The number of new cases of whooping cough in California continued on a two-month downward trend, the state public health department said Friday. But the state epidemiologist warned that the trend could reverse at any time.
The California Department of Public Health reported 573 new cases of whooping cough in the past two weeks. That brings the statewide total so far this year to 7,503 cases.
The number of new cases peaked in mid-June, when the state recorded 1,100 cases in a two-week period. The number of new cases has trended steadily downwards since then.
But state epidemiologist Gil Chavez warns that it's impossible to say whether that number will keep going down. He says whooping cough – like other infectious diseases – can be "quite unpredictable."
Infants younger than four months are most vulnerable to severe cases of whooping cough, also known as pertussis. Of the 214 people who have been hospitalized due to the disease this year, almost two-thirds have been babies younger than four months.
For that reason, the health department continues to recommend that all pregnant women in their third trimester get the Tdap vaccine, which protects against tetanus, diphtheria and pertussis. This protects infants against the disease until they’re old enough to get vaccinated.
The state health agency has vaccination information for mothers in 43 percent of the cases in infants younger than four months. Of those, 81 percent of mothers didn't receive the Tdap shot.
Of the 82 percent of pediatric cases - ranging from infants to 16-year-olds - 9 percent had never received any doses of pertussis-containing vaccine, according to the health department.