Whooping cough, a childhood scourge in the 1940s, has had a resurgence in Connecticut as part of a national epidemic.
The outbreak peaked in Connecticut in September with 178 cases reported in 2012, though numbers are still coming in. This is a big increase from 68 cases last year, and roughly double the normal caseload for the state, said Kathy Kudish, epidemiologist with the state Department of Public Health.
"Compared to the last decade, this is the highest number of cases we've seen," Kudish said.
Many of the cases were reported in the western part of the state, predominantly in Fairfield and Litchfield counties, Kudish said. She said it is unclear precisely why that area had higher numbers. It could be that the disease is circulating more there or simply that the area is better about testing for and reporting the illness, she said.
Whooping cough, also known as pertussis, is a highly contagious airborne bacterial disease characterized by coughing fits that can last several minutes, often followed by a high-pitched "whoop" noise when a patient gaps for breath.
Symptoms in the beginning are similar to a cold with a runny nose and a cough that gradually gets worse. Other symptoms can include vomiting and exhaustion after violent coughing fits, said Dr. Paul R. Skolnik, an infectious disease expert and chairman of the Department of Medicine at the UConn Medical School.
Public health officials think the dramatic increase this year nationally and in Connecticut could be due to the waning immunity of the vaccine. The Centers for Disease Control is looking into whether switching from a whole-cell to an acellular vaccine in 1997 is a factor. The new vaccine has fewer side-effects, such as fever and seizures, but the immunity may not last as long as the older version.
There has been an uptick in cases in children age 7 and going though the teenage years who have had the newer vaccine, Kudish said.
"We're learning that the length of immunity has collapsed," Skolnik said.
"The whole strategy of what vaccine to use and how often to give it is being rethought because of the epidemic."
As a result, state public health officials are encouraging adults and parents of older children to check with their doctor and make sure they have received the Tdap booster, Kudish said
Another contributing factor could be enclaves of people and populations who refuse to get vaccinated or who just don't get vaccinated, Skolnik said.
There is a cadre of people who think that vaccines can cause autism. That now has been well studied and debunked. But it's still out there," Skolnik said.
Still others think they are doing their children a favor by not getting their kids vaccinated, sparing them the pain of the injection, he said.
"Those out there who are militantly against vaccine are doing a disservice to themselves, their kids and their neighbors, who they are putting at risk," he said.
Older adults and young children are particularly vulnerable to severe illness and possibly death from pertussis, though no fatalities have been reported recently in Connecticut. The disease can cause serious complications in newborns.
To help protect infants, the state began a "Cocoon" program in 2008 that aims to vaccinate parents and family members who will be around a newborn and have not previously received a dose.
The idea is to help prevent the baby from catching the illness from family members. Under the program, the state pays for free vaccines to be administered to new mothers in the hospital and to family members in outpatient health clinics, Kudish said.