Molecular detection of hepatitis E virus among swine and poultry birds in Lagos, Nigeria

1,2Salu, O. B., 3,4Mutiu, B. P., 1Etok, M. J., 2Orenolu, M. R., 2Anyanwu, R. A., 2Abdullah, M. A., 3,5Saka, B. A., 3,6Abdus-Salam, I. A., 7Macaulay, R. M., 2,8Oyedeji, K. S., and *1,2,9Omilabu, S. A.

1Department of Medical Microbiology and Parasitology, College of Medicine University of Lagos (CMUL), P.M.B. 12003, Lagos, Nigeria

2Centre for Human and Zoonotic Virology (CHAZVY), Central Research Laboratory, College of Medicine, University of Lagos (CMUL)/Lagos University Teaching Hospital (LUTH), Lagos, Nigeria

3Lagos State Bio-bank Laboratory, Mainland Hospital, Yaba, Lagos, Nigeria

4Department of Medical Microbiology and Parasitology, Lagos State University College of Medicine (LASUCOM), Ikeja, Lagos, Nigeria

5Centre for Biomedical Research Initiatives (CBRI), Nigeria

6Lagos State Ministry of Health (LSMOH), Alausa Ikeja, Lagos, Nigeria

7Lagos State Ministry of Agriculture (LSMOA), Alausa Ikeja, Lagos, Nigeria

8Department of Medical Laboratory Science, College of Medicine University of Lagos (CMUL), P.M.B. 12003, Lagos, Nigeria

9Department of Microbiology, Nigerian Institute of Medical Research, P.M.B. 2013, Yaba, Lagos, Nigeria

*Correspondence to: somilabu@unilag.edu.ng; Tel: +2348023119431

Abstract:
Background: Hepatitis E virus (HEV), the only hepatitis virus that replicates in humans and a wide range of animal hosts, is a significant public health enteric virus with a growing trend of infection globally. The public and environmental implications associated with HEV as a zoonotic transmitted virus remain to be fully elucidated. Thus, with the limited information on HEV in other species other than humans in Nigeria, this study aimed to detect by molecular methods HEV among some livestock in Lagos, Nigeria.

Methodology: A cross-sectional study of 172 (42.0%) poultry birds aged between 5 and 18 months, and 238 (58.0%) swine aged between 2 and 18 months purposively selected from Ojo, Ikorodu and Agege Local Government Areas (LGAs) of Lagos State, Nigeria between November 2017 and July 2019 was conducted. A total of 410 non-repetitive stool samples collected were analysed by molecular technique for the detection of HEV RNA. Descriptive statistics were computed for all relevant data. The association between gender and age with HEV RNA positivity was tested using Chi-square. All significant associations were recorded at p≤0.05.

Results: On the overall, 15 (3.7%) of the 410 stool samples were positive for HEV RNA with 5 (2.9%) and 10 (4.2%) of the 172 and 238 poultry birds and swine respectively. More female livestock (6.0%) had detectable HEV RNA than their male counterparts (1.0%) and the infection clustered majorly among age groups 1-6 months, and 7-12 months with a detection rate of 9.3%, 3.2% and 5.6%, 3.2% for both the swine and poultry birds respectively. Approximately 11.1% of the swine and 5.0% of the poultry birds’ samples from Ikorodu LGA were positive for HEV RNA. Only 3.0% of the swine samples from Ojo LGA had detected HEV RNA. No sample from Agege LGA had detectable HEV RNA.

Conclusion: The detection of HEV in both the swine and poultry birds in Lagos, Nigeria further confirms the endemicity of HEV and a cause for public health concern regarding the epidemiology of HEV in Nigeria. There is an urgent need for active and continuous surveillance to further detect and subtype the circulating HEV among livestock to prevent the advent of virulent strains that may be transmitted to handlers and the community at large.

Keywords: Hepatitis E Virus, Swine, Poultry birds, Zoonotic Transmission, Polymerase Chain Reaction

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Molecular detection of hepatitis E virus among swine and poultry birds in Lagos, Nigeria