View article

A 4-month-old girl presented to the emergency department after 10 days of persistent cough, 2 days of vomiting, and respiratory distress. Her parents had had a persistent cough for over a month, and she had not received any vaccination against pertussis. Her peripheral white blood cell count was 24 640 cells per μL and 78% of cells were lymphocytes. A Giemsa stain of the peripheral blood smear showed atypical lymphocytes (figure) with cleaved or lobulated nuclei. A PCR assay of the nasopharyngeal aspirates for Bordetella pertussis DNA was positive, which confirmed the diagnosis of pertussis. The girl completed oral therapy with azithromycin and her respiratory distress gradually improved, but her cough persisted for another month before complete resolution. The incidence of pertussis is increasing in young adults in Japan. This is possibly a result of waning immunity, in view of the fact that the pertussis …