CIRCULATION OF HEPATITIS E IN ISRAEL: HIGH PREVALENCE IN PIGS, DROMEDARY CAMELS AND IN SPECIFIC HUMAN POPULATIONS

Rachel Shirazi ¹ Shaul Pozzi ² Ravit Bassal ³ Itay Bar-Or ¹ Dan David ² Marina Wax ¹ Hazzan Rawai ⁴ Efrat Asulin ¹ Yaniv Lustig ¹ Ella Mendelson ^1,5 Ziv Ben-Ari ^5,6 Eli Schwartz ^5,7 Orna Mor ^1,5

¹Central Virology Laboratory, Ministry of Health, Ramat Gan, Israel
²Veterinary services, Ministry of Agriculture and Rural Development Plant Protection and Inspection Services, Beit Dagan, Israel
³Israel Center for Disease Control, Ministry Of Health, Ramat Gan, Israel
⁴Liver unit, Haemek Medical Center, Afula, Israel
⁵Sackler school of Medicine, Tel Aviv University, Ramat Aviv, Israel
⁶Liver disease center, Chaim Sheba Medical Center, Ramat Gan, Israel
⁷Tropical Disease Unit, Chaim Sheba Medical Center, Ramat Gan, Israel

Introduction: Hepatitis E virus (HEV) is an emerging cause for viral hepatitis worldwide. Eight HEV genotypes are currently known of which the non-zoonotic genotype 1 (HEV-G1) and the zoonotic (transmitted mainly by pigs) genotype 3 (HEV- G3) are common in Europe. HEV genotype 7 (HEV-G7) was recently identified in Dromedary camels and in a chronic hepatitis patient.

Objectives: To study HEV in pigs and in Dromedary camels and to compare HEV seroprevalence between pig-workers, Bedouins, Muslim-Arabs and Jews in Israel.

Methods: Pig blood (n=141) and fecal samples (n=39), pig-farms sewage samples (n=8) and blood from pig-farms workers (n=24) were collected between 2016 and 2017. Sera from Dromedary camels (n=86), Bedouins (n=305), Arabs (Muslims, n=320) and Jews (n=195) collected between 2009 and 2016 were also assessed. Anti-HEV IgG was detected by Wantai (China); HEV RNA by RealStar (Altona, Germany). HEV ORF1 was used for phylogenetic analysis.

Results: Overall prevalence of anti-HEV antibodies in pigs and camels was 75.9% (107/141) and 69.8% (60/86) respectively. 21.6% (66/305), 15% (48/320) and only 3.1% (6/195) Bedouins, Muslim-Arabs and Jews were HEV positive (p<0.01). Almost all (96%, 23/24) pig-farms workers were HEV seropositive although none were viremic or reported previous clinical signs. Seropositivity, ubiquitously and significantly was increased with age. HEV RNA was detected in blood (2.1%, 3/141), fecal (22.9%, 18/79) and pigs-sewage (50%, 4/8) samples. Pig and sewage-derived viruses clustered with HEV-G3 sequences previously identified in Israel.

Conclusion: Presence of HEV-G3 and the high HEV seropositivity in pigs and camels and pig workers clearly show that HEV is endemic and is circulating in Israel. The high seroprevalence specifically among Bedouins and Arabs could be attributed to low socioecomonic status. The clinical impact of all these findings on public health should be further explored.