral infection as well as reduced infection prevalence, viral titers, and transmission potential in mosquitoes.

Background An outbreak of monkeypox virus infections in non-endemic countries was recognised on May 12, 2022. As of September 29, more than 67 000 infections have been reported globally, with more than 3400 confirmed cases in the UK by September 26. Monkeypox virus is believed to be predominantly transmitted through direct contact with lesions or infected body fluids, with possible involvement of fomites and large respiratory droplets. A case of monkeypox in a health-care worker in the UK in 2018 was suspected to be due to virus exposure while changing bedding. We aimed to measure the extent of environmental contamination in the isolation rooms of patients with symptomatic monkeypox. Methods We investigated environmental contamination with monkeypox virus from infected patients admitted to isolation rooms at the Royal Free Hospital (London, UK) between May 24 and June 17, 2022. Surface swabs of hightouch areas in five isolation rooms, of the personal protective equipment (PPE) of health-care workers in doffing areas in three rooms, and from air samples collected before and during bedding changes in five rooms were analysed using quantitative PCR to assess monkeypox virus contamination levels. Virus isolation was performed to confirm presence of infectious virus in selected positive samples. Findings We identified widespread surface contamination (56 [93%] of 60 samples were positive) in occupied patient rooms (monkeypox DNA cycle threshold [Ct] values 24 center dot 7-37 center dot 4), on health-care worker PPE after use (Ct 26 center dot 1-35 center dot 6), and in PPE doffing areas (Ct 26 center dot 3-36 center dot 8). Of 20 air samples taken, five (25%) were positive. Three (75%) of four air samples collected before and during a bedding change in one patient's room were positive (Ct 32 center dot 7-36 center dot 2). Replicationcompetent virus was identified in two (50%) of four samples selected for viral isolation, including from air samples collected during bedding change. Interpretation These data show contamination in isolation facilities and potential for suspension of monkeypox virus into the air during specific activities. PPE contamination was observed after clinical contact and changing of bedding. Contamination of hard surfaces in doffing areas supports the importance of cleaning protocols, PPE use, and doffing procedures. Funding None. Copyright (c) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license.