The Frequency and Risk Factors for COVID-19 Infection among Healthcare Workers in a Large-Scale University Teaching Hospital: A Case Control Study

Objective: This study aims to find out the frequency and risk factors responsible for COVID-19 infection among healthcare workers in a large-scale university teaching hospital. Methods: This case-control study was conducted on 185 healthcare workers sampled from the database of 1309 participants maintained at Dr. Ruth K. M. Pfau Civil Hospital, Karachi. Both the cases and controls were derived from the hospital’s database of COVID-19 Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and COVID-19 antibody tests performed on the said population. The participants included were physicians working in the hospital. They were grouped into cases and controls based on the positive diagnostic tests. We administered a simple structured questionnaire over the telephone and face to face for the interview. Statistical analyses were performed on IBM SPSS version 25. Results: The mean age of cases was significantly different than controls [cases (32.7±9.9) vs controls (38.8±10.6), p-value=0.002]. More cases 29/37 (78.3%) were working at a single setting compared to controls 54/148 (36.5%) (P-value <0.001). The use of Personal Protective Equipment (PPE), exposure to COVID-19 patients and experiencing symptoms also had statistical significance with the odds of infection (p-value <0.05). Conclusion: This study concludes that younger age, exposure to a known COVID-19 patient and longer duration of exposure among the hospital physicians is associated with positive COVID-19 results. Therefore, it is imperative that adequate measures be undertaken to limit the exposure to COVID-19 patients in this age group.