The United States is heading for the highest number of reported cases of pertussis (whooping cough) in fifty-three years, according to predictions by the Centers for Disease Control and Prevention. So far, nearly 18,000 cases have been reported this year; this is over double the total recorded for the same period in 2011. At this rate, 2012 will have the highest number of reported whooping cough cases since 1959.

Rear Admiral Anne Schuchat, M.D., Director of the National Center for Immunization and Respiratory Diseases, CDC, said:

“There is a lot of this out there, and there may be more coming to a place near you.”

Washington state Secretary of Health, Mary Selecky, said that the number of pertussis cases in her state reached 2,520 by 16th June, 2012, and surpassed the 3,000-mark this week. The state declared an emergency in April this year. Washington Dept of Health says pertussis incidence is 1,300% higher now than during the first six months of last year.

Health authorities in the state of Wisconsin say there have been over 3,000 reported cases pertussis so far this year. Several other states, including New York, Kansas, Arizona, and Minnesota are also reporting significantly higher numbers compared to last year.

What is whooping cough (pertussis)?

Bordetella pertussis

Gram stain of the bacteria Bordetella pertussis, which causes pertussis (whooping cough)

Whooping cough, also known as pertussis, is a highly contagious bacterial infection of the lining of the airways caused by Bordetella pertussis. The infection mainly affects the trachea and the bronchi. The trachea is the windpipe, and the bronchi are the two airways that branch off from the trachea to the lungs.

The infection is transmitted from human-to-human through airborne droplets after coughing or sneezing. Babies and young children are usually the most at risk of infection, followed by teenagers and young adults.