Nipah virus encephalitis
Overview
Nipah virus encephalitis: Inflammation of the brain caused by the Nipah virus which can infect pigs and humans so transmission usually occurs through contact with pigs.
Symptoms
The list of signs and symptoms mentioned in various sources for Nipah virus encephalitis includes the 19 symptoms listed below: * Neuronal dysfunction * Microinfarction * Ischemia * Thrombosis * Vasculitis * Damage to small blood vessel walls * Fever * Headache * Dizziness * Reduced consciousness * Prominent brainstem dysfunction * Myoclonus * Areflexia * Hypotonia * Hypertension * Tachycardia * Brain lesions * Mental confusion * Respiratory illness
Causes
WNV is transmitted to humans by the bite of a mosquito (primarily the Culex species) infected with the virus. It's considered the primary vector for WNV and the source of the August 1999 outbreak in New York, New Jersey and Connecticut. Mosquitoes become infected by feeding on birds contaminated with the West Nile virus and then transmitting it to humans and animals during a blood meal or “bite.” (See Transmission routes of West Nile virus, page 256.) Ticks have been found infected with WNV in Africa and Asia only. The role of ticks in the transmission and maintenance of the virus remains uncertain, and to date they aren't considered vectors for WNV in the United States. The Centers for Disease Control and Prevention has reported that there is no evidence that a person can contract the virus from handling live or dead infected birds. However, avoid barehanded contact when handling dead animals, including birds, and use gloves or double plastic bags to dispose of a carcass. Report the finding to the local health department.
Prevention
These diseases can be prevented by avoiding animals that are known to be infected and using appropriate personal protective equipment devices when it is necessary to come into contact with potentially infected animals.
Diagnosis
Laboratory tests that are used to diagnose Hendra virus (HV) and Nipah virus (NV) include detection of antibody by ELISA (IgG and IgM), real time polymerase chain reaction (RT-PCR), and virus isolation attempts. Laboratory diagnosis of a patient with a clinical history of HV or NV can be made during the acute and convalescent phase of the disease by using a combination of tests including detection of antibody in the serum or the cerebrospinal fluid (CSF), viral RNA detection (RT-PCR) in the serum, CSF, or throat swabs, and virus isolation from the CSF or throat swabs.
Treatment
There is no specific therapy utilized to treat West Nile encephalitis and no known cure. Treatment is generally aimed at controlling the specific symptoms. Supportive care, such as I.V. fluids, fever control, and respiratory support, is rendered when necessary. There is no vaccine present to prevent the transmission of West Nile encephalitis. Research trials are underway to determine if ribavirin, an antiviral drug, may be helpful.