First Human West Nile Virus Cases in Illinois For 2011 Reported
The Illinois Department of Public
Health (IDPH) has confirmed the first human West Nile
virus cases reported in Illinois for 2011. The Cook
County Health Department reported a man in his 80s
became ill earlier this month and the
Franklin-Williamson Bi-County Health Department
reported a man in his 30s became ill in July.
“West Nile virus activity in mosquitoes and birds
continues to increase across Illinois, which means a
higher risk of people contracting the virus,” said
Illinois Department of Public Health Director Dr.
Damon T. Arnold. “People should protect themselves
against mosquitoes by wearing insect repellent and
getting rid of any standing water around their
So far this year, 13 counties have reported mosquito
batches, birds or a person testing positive for West
Nile virus; Champaign, Cook, DuPage, Franklin,
Gallatin, Jackson, Kane, Kendall, LaSalle, Macon, St.
Clair, Tazewell and Will counties. The first West
Nile virus positive results this year were collected
on June 8 and included two birds from LaSalle County.
In 2010, the first positive mosquito samples were
collected on June 3 in Gallatin County. Last year,
30 of the state’s 102 counties were found to have a
West Nile positive bird, mosquito, horse or human
case. A total of 61 human cases of West Nile disease
were reported in Illinois last year, the first
reported on August 31.
West Nile virus is transmitted through the bite of a
mosquito that has picked up the virus by feeding on
an infected bird. Most people with the virus have no
clinical symptoms of illness, but some may become ill
three to 15 days after the bite of an infected
Only about two people in 10 who are bitten by an
infected mosquito will experience any illness.
Illness from West Nile is usually mild and includes
fever, headache and body aches, but serious illness,
such as encephalitis and meningitis, and death are
Persons older than 50 years of age have the highest
risk of severe disease.
The best way to prevent West Nile disease or any
other mosquito-borne illness is to reduce the number
of mosquitoes around your home and to take personal
precautions to avoid mosquito bites. Precautions
• Avoid being outdoors when mosquitoes are most
active, especially between dusk and dawn.
• When outdoors, wear shoes and socks, long pants and
a long-sleeved shirt, and apply insect repellent that
contains DEET, picaridin, oil of lemon eucalyptus or
IR 3535, according to label instructions. Consult a
physician before using repellents on infants.
• Make sure doors and windows have tight-fitting
screens. Repair or replace screens that have tears
or other openings. Try to keep doors and windows
shut, especially at night.
• Eliminate all sources of standing water that can
support mosquito breeding, including water in bird
baths, ponds, flowerpots, wading pools, old tires and
any other receptacles. In communities where there
are organized mosquito control programs, contact your
municipal government to report areas of stagnant
water in roadside ditches, flooded yards and similar
locations that may produce mosquitoes.
Public health officials believe that a hot summer
increases mosquito activity and the risk of disease
from West Nile virus.
Additional information about West Nile virus can be
found on the Illinois Department of Public Health’s
Web site at www.idph.state.il.us/envhealth/wnv.htm.