Unrestricted Social Interaction: Underappreciated Cause of COVID 19 Surge

Abstract India had the worst conditions during the second wave, and yet, its cause for the enormous spike of COVID-19 cases in short time span remains unexplained. We retrospectively studied the comparative secondary attack rate, incidence proportion rate and extent of unrestricted social interactions’ contribution between the first and second wave of COVID-19 to decipher what caused the second wave's enormous spike in COVID-19 cases. We found that the unrestricted social interaction accounted equally, i.e., >42% of all COVID-19 cases in the both waves. Overall secondary attack rate rose 58% in the second wave's, among which, we find increment of 2.5-fold and 88% for the age group <10 years and >50years, respectively, while it remains stable in the age group 10-50years. We find significantly higher incidence proportion rate, ~39%, in household size of two- and three members in the second wave while it was significant in household size of four or more members in the first wave. We anticipated that changes in the pattern of unrestricted social interaction amongst household members escalated the secondary attack rate and higher incidence proportion rate even in two members family size could lead to the unprecedented surge of COVID-19 cases in the second wave.