Diversity of rotavirus strains circulating in Maiduguri, Borno State, Northeast, Nigeria

Abstract

This study aimed at investigating the circulating Rotavirus strains in Maiduguri, Borno State, Northeastern Nigeria. A total of 404 stool samples were collected from children with clinical presentation of diarrhea. All samples were screened using Enzyme Linked Immunosorbent Assay (ELISA) kit produced by Diagnostic Automation/Cortez Diagnostics, USA, REF 8306-3), for the presence of Rotavirus antigen. The Rotavirus positive samples were further analyzed by Polyacrylamide Gel Electrophoresis (PAGE), to determine their RNA electropherotypes, Reverse Transcriptase Polymerase chain reaction (RT-PCR) to determine their VP7 (G) and VP4 (P) Genotypes and nucleotide sequencing. A total of 154 stool samples (38.1%) were Rotavirus positive with peaks observed in cold dry season, among male children and 0-5 years age group. A total of 88 selected Rotavirus positive samples were subjected to Polyacrylamide Gel Electrophoresis (PAGE), with only 25 (28.4%) were positive, given 16 (57.1%) with long pro?les and 12 (42.9%) with short profiles. Among the 25 Rotavirus positive samples subjected to RT-PCR and PCR genotyping, all the samples (100%) were positive for RT-PCR. The samples exhibited mixed G and Ptypes. The most commonly detected VP7 type was G2 (36%), followed by G12 (27%), G1 (18%), G9 (12%) and G3 (7%). The most commonly detected VP7 type was G2 (36%), followed by G12 (27%), G1 (18%), G9 (12%) and G3 (7%). For VP4 type detected, the most common types were P8 (36%) and P4 (32%) followed by P6 (32%). The P/G combinations circulating in Borno State are G12P[8] (29%), G2P[4] (29%), G2P[6], G1P[6][8], G1P[6], G3P[6] , G9P[6] and G2,3P[6][8] gave 7%. The sequence of the VP4 gene of Maiduguri, Borno State P[4], P[6] and P[8] strains were compared with other published VP4 gene sequences. Strains from Maiduguri sequenced were similar (97-99%) to others in Ghana, Cameroun, Mali, Ethiopia and United State of America strains. A safe and effective rotavirus vaccine is urgently needed in Nigeria, particularly in Borno State.

Keywords: Diversity, Rotavirus, Maiduguri, children