Whooping cough epidemic in Belgium

Between January and October, 2014, there were 1,200 cases of whooping cough diagnosed in Belgium. "Epidemic proportions," says microbiologist Denis Piérard of the University Hospital of Brussels in De Morgen.

Whooping cough, or pertussis, is a highly contagious respiratory disease caused by a type of bacteria that is mainly transmitted through droplets in the air after someone coughs. The disease is especially dangerous for infants up to one year of age. "No deaths due to pertussis have been reported in the last three years," Piérard said in an interview with Belga. "Before then, it was the cause of more than two deaths a year."

The 1,200 cases of pertussis in Belgium this year are enough to call it an epidemic, confirms Piérard, who says that the peak of the epidemic occurred in the month of June, so that we are now noticing a decrease in the number of cases. It remains to be seen whether the downward trend will continue after the new year.

There are several possible explanations for the increase, according to Piérard. "Ten years ago, we switched from a whole-cell vaccine to an acellular vaccine," he explains. "The major difference is that the duration of the protection provided by the new vaccine is not so well known." Another reason may be that doctors are more aware of disease and therefore more vigilant in their diagnoses. "And finally,” says Piérard, “it is also possible that the virulence of the circulating strains has changed, and that they have become more resistant."