key: cord-0881682-69jikv6s authors: Ran, Li; Chen, Xuyu; Wang, Ying; Wu, Wenwen; Zhang, Ling; Tan, Xiaodong title: Risk Factors of Healthcare Workers with Corona Virus Disease 2019: A Retrospective Cohort Study in a Designated Hospital of Wuhan in China date: 2020-03-17 journal: Clin Infect Dis DOI: 10.1093/cid/ciaa287 sha: e172504d2dc665ac8274be2a2bc7453813eb55f7 doc_id: 881682 cord_uid: 69jikv6s Corona Virus Disease 2019 (COVID-19) originated in Wuhan, China has caused many healthcare workers (HCWs) infected. Seventy-two HCWs manifested with acute respiratory illness were retrospectively enrolled to analyze the risk factors. The high-risk department, longer duty hours, and suboptimal hand hygiene after contacting with patients were linked to COVID-19. At present, the pneumonia epidemic caused by SARS-Cov-2 originating in Wuhan, China is still alarming, having drawn a high-level concern over the world. According to the experience during the 2002 severe acute respiratory syndrome (SARS) outbreak, more emphasis should be placed on healthcare workers (HCWs) protection, because an approximately 1725 of frontline HCWs were infected by SARS [1] . Given the current Corona Virus Disease 2019 (COVID-19) epidemic, the infection among medical and nursing personnel is a common occurrence, ever since the first 15 affected cases were reported in Wuhan [2] . It was estimated that a total of 1716 Chinese HCWs were infected by COVID-19 till February 11, 2020 [3] . To better understand how to protect staff, it is necessary to understand the predisposing factors for HCWs infection and nosocomial transmission. This retrospective cohort study of HCWs with acute respiratory illness in the designated hospital of Wuhan University sought to determine risk factors and behaviors associated with the development of COVID-19. We conducted a retrospective cohort study among the HCWs (>18 years of age) with acute respiratory symptoms in a single-center setting, who worked at the forefront to fight against COVID-19 since it outbroke. To define the cohort, all participants were clinicians and nurses from a designated hospital. The designated Hospital is a 3300-bed grade-A tertiary hospital serving for the medical treatment in this outbreak. The case with acute respiratory symptoms was defined by any or multiple of the present symptoms like cough, fever, brachypnea, chest distress, headache, hemoptysis, others related to acute respiratory illness, and diarrhea, testing with radiologic characters and laboratory evidence. All participants were given informed consent. HCWs in different departments were divided into two groups based on risk exposure. High-risk exposure was defined as the high-risk department (HRD) with interventional medical or surgical procedures that generate respiratory aerosols, including the respiratory department, infection department, ICU and surgical department. Other low-risk clinical departments were regarded as general groups (GD). Diagnosed cases of SARS-CoV-2 infection was identified as outcome variables. The follow-up was ended on Jan 28 because all HCWs were confirmed with COVID-19 infection or non-infection. HCWs were required to fulfill an online questionnaire giving detailed information on sociodemographic characteristics, time to symptomatic progression, contact history, medical practice, hand hygiene, and proper personal protective equipment (PPE) (Appendix 1). A total of 83 questionnaires were collected, of which 72 were valid, with an effective rate of 86.75%. The outcome variable was regarded as diagnosed COVID-19, which is defined according to "The diagnosis of COVID-19 conformed to Diagnosis and treatment of novel coronavirus pneumonia (Trial Version 3)" issued by the National Health Commission of the People's Republic of China. All cases were diagnosed with the test by PCR nucleic acid. The novel coronavirus nucleic acid was detected by real-time fluorescence RT-PCR, and the virus gene was sequenced, which was highly homologous with the known new coronavirus. Continuous variables were described as mean (standard deviation) and median (interquartile range), while categoric variables were presented as counts (frequency or percentages). Relative risk (RR) and its 95% confidence interval (95% CI) were calculated to compare outcomes between groups. Mentel-Haenszel tests and multivariate logistic regression were respectively used to identify the confounding factors and to assess the interaction effect between two variables. Kaplan-Meier survival curve was established, and the log-rank test was for subgroup differences. Statistical analyses were conducted using STATA software (version 14.0). P-value <0.05 was considered to be statistically significant. Of these 72 people, 39 were classified in GD and 33 in HRD. Ages ranged from 21 to 66 years with a median (interquartile range, IQR) of 31 (28-40,12). The median (IQR) of daily work was 8 (8-10, 2) hours (Table 1) . Before the cohort started, subject baseline characteristics were compared. Gender (χ 2 =2.243, P =0.134), types of HCWs (χ 2 =0.076, P =0.782), and age (35.24 versus 37.98, P =0.579) were generally well-balanced between the exposed and non-exposed group. Common symptoms were fever (85.71%), cough (60.71%), brachypnea (7.14%), chest distress (7.14%), headache (7.14%), diarrhea (7.14%), and hemoptysis (7.14%) among the 28 HCWs diagnosed with COVID-19. Illustrated in Table 2 , the relative risks and their 95% confidence intervals of unqualified