ST. LOUIS — A spike in the number of whooping cough cases in St. Louis County and other parts of eastern Missouri has health officials calling for more frequent vaccinations.
St. Louis County on Thursday reported 146 cases of pertussis, or whooping cough, so far this year compared to eight last year at this time.
Many of the cases are among children 14 and younger. They were not clustered in one community or school but dispersed throughout the county.
St. Charles, Jefferson and Franklin counties in eastern Missouri and some southeast Missouri counties also are reporting an increase in cases, but the spike is not a statewide phenomenon, experts with the Missouri Department of Health said.
Missouri children are required to be immunized at 2, 4, 6 and 15 months, and again before entering school at age 4 or 6.
But the immunity against pertussis wanes after a while, and increasingly health officials have called for boosters at age 11 or 12.
"The cases we've seen (are children who) have been immunized," said Cindy Butler, a state Department of Health epidemiologist for eastern Missouri.
"The problem is waning immunity, meaning their immunity level fades over time. We may need to evaluate the immunization schedule as a nation."
Whooping cough is a bacterial infection that causes spasmodic bursts of rapid coughs, a high-pitched "whoop" sound and desire to vomit. It is highly contagious and can be deadly in infants.
Mike Williams, director of communicable disease control for St. Louis County, said a new vaccine licensed in 2005 for children 10 to 12 years old will help control future outbreaks in school-age children.
He said boosters also are recommended for new mothers before they leave the hospital, and for teaching and medical professionals.
"It's not fully implemented yet, but the sooner we get to full implementation, the less likely we'll have these outbreaks."
Missouri children are required to have a pertussis booster before starting school unless they have a medical or religious exemption.
But starting next year, they'll be required to have an additional booster at age 11 or 12.
Spokeswoman Nanci Gonder said the Missouri Department of Health is recommending that additional booster based on national recommendations.
The department is in the process of developing the new rule, she said.
Butler said Missouri has one of the highest pertussis immunization rates in the country.
Besides immunizations, "proper respiratory etiquette" — like coughing into an elbow rather than the hand — is recommended to prevent infection, she said.