West Nile Virus Infection in the Immunocompromised Patient.
West Nile virus infection has become the predominant cause of flavivirus-associated encephalitis in the US. While 80 % of infected individuals are asymptomatic, 20 % develop symptoms including fever, headache, transient rash and gastrointestinal symptoms. Among the immunocompetent population, 1 in 150 develop neuroinvasive disease characterized by acute flaccid paralysis, Parkinsonian cogwheel rigidity, meningitis, encephalitis, meningoencephalitis and asymmetric muscle weakness (Mostashari et al. in Lancet 358:261-264, 2001). In the immunocompromised population such as transplant recipients and HIV-infected and chemotherapy patients, the incidence of neuroinvasive disease may be increased. The largest population studied is recipients of solid organ transplants, with data on both donor-derived and naturally occurring transmissions. The risk of neuroinvasive disease in donor-derived infection is estimated to be between 50 % and 75 % while in those with mosquito-borne transmission the risk is estimated at 40 % of those infected (Kumar et al. in Am J Transplant 4:1883-1888, 2004). With significant morbidity associated with donor transmission, specific pretransplant screening recommendations are reviewed. Treatment includes supportive care and consideration for the use of intravenous immunoglobulin.
Transplant Infectious Diseases, University of Colorado Denver, Denver, CO, USA, Marilyn.Levi@ucdenver.edu.
Marilyn E
ME
Levi