Diagnosis
Diagnosis is mostly made through laboratory testing for IgM antibodies on serum and, where indicated, cerebrospinal fluid (CSF). Antibodies can persist beyond the patient’s period of illness (up to 1 year). Therefore, a positive result may indicate a previous infection. Samples collected within 8 days of the onset of symptoms may appear negative; it is therefore advisable to repeat the laboratory test further down the line before excluding the disease. Alternatively, diagnosis may be obtained through polymerase chain reaction or viral culture testing on samples of serum or CSF.
Prevention
A vaccine for West Nile fever does not exist. Prevention consists, above all, of reducing exposure to mosquito bites.
It is advisable that people protect themselves against bites and avoid places where mosquitoes can reproduce easily. The following are recommended:
- Using repellents and wearing of trousers and long-sleeve tops when out in the open, especially at dawn and sunset.
- Using mosquito nets on windows.
- Frequently emptying vases or other containers (for example, buckets) that contain stagnant water.
- Frequently changing the water in animal drinking bowls.
- Keeping child paddling pools in a vertical position when not in use.
- Using authorized repellents and insecticides where the vector may reproduce, such as in stables. For horses, a vaccine is available for veterinary use, which can further reduce the reservoir of viral circulation.
It is important that physicians inform patients in at-risk areas of the presence of this virus, the possible symptoms, and the preventive measures to adopt.
Therapy and treatment
There is no specific therapy for West Nile fever. In most cases, symptoms appear after a few days, but they can last for a few weeks. For the most severe cases, hospital admission is necessary; occasionally, treatment in the intensive care unit is necessary.
This article was translated from Univadis Italy. A version appeared on Medscape.com.