Murray Valley encephalitis virus

Murray Valley encephalitis virus (MVEV) is a rare but potentially severe disease caused by a flavivirus that is native to Australia and Papua New Guinea. The virus is named after the Murray River, where it was first identified. MVEV is a member of the Japanese encephalitis virus serocomplex and is closely related to Kunjin virus, another flavivirus endemic to Australia.

Transmission

MVEV is primarily transmitted to humans through the bite of an infected mosquito. The primary vector is the mosquito species Culex annulirostris, but other species can also transmit the virus. The virus is maintained in a cycle involving water birds and mosquitoes, with humans and other mammals considered incidental hosts.

Clinical Features

Infection with MVEV can result in a range of clinical manifestations, from asymptomatic infection to severe encephalitis. Symptoms typically begin with fever, headache, and malaise, followed by neurological symptoms such as confusion, drowsiness, and seizures. Severe cases can result in death or long-term neurological complications.

Diagnosis

Diagnosis of MVEV is typically based on clinical symptoms and confirmed by laboratory testing. Tests include polymerase chain reaction (PCR) to detect viral RNA, and serology to detect antibodies against the virus.

Prevention and Control

There is currently no specific treatment or vaccine for MVEV. Prevention strategies focus on reducing exposure to mosquitoes, such as using insect repellent, wearing long-sleeved clothing, and avoiding outdoor activities during peak mosquito activity times.

Epidemiology

MVEV is endemic in northern Australia and Papua New Guinea, with sporadic outbreaks occurring in other parts of Australia. The incidence of MVEV is closely related to environmental conditions, particularly rainfall and flooding, which can increase mosquito populations.

See Also

• Arbovirus
• Japanese encephalitis
• West Nile virus