INDIANAPOLIS — State health officials reported Monday that Indiana has its largest outbreak of whooping cough cases since the 1950s.
More than 500 cases of the highly contagious illness have been identified in the state so far this year, including two infant deaths, according to the state health department.
Experts don't have a specific reason for the increased number of Indiana cases, and federal health officials have reported more infections across the country. The illness peaks in waves every three to five years, and in the last spike in 2004, Indiana had 361 cases of the illness, also known as pertussis.
State Health Commissioner Gregory Larkin encouraged checking that children and adults are up to date on vaccinations and booster shots for the illness, which is typically most dangerous for infants.
"The key to the success of the pertussis vaccine is for everyone to be vaccinated," Larkin said. "When an infant is hospitalized or dies from pertussis, it is because someone in the child's environment of family, friends, community members, and health care providers were themselves not vaccinated and therefore exposed a susceptible child to infection.
A persistent cough that lasts weeks is the tell-tale symptom of the illness. Health officials are urging booster shots for teenagers and adults because the childhood vaccine's strength fades over time.
No one ever mentioned the vaccine to Katie and Craig van Tornhout when their daughter Callie was born last December in South Bend. Six weeks premature, Callie spent a few days after birth in the neonatal intensive care unit.
One month after her birth, Callie developed a dry cough. Neither her mother nor the doctor thought much of it until the baby's condition worsened over the next few days.
"That's when they tested her for everything under the sun but never for pertussis," Katie van Tornhout told The Indianapolis Star.
The doctors said it was likely a virus and that Callie would recover. But she died 37 days after her birth.
After her death, the local health department called van Tornhout and told her Callie had died from pertussis.
"When they called me back, the health department called and said, 'Did you get your booster?'" van Tornhout said. "I said, 'What booster?'"
A few months after Callie's birth, van Tornhout had her booster shot and she's now expecting another child.
Parents are responsible for passing on the disease to their infants, who are too young to be immunized, in about half the cases where a source is identified, says Dr. Christopher Belcher, director of pediatric infectious disease at Peyton Manning Children's Hospital in Indianapolis.
"We want to break the cycle," said Belcher, a physician with Infectious Disease of Indiana. "With the vaccine, we may see this disease get under better control."