# 6523
For the second week in a row the CDC, in conjunction with the Texas Department of State Health Services, today presented an extended teleconference on this year’s record setting West Nile Virus epidemic.
While the totals are constantly changing, the DVBID has updated the nation’s numbers as reported to ArboNet as of yesterday. Of concern, the number of neuroinvasive cases is the highest that’s ever been reported through the end of August.
Forty-three states are reporting human infections, and only Hawaii and Alaska have not reported detecting the virus in humans, birds, or mosquitoes.
So far in 2012 there have been 1590 human infections reported, 889 of which were of the more severe, neuroinvasive type. In addition, 66 deaths have been reported.
Texas, which has been particularly hard hit this year, has reported 31 deaths, and 416 neuroinvasive cases.
Neuroinvasive cases (which present with meningitis, encephalitis, or flaccid Paralysis) are severe enough that they result in hospitalization and diagnosis, and so they are considered a better indicator of the scope of each year’s epidemic.
Mild cases – called West Nile Fever – often go undiagnosed, with probably only 2%-3% being identified.
In terms of impact, based on incidence per 100,000 population, 6 states - Texas, Oklahoma, South Dakota, Louisiana and Mississippi – have been hardest hit.
Given the incubation period of 10-14 days, and delays in diagnosis and reporting, human case counts are considered lagging indicators. Even though transmission generally peaks in mid to late August, it may be late September or early October before we start to see a noticeable decline in numbers.
For reasons that are complex, and not completely understood, the rate of transmission of the WNV virus to humans varies widely from place to place, and from one year to the next.
Last year was a relatively quiescent year for the West Nile virus, with just 712 cases reported, along with 43 deaths. In comparison, in 2003 more than 4,150 cases were reported, with 284 fatalities.
While some have expressed concerns over the heavy rains associated with hurricane Isaac, the CDC is not expecting them to greatly exacerbate the transmission of the virus.
A transcript, and an audio recording of today’s 50 minute teleconference should be available later today at http://www.cdc.gov/media/index.html
The bottom line is that the West Nile Virus is now endemic across most of the United States, and while the absolute risk of infection in many places may be low, the prudent move is to take the recommended precautions against mosquito bites.
And finally, to find out about the West Nile threat in your area, you can visit the DVBID website below:
Links to State and Local Government West Nile Virus Web Sites
Click on a state to link directly to their West Nile virus Web page.
See list below for additional city-level and main State Health Department Web sites.
