# 8801
The West Nile Virus season is really only just getting started, but so far in 2014 the CDC has been notified of human infections in six states: Arizona, California, Mississippi, Missouri, South Dakota, and Tennessee.
WNV infections in mosquitoes, birds, sentinel animals, or veterinary animals have been reported to CDC’s ArboNET from sixteen additional states: Alabama, Colorado, Florida, Idaho, Illinois, Indiana, Louisiana, Michigan, Nebraska, New Jersey, New York, Pennsylvania, Tennessee, Texas, Utah, Wisconsin, and Wyoming.
Unlike Chikungunya – which primarily affects humans and non-human primates – WNV is primarily a disease of birds. Humans and horses are considered `incidental’ infections (see WNV vs CHIKV: A Host Of Differences).
The least severe form of the disease – West Nile Fever - probably infects more than 100,000 Americans every year, although most are so mildly affected they have no idea the are infected.
Neuroinvasive cases (which present with meningitis, encephalitis, or flaccid Paralysis), while less common, are severe enough that they nearly always result in hospitalization and diagnosis, and so they are considered the best indicator of the scope of each year’s epidemic.
The number of cases varies widely each, with a record of nearly 3,000 cases of neuroinvasive WNV, and 286 deaths reported in 2012. Last year saw more than a 50% reduction, down to 1247 neuroinvasive cases and 119 deaths.
So far, in 2014 just 6 neuroinvasive cases have been reported, but case reporting tend to lag behind actual events by a week or two, so it is too soon to know what kind of WNV season we will see this year.
West Nile isn’t the only arbovirus we keep track of. Last year – excluding Dengue – the United States also recorded (see West Nile Virus and Other Arboviral Diseases — United States, 2013):
- 2,469 cases of WNV disease
- 85 cases of La Crosse virus (LACV)
- 22 cases of Jamestown Canyon virus (JCV
- 15 cases of Powassan virus (POWV)
- 8 cases of eastern equine encephalitis virus (EEEV)
To this mix we can add a smattering of locally acquired Dengue in Florida and Texas, with the added threat that this year (or next) Chikungunya will likely make its way into the local mosquito population as well (see Study: Chikungunya’s Growing Threat To The Americas).
.
While the odds of contracting a serious illness from mosquito bites in the United States remains very low – they are increasing with the addition of new arboviral threats – so if you visit or live in mosquito territory – it is worth remembering Florida Department of Health’s, (FDOH) recommendation that individuals protect themselves by following the “5 D’s”.
