Wednesday, September 12, 2012

CDC West Nile Update: Sept 12th

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Source  DVBID 

 

# 6551

 


For the fourth week in a row, the CDC hosted a teleconference on the ongoing West Nile Virus outbreak across the nation, today featuring Lyle R. Petersen, M.D., M.P.H.  and Roger S. Nasci, PhD of the CDC’s DVBID.

 

While hopeful that we may have reached the peak of this year’s West Nile season (based on historical trends), the CDC says new infections (and deaths) are expected to continue to rise over the next couple of months.

 

The number of neuroinvasive cases reported to date is the highest number ever recorded in the United States through the second week of September.

 

 

As of yesterday, more than 2630 WNV infections have been reported via ArboNet – an increase of roughly 35% over last week’s numbers.  Of those, 1405 involve the more serious neuroinvasive disease.

 

Neuroinvasive cases (which present with meningitis, encephalitis, or flaccid Paralysis) are severe enough that they almost always 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.

 

Since it can take several weeks after a person becomes infected before they are diagnosed and reported to the CDC – and deaths may occur months after infection - the numbers reported as of today are considered `lagging indicators’. 

 

The CDC expects, based on the numbers today, that this will end up being the worst year for the WNV since it arrived in the United States in 1999.

 

Only Hawaii & Alaska have not reported the WNV in either humans, animals, or mosquitoes. The bulk of the cases this year have been seen across just 6 states; Texas  Mississippi, Louisiana, Oklahoma, South Dakota and Michigan.

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Of the 2,636 WNV cases, 1,405 (53%) were reported as neuroinvasive disease cases and 1,231 (47%) were reported as nonneuroinvasive disease cases. Three hundred and eighty five WNV presumptive viremic blood donors (PVDs) have been reported at this time.- Cite DVBID

 

 

With no vaccine, and the virus now endemic across much of the country - health departments are urging people to follow the `5 D’s’ of mosquito protection:

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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.

 

Image: West Nile Virus Map of States with links to their West Nile Virus pages

 

The CDC is investigating why this year’s outbreak has been so severe, and hopes to release a report with their findings before next year’s WNV season.

 

A transcript, and audio recording of today’s conference will be posted later today on the CDC NEWSROOM webpage.

 

UPDATE:  Transcript & Audio are now posted.

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