Serological evidence from one study suggests that a large number of horses in Brazil are exposed to hepatitis E virus (HEV).
Serology results suggested previous exposure to the virus due to the presence of antibodies to the virus, but no viral DNA was detected in the horses in the study.
Caroline Roberta Soares Salgado and her research colleagues write in the journal microorganismsaid HEV infection has been confirmed in a variety of animal species.
They say hybrid cars have become a global public health concern due to their potential to cross the species barrier and infect humans.
Of the eight genotypes (HEV-1 to HEV-8) identified to date, HEV-1 and HEV-2 are transmitted by the oral-fecal route, infect only humans, and are often associated with outbreaks of waterborne acute hepatitis in developing countries . nation.
HEV-3, HEV-4 and HEV-7 are zoonotic diseases, meaning they can be transmitted between animals and humans. They are spread primarily through the consumption of raw or undercooked animal products.
HEV-3 is associated with hepatitis cases in high-income and developing countries. Other potential zoonotic reservoirs have been reported, such as horses, cattle, goats, sheep, dogs, rodents, rabbits, and camelids. HEV-5 and HEV-6 have been described in Japanese wild boars. HEV-7 was described in dromedary camels from the Middle East, and its zoonotic transmission was confirmed in an immunocompromised transplant patient. HEV-8 has been described in farmed camels from China.
In Brazil, HEV-3 is the only genotype found in humans and pigs throughout the country. This phenomenon has also been found in group-breeding cynomolgus monkeys and, more recently, in cattle and capybara rodents.
“The epidemiology of HEV in Brazil is thought to be similar to that in high-income countries, with HEV-3 circulating as asymptomatic (mainly asymptomatic) infections in pigs and humans,” the researchers said.
The expansion of host range and the recent increase in human infections associated with zoonotic HEV-3 in some countries (e.g., EU and Brazil) highlight that other susceptible animals may contribute to HEV transmission, including through consumption of Raw animals or their undercooked meat, direct contact or occupational means. “
Overseas studies have shown that horses are susceptible to HEV infection since 2007, and the contribution of horses as a natural host has been assessed in recent years, they said.
Their role in zoonotic transmission cannot be ruled out, as contact with horses in Denmark is significantly associated with a higher risk of exposure to HEV, and anti-HEV antibody and RNA detection rates ranged from 11% to 16.3% and from 0% to 4%. It has been reported in horses in Africa, Asia and Europe.
Brazil has one of the largest horse populations in the world, with approximately six million animals used for work, sport, breeding, pets and meat production.
Given the lack of information on HEV transmission in horses in that country, the research team sought to investigate the exposure of Brazilian horses to HEV infection.
The study subjects included 257 horses from three Brazilian states: Bahia, Goiás and Rio de Janeiro. A total of 132 were raised for slaughter and 125 for sport/breeding purposes.
Serum samples were grouped according to the breeding purpose of the horses.
Researchers from multiple institutions in Brazil tested the samples for viral antibodies as well as viral RNA.
The overall seroprevalence of antiviral antibodies was 26.5% (68 of 257 samples). No HEV RNA was detected. Most horses in cities (53.3%) and farms (58.8%) tested positive.
Animals slaughtered for human consumption have a higher risk of exposure to HEV (45.5%) than animals raised for sport or breeding (6.4%).
Studies have found that men are approximately 1.9 times more likely to be exposed to HEV than women.
Of the positive animals, 45.6% (31 of 68 horses) were raised in contact with other animals such as pigs and cattle.
“In Brazil, co-grazing of horses with other animals is practiced across the country, which benefits the ecosystem and improves vegetation and animal health (e.g. reducing parasitism).
“In this study, a large proportion of the animals investigated were housed with mules, donkeys, cattle, pigs and/or other animals (45.6%), further supporting the possible impact of the housing environment on HEV exposure.”
The authors say their findings are the first serological evidence of HEV circulation in Brazilian horses and reinforce the need for a One Health approach to monitor HEV reservoir expansion.
“Although no viral genome was detected, a significant proportion of horses destined for human consumption have been exposed to the virus, challenging researchers and authorities to further investigate the potential of horses as HEV hosts and the possible routes of HEV transmission. to humans and other animals.
“Further studies are needed to evaluate other potential risk factors and confirm the prevalence of HEV infection in Brazilian horses.”
The research team includes Salgado, Aldaleia do Nascimento e Silva, Igor Falco Arruda, Patricia Riddell Millar, Maria Regina Reis Amendoeira, Luciane Almeida Amado Leon, Raffaella Bertoni Cavalcanti Teixeira, Jorge Tiburcio Barbosa de Lima, Flávia Löwen Levy Chalhoub, Ana Maria Bispo de Filippis , Ana Beatriz Monteiro Fonseca, Jaqueline Mendes de Oliveira, Marcelo Alves Pinto and Andreza Soriano Figueiredo.
Salgado, CRS; Silva, Adene; Arruda, IF; Miller, PR; Armendoela, MRR; Leon, LA; Teixeira, RBC; De Lima, JTB; Chalhoub, FLL; Bishop of Philippi, AM; et al. Serological evidence of hepatitis E virus infection in Brazilian horses. Microbiology 2023, 11, 2743. https://doi.org/10.3390/microorganisms11112743
The research was published in Creative Commons LicenseCan read here.
• Get notified when new articles are published: