Whooping cough cases are on the rise in the suburbs, and public health officials urge residents of all ages to get vaccinated.
Officials in the collar counties have issued pertussis alerts and put information on their websites. In McHenry County the number of cases has set a record, and Lake County has sent out an alert because its numbers have leapt in recent weeks.
Pertussis (whooping cough) symptomsŸ Unfortunately, people are most contagious in the first two weeks, before the symptoms are fully developed. Symptoms can start five to 10 days after exposure or take as long as 21 days.
Ÿ Pertussis/whooping cough acts like a cold in the beginning and can include a mild fever and/or cough.
Ÿ A severe cough develops in a week or two. Some people cough so violently and rapidly that the air is gone from their lungs and they gasp to inhale, making the "whooping" sound that gives the disease its name.
Ÿ The violent coughing fits can go on for 10 weeks or more, especially at night; and can cause vomiting and exhaustion.
Ÿ Teens and adults generally do not "whoop" and have a lesser infection, especially if they have been vaccinated.
Ÿ If an infant isn't whooping, don't assume the best: Infants might not cough at all but could display apnea or a pause in their breathing pattern.
Sources: Kane County Health Department; U.S. Center for Disease Control.
McHenry County's outbreak has raised Kane County's vigilance, and numbers of cases are up in DuPage County, but that is considered a general trend since about a year ago.
While numbers are up in suburban Cook County, they are relatively consistent with previous years, officials say, and are not considered a serious outbreak or expected to set a record this year.
In suburban Cook County, 184 cases have been reported through Nov. 30, up from 142 in 2010, according to the Cook County Health and Hospitals System. The record in Cook County was 298 cases in 2004, which was also the record year for the state of Illinois, with 1,604 reported cases.
A new vaccine on the market in 2004 was less effective, which contributed to the heightened number of cases, said Leslie Piotrowski, spokeswoman for the Lake County Health Department.
"Sometimes increases like this represent reporting or testing phenomenon and sometimes they are actual increases in disease," said Alicia Siston, assistant director for the communicable disease unit in the Cook County department.
The bacteria-caused disease is most dangerous for very young children, but so far no pertussis-related deaths have occurred this year.
Deaths from whooping cough are always rare, according to the Illinois Department of Public Health.
In Illinois, 1,101 cases of whooping cough have been reported through November, compared with 1,057 for all of last year.
In McHenry County the 192 cases reported by Wednesday topped the 191 recorded in 2004, said Debra Quackenbush, spokeswoman for the county health department. She urged people to get vaccinated because pertussis is contagious through the air, and lots of people will be visiting friends and family for the holidays.
Lake County officials are reporting 138 cases, up from 91 about three weeks ago. The record there was 153 in 2004.
"It's a false notion to assume that pertussis is a mild disease limited only to babies, toddlers, and unvaccinated people," said Irene Pierce, executive director of the Lake County Health Department, also urging people of all ages to get the vaccine.
In DuPage County 195 cases have been reported as of a week ago, compared with 92 in 2010. But here, the numbers started to rise almost a year ago and there hasn't been a sudden surge, said Dave Hass, public information officer.
For example, there were 32 cases in October and 11 in November, and they have been located throughout the county, he said.
The spikes in pertussis cases are a mystery. The medical profession can often figure out why incidents of some diseases increase, but they cannot explain increases in pertussis, said Melanie Arnold, spokeswoman for the Illinois Department of Public Health.
Pertussis is treated with antibiotics, and early treatment is important.
But many cases are not reported because the patient does not seek medical treatment, said Siston, who added that the more people go for testing, the more likely numbers are to rise.
Between four and 13 cases have been reported at each of five schools in the Cook County suburbs, said Siston, but officials won't say where.
"We want everyone to take precautions," said Amy Poore, spokeswoman for the department. She said a school community would be notified if there was an outbreak at that school.
One case was reported at Palatine High School, but no other cases have been found in District 211, said Tom Petersen, director of communication.
The biggest worry is for children under the age of 1 year because they have the most chance of complications. The U.S. Center for Disease Control says more than half of those infected in this age group require hospitalization.
Vaccines for infants start at 2 months, and they have four doses by the time they are 15 months old. But in the early periods they are not fully protected, said Siston.
Five years after the booster shot, given between ages 4-6, the immunity starts to wane.
That is why the state codes now require students entering sixth grade to receive boosters, rather than waiting until they enter high school. The state will enforce it next year.
Boosters are available for adults, too, and are especially urged for those who are around young children.