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.

Multiple HPV Infections and Viral Load Association in Persistent Cervical Lesions in Mexican Women.

Persistent high-risk human papillomavirus (HR-HPV) infections play a major role in the development of invasive cervical cancer (CC), and screening for such infections is in many countries the primary method of detecting and preventing CC. HPV typing can be used for triage and risk stratification of women with atypical squamous cells of undetermined significance (ASC-US)/low-grade cervical lesions (LSIL), though the current clinical practice in Mexico is to diagnose CC or its preceding conditions mainly via histology and HR-HPV detection. Additional information regarding these HPV infections, such as viral load and co-infecting agents, might also be useful for diagnosing, predicting, and evaluating the possible consequences of the infection and of its prevention by vaccination. The goal of this follow-up hospital case study was to determine if HPV types, multiple HPV infections, and viral loads were associated with infection persistence and the cervical lesion grade. A total of 294 cervical cytology samples drawn from patients with gynecological alterations were used in this study. HPV types were identified by real-time PCR DNA analysis. A subset of HPV-positive patients was reevaluated to identify persistent infections. We identified HPV types 16, 18, and 39 as the most prevalent. One hundred five of the patients (59%) were infected with more than one type of HPV. The types of HPV associated with multiple HPV infections were 16, 18, and 39. In the follow-up samples, 38% of patients had not cleared the initially detected HPV infection, and these were considered persistent. We found here an association between multiple HPV infections and high viral loads with and infection persistence. Our findings suggest there are benefits in ascertaining viral load and multiple HPV infections status of HR-HPV infections for predicting the risk of persistence, a requirement for developing CC. These findings contribute to our understanding of HPV epidemiology and may allow screening programs to better assess the cancer-developing risks associated with individual HR-HPV infections.