West Nile Encephalitis
Encephalitis means in infection of the brain that can be caused by viruses and bacteria.Including viral infections transmitted by mosquitoes. In its natural cycle, the virus is transmitted primarily between pigeons and crows by Culex mosquitoes. Classically West Nile fever virus causes a non-specific febrile illness, and until recently nervous system manifestations were considered a rarity. Viruses that are transmitted from one animal host to the next by insects (arthropods) are known as 'arboviruses'. They have evolved from a variety of backgrounds, belong to different families, and cause a wide spectrum of diseases. Viruses comprise small pieces of genetic material (nucleic acid) whose sole purpose in life is to self-replicate.Because they don't have all the enzymes they need to do this, they have to muscle into 'host' cells, and borrow bits of their machinery. The host develops an immune response to fight off this unwanted invasion, and the rest follows as a consequence of this eternal struggle.
The virus is not transmitted from person to person. There is no evidence that a person can get the virus from handling live or dead infected birds. However it is still recommended that barehanded contact with dead animlas is avoided. The incubation period of a West Nile virus infection is usually 5 - 15 days. Mild infections are common and include fever, headache and body aches, often with skin rash and swollen lymph glands. Encephalitis results when the virus invades the central nervous system destroying the brain substance with accompanying inflammation. The clinical features range from muscle weakness and paralysis; mild confusion and behavioural changes (which may be mistaken for hysteria) Convulsions and deep coma.
Causes of West Nile Encephalitis
Common causes of West Nile Encephalitis
- Mosquitoes.
- Wild migratory birds.
- Prolonged contact.
- West Nile encephalitis virus.
- Mild infection.
Symptoms of West Nile Encephalitis
Common symptoms of West Nile Encephalitis
- Fever.
- Headache.
- Body aches
- Neck stiffness.
- Stupor (sleepiness).
- Nausea.
- Vomiting.
- Disorientation.
- Coma.
- Tremors.
- Occasional convulsions.
- Paralysis.
- Rarely death.
- Skin rash.
- Swollen lymph glands.
- Disorientation.
Treatment of West Nile Encephalitis
Common Treatment of West Nile Encephalitis
- Provide supportive care to minimize the potential for cerebral edema.
- In comatose patients, pay special attention to maintaining a clear airway.
- Replace fluids and electrolytes as they are lost through insensible losses due to fever and decreased or absent intake.
- Minimise the risk of mosquito bites by wearing appropriate clothing, using DEET insect repellent and impregnated bed nets.
- Avoiding areas where stagnant water can be found, mosquito larvae need still water to develop.
- Never put repellant on a child's hands.
- Stay indoors at dawn, dusk, and in the early evening when mosquitoes are most active.
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