Molecular Study of Rotavirus A Infection in Children with diarrhea, before and after Vaccine Introduction in Brazzaville and Pointe-Noire, Republic of the Congo

Author(s): Léadisaelle Hosanna LENGUIYA, Fabien Roch NIAMA, PEMBE ISSAMOU MAYENGUE, Leblanc GAMPOUO GANDZA, Cynthia NKOUA BADZI, Igor Judicael LOUZOLO, Nadia Claricelle LOUKABOU MBONGOLO, Grâce Petula Urielle FILA-FILA, Sagesse Raïssa Ginelle LOKO, Louis Régis DOSSOU-YOVO, Félix KOUKOUIKILA-KOSSOUNDA

Introduction: Acute gastroenteritis due to Rotavirus A infection is common in both developing and developed countries and is responsible for approximately 215,000 annual deaths especially in developing countries. This study aimed to determine the prevalence of rotavirus and the molecular distribution of stains in congolese children under five years old in Brazzaville and Pointe-Noire before and after the Rotarix vaccine introduction.

Method: From February to September 2013 and from August 2017 to February 2018, stool samples were collected from children under 5 years of age suffering from gastroenteritis in Congolese hospitals before and after vaccine introduction. Rotavirus was detected using the ELISA and the VP7 and VP4 genes were genotyped by multiplex RT-PCR.

Results: Of 154 stool samples analyzed, 84 male and 70 female children were included, ranging in age from 4 days to 59 months. A total of 45.4% (n=49) tested positive before vaccination versus 10.86% (n=5) after vaccination (P<0.0002). Also, a change in genomic profile was observed between the two periods with G1P[8] (77.5%), G9P[8] (2%), G1G2P[6]P[8] (6%) and G1G9P[8] (2%) genotypes before vaccination and G1P[8] (40%), G1P[4]P[6] (20%), G8P[8] (20%) and G12P[8] (20%) genotypes after vaccination.

Conclusion: Although based on a limited number of samples, these results improve our knowledge of rotavirus A circulation in the Republic of Congo, particularly the positive impact of vaccination. In addition, the emergence of recombinant strains after vaccination may suggest a possible change in the molecular profile and therefore requires increased surveillance of these strains and their potential escape from vaccination.