Epidemiology of Intussusception Hospitalizations in Children Under 2 Years of Age Post Rotavirus Vaccine Introduction in Tamil Nadu and Puducherry, India.

Objective: High burden of rotavirus associated diarrhea has been documented among Indian children. The phased introduction of an indigenous rotavirus vaccine 'ROTAVAC' in India's national immunization programme began in 2017. Phase-III trial showed the vaccine to have a low-intussusception-risk profile. However, evaluation of post-licensure trends of intussusception is necessary to assess potential vaccine-associated intussusception risk. This study's objective was to describe the epidemiology of intussusception hospitalizations in children under two years of age in Tamil Nadu and Puducherry following ROTAVAC introduction.

Methods: A cross-sectional surveillance was established in six hospitals in Tamil Nadu and Puducherry. Children under two years of age with intussusception fulfilling Brighton Collaboration's criteria for level 1 diagnostic certainty were enrolled. Patient and disease characteristics were captured using a standardized questionnaire. Descriptive and inferential statistical analyses were performed using Stata Version 13.

Results: Overall, 287 cases were enrolled and had a median age of seven months. Frequently presenting symptoms were vomiting (78%), abdominal pain (76%), and blood in stool (71%). Abdominal ultrasonography or radiography confirmed diagnosis in 65% of cases and managed by nonoperative measures. Remaining 35% of cases were diagnosed and managed with surgery. Over 98% of the cases had positive treatment outcomes. Age less than five months (OR = 4.36), and hospitalization at a state government health facility (OR = 5.01) were significant predictors for children to receive surgical management.

Conclusions: The present study documents the epidemiology of intussusceptions immediately after the rollout of rotavirus vaccine in Tamil Nadu and Puducherry. No appreciable increase in intussusception hospitalizations was seen in the study hospitals after vaccine introduction.