West Nile virus is a disease which is transmitted due to mosquito bites. The virus belongs to flavivirus family. Way back in 1937, the disease was first detected in Uganda. The virus is usually found in African continent and in Middle Eastern countries. In United States, the virus was first time isolated from an outbreak in 1999 in the state of New York, since then it has spread all over America.
According to researchers, the spread of West Nile virus takes place when mosquitoes bite an infected bird and then bite humans.Culex mosquitoes are generally responsible for the spread of this viral disease.
People who are infected with West Nile virus may experience symptoms that may range from mild to severe. Fever, body ache, headache are few milder symptoms. West Nile virus may affect the central nervous system and this condition is serious and life threatening.
Generally in milder variety, the disease heals on its own. But in cases where central nervous system is involved, immediate medical attention is of prime importance.
What Causes West Nile Virus Infection?
- As said earlier, a person becomes infected with West Nile virus when an infected mosquito bites him. The mosquito gets infected when it bites an infected bird. In this way the spread occurs from birds to mosquito and then in humans. The disease does not spread by touch of an infected person.
- Most of the time the incidence of West Nile virus is high in warm climate; this is the time when mosquito population is at its peak. Culex mosquito gets infected with this virus.
- Generally the time taken for appearance of symptoms after mosquito bite is between 3 to 14 days. This is called incubation period by medical people.
- West Nile virus can also spread through transfusion of infected blood. Rarely the disease can spread from an infected mother to the child who is breast feeding.
- Risk factors include the time of the year when the climate is favorable for mosquitoes to multiply. Old people, people with low immunity and pregnant women are vulnerable to West Nile virus.
Symptoms Of West Nile Virus
Most people who suffer from West Nile virus infection remain asymptomatic, meaning they do not present with any symptoms. Few people may experience the symptoms in milder form which include;
- Body ache.
- Skin rash on tongue.
- Lymph node swelling.
- Sore throat.
- Nausea and vomiting.
Many people refer it as West Nile fever. The symptoms may remain for 2 to 6 days. Rarely few symptoms may prolong for several weeks even if the person is otherwise healthy.
When the disease is severe, the virus affects brain and central nervous system resulting in giving rise to inflammation of brain called encephalitis and meningitis. However this is less common. Symptoms include;
- High fever.
- Severe headache.
- Neck stiffness.
- Muscle jerks and weakness.
- Lack of coordination.
The long time effects after severe West Nile encephalitis include loss of memory, depression, confusion, irritability etc. Difficulty in walking, tiredness, and sleep difficulty are other symptoms that may prevail for some time.
West Nile Virus Infection Treatment
Blood tests and cerebrospinal fluid test helps to confirm the diagnosis of West Nile virus disease. There is no specific treatment for West Nile virus disease.
Most people who suffer from West Nile virus do not require any treatment. Recovery is uneventful in most cases. Symptomatic treatment may be required occasionally to reduce fever and body ache. The doctor may prescribe antipyretic and pain killers on such occasions.
In case if the symptoms are severe, the patient may need hospitalization for supportive care and monitoring. Intravenous fluids and other medicines may be required in the hospital. Since it is a viral disease there is no role of antibiotics in this condition. However, at times doctors may prescribe to prevent impending secondary bacterial infection, especially in old and in those whose immune system is weak.