SPRINGFIELD, Ill. – Dr. Eric E. Whitaker, state public health director, today urged parents to ensure their young children are properly immunized against pertussis and asked that anyone exhibiting symptoms of this highly contagious disease to immediately consult a health care provider.

Dr. Whitaker's warning was prompted by an ongoing outbreak of pertussis, commonly known as whooping cough, that has sickened at least 56 people in Rock Island County since July 1, including the recent illness of 12 coaches and members of a local athletic team. Other reports of pertussis illness have been received from Iowa counties located across the Mississippi River from Rock Island.

"Although it generally is not a severe disease for adults, it can be a critical illness and can cause death, particularly among children younger than 1 year of age," Dr. Whitaker said. "In an outbreak such as this, it is important that infants, especially those under 2 months of age who have yet to be immunized, be completely isolated from persons exhibiting symptoms."

The Rock Island outbreak is being investigated by the Rock Island County Health Department with the assistance of the Department's infectious diseases Rapid Response Team. Cases range in age from 2 months to 61; there have been no deaths.

Dr. Whitaker called on health care providers in northwestern Illinois to promptly report suspect cases to their local health departments to assist public health workers to make sure those who are ill receive the appropriate treatment - usually erythromycin - and close contacts of those who are infected are identified and treated with antibiotics to stop the disease from spreading.

Pertussis, which is a bacterial disease, is easily spread from person-to-person through coughing and sneezing and an infected person is contagious from just before the onset of symptoms until up to three weeks after symptoms start.

Symptoms usually appear five to 10 days after exposure, but can take as long as 21 days. The first symptoms to appear are similar to a common cold - runny nose, sneezing, low-grade fever and a mild, occasional cough. The cough gradually becomes severe and, after one to two weeks, the patient has spasmodic bursts of numerous, rapid coughs.

The characteristic high-pitched "whoop" comes from breathing in after a coughing episode. During such an attack, the patient may turn blue, vomit and become exhausted. Between coughing attacks, the patient usually appears normal. Some patients do not have "whooping" and may only experience a persistent cough.

The attacks tend to increase in frequency for a couple weeks, then remain at the same level for two to three weeks, and then gradually decrease. Coughing may last as long as 10 weeks and occasionally longer. Recovery is gradual and coughing episodes can recur with subsequent respiratory infections for months after the onset of pertussis.

The five-dose pertussis vaccine is recommended for every child beginning at 2 months of age. Other doses are given at 4, 6 and 15 months and a final dose at 4 to 6 years of age. The vaccine is given in the same shot with diphtheria and tetanus and is required for school attendance.

The vaccination provides protection when children are most susceptible to serious illness. Immunization, however, begins to wane three years after the last shot and its protection can be fully gone 12 years after the last shot.

Over the past five years, Illinois has averaged about 160 cases of pertussis a year.