Structure:

Introduction: (up to 30 words) In short, explain Acute Encephalitis syndrome or that Encephalitis is inflammation in the brain.

Body: (up to 100 words) Write about the West Nile Virus, its transmission, the symptoms and treatment.

Conclusion: (up to 30 words) Since there is no vaccine for humans, mention the importance of prevention rather than cure. To ensure no breeding of mosquitos and taking preventive measures against mosquito bites.

Supporting Points:

Acute encephalitis syndrome (AES) is characterized by an acute onset of fever and clinical neurological manifestation that includes mental confusion, disorientation, delirium, or coma. This may be caused by a virus or bacteria.

West Nile virus (WNV):

1. It is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, specifically from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus.
2. West Nile virus is primarily transmitted by mosquitoes, mostly species of the genus Culex, but ticks have also been found to carry the virus, although it is exceptional and they are not likely to play a major role in the transmission of WNV. The primary hosts of WNV are birds, so that the virus remains within a "bird-mosquito-bird" transmission cycle
3. West Nile Virus has been reported in Europe, Africa, Asia, Australia, and North America.
4. Many cases may be reported a year, with most occurring in August and September. It can occur in outbreaks of disease. Severe disease may also occur in horses and a vaccine for these animals is available.
5. A surveillance system in birds is useful for early detection of a potentioal human outbreak.

Symptoms:

1. Symptoms include fever, headache, tiredness, body ache, nausea, vomiting, and occasionally skin rash on the trunk of the body, and swollen lymph glands.
2. Severe infection can lead to West Nile encephalitis or meningitis (inflammation of the brain and surrounding tissues) with symptoms of headache, high fever, neck stiffness, disorientation, tremors, convulsions, muscle weakness, and paralysis, leading the patient into coma. Incubation period of West Nile fever is three to 14 days.
3. According to the World Health Organisation, West Nile virus infection is transmitted to human beings through bites from infected mosquitoes. Mosquitoes become infected when they feed on infected birds. Birds are the natural hosts of the virus, and vaccine is not available for the infection.

Treatment and vaccine:

Treatment is supportive for patients with neuro-invasive West Nile virus, often involving hospitalization, intravenous fluids, respiratory support, and prevention of secondary infections. No vaccine is available for humans.