Tuesday, August 09, 2016

West Nile Activity - August 2nd


With the Zika virus capturing most of the media's attention this summer it is easy to forget that there are other mosquito-borne threats in North America to consider, particularly West Nile Virus.

The good news with WNV is the vast majority who are infected - about 80% - experience at worst only mild, or sub-clinical symptoms. Most of the rest may experience a brief febrile illness (West Nile Fever).  Both are likely highly underreported.

But a very small percentage of those infected develop WNV neuroinvasive disease (WNND), a form of encephalitis that can sometimes prove fatal.

Those over the age of 50 appear to be the most vulnerable to the most serious form of the illness, and as most of those are hospitalized, those numbers are the most reliable.

Some summers West Nile activity is admittedly much worse than others, with 2012 seeing more than 5600 cases of WNV disease reported to the CDC, including 286 deaths. 

Last year was far less active, with 2175 cases, and 147 deaths, reported across the country. 

The CDC, in their first West Nile Virus update of 2016, report:

As of August 2, 2016, a total of 36 states have reported West Nile virus infections in people, birds, or mosquitoes in 2016. Overall, 89 cases of West Nile virus disease in people have been reported to CDC. Of these, 36 (40%) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 53 (60%) were classified as non-neuroinvasive disease.

Although no deaths are reported in this first update, it can take several weeks for someone diagnosed to be reported to the CDC – and deaths may occur months after infection.

Regardless of whether it is Zika, WNV, or one of the rarer arboviral threats (SLEV, EEE, Dengue or CHKV) - if you are likely to be exposed to mosquitoes - you'll want to follow the 5 D's of mosquito protection.