Trend of Anti-SARS-COV-2 Seropositivity in Karachi

Objective: This study aims to determine the trend of seropositivity of anti-SARS-CoV-2 antibodies (total including IgM, Ig G) in patients presenting at a private hospital in Karachi. Materials & Methods: A total of 2500 patients were included in the study. Informed consent was obtained and a questionnaire including patient’s age, gender, symptoms, history of traveling, contact with people who had travelled recently, contact with confirmed/suspected COVID-19 patient at home or work was filled. Samples were analyzed for anti-SARS-CoV-2 antibodies on Roche Cobase601. Results: The mean age of the patients was 41.045±20.48 years. 674(26.96%) were reactive, while 1826(73.04%) were non-reactive. Mostly patients were males 1388(55.52%).The seroprevalence was higher in males 29.75% while females showed 23.47% seroprevalence. Commonest symptoms were found to be fever(88.73%) and dry cough(57.20%).The frequency of seropositive patients revealed an increasing trend with 20.5%and 27.8 % in first andlast 15 days of June respectively, 30.7% and 31.4% in first andlast 15 days of July 2020 respectively.Only221(32.79%) reactive patients reported recent symptoms while 453(67.21%)patients were completely asymptomatic.Odds Ratio(OR) for participants with recent history of travelling, contact with people who had travelled recently,exposure with COVID-19 patients at home or work was 11.50, 3.28, 8.45 and 0.72 respectively. Conclusion: The seropositivity has shown a definite gradual upward trend over the study period and approximately two thirds of the patients being completely asymptomatic pointing towards the fact that many people are silently exposed to the disease and develop antibodies through their natural immune mechanism. Keywords: COVID 19, Anti-SARS-CoV-2 antibodies, Trend, Seropositivity, Dry cough, Diarrhea.