Evaluation of SARS-COV-2 transmission through indoor air in hospitals and prevention methods: A systematic review.

Hospitals are the places for COVID-19 treatment but on the other hand, they are a dangerous source for SARS-COV-2 transmission. If we assume that the SARS-COV-2 is transmitted by air to hospitals, what are the strategies to reduce the SARS-COV-2 transmission and its removal? Therefore, this study aimed to evaluate SARS-COV-2 transmission through indoor air in hospitals and its prevention methods.This study is a systematic review by searching among published articles in reputable international databases such as Scopus, Google scholar, PubMed, Science Direct and ISI (Web of Science). Data were collected according to inclusion and exclusion criteria and by searching for relevant keywords. Qualitative data were collected using the PRISMA standard checklist. Information was entered into the checklist, such as the name of the first author, the year of the study publication, the country, the type of study, the number of samples, the type of air sample, the results, the methods for SARS-COV-2 transmission prevention in the hospital. After reviewing the information and quality of articles, 11 articles were included in this study. An analysis of the articles showed that Asian countries (Iran, China, Singapore) were more concerned with the SARS-COV-2 transmission through hospital air. Four articles did not confirm SARS-COV-2 in the air, but seven articles reported the SARS-COV-2 from air samples. The results of this study showed that many factors could affect the positive or negative SARS-COV-2 detection in the air, such as environmental conditions in hospitals, sampling methods, sampling height and distance from patients, flow rate and sampling time, efficiency and functionality of ventilation systems, use of disinfectants.Therefore, due to the possibility of SARS-COV-2 in the air of hospitals, preventive measures should be taken such as physical distance, personal hygiene, ventilation, and air filtration. We hope that this research will help to reduce the transmission of SARS-COV-2 and cut the airborne transmission pathway of SARS-COV-2 in hospitals.