August 15, 1995
COOK AND WILL COUNTY RESIDENTS URGED TO TAKE PRECAUTIONS AGAINST MOSQUITO-BORNE DISEASE
SPRINGFIELD, IL -- Dr. John R. Lumpkin, director of the Illinois Department of Public Health, today advised residents of southern Cook County and northern Will County to take immediate precautions to prevent and control a possible outbreak of a mosquito-borne disease.
Eleven possible cases of St. Louis encephalitis, a disease transmitted to humans by the bite of the Culex mosquito, have been reported in the two counties since last Wednesday. The persons affected range in age from 2 to 48 years of age.
Blood tests completed by the Department's laboratory have given preliminary indications of St. Louis encephalitis, while additional tests are being conducted by the U.S. Centers for Disease Control and Prevention (CDC).
"The reports of these possible cases indicate a need for increased awareness, surveillance and control activities," Dr. Lumpkin said. "The most effective way to curb the threat of St. Louis encephalitis is to eliminate mosquito breeding sites in our own yards."
The Culex mosquito, also known as the house mosquito, breeds in containers, such as buckets, tin cans and bird baths, that hold small pools of stagnant water, and in drainage ditches and low spots in the ground that hold water. The mosquitoes lay their eggs on small puddles of standing water and do not fly very far from where they are hatched.
St. Louis encephalitis is a serious disease that affects the central nervous system and can cause permanent neurological damage or be fatal.
Symptoms of St. Louis encephalitis, which is most common among older adults, usually begin five to15 days following the bite of an infected mosquito and range from a slight fever or headache to rapid onset of severe headache, high fever, muscle aches, stiffness in the back of the neck and disorientation.
"If two or more of these symptoms exist, contact a physician immediately and inform the doctor of any recent mosquito bites," Dr. Lumpkin said.
The Culex mosquito can easily go unnoticed because it is a small insect and gentle biter. The mosquitoes normally feed on birds during the first half of the summer, at which time they can pick up the virus from infected birds. The mosquitoes then can transmit the virus to other birds, which in turn, infect other mosquitoes.
In mid to late summer, the mosquitoes change their feeding habits from birds to other animals and humans. The Culex mosquito bites from dusk to dawn.
Besides the possible cases in Cook and Will counties, only one confirmed case of St. Louis encephalitis has been reported in Illinois this year -- a 51-year-old man from Williamson County in southern Illinois.
There have been only sporadic cases of St. Louis encephalitis in the state since 1975 when a major outbreak of the disease caused illness to 578 persons and another 700 suspect cases. Forty-seven persons died from the disease that year.
Dr. Lumpkin encouraged householders and others to --
The Department conducts an early warning surveillance program beginning each spring that monitors birds and mosquitoes for evidence of St. Louis encephalitis. Birds and mosquitoes are trapped and their blood tested in about 50 counties, including Cook and Will. So far, around the state more than 2,000 birds and hundreds of pools of mosquitoes have been tested, but all have been negative for St. Louis encephalitis.
As a result of the possible St. Louis encephalitis cases, the Department will increase surveillance activities in Cook and Will counties by collecting additional bird and mosquito samples. In addition, hospitals and doctors will be alerted to be on the lookout for symptoms of St. Louis encephalitis.
of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
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