West Nile virus infection. What you need to know about this emerging threat.

The most important aspects to remember about West Nile virus infection are summed up in the following points: West Nile virus is transmitted by bites from infected Culex species mosquitoes. Most infections do not result in serious illness. Encephalitis and serious morbidity and mortality are more likely to occur in elderly persons than in any other age-group. No effective antiviral treatment is available. Avoiding contact with mosquitoes is the key preventive measure.