Metagenomic Detection and Genetic Characterization of Human Sapoviruses among Children with Acute Flaccid Paralysis in Nigeria.

Using a metagenomic sequencing approach on stool samples from children with Acute Flaccid Paralysis (AFP), we describe the genetic diversity of Sapoviruses (SaVs) in children in Nigeria. We identified six complete genome sequences and two partial genome sequences. Several SaV genogroups and genotypes were detected, including GII (GII.4 and GII.8), GIV (GIV.1), and GI (GI.2 and GI.7). To our knowledge, this is the first description of SaV infections and complete genomes from Nigeria. Pairwise identity and phylogenetic analysis showed that the Nigerian SaVs were related to previously documented gastroenteritis outbreaks with associated strains from China and Japan. Minor variations in the functional motifs of the nonstructural proteins NS3 and NS5 were seen in the Nigerian strains. To adequately understand the effect of such amino acid changes, a better understanding of the biological function of these proteins is vital. The identification of distinct SaVs reinforces the need for robust surveillance in acute gastroenteritis (AGE) and non-AGE cohorts to better understand SaVs genotype diversity, evolution, and its role in disease burden in Nigeria. Future studies in different populations are, therefore, recommended.

Serologic evidence of silent Rift Valley fever virus infection among occupationally exposed persons in northern Nigeria.

INTRODUCTION: Rift Valley fever (RVF) is a zoonotic disease caused by RVF virus (RVFV) and transmitted primarily by mosquitoes and contact with fluids and tissues of infected animals. First described in Kenya, it has spread to many African countries and beyond. In humans, it is sometimes misdiagnosed because the symptoms resemble those of influenza and/or malaria. Butchers, abattoir workers, and livestock keepers have the highest risk of infection. METHODOLOGY: In this study, serum samples collected between February and September 2019 from 196 individuals comprising of butchers (n = 121), abattoir/slaughterhouse workers (n = 55), and livestock keepers (n = 20) in Benue, Sokoto, and Borno States of northern Nigeria were screened using a commercial ELISA that detected anti-RVFV IgM and IgG alike (i.e., without discrimination). Data from administered questionnaires and the ELISA results were statistically analyzed. RESULTS: Thirty-nine (19.9%) of the 196 samples were positive for RVFV antibodies. The distribution by states showed that 17.4% (8/46), 21.7% (15/69), and 19.8% (16/81) of samples from Benue, Sokoto, and Borno States were seropositive, respectively. Additionally, 21.5% (26/121) butchers, 16.4% (9/55) abattoir workers, and 20% (4/20) livestock keepers were seropositive. CONCLUSIONS: These findings provide serological evidence for exposure of occupationally at-risk individuals in northern Nigeria to RVFV. The higher seropositivity obtained in Sokoto and Borno states could be due to contact of these individuals with infected animal blood/tissues, aborted fetuses, and unhindered transboundary movement of animals and animal products into these states which share international borders with Niger, Chad, and Cameroon where evidences of RVFV infections were recently reported.