Epidemiology of intussusception among children less than 2 years of age; findings from baseline surveillance before rotavirus vaccine introduction in Myanmar

Background: Rotavirus vaccine was planned to be introduced in the National Immunization Program of Myanmar in 2020. Reported potential association of a small increased risk of intussusception after rotavirus vaccination in some countries is a major safety concern and it is mandatory to collect baseline information before vaccine introduction. Methods: Retrospective study reviewed medical records of intussusception cases for past 3 years (2015-2018) and prospective, active study was conducted from August 2018 to January 2020 at three tertiary children hospitals where pediatric surgical facility is present. Brighton Level 1 Criteria was used for confirmation of intussusception among children <2 years of age admitted to surgical wards. Demographic, clinical, diagnostic and treatment practices data were collected and descriptive data analysis was performed. Results: A total of 697 (421 in retrospective and 276 in prospective) confirmed intussusception cases were identified. Majority of intussusception cases (550/697, 78.9%) were observed in the first year of life and most frequent between 5-7 months of age (292/697, 41.9%) with a peak at 6 months (114/697, 16.4%). The most common clinical presentations were vomiting and bloody diarrhea accounting 82.1% and 77.5% respectively. Regarding diagnosis and treatment, 458/697 (65.7%) required surgical intervention either manual reduction or intestinal resection and 34.4% by either air or barium enema. Overall mortality was 0.7% (5/697) and four out of five children died needed intestinal resection. Late arrival to hospital (>3days after onset) is significantly associated with requirement of surgery (61/85, 71.8%), which in turn is significantly associated with longer hospital stay (296/452, 65.5%) (p < 0.05). Conclusions: Intussusception occurrence is most frequent between 5-7 months age group which is old enough to be vaccinated under the schedule that has now been introduced in Myanmar. More than half of the cases were treated by surgery and late arrival to hospital enhances requirement of surgery and poor outcome. Findings of this baseline surveillance provide important facts for public health officials in balancing risks and benefits of rotavirus vaccine introduction, defining targeted age and dosage scheduling and facilitate monitoring system in post-vaccination.