Two free vaccination clinics will help stem the spread of pertussis — also known as whooping cough — which has spiked dramatically statewide and in San Joaquin County.

The San Joaquin county Public Health Department has seen 47 cases of whooping cough in the county so far this year, an increase from last year’s total of seven cases for the entire year. Statewide, the number of confirmed or suspected cases of whooping cough is nearly 3,000, up from 434 in 2009.

Eight deaths have been attributed to whooping cough throughout the state so far this year — all were infants younger than 3-months-old, and none were in San Joaquin County.

According to county public health’s Dr. Karen Furst, infants are at highest risk of the current rise in whooping cough infection. Infants have no natural immunity, and until their immunization shots at 2, 4 and 6 months of age, they are most susceptible to the disease.

Furst urged anyone in contact with an infant or a pregnant woman, or anyone who is a care provider that comes in contact with young children, to get a vaccine booster shot. The booster vaccine is for people ages 11 and older, about the age at which their vaccinations tend to wane.

The California Public Health Department has contracted to provide free booster vaccinations at two events.

One will be at the Tracy Dry Bean Festival. The other will be part of the Tracy Sutter Community Hospital Health Resource Fair on Sept 25 from 9 a.m. to 1 p.m.

The vaccination for ages 11 and older will be available — in addition to the pertussis booster, it includes a booster shot for tetanus and diphtheria.

Children younger than 11 should have their parents contact their primary care physician or one of the county health clinics, which should have the proper vaccine for that age group. Anyone who has had a tetanus booster recently should check to see if they also received a pertussis vaccination at the same time.

Symptoms of whooping cough are an intense cough followed by a whooping sound as the person tries to catch their breath from the coughs, along with post-cough vomiting from the spasm.

Whooping cough can last for several weeks, and anyone with a cough lasting more than a week or two is urged to see a doctor. Complications from whooping cough can include pneumonia and seizures.