Comparison of SARS-COV-2 Infection Between Sero Positive and Sero Negative Healthcare Workers After Six Months in a Tertiary Care Hospital

Abstract

Objective: To compare the frequency of SARS- CoV-2 infection between Sero-positive and Sero-negative healthcare workersafter 6 months in a tertiary care hospital. Study Design: Prospective Cohort study. Place and Duration of Study: Combined Military Hospital, Kohat Pakistan, from Aug 2020 to Jan 2021. Methodology: Two Hundred and eighty-eight healthcare workers were included by non-probability consecutive sampling. They were divided into two groups according to SARS-CoV-2 IgG-Ab status at baseline as sero-positive and sero-negative. They were followed for six months period and symptomatic healthcare workers were tested for SARS- CoV-2 infection by RT PCR. Individuals from all departments were included and used standard personal protective equipment. Results: Out of 288 Healthcare workers 240(83.33%) were male and 48(16.67%) were female. At baseline, 42(14.58%) individuals were sero-positive and 246(85.42%) were sero-negative for SARS-CoV-2 Ab. During 6 months of follow up 28(11.38%) symptomatic sero-negative Health Care Workers were tested positive for COVID-19 infection by RT PCR. None of the sero-positive Health Care Workers was tested positive for SARS-CoV-2 infection. Risk of infection was higher in sero-negative group (Odds ratio 1.19 with 95% CI; 1.13- 1.26). Conclusion: SARS-CoV-2Ab may offer immunity againstCOVID-19 infection as no infection was observed in sero-positive individuals as compared to 11.2% in sero-negative individuals.

Keywords

• COVID-19, Healthcare workers, SARS-CoV-2 Ab, Sero-negative, Sero-positive.