As reported in a Letter to the Editor in the journal Emerging Infectious Diseases, a veterinary student in South Africa got sickened with West Nile Virus (WNV) last year after doing an autopsy on a 4 month old Welsh pony.
According to the report, the vet student who removed the brain of the pony was sickened with fever, malaise, body aches, stiff neck and a severe headache 6 days after handling the horse brain at autopsy. A rash later appeared and the symptoms lasted for 10 days.
The genetic material from the student and the horse revealed a fatal form of WNV known as lineage 2.
According to the report, the only personal protective equipment the vet student used during the autopsy was latex gloves. However when using bone saws such as the type required to cut open the skull, both tissue particles and potential pathogenic organisms can be aerosolized.
Exposure through the mucous membranes such as the eyes or through inhalation was the likely route of transmission since neither eye protection nor masks were used.
Since no one else involved in the autopsy was sickened or developed antibodies to WNV, it is suspected that the concentration of WNV is higher in nerve tissue.
It has been reported that the vet student had fully recovered and is now a practicing veterinarian.
West Nile virus is a mosquito-borne disease that can cause encephalitis, a brain inflammation. WNV is closely related to St. Louis encephalitis virus (SLEV) which is found in the United States and to Kunjin virus (KV) which is found in Australia, some Western Pacific islands and parts of South East Asia. West Nile virus was first detected in North America in 1999 in New York. Prior to that it had only been found in Africa, Eastern Europe, and West Asia.
According to the Centers for Disease Control and Prevention (CDC), approximately 80 percent of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all.
Up to 20 percent of the people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.
About one in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.
There is no specific treatment for WNV infection.