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West Nile Fever

West Nile fever is a mosquito-transmitted, acute, self-limited illness that presents chiefly with fever, malaise, lymphadenopathy, and rash. Virus transmission involves mosquitoes and wild birds, with mammals, including humans, as incidental end-stage hosts. In endemic areas, human infections are extremely common, with over 60% of young adults having antibodies; this suggests a high prevalence of inapparent or undifferentiated febrile illness.

CLINICAL FEATURES.

Following an incubation period of 1 to 6 days, the onset is usually abrupt without prodromal symptoms. The temperature rises quickly to 38.3 to 40°C.

Symptoms include drowsiness, severe frontal headache, ocular pain, myalgia, and pain in the abdomen and back. A small number of patients have dryness of the throat, anorexia, and nausea.

Examination shows facial flushing, conjunctival injection, and coating of the tongue. The predominant finding is generalized lymphadenopathy. Nodes are of moderate size and nontender and usually include the occipital, axillary, and inguinal chains. The spleen and liver.

The temperature curve may be 

Infection also may result in aseptic meningitis or meningoencephalitis.

Treatment is

Ribavirin has activity against West Nile fever virus

The disease is  fatal, its 

Until a bacterial cause is excluded by culture of blood and CSF, parenteral antibiotic therapy should be administered. Treatment.

Acetaminophen is recommended for fever. Codeine, morphine, and the phenothiazine derivatives may be necessary for pain and vomiting, but if possible, their use in children should be minimized because they may induce misleading signs and symptoms. Intravenous fluids are occasionally necessary because of poor oral intake. More severe disease may require hospitalization.

It is important to anticipate and be prepared for convulsions, cerebral edema, hyperpyrexia, inadequate respiratory exchange, disturbed fluid and electrolyte balance, aspiration and asphyxia, and cardiac.

In patients with evidence of increased ICP, placement of a pressure transducer in the epidural space may be indicated for monitoring ICP. The risks of cardiac and respiratory failure or arrest are high with severe disease. All fluids, electrolytes, and medications are initially given parenterally. In prolonged states of coma, parenteral alimentation.

SIADH is quite common in acute CNS disorders; thus, constant evaluation is required for its early detection. Normal blood levels of glucose, magnesium, and calcium must be maintained to minimize the threat.

If cerebral edema or seizures become evident, vigorous treatment should be initiated.