The number of new West Nile virus (WNV) infections dropped somewhat last week in comparison with the week before, but cases continued to pile up, especially in hard-hit states like Texas.
The number of cases rose 19%, compared to 35% the previous week, when officials from the US Centers for Disease Control and Prevention (CDC) said they saw signs that disease activity might have peaked.
In an update today, the CDC said it has received a total of 3,142 case reports so far, an increase of 506 from the week before. The number of neuroinvasive disease cases climbed to 1,630, which is 225 more than the previous week. Sixteen more WNV deaths were reported, pushing the nation's total so far to 134.
The number of cases reported so far is the highest the CDC has recorded through the third week of September since 2003. However, last week CDC officials said the number of neuroinvasive disease cases—considered the best indicator of the size of the epidemic—was on track to be the highest since 1999, when WNV was first detected in the United States.
Rising numbers of cases in California landed it on the list of states accounting for two thirds of WNV cases in the United States. Other states that are still reporting high case counts are Texas, South Dakota, Mississippi, Oklahoma, Louisiana, and Michigan. Texas, and especially Dallas County, has been the epicenter of WNV activity, reporting nearly 40% of all of the nation's cases, the CDC reported.
As of yesterday, the California Department of Public Health (CDPH) reported 126 WNV infections from 23 counties, along with 6 deaths. Background information on the CDPH's WNV Web page said fewer people have been sickened in California than in hard-hit states such as Texas, but the disease showed up in California earlier than usual this year.
As of yesterday the Texas Department of State Health Services (TDSHS) reported 1,303 WNV infections, an increase of 153 from the week before. It reported 60 more cases of neuroinvasive disease, pushing the season's total to 624, along with 9 more deaths, which increased the toll to 59.