hev

HeV is the abbreviation commonly used for Hendra virus, a highly pathogenic member of the genus Henipavirus in the family Paramyxoviridae. It was first identified in 1994 after an outbreak in the Brisbane area in Queensland, Australia, in horses that led to several human infections and deaths. HeV is considered a zoonotic virus with bats as the natural reservoir.

Natural reservoir and transmission pathways are central to its ecology. Flying foxes (fruit bats of the genus Pteropus) shed the virus in urine, saliva, or birth fluids. Horses are typically the intermediary hosts and become infected through exposure to contaminated materials or secretions. Humans acquire infection mainly through close contact with infected horses or their bodily fluids; there is no sustained human-to-human transmission documented in routine settings. Transmission risk can be mitigated by minimizing exposure to infected horses and by managing bat–horse interfaces.

Clinical features vary by species. In horses, initial signs include fever, depression, nasal discharge, and respiratory distress. In humans, infection can cause rapidly progressing pneumonitis and, in some cases, encephalitis; case fatality rates have been high in past outbreaks. Diagnosis relies on molecular testing (RT-PCR) and serology on clinical samples. There is no approved human vaccine or specific antiviral treatment; management is supportive. Ribavirin has been used in some cases, but evidence for effectiveness is limited.

Prevention and control focus on reducing spillover risk. An approved equine vaccine (Equivac HeV) introduced in the early 2010s has significantly lowered the risk of horse-to-human transmission. Biosecurity measures include minimizing contact with bat excreta, securing horse feed and water sources, and implementing appropriate personal protective equipment during suspected cases. HeV is geographically tied to Australia, with sporadic outbreaks reported primarily in Queensland and New South Wales.