[West Nile virus infection during pregnancy--a rare or an underreported disease?].

West Nile virus infection has been known since 1937, yet only in 2002 primary reports about its prevalence among pregnant women appeared in the Western medical Literature. The questions of maternal-fetal transfer of the infecting virus through the placenta or via breastfeeding in the neonate are currently unresolved. There is no specific treatment against the infection during pregnancy and currently only supportive therapy is available. Recommendations regarding prevention, as well as fetal or neonatal follow-up for an offspring of an infected mother exist, but their validity is questionable. Experience with the natural expression of this infection during pregnancy is still being gathered. In Israel, no cases of West Nile virus infection during pregnancy have been reported. Considering that this infection is endemic in Israel and based on reported cases from the U.S.A., this disease merits attention.