Prospective surveillance for intussusception in Indian children aged under two years at nineteen tertiary care hospitals

India introduced rotavirus vaccines (RVV, monovalent, Rotavac™ and pentavalent, Rotasiil™) in April 2016 with 6, 10 and 14 weeks schedule and expanded countrywide in phases. We describe the epidemiology of intussusception among children aged 2-23 months in India. The prospective surveillance at 19 nationally representative sentinel hospitals from four regions recruited children with intussusception from April 2016 to September 2017. Data on sociodemography, immunization, clinical, treatment and outcome were collected. Along with descriptive analysis, key parameters between four regions were compared using Chi-Square/Fisher's exact/Mann-Whitney U/Kruskal-Wallis tests. The pre- and post-RVV periods were compared to estimate the risk ratios. Six hundred twenty-one children with intussusception from South (n = 262), East (n = 190), North (n = 136) and West (n = 33) regions were recruited. Majority (n = 465, 74.8%) were infants (40.0% aged 4-7 months) with median age 8 months (IQR 5, 13 months), predominantly males (n = 408, 65.7%) and half (n = 311, 50.0%) occurred during March-June months. A shorter interval between weaning and intussusception was observed for ragi based food (median 1 month, IQR 0-4.2 months) compared to rice (median 4 months, IQR 1-9 months) and wheat (median 3 months, IQR 1-7 months) based food (p