write a brief description of what has happened to the population since 1997 from the west nile virus.

Following the outbreak of 1996 wnv in romania, several subsequent epidemics associate with relatively high rate of central nervous system (cns) infection were observed throughout the middle east and europe, including tunisia in 1997 and large outbreaks in italy and israel in 1998. outbreaks of wnv were occurring more frequently and these outbreaks were associated with high rates of sever cns disease and higher fatality rates most commonly in older individuals. the tunisian outbreak of 1997 involved 173 hospitalized with meningitis or meningoencephalitis. and 8 died. a larger outbreak occurred in russia in 1999 that involved 40 fatalities. the epidemic was associated with high rates of cns involvement . as of january 2003, the provisional human case count from 2002 season was 4156, including 2354 cases of meningoencephalitis and 284 death. the initial suspicion was that of a arthropod-borne virus (arbovirus) encephalitis. early testing was directed at common eastern north american arboviruses.

Ther are many reasons.. is it a multiple choice?