hand-washing, suboptimal hand hygiene before and after contact with patients, and improper PPE were 2.64 (95%CI = 1.04-6.71, P<0.05), 3.10 (95%CI = 1.43-6.73, P<0.01), 2.43 (95%CI = 1.34-4.39, P<0.01), and 2.82 (95%CI = 1.11-7.18, P<0.05), respectively. The interaction effect between exposure and other factors was conducted with logistic regression. It revealed that : 1) male + HRD (RR=2.45, 95%: 1.38-3.45, P<0.01) with control for HCW; 2) clinician + HRD (RR=2.00, 95%: 1.03-2.89, P<0.05) with control for gender; and 3) unclean hand after contact with patients (UHA) + HRD (RR=3.07, 95%: 1.14-5.15, Nosocomial infections of respiratory infectious diseases are common to see, and COVID-19 was found linked with the exposed department, duty hour, and hand hygiene in this study. Similar to our finding, previous researches have proved the higher susceptibility of respiratory infectious disease for HRD workers [4] . This phenomenon has also been discovered in epidemics of SARS [5, 6] . For example, data from 7 hospitals in China showed an incidence of HCWs infected by SARS up to 13.53% in ICU [6] . We speculated that HRD experienced more exposures, such as a higher frequency of interventional medical operation and aerosol-generating procedure [7] . CHWs in China are generally working with long hours, with an average workweek exceeding 54 hours [8] . Moderate work hour benefits the health and safety of CHWs, while prolonged work (> 10 hours/day) would possibly increase the risk of respiratory infections [9, 10] . An obvious COVID-19 infection ascending with daily workhour was found in this study. Consideration of duty hour restrictions (less than 10 hours/day) should be considered, depending on the medical staff's specific role. Contact transmission is one of the main routes of the SARS-CoV-2. Transmission from patients to HCWs usually follows contamination of the HCWs' hands after touching either patients or fomites, whereas hand hygiene is considered the most important prevention measure for healthcare-associated infections. Our results highlight the importance of hand hygiene after contacting or caring for COVID-19 patients, which is highly consistent with other researches [11, 12] . As we all know, washing hands can significantly reduce the residual viruses or bacteria on your hands. Our research has some limitations. Recall bias on the part of HCWs is possible inherent in the survey study. To minimize the bias, investigators were required to verify the information using medical records in the hospital information system. Potential unmeasured confounding, especially with regards to gender differences was possibly another limitation. Hence, effect confounding was controlled as much as possible in the analysis. Limitations lie in small sample size, single-center aspect, and less representative research subjects, making the results difficult to be generalized. Nevertheless, the results support current recommendations for hand hygiene and duty hour reduction among HCWs. HCWs worked in HRD and with suboptimal hand hygiene after contacting patients had a higher risk of COVID-19. Higher risk with longer duty hours was found, especially in HRD. A call to confirm these risk factors in other larger cohorts, as well as work to mitigate these, would be appropriate. Note: IQR, interquartile range; HRD, high-risk department; GD, general department. Heroes of SARS: professional roles and ethics of health care workers Xinhua Net. 15 medical staff are diagnosed as COVID-19 in Wuhan The Beijing News. A total of 1716 Chinese HCWs were infected by COVID-19 till Quantifying the risk of respiratory infection in healthcare workers performing high-risk procedures Cluster of severe acute respiratory syndrome cases among protected health-care workers Study on Severe Acute Respiratory Syndrome Nosocomial Infection of Doctors and Nurses in Intensive Care Units Transmission of 2009 pandemic influenza A (H1N1) virus among healthcare personnel-Southern California Doctor's Workload in China: A Status-quo Study Analysis on the health status and influencing factors of medical workers in a city of Fujian province The association between resident physician work hour regulations and physician safety and health Correlation between hand hygiene compliance and nosocomial infection in medical staff Screening for Methicillin-resistant Staphylococcus aureus Carriage on the Hands of Healthcare Workers: An Assessment for Hand Hygiene Practices We thank the designated hospital of Wuhan University and the teammates who completed the survey. We thank all medical staff who works on the frontline. We also like to thank teacher Tan and Wuhan University for making this study possible. The datasets supporting the conclusions of this article are available. The research is a designated hospital of Wuhan University and supported by Wuhan University. Due to the severe epidemic situation in Wuhan, the consent we obtained from study participants was verbal. We will upload a written ethics statement after the epidemic is over. This study has no fund support. LR, designed the survey, analyzed data and wrote the manuscript; XyC, designed the survey, collected and analyzed data, and wrote the manuscript; YW, collected data, and wrote the manuscript; WwW, collected data, and wrote the manuscript; LZ, collected and analyzed data, and wrote the manuscript; XdT, edited the manuscript. All authors have read and approved the manuscript in its final form. The authors report no conflicts of interest.