Rotavirus Genotypes in Hospitalized Children with Acute Gastroenteritis before and after Rotavirus Vaccine Introduction in Blantyre, Malawi, 1997-2019

Abstract

Background: Rotavirus vaccine (Rotarix [RV1]) has reduced diarrhea-associated hospitalizations and deaths in Malawi. We examined the trends in circulating rotavirus genotypes in Malawi over a 22-year period to assess the impact of RV1 introduction on strain distribution. Methods: Data on rotavirus-positive stool specimens among children aged <5 years hospitalized with diarrhea in Blantyre, Malawi before (July 1997-October 2012, n = 1765) and after (November 2012-October 2019, n = 934) RV1 introduction were analyzed. Rotavirus G and P genotypes were assigned using reverse-transcription polymerase chain reaction. Results: A rich rotavirus strain diversity circulated throughout the 22-year period; Shannon (H′) and Simpson diversity (D′) indices did not differ between the pre- and postvaccine periods (H′ P