Whooping Cough in Central Texas
Administrators at Gorzycki Middle School sent a note to parents earlier this month, informing them that a student had pertussis, also known as whooping cough. The case is part of an outbreak that began in Travis County in the fall of 2009. It peaked in February 2010. Health officials say Central Texas appears to be on a downward trend…but that doesn’t mean the risk is over. Cases are still cropping up this year and over the past three years more people getting the disease in Travis County say they were vaccinated against it.
Pertussis is a highly contagious bacterial disease marked by fits of severe coughing. It’s called “whooping cough” because of the whooping sound some people make when they gasp for air during a coughing fit. Pertussis can be fatal to infants.
Kim Frey of Georgetown says life is slowly calming down. Not too long ago every one of Frey’s five children had whooping cough.
“Their symptom, the reason I took them in was it was cough, cough, cough and then throw up, because they would get in such a coughing fit that it would make them puke,” Frey told KUT.
Like dominoes, each child got the cough, one after another. Frey said while it was miserable for her older children, it was life threatening for her then two week-old, Hadalin.
Frey said she started off with a tiny cough, “and it didn’t even seem that bad and then she turned blue so I called EMS. Right around her mouth she turned blue and by that night she was on pretty much life support. Various parts of her just shut down so she was on about 15 machines to keep her alive.”
Hadalin was the last of all her siblings to get sick. Frey says her children likely got whooping cough from her mother in law, who was confirmed to have had it.
“But I mean we were all vaccinated so I thought that it wouldn’t matter; you would think that it wouldn’t spread.”
Hadylin was too young to get the DTaP shot, which includes protection against pertussis. But Frey says the four who were old enough to be vaccinated were up to date.
Preliminary data show Williamson County, where Frey lives, had more than 700 confirmed and probable cases of pertussis in 2010. Travis County had more than 900. Of the people in Travis County who had the whooping cough last year, 80 percent said they had received the vaccine.
(Graphic by Ryland Barton for KUT News)
Travis County health officials were concerned. So in January 2011 they did an analysis of 217 cases in babies younger than one year between October 2009 (when the outbreak started) through December 2010. Those cases accounted for about 19 percent of the total cases in Travis County during that time period.
“It’s a very basic question: Have they received the vaccination? But it’s not as detailed of, are they actually up to date on the vaccination? So even though some of the numbers were reporting for that simple question, when we actually looked at the number that were up to date, it’s probably more about 40 percent,” said Dr. Phil Huang, medical director for the Austin/Travis County Health and Human Services Department.
The analysis only focused on cases in babies. Travis County doesn’t have in-depth data as to whether the rest of the children and adults were on schedule with their shots.
But in 2010, 31 percent of the pertussis cases in Travis County were in children 4-12 years old. School-aged children are required to be up to date on their DTaP boosters to attend public school. Dr. Huang says while some children may technically meet school requirements, they might not be fully protected, depending on how closely they’re following the recommended immunization schedule. And even if a person is up to date, no vaccine is 100 percent effective.
“And actually it’s a very effective vaccine. It’s still the best prevention and control measure that we have and it’s working as expected, about 80 to 85 percent efficacy,” Dr. Huang said.
That means in clinical studies, the childhood vaccines were shown to prevent infection in 80-85 percent of the children who got the shots.
“Again, one of the benefits of us doing the immunizations is that it’s preventing severe illness, the hospitalizations, it’s also preventing infection of other people and transmission.”
Whooping cough is usually milder in adolescents and adults and health officials say many of them aren’t getting the recommended boosters. Experts say the boosters are needed because immunity wanes, you become less protected as time goes by.
“The actual vaccination rates for that population are much lower than we have for the children, so we know that some of the transmission is coming from adolescents and adults that are around some of the kids,” Dr. Huang said.
The big worry is that adolescents and adults will spread pertussis to babies. That’s why doctors strongly recommend “cocooning.”
“The big push since we have seen that whooping cough is so dangerous in young infants, because they’re the ones that end up in the hospital with all the complications, [is] that the people in the family that are around that baby, the older people, including people over 65, that they also get vaccinated, and that’s with Tdap” said Sarmistha Hauger, a pediatrician with Dell Children’s Medical Center of Central Texas.
Tdap, licensed in 2005, is the vaccine that protects adolescents and adults from pertussis. Austin hospitals give new moms information about the vaccine and encourage them to get it as soon as possible after delivery. Many clinics that serve low income families in Austin are also promoting “cocooning” to protect newborns.
County officials say one reason for a spike in the number of pertussis cases in Central Texas may be better surveillance and reporting. Doctors test for it more often than in previous years.
Even so, parents who follow childhood immunization charts, like Kim Frey, say they’re frustrated that their children are getting sick. Many wonder whether the vaccine is effective enough, others fear that the bacteria might be mutating.
“No bug is static because it’s to its survival right…it needs to be spread,” Dr. Hauger of Dell Children’s said.
If so, just how is the bug changing? And is that affecting the vaccine’s effectiveness? We explore those questions in part two of our series on whooping cough.
You can take an in depth look at Travis County’s data on pertussis cases below:
Travis County Pertussis Cases
For more information about pertussis in Williamson County click here.