At least 3,458 cases of whooping cough have been reported in California this year—more than the number reported through all of last year. Facing 800 cases in the past two weeks, the state has now declared an epidemic, the San Jose Mercury News reports. "We urge all pregnant women to get vaccinated," says state public health director Ron Chapman. "We also urge parents to vaccinate infants as soon as possible." Though it doesn't offer lifetime immunity, "vaccination is still the best defense against this potentially fatal disease," he notes.
Adults should generally receive booster shots against the disease, CNN notes; the Mercury News cites a special risk to those who spend time around infants. The bacterial infection, also called pertussis, may begin with coughing and a runny nose in children. After a week or two, coughing may finish with a "whoop" sound. The greatest danger is to infants too young to receive full immunization, officials say. In California, two babies have died, and two-thirds of cases have been in kids four months old or younger. The highly contagious disease has increased 24% nationwide this year compared to the period from January to April 2013, CNN notes.