Scientists say a germ possibly resistant to the whooping cough vaccine may be causing new cases of the disease to crop up in the United States.
But a local doctor said there still is plenty of regular whooping cough, or pertussis, going around for people to combat with the inoculation available in most doctors' offices.
Health officials are looking into whether cases like the dozen found in Philadelphia might be one reason the nation just had its worst year for whooping cough in 60 years. The new bug was previously reported in Japan, France and Finland.
File photo by Shelley Hanson
Dr. William Mercer says adults should receive a booster shot of Tdap to prevent spreading whooping cough to children.
''It's quite intriguing. It's the first time we've seen this here,'' said Dr. Tom Clark of the Centers for Disease Control and Prevention.
Ohio County Health Officer Dr. William Mercer said it is ''a little concerning'' the vaccine won't impact that particular strain.
''That's why there's been a push for adults to get the vaccine. ... Adults can get (whooping cough) and they are not nearly as sick, but they can spread it to infants,'' Mercer said. ''If you've had a cough for more than two weeks, there is a 20 percent chance it's pertussis.''
The U.S. cases are detailed in a brief report from the CDC and other researchers in the New England Journal of Medicine.
Whooping cough is a highly contagious disease that can strike people of any age but is most dangerous to children. It was once common, but cases in the U.S. dropped after a vaccine was introduced in the 1940s. An increase in illnesses in recent years has been partially blamed on a version of the vaccine used since the 1990s, which doesn't last as long. Last year, the CDC received reports of 41,880 cases, according to a preliminary count. That included 18 deaths.
Mercer said last year Ohio County had a small outbreak of pertussis that involved children in two families. The children were home schooled and had never had the pertussis vaccine. They were treated with Zithromax, an antibiotic.
The new study suggests the new whooping cough strain may be causing more people to become sick. Experts don't think it's more deadly, but the shots may not work as well against it.
In a small, soon-to-be published study, French researchers found the vaccine seemed to lower the risk of severe disease from the new strain in infants. But it didn't prevent illness completely, said Nicole Guiso of the Pasteur Institute, one of the researchers.
The new germ was first identified in France, where more extensive testing is routinely done for whooping cough. The strain now accounts for 14 percent of cases there, Guiso said.
''Any bacteria that is resistant gets our attention,'' Mercer said.
Mercer noted people should ask their doctor about getting a booster Tdap shot, which includes the vaccines against tetanus, diphtheria and pertussis. In addition to the seasonal flu shot for those 6 months old and older, people 50 years old or older should inquire about the shingles vaccine and those 65 years old, the pneumonia vaccine, he said.
In the United States, doctors usually rely on a rapid test to help make a diagnosis. The extra lab work isn't done often enough to give health officials a good idea how common the new type is here, experts said.