First Insight into the Seroepidemiology of Hepatitis E Virus (HEV) in Dogs, Cats, Horses, Cattle, Sheep, and Goats from Bulgaria

Abstract

In recent years, hepatitis E virus (HEV) infection has been found to be widespread among different animal species worldwide. In Bulgaria, high HEV seropositivity was found among pigs (60.3%), wild boars (40.8%), and East Balkan swine (82.5%). The aim of the present study was to establish the seroprevalence of HEV among dogs, cats, horses, cattle, sheep, and goats in Bulgaria. In total, 720 serum samples from six animal species were randomly collected: dogs—90 samples; cats—90; horses—180; cattle—180; sheep—90; and goats—90. The serum samples were collected from seven districts of the country: Burgas, Kardzhali, Pazardzhik, Plovdiv, Sliven, Smolyan, and Stara Zagora. The animal serum samples were tested for HEV antibodies using the commercial Wantai HEV-Ab ELISA kit (Beijing, China). The overall HEV seroprevalence among different animal species from Bulgaria was as follows: dogs—21.1%; cats—17.7%; horses—8.3%; cattle—7.7%; sheep—32.2%; and goats—24.4%. We found the lowest overall HEV seropositivity in Plovdiv district (6.2%; 4/64; p = 0.203) and Smolyan district (8.8%; 4/45; p = 0.129), vs. the highest in Pazardzhik district (21.6%; 29/134; p = 0.024) and Burgas district (28.8%; 26/90; p = 0.062). To the best of our knowledge, this is the first serological evidence of HEV infection in dogs, cats, horses, cattle, sheep, and goats from Bulgaria. We found high HEV seropositivity in small ruminants (sheep and goats), moderate seropositivity in pets (dogs and cats), and a low level of seropositivity in large animals (horses and cattle). Previous Bulgarian studies and the results of this research show that HEV infection is widespread among animals in our country. In this regard, the Bulgarian health authorities must carry out increased surveillance and control of HEV infection among animals in Bulgaria.

Detection of anti-HEV antibodies but no molecular positivity in dogs in the Campania region, southern Italy

“…A study performed in the Netherlands found HEV-specific antibodies in 18.52% of pet dogs but viral RNA was not detected in these animals [ 16 ]. Similarly, a seroprevalence of 21.1% was found in Bulgaria [ 17 ]. Even in Germany and Switzerland, where >50% and 38% of the animals showed antibodies against HEV, respectively, the virus was not detectable [ 18 , 19 ].…”

Severe hepatitis E virus genotype 3b in a patient with alcohol‑associated liver disease: A case report

“…The patient in the present study had consumed horse sashimi approximately 1 month prior to the onset of his symptoms, such as abdominal distention, loss of appetite, epigastric pain and dark urine (jaundice). It has been reported that anti-HEV IgG antibody and/or HEV RNA are positive in workhorses or horses in Egypt ( 28 ), China ( 29 ), the Netherlands ( 30 ), Bulgaria ( 31 ) and Germany ( 32 ). However, since whether horses play a role in the transmission of HEV remains unknown, further studies are warranted in this regard.…”

Hepatitis E Virus in Domestic Ruminants and Virus Excretion in Milk—A Potential Source of Zoonotic HEV Infection

“…Seroprevalence in sheep varies from 0% to 24.4%. The highest seroprevalence was observed in Bulgaria (24.4%) [60]; followed by Italy (21.3%) [81] and (21.6%) [82]; Portugal (16.6%) [83]; and Spain (2.1%) [84] and (1.92%) [65]. In the Americas there has been only one study from Brazil, which showed 0% seropositivity [67].…”

“…Worldwide, the HEV seroprevalence in cows varies from 0.0% to 29.35%; in Europe, anti-HEV antibodies (Abs) were proven in only one study from Bulgaria (7.7%) [60], it was excluded in Spain (0.0%) [65]. In the Americas, data vary widely: the USA (20.4%) [66] and Brazil (1.42%) [67].…”

“…Of all the abovementioned animals, pigs, boars, and deer remain the primary zoonotic hosts, with rabbits, rats, and camels implicated on rare occasions. Recently, a growing awareness of the zoonotic potential of HEV in domesticated ruminants has risen, especially concerning the excretion of HEV in milk and the implications of a possible milk-borne transmission [59][60][61][62][63]. However, the information regarding the possibility of milk-borne transmission of the virus is either sparse or contradictory.…”