Abstract
This report describes a local epidemic of pertussis in Kita-Akita City, Akita, Japan between December 2015 and September 2016 that mainly affected primary school children. There were 138 patients with clinically suspected pertussis;diagnosis was confirmed in 74 patients by laboratory tests. In total, 62 patients with typical symptoms and laboratory findings satisfied the legal criteria in 2018. A table of incidence over time in the local educational institution suggested that contagion occurred in the classroom first, in the home next, and then spread in the community last. Epidemiological information was shared among local clinics and hospitals, health centers, and educational committees. The epidemic lasted about 10 months. Pertussis usually presents with cold-like symptoms and the classical symptoms develop gradually. Before 2017, the legal criteria for registering cases in an epidemic survey was a duration of illness over 14 days. Twenty-six (35％) patients visited the clinic before day 6 of illness, and for most patients, cough stopped before day 14 of illness. Pertussis may not usually be a common disease, but it can be diagnosed and treated rapidly in a local epidemic situation by ensuring appropriate specific laboratory testing and by collecting epidemiological information.
