Ohio’s first human case of West Nile virus (WNV) in 2012 was confirmed Friday by the Ohio Department of Health (ODH), which also reported a sharp increase in the number of WNV-positive mosquitoes. A case of WNV encephalitis was confirmed in an 85- year-old man who is hospitalized in Clermont County.
“This first human case is about a month earlier than what we’ve seen over the last several years,” said ODH Director Ted Wymyslo, M.D. (pictured) “The number of West-Nile positive mosquito pools are up significantly across the state and it’s important that residents of Ohio take note and are diligent in protecting themselves against mosquito bites.”
So far in 2012, 374 mosquito pools have tested positive for WNV. At this time last year, the ODH lab had only recorded 59 WNV-positive mosquito pools. The current year’s early increase in WNV activity is similar to 2002, during which there were 299 positive pools by the end of July. By the end of the 2002 season, there were 441 human WNV cases and 31 fatalities in Ohio.
Culex mosquitoes (the type that transmit WNV) do well in drought-like conditions, preferring to breed in organically rich water sources, such as shrinking water in ditches and catch basins. Recent heat across the region has also sped up the mosquitoes’ life cycle and virus amplification.
To avoid possible infection from mosquito bites:
- If you are outdoors between dusk and dawn when mosquitoes are most active, be sure to wear long pants, a long-sleeved shirt, shoes and socks.
- Light colors are least attractive to mosquitoes.
- Use insect repellent and follow the label directions.
To eliminate mosquito breeding sites near your home:
- Remove all discarded tires and other water-holding containers, such as tin cans and unused flower pots, from your property.
- Eliminate standing water from your property.
- Make sure all roof gutters are clean and properly draining. Clean and chlorinate pools, outdoor saunas and hot tubs. Keep them empty when not in use and drain water from pool covers.
- Change water in bird baths weekly.
WNV can have no symptoms, or can lead to West Nile fever or severe West Nile disease.
- Most people (about 4 out of 5) who are infected with West Nile virus will not develop any type of illness. However, you cannot know ahead of time if you'll get sick once infected.
- The Centers for Disease Control and Prevention (CDC) estimate that about 20 percent of people who become infected with WNV will develop West Nile fever. Symptoms include fever, headache, tiredness, and body aches, occasionally with a skin rash and swollen lymph glands. While the illness can be as short as a few days, even healthy people have reported being sick for several weeks.
CDC estimates that approximately 1 in 150 persons infected with WNV will develop a more severe form of disease such as West Nile encephalitis or meningitis or West Nile poliomyelitis:
- Severe symptoms include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.
- Serious illness can occur in people of any age, however people over age 50 and some immune-compromised persons (for example, transplant patients) are at the highest risk for getting becoming ill when infected with WNV.
Ohio has recorded human cases of WNV each year since 2002. There were 108 in 2003, 12 in 2004, 61 in 2005, 48 in 2006, 23 in 2007, 15 in 2008, 2 in 2009, 5 in 2010 and 21 in 2011. For more information, visit the ODH website at www.odh.ohio.gov or the ODH mosquito information page: http://1.usa.gov/l8HkPt.