Detection and genomic characterization of hepatitis E virus genotype 3 from pigs in Ghana, Africa

Philip El-Duah; Dickson Dei; Tabea Binger; Augustina Sylverken; Robert Wollny; William Tasiame; Samuel Oppong; Yaw Adu-Sarkodie; Benjamin Emikpe; Raphael Folitse; Jan Felix Drexler; Richard Phillips; Christian Drosten; Victor Max Corman

doi:10.1186/s42522-020-00018-3

Detection and genomic characterization of hepatitis E virus genotype 3 from pigs in Ghana, Africa

One Health Outlook. 2020 Jul 20:2:10. doi: 10.1186/s42522-020-00018-3. eCollection 2020.

Authors

Philip El-Duah^{1

2}, Dickson Dei^{3

4}, Tabea Binger², Augustina Sylverken^{2

5}, Robert Wollny⁶, William Tasiame^{1

4}, Samuel Oppong⁷, Yaw Adu-Sarkodie⁸, Benjamin Emikpe⁴, Raphael Folitse⁴, Jan Felix Drexler¹, Richard Phillips², Christian Drosten^{1

9}, Victor Max Corman^{1

9}

Affiliations

¹ Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Institute of Virology, Berlin, Germany.
² Kumasi Centre for Collaborative Research in Tropical Medicine, Kumasi, Ghana.
³ Ghana Veterinary Service, Kumasi, Ghana.
⁴ School of Veterinary Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
⁵ Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
⁶ Institute of Virology, University of Bonn Medical Centre, Bonn, Germany.
⁷ Department of Wildlife and Range Management, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
⁸ Department of Clinical Microbiology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
⁹ German Centre for Infection Research, Berlin, Germany.

Abstract

Background: Hepatitis E virus (HEV) is a major cause of human hepatitis worldwide. Zoonotic genotypes of the virus have been found in diverse animal species with pigs playing a major role. Putative risk of zoonotic infection from livestock particularly swine in Sub-Saharan Africa including Ghana is poorly understood due to scarcity of available data, especially HEV sequence information.

Methods: Serum samples were collected from cattle, sheep, goats and pigs from Kumasi in the Ashanti region of Ghana. Samples were subjected to nested RT-PCR screening and quantification of HEV RNA-positive samples using real-time RT-PCR and the World Health Organization International Standard for HEV. Testing of all pig samples for antibodies was done by ELISA. Sanger sequencing and genotyping was performed and one representative complete genome was generated to facilitate genome-wide comparison to other available African HEV sequences by phylogenetic analysis.

Results: A total of 420 samples were available from cattle (n = 105), goats (n = 124), pigs (n = 89) and sheep (n = 102). HEV Viral RNA was detected only in pig samples (10.1%). The antibody detection rate in pigs was 77.5%, with positive samples from all sampling sites. Average viral load was 1 × 10⁵ (range 1.02 × 10³ to 3.17 × 10⁵) International Units per mL of serum with no statistically significant differences between age groups (≤ 6 month, > 6 months) by a T-test comparison of means (t = 1.4272, df = 7, p = 0.1966). Sequences obtained in this study form a monophyletic group within HEV genotype 3. Sequences from Cameroon, Ghana, Burkina Faso and Madagascar were found to share a most recent common ancestor; however this was not the case for other African HEV sequences.

Conclusion: HEV genotype 3 is highly endemic in pigs in Ghana and likely poses a zoonotic risk to people exposed to pigs. HEV genotype 3 in Ghana shares a common origin with other virus strains from Sub-Saharan Africa.

Keywords: Foodborne diseases; Infectious disease reservoirs; Livestock; One health; Viral hepatitis; Zoonoses.