Lassa virus (LASV) is endemic in parts of West Africa where it causes Lassa fever (LF), a viral hemorrhagic fever with frequent fatal outcomes. The diverse LASV strains are grouped into six major lineages based on the geographical location of the isolated strains. In this study, we have focused on the lineage II strains from southern Nigeria. We determined the viral sequences from positive cases of LF reported at tertiary hospitals in Ebonyi and Enugu between 2012 and 2016. Reverse transcription-polymerase chain reaction (RT-PCR) showed that 29 out of 123 suspected cases were positive for the virus among which 11 viral gene sequences were determined. Phylogenetic analysis of the complete coding sequences of the four viral proteins revealed that lineage II strains are broadly divided into two genetic clades that diverged from a common ancestor 195 years ago. One clade, consisting of strains from Ebonyi and Enugu, was more conserved than the other from Irrua, although the four viral proteins were evolving at similar rates in both clades. These results suggested that the viruses of these clades have been distinctively evolving in geographically separate parts of southern Nigeria. Furthermore, the epidemiological data of the 2014 outbreak highlighted the role of human-to-human transmission in this outbreak, which was supported by phylogenetic analysis showing that 13 of the 16 sequences clustered together. These results provide new insights into the evolution of LASV in southern Nigeria and have important implications for vaccine development, diagnostic assay design, and LF outbreak management.

Rotavirus gastroenteritis is a major public health concern globally, estimated to cause 215,000 deaths among children < 5 years of age in 2013; with majority of mortality occurring in developing countries. In 2013, it was estimated that Nigeria was the second country with the highest number of rotavirus deaths. Monitoring of circulating rotavirus strains in Enugu, Nigeria is part of ongoing rotavirus surveillance before the introduction of rotavirus vaccination. A total of 2694 stool samples were collected from enrolled under 5 years old children with diarrhoea between January 2011 and December 2016 and tested the virus using an antigen enzyme immunoassay. Randomly selected rotavirus positive samples were further characterized by rotavirus genotype methods to identify the G and P types circulating during the study period. Rotavirus was detected in 1242 (46%) of the 2694 samples collected over the six years period. Of these, 867 were randomly selected for genotyping. G and P types could be assigned for 832 samples (96%), while 31 (3.6%) could only #

Globally, diarrhoea is the second commonest infectious cause of death in children less than 5 years old. It is estimated that more than one billion diarrhoea episodes occur every year causing up to 700,000 deaths among children younger than 5 years of age. Seventy-two percent of these deaths occur in children below two years and enteric viruses have been recognized as a major cause of childhood diarrhoea. This study was undertaken to determine the prevalence of enteric Adenoviruses and Rotaviruses in children with diarrhoea in rural Enugu communities of Enugu State South East Nigeria. Methods: Stool samples were collected from children less than 5 years with diarrhoea seen in any of the participating hospitals in Enugu State. Samples were collected between June 2015 and May 2017. Detection of rotavirus and enteric adenovirus antigens were performed using commercially available ELISA kit (Oxoid-ProspecT®). Demographic data of the children were also collected. Results: Of the 290 stool samples that had sufficient materials for adenovirus and rotavirus ELISA, 14 (4.8%) and 89 (30.7%) were positive for enteric adenovirus and rotavirus respectively. 3 (1%) were co-infected with adenovirus and rotavirus. Rotavirus positive cases were more among hospitalized patients while enteric adenovirus was more among outpatients. Marked peaks of rotavirus positivity were seen in January of each year but no peak was seen among adenovirus positive cases. Higher vomiting frequencies and severe dehydration were more among rotavirus positive cases compared to adenovirus positive cases (p = 0.030 and 0.001 respectively). Conclusion: Many diarrhoea cases among children aged <5 in the population studied were associated with enteric adenoviruses and rotavirus. This finding suggests that en

Lassa virus (LASV) causes Lassa fever (LF), a viral hemorrhagic fever endemic in West Africa. LASV strains are clustered into six lineages according to their geographic location. To confirm a diagnosis of LF, a laboratory test is required. Here, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay using a portable device for the detection of LASV in southeast and south-central Nigeria using three primer sets specific for strains clustered in lineage II was developed. The assay detected in vitro transcribed LASV RNAs within 23 min and was further evaluated for detection in 73 plasma collected from suspected LF patients admitted into two health settings in southern Nigeria. The clinical evaluation using the conventional RT-PCR as the reference test revealed a sensitivity of 50% in general with 100% for samples with a viral titer of 9500 genome equivalent copies (geq)/mL and higher. The detection limit was estimated to be 4214 geq/mL. The assay showed 98% specificity with no cross-reactivity to other viruses which cause similar symptoms. These results suggest that this RT-LAMP assay is a useful molecular diagnostic test for LF during the acute phase, contributing to early patient management, while using a convenient device for field deployment and in resource-poor settings.

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