Assessment of Risk Factors for COVID-19 in Health Care Workers: A Nested Case-Control Study

OBJECTIVES

To study the risk factors for SARS-CoV-2 infection in health care workers (HCWs) exposed to COVID-19 patients.

MATERIAL AND METHODS

This was a nested case-control study of health care workers(HCWs) in a Dedicated COVID Hospital(DCH). The data collection was done from Dec 2020 to Feb 2021. The study was part of an international multicenter study by the World Health Organisation (WHO).2 The Doctors, nurses, housekeeping staff, clerks, and other staff working in this DCH were considered as HCWs. HCWs working in this DCH with confirmed COVID-19 were recruited as cases and other HCWs working in this DCH in the same Ward/ICU/office without infection were recruited as controls (incidence density sampling). Three controls were taken per case. The questions were in the Likert scale.

RESULTS

There were 25 cases and their 75 controls. There was no significant difference between cases and controls with respect to age, sex, occupation, education, and comorbidities and all controls were negative for antibodies at the time of the interview. Most (70%) of the HCWs were doctor by profession followed by nurses (19%). All HCWs were trained in IPC (infection Prevention and Control). Most (96%) HCWs reported that PPE (personal protective equipment) is available in sufficient quantity. There was no significant difference between cases and controls with respect to those having direct contact with the patient's materials, surroundings, and following hand hygiene.

CONCLUSION

Adequate availability of PPE, IPC training of HCWs are important for preventing COVID-19 but do not completely reduce risk among HCWs.