Molecular study of Rotavirus A infection in children with diarrhea, before and after vaccine introduction in Brazzaville and Pointe-Noire, Republic of Congo

Abstract

Abstract Background: 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. In 2014, the Republic of Congo joined the immunization program recommended by WHO and introduced Rotarix (GlaxoSmithKline Biologicals, Belgium) into its national immunization schedule. However, information on the genetic diversity of Rotavirus strains in Congo is derived from a single pre-vaccination study conducted in the southern Brazzaville area. To determine RVA prevalence and genotype distribution in Brazzaville and Pointe-Noire before and after the Rotarix vaccine introduction. Methods: 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. RVA was detected using the ELISA and the VP7 and VP4 genes were genotyped by multiplex RT-PCR. All data analyses were performed using the R software, version 3.4. Results: Of 154 stool samples analyzed, 45.4% were positive from 108 samples before vaccination introduction and the genotypes G1P [8] (77.5%), G9P [8] (2%), G1G2P [6] P [8] 6%) and G1G9P [8] (2%) were detected. In the post-vaccination period, cases of Rotavirus gastroenteritis were 16% and 4.7% in Brazzaville and Pointe-Noire, respectively representing 52.17% of 46 samples. The genotypes G1P [8] (40%), G1P [4] P [6] (20%), G8P [8] (20%) and G12P [8] (20%) were detected. Conclusions: RVA is the most common cause of acute gastroenteritis in children under five years of age. In the Republic of Congo, we found a considerable genetic diversity of Rotavirus strains and a decrease in cases of gastroenteritis five years after vaccine introduction. Some cases of vaccinated patients who have developed Rotavirus diarrhea have been reported. As a result, it is still important to continue monitoring Rotavirus strains and evaluate the impact of Rotavirus vaccine in Congo.