Contra Costa County health officials are warning of that the number of whooping cough cases could set a record this year. They have scheduled free immunization clinics for residents who are patients at county health centers.

So far in 2011, there have been 78 reported cases of whooping cough, which is also called pertussis, in the county. Statewide there have been 733.

In 2010, the county had 205 cases of pertussis.

Three of this year's reported cases in Contra Costa were infants who were hospitalized with the illness, which affects the respiratory system and is treated with antibiotics.

Infants are especially vulnerable to the disease, in part because they are too young to have received the full battery of shots against it. In 2010, 10 California infants died of whooping cough. Health officials now broadly recommend immunization against the disease, but argue it is especially crucial for those who live with infants or care for them. 

A state law now mandates that students in grades 7 through 12 show proof of vaccination for pertussis before they can be admitted to school. The vaccination is called Tdap and includes protection against tetanus and diptheria as well.

Early treatment, in the first two weeks of illness before deep coughing begins, can prevent symptoms from getting worse, according to the Centers for Disease Control and Prevention.

Contra Costa County's health centers are offering vaccinations to its members on Wednesday and Thursday this week and other drop-in clinics will offer immunizations for people with no health insurance.

Go online to the county's health services website for clinic times and locations.