Researchers have discovered the nation’s first cases of whooping cough caused by a new germ that may be resistant to the vaccine, according to a report published in Thursday's New England Journal of Medicine.
Health officials from the Centers for Disease Control and Prevention (CDC) and other researchers are investigating whooping cough cases, including 12 in Philadelphia, for clues that may explain why this has been the nation’s worst year for whooping cough in six decades. The new germ causing the latest U.S. cases was previously reported in Japan, France and Finland.
"It's quite intriguing. It's the first time we've seen this here," said Dr. Tom Clark of the CDC.
Whooping cough is a highly contagious disease that can strike people of any age, although it can be especially dangerous in children. After a vaccine was introduced in the 1940s, the number of whooping cough cases significantly decreased.
In recent years, however, more whooping cough cases have been reported due, in part, to a short-acting version of the vaccine in use since the 1990s.
Just this past year, at least 41,880 cases of whooping cough, including 18 deaths, were reported to the CDC, which the new study suggests may explain why more people have been getting sick, especially given the new strain that appears resistant to the vaccine.
The U.S. cases were discovered over the last two years in patients at St. Christopher's Hospital for Children in Philadelphia. One of the researchers in the new study works for a subsidiary of Johnson & Johnson, which makes a version of the old whooping cough vaccine that is sold in other countries.