Group A rotaviruses circulating prior to a national immunization programme in Nigeria: Clinical manifestations, high G12P[8] frequency, intra-genotypic divergence of VP4 and VP7.

Nigeria having approximately 50 000 Rotavirus A (RVA) deaths annually is yet to introduce RVA vaccine into routine national immunization; therefore surveillance of RVA strains circulating before vaccine introduction is essential in evaluating impact of the intervention. Stool samples and sociodemographic data of diarrhoeic children, <5 years were collected between August 2012 and December 2013. While a high prevalence of RVA infection (47.6%; 49/103) was observed by quantitative reverse transcription real time PCR, only 25% (26/103) had high RVA genome concentrations and were antigen positive. G and P types were obtained for 31 and 37 samples respectively. G12P[8] strains were predominant (30.6%; 16/31); Other genotypes found included G9, G3, G2 and P[4], P[6], P[8]. A G12 + G2/P[8] + P[6] mixed infection was detected. The P[8] genotype showed divergence with strains distributed in lineage III and IV. Compared to the vaccines, changes in antigenic sites of VP8* and VP7 were found. The finding of the G2P[6] genotype combination and emergence of G12 strains support observations in most of the recent RVA studies from Africa. P[6] is common in many African countries, in contrast to countries in Europe and the Americas. In conclusion, this study shows the circulation of other RVA genotypes compared to the common RVA genotypes in Nigeria. PCR results should be interpreted with caution to avoid significant bias from samples with low RVA genome concentrations. These findings provide important information on the detection and molecular epidemiology of RVA prior to vaccination and contribute as a baseline for future evaluations after possible vaccine introduction.

Incidence of dengue virus infections in febrile episodes in Ile-Ife, Nigeria

Background: Dengue viruses have been identified as the most important arboviral pathogen in the world. They are transmitted by mosquitoes of Aedes species. While dengue infection is accompanied by little or no subclinical signs in many; about 1-2% may produce clinically severe Dengue Haemorrhagic Fever/Dengue Shock Syndrome. Early recognition; appropriate treatment and elimination of mosquito vectors will help control it. The study is aimed at determining the incidence of dengue infections in Ile-Ife. Materials and Methods: Three millilitres venous blood was collected from each of one hundred and seventy nine patients presenting with fever in the last two weeks; and analyzed for the presence of anti-dengue IgM antibodies using Dengue Virus IgM ELISA kit (DIA.PRO; Italy) according to the manufacturer's instructions while the results and demographic data were analyzed using SPSS version 16. Results: It was observed that 46 (25.7%) of the 179 had detectable IgM antibodies to dengue virus with 9 of them having no detectable malaria parasite. The incidence was 26.5% and 25% in male and female respectively. Further studies will be necessary to confirm the relatedness of blood transfusion as an important risk factor to the transmission of dengue virus.Conclusion: The study established the presence of fresh dengue infections for the first time in Ile-Ife among different groups of people. Clinicians are advised to prioritize laboratory diagnosis; especially of fever