Asymptomatic Carriers May Help Fuel Rise In Pertussis Cases.

reports that the quick rise in pertussis rates “may largely be a result of transmission from people who are infected with the bacterium but show no symptoms of disease,” according to a study published in BMC Medicine. Even though “the protection afforded by the vaccine wanes over time, the bacterium has evolved to evade immunity, [and] vaccine coverage has not been wide enough,” investigators “found that...asymptomatic transmission may be the most important cause of all.” For that reason, the study authors recommended keeping “vaccination levels high.” http://well.blogs.nytimes.com/2015/06/29/symptom-free-carriers-may-be-spreading-whooping-cough/?ref=health&_r=0