[A CASE OF PERTUSSIS IN ADULT THAT COULD BE DIAGNOSED BY DETECTION OF BORDETELLA PERTUSSIS FROM SPUTUM].

Bordetella pertussis isolation by culture has low detection