Molecular surveillance of rotavirus infection in Bangui, Central African Republic, October 2011-September 2013

Abstract

Background: The World Health Organization (WHO) recommends the introduction of rotavirus vaccine in the immunization program of all countries. In the Central African Republic (CAR), sentinel surveillance for rotavirus gastroenteritis was established in 2011 by the Ministry of Health, with the support of the Surveillance en Afrique Centrale Project (SURVAC). The purpose of this study was to assess the burden of rotavirus gastroenteritis and to identify rotavirus strains circulating in CAR before the introduction of rotavirus vaccine planned for this year, 2014.

Methods: One sentinel site and one laboratory at the national level were designated by the CAR Ministry of Health to participate in this surveillance system. Stool samples were collected from children who met the WHO rotavirus gastroenteritis case definition (WHO, 2006). The samples were first screened for group A rotavirus antigen by enzyme immunoassay (EIA), and genotyping assays performed using a multiplex reverse transcriptase PCR (RT-PCR) technique.

Results: Between October 2011 and September 2013, 438 stool samples were collected and analyzed for detection of rotavirus antigen; 206 (47%) were positive. Among the 160 (78%) that could be genotyped, G2P[6] was the predominant strain (47%) followed by G1P[8] (25%) and G2P[4] (13%).

Conclusions: Almost half of stool samples obtained from children hospitalized with gastroenteritis were positive for rotavirus. These baseline rotavirus surveillance data will be useful to health authorities considering rotavirus vaccine introduction and for evaluating the efficacy of rotavirus vaccine once it is introduced into the routine immunization system.

Keywords: Central African Republic; Gastroenteritis; Pediatrics; Rotavirus; Surveillance.

Fig. 1.

Seasonality of rotavirus diarrhea CAR, from October 2011–September 2013. Number of rotavirus-positives (shaded dark bars), rotavirus-negatives (shaded gray bars) and percentage of rotavirus-positives (dotted line) are indicated. *Enrollment during these months declined as a result of staffing issues at the sentinel site.

Fig. 2.

Distribution of diarrhea cases by age group of children less than 5 years of age admitted with gastroenteritis to the Complex Pediatrique hospital in Central African Republic, October 2011 to September 2013. Number of rotavirus-positives (shaded dark bars), rotavirus negatives (shaded gray bars) and Cumulative RoV positivity rate (dotted line). RoV = rotavirus.