Trends and Geographic Distribution of Rotavirus Genotypes Among Children Aged Under 5 Years Hospitalized with Acute Gastroenteritis in India, 2019-2023.

Objectives: Rotavirus is a primary cause of severe childhood diarrhea, particularly in low- and middle-income countries, with high mortality rates in Asia and sub-Saharan Africa. Among children aged under 5 y, 22% of rotavirus-related deaths reported globally are from India. Thus, the authors aimed to characterize rotavirus genotypes among children aged under 5 y hospitalized due to acute gastroenteritis in India to track the changes in rotavirus genotypes and the emergence of new variants since the addition of rotavirus vaccines to the Universal Immunization Program.

Methods: This descriptive study was conducted among children aged under 5 y hospitalized due to acute gastroenteritis between 2019 and 2023 in 32 hospitals in seven Indian states. Stool samples were collected, stored, and tested for rotavirus antigens using enzyme-linked immunosorbent assay kits, followed by genotyping of positive samples. The distribution of rotavirus genotypes was analyzed by region and year.

Results: Of the 4,996 stool samples tested, 1,396 (27.9%) tested positive for rotavirus. The major circulating genotypes were G3P[8] (35%), G2P[4] (31.1%), G1P[8] (15.2%), and mixed variants (8.5%). G3P[8] was more prevalent in the southern and western regions, whereas G2P[4] was dominant in the eastern region. The proportion of the mixed genotypes increased during the study period.

Conclusions: The rotavirus genotypes circulating in India vary by time and region. Ongoing surveillance and further research are warranted to understand the emergence of rotavirus genotypes so that rotavirus vaccines can be adapted accordingly to provide enhanced protection against the major circulating genotypes.