First case of West Nile fever in Texas in 2008

The first case of West Nile Fever in 2008 has been reported in Texas, Montgomery County, according to ProMedMail and the Houston Chronicle. The report states that although West Nile season typically starts in the summer, with mid-August through
mid-September being peak months because they're the hottest and driest months, it is not unusual to see cases as early as March and as late as December. However, one wonders how many cases of asymptomatic or mild West Nile infections must have been already gone unreported in the same area, given that 80% of infected people do not have any symptoms, and whether this early start signals an increased West Nile activity for Texas this year. Last year, Texas reported 170 neuroinvasive and 90 fever cases, and 17 deaths, according to state health records. The Centers for Disease Control and Prevention map of West Nile virus activity (as of 6 May 2008;  http://www.cdc.gov/ncidod/dvbid/westnile/Mapsactivity/surv&control08Maps.htm) as well as ArboNet shows that 2 human cases have been reported in Mississippi, one in Arizona, and one in Tennessee.