Whooping cough vaccines offered

Bay Area counties are offering free or discounted whooping cough vaccines to adolescents and adults as the bacterial infection spreads throughout California, with more than four times as many cases so far this year as last year.

The state has declared the whooping cough outbreak an epidemic. As of mid-June, there were 910 confirmed cases statewide, compared with 219 cases in the same period last year. Five infants have died this year - none died in 2009. All of those infants contracted the disease from their mothers or other close family members.

In San Francisco, 26 cases have been confirmed this year, compared with 20 cases in all of 2009. Public health officials note that many more people are assumed to be sick with whooping cough, but not diagnosed.

Just last week, a San Francisco mother passed whooping cough to her newborn, although that child is doing fine, said Dr. Susan Fernyak, director of communicable disease control and prevention at the San Francisco Department of Public Health.

To help stem the epidemic, public health experts are encouraging all adults and adolescents to get vaccinated, but especially those who have regular contact with infants. Because the whooping cough vaccine doesn't provide lifetime protection from the disease, even adults and adolescents who received the vaccine when they were younger should get a booster shot now.

Babies younger than 2 months old are vulnerable because they have weak immune systems and they are too young to be vaccinated. Public health officials recommend "cocooning" infants by keeping them surrounded by family and caretakers who are known to be vaccinated.

San Francisco is offering a $30 discount to all adults who want the whooping cough vaccine, which comes with a tetanus booster and is known as the Tdap vaccine. The vaccine costs $35 with the discount.

Many other counties are offering free Tdap vaccines, either by offering coupons or holding vaccine clinics in the community. For more information, residents should check their local public health department.

Whooping cough gets its name from the noise children make when they gasp for breath between violent coughs. Formally known as pertussis, it is a respiratory infection that can be deadly in babies but is usually just an annoying illness in older children and adults.

People who think they may have whooping cough should talk to their doctor about being treated with antibiotics. Whooping cough starts with cold-like symptoms and progresses to a bad cough that can linger for many weeks. People with whooping cough are infectious for three weeks, but treatment with antibiotics can reduce that period to just five days.

E-mail Erin Allday at eallday@sfchronicle.com.

This article appeared on page C - 1 of the San Francisco Chronicle