Hospital based contact tracing of COVID-19 patients and health care workers during the COVID-19 Pandemic in Eastern India (Preprint)

BACKGROUND Contact tracing and subsequent quarantining of Health Care Workers (HCWs) is essential to minimize further transmission of SARS-CoV2 infection. OBJECTIVE In this study, we have reported the yield of contact tracing of COVID-19 cases and risk stratification of HCWs exposed to them. METHODS This is an analysis of routine data collected for contact tracing of COVID-19 cases from 19th March to 31st August 2020 at All India Institute of Medical Sciences, Bhubaneswar, Odisha, India. COVID-19 cases were either admitted patients, out-patients, or HCWs in the hospital. HCWs who were exposed to COVID-19 cases were categorized as per the risk stratification guidelines into high-risk contacts and low-risk contacts RESULTS During contact tracing, 3411 HCWs were identified as exposed to 360 COVID-19 cases. Out of 360, 269 (74.7%) were either admitted or out-patients and 91(26.1%) were HCWs. After risk stratification 890 (26.1%) were categorized as high-risk contacts and 2521 (73.9%) were categorized as low-risk contacts. The test positivity rate of high-risk contact and low-risk contacts were 3.82% and 1.90%, respectively. The average number of high-risk contacts was significantly higher when the COVID-19 case was an admitted patient (6.6) rather than when the COVID-19 case was an HCW (4.0) or outpatient (0.2), p-value = 0.009. Similarly, the average number of high-risk contacts was higher when the COVID-19 case was admitted in non-COVID-19 area (15.8) as compared to COVID-19 area (0.27), p value < 0.001. There was significant decline in mean number of high-risk contacts over the study period. CONCLUSIONS Contact tracing and risk stratification was effective and helped in reducing the number of HCWs going for quarantine. There was also a decline in high-risk contacts during study period suggesting role of implementation of hospital based COVID-19 related infection control strategies. This contact tracing and risk stratification approach designed in the current study can also be implemented in other healthcare settings.