# 6565
The CDC’s DVBID (Division of Vector Borne Infectious Diseases) has updated their West Nile Virus numbers, current as of yesterday. And as discussed last week by the CDC, we see a continued rise the number of new cases and deaths.
The peak of West Nile Virus (WNV) activity traditionally occurs in late August, but the 2-3 week incubation period, and the time it takes to get diagnosed and reported - or, in some cases, succumb to the illness – ensures that we’ll see new reported cases for months to come.
Neuroinvasive cases (which present with meningitis, encephalitis, or flaccid Paralysis) are considered the best gauge of an outbreak, as these cases are severe enough that they almost always result in hospitalization and diagnosis.
Non-neuroinvasive West Nile Fever – a much milder disease – is badly under-reported, with only 2%-3% of cases believed identified.
As of last week, the summer of 2012 was on track for becoming the worst WNV season to date, since the virus was introduced into this country in 1999. Today’s numbers reflect a roughly 20% rise over last week (excluding presumptive viremic blood donors), and an additional 16 deaths.
We continue to see the majority of cases reported out of Texas Mississippi, Louisiana, Oklahoma, South Dakota and Michigan and now California. But other areas, including the Mid-Atlantic states, are seeing increasing activity as well.
2012 West Nile virus update: September 18
As of September 18, 2012, 48 states have reported West Nile virus infections in people, birds, or mosquitoes. A total of 3,142 cases of West Nile virus disease in people, including 134 deaths, have been reported to CDC. Of these, 1,630 (52%) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 1,512 (48%) were classified as non-neuroinvasive disease.
The 3,142 cases reported thus far in 2012 is the highest number of West Nile virus disease cases reported to CDC through the third week in September since 2003. Two thirds of the cases have been reported from seven states (Texas, Mississippi, Michigan, South Dakota, Louisiana, Oklahoma, and California) and almost 40 percent of all cases have been reported from Texas.
It should be noted that the latest numbers reported via ArboNet can lag behind the current totals being reported by each state.
Case in point: Texas, which is shown to have 1225 cases and 50 deaths in today’s report, is reporting somewhat higher numbers on their website:
Although the peak period of transmission for WNV may have passed, infected mosquitoes are still out there and are still biting and infecting people.
So we still need to heed the advice of our local health departments to follow the `5 D’s’ of mosquito protection:
And as a final note, the CDC recently updated their information on mosquito repellants.
Updated Information regarding Insect Repellents
Download PDF version formatted for print
(32 KB/3 pages)
Repellents are an important tool to assist people in protecting themselves from mosquito-borne diseases.
