Ohio's first two clinical human cases of West Nile virus in 2011 were confirmed Tuesday by the Ohio Department of Health, which also reported a sharp increase in the number of WNV-positive mosquitoes.
A case of WNV meningitis was confirmed in a 19-year-old Cleveland-area woman who was hospitalized in Cuyahoga County. A 14-year-old boy in Putnam County was confirmed with WNV fever, but was not hospitalized. Both are recovering.
Meanwhile, the number of WNV-positive mosquito pools in the State of Ohio increased from 52 to 450 during the month of August. Because humans most often get WNV from the bite of an infected mosquito, ODH reminds Ohioans to take steps to help prevent infection.
"We see human cases of West Nile virus each year in Ohio," said ODH Director Ted Wymyslo, M.D. "You can protect yourself and your loved ones from West Nile by taking simple preventive steps such as using insect repellent and eliminating containers that can collect water from your property."
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 or not when 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 immunocompromised persons (for example, transplant patients) are at the highest risk for getting severely ill when infected with WNV.
Ohio has recorded human cases of WNV each year since 2002 when there were 441 cases. There were 108 in 2003, 12 in 2004, 61 in 2005, 48 in 2006, 23 in 2007, 15 in 2008, 2 in 2009 and 5 in 2010.
Ohio has also confirmed eight cases of La Crosse encephalitis virus (LACV) in 2011. This is a mosquito-borne virus, similar to WNV, which affects mostly children and teenagers and is transmitted by the treehole mosquito, Aedes triseriatus. Many people infected with LACV have no apparent symptoms. Among people who become ill, initial symptoms include fever, headache, nausea, vomiting, and tiredness. Some of those who become ill develop a disease that affects the nervous system. Severe LACV disease often involves encephalitis (an inflammation of the brain) and can include seizures, coma, and paralysis. Severe disease occurs most often in children under the age of 16.