Molecular and serological evidence of hepatitis E virus genotype 3 circulation in pigs in Senegal

In Senegal, data on the epidemiology of hepatitis E virus (HEV) are limited, despite the emergence of a human epidemic in 2014. The objective of this study is to assess the prevalence, molecular characteristics, and seroprevalence of HEV in pigs in Senegal.

Blood samples were collected from pigs immediately after slaughter between September 2018 and December 2019. HEV RNA was detected using real-time reverse transcription polymerase chain reaction, and positive samples were subjected to Sanger sequencing targeting a fragment of approximately 300 bp of the ORF2 gene for molecular characterization. An enzyme immunoassay was performed to assess the seropositivity for anti-HEV antibody.

Among the 1600 serum samples tested, HEV RNA was detected in 69 serum samples (4.3%). Of these, 13 were successfully sequenced, and phylogenetic analysis showed that all strains belonged to genotype 3. Among 1161 selected RT-qPCR-negative serum tested, 76.6% were positive for anti-HEV antibodies.

Pigs have been identified as an important reservoir of HEV genotype 3 in Senegal, highlighting the need for integrated "One Health" surveillance to better understand viral circulation and assess the potential risk of zoonotic transmission.