A British hospital study is investigating whether monkeypox can be transmitted through aerosolized droplets and fomites

A British hospital study is investigating whether monkeypox can be transmitted through aerosolized droplets and fomites

In a recent study published in The Lancet microbe Researchers conducted an observational study to determine environmental contamination with monkeypox virus in hospital isolation rooms of monkeypox patients to understand potential exposures for healthcare workers.

Lernen: Luft- und Oberflächenprobenahme auf Affenpockenviren in einem britischen Krankenhaus: eine Beobachtungsstudie. Bildnachweis: Dotted Yeti/Shutterstock

background

Numerous cases of monkeypox were reported in 2022 outside of the endemic areas in Central and West Africa. The etiological agent of monkeypox is the monkeypox virus, which belongs to the genus Orthopoxvirus of the family Poxviridae and is similar to the smallpox virus. It is a double-stranded deoxyribonucleic acid (DNA) virus that is thought to be transmitted to humans primarily through contact with lesions, body fluids, and respiratory droplets.

Evidence of transmission between nonhuman primates through inhalation of aerosolized monkeypox virus suggests that the disease may be able to spread to humans via aerosolized respiratory droplets. Stable orthopoxviruses have been detected in aerosols for almost 90 hours.

A case of monkeypox in a hospital worker in the United Kingdom (UK) was attributed to exposure while changing bed linen in the isolation room of a monkeypox patient. Additionally, studies in Germany have reported widespread contamination with monkeypox virus in hospital rooms housing monkeypox patients. These cases highlight the need to understand the risk of transmission of monkeypox through environmental pollution.

About the study

In the present study, researchers identified adult patients hospitalized at the Royal Free Hospital in London, United Kingdom, who had confirmed cases of monkeypox and visible skin lesions. They examined the air and surfaces in their isolation rooms after obtaining informed consent. Air and surface swab samples were also collected from the outdoor corridor and vestibules surrounding the isolation rooms, as well as from the personal protective equipment (PPE) of hospital staff caring for monkeypox patients.

Swab samples were also collected from frequently touched areas in the isolation room, such as the doorbell, door handles, television remote controls, light switches, faucet handles, etc. Nucleic acid was isolated from the samples and tested for the presence of monkeypox DNA using quantitative polymerase chain reaction (qPCR). To confirm the presence of monkeypox virus, virus isolation was performed from selected positive samples.

Results

Results showed that 93% (56 of 60) of swab samples tested positive for monkeypox virus DNA. The cycle threshold (Ct) values ​​for qPCR of the positive models indicated infectious levels of monkeypox virus. An air sample during bedding change in the isolation room and a swab sample from the floor of the anteroom where PPE was removed after use were positive for replication-competent monkeypox virus.

Hard surface swab samples had lower Ct values ​​(≤30), which may be explained by the use of hard surface cleaners. Monkeypox virus contamination has also been detected in swab samples of PPE and fingertips from gloves following visits to isolation rooms.

Contamination in air samples highlighted the need for effective respiratory protective equipment for hospital staff who change bed linens and perform other ancillary tasks for monkeypox patients.

According to the authors, contamination of the environment and surfaces with the monkeypox virus, even with a replication-competent virus, is not sufficient to detect infection in a person exposed to the virus. The susceptibility of the host, environmental factors that weaken the virus, the route of transmission, and the extent of virus exposure all contribute to successful infection.

Isolation areas tested were well ventilated and regularly cleaned with 5,000 to 10,000 parts per million sodium chlorine hypochlorite. The authors expect the results to apply to other areas where ventilation and disinfection procedures vary or where patients are absent for long periods of time, such as: B. clinics and outpatient areas could be different. Therefore, further research is needed to understand how pollution levels vary across hospitals.

Conclusions

In conclusion, the study examined air and surface samples from isolation rooms of monkeypox patients, surrounding anterooms, and PPE worn by hospital staff caring for patients for monkeypox virus infection. The researchers found that 93% of the samples were contaminated with the virus, with two samples showing the presence of replication-competent viruses.

The results highlighted the need for more effective preventive measures, including effective respiratory protection for hospital staff, to limit the transmission of monkeypox in the hospital. Contamination of hard surfaces indicates possible pathogen transmission and requires the use of strict cleaning protocols and personal protective equipment.

Reference:

• Gould, S., Atkinson, B., Onianwa, O., Spencer, A., Furneaux, J., Grieves, J., Taylor, C., Milligan, I., Bennett, A., Fletcher, T., Dunning, J., Dunning, J., Price, N., Beadsworth, M., Schmid, M., Emonts, M., Tunbridge, A., Porter, D., Cohen, J. & Whittaker, E. (2022). Luft- und Oberflächenprobenahme auf Affenpockenviren in einem britischen Krankenhaus: eine Beobachtungsstudie. Die Lancet-Mikrobe. doi: https://doi.org/10.1016/s2666-5247(22)00257-9 https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(22)00257-9/fulltext

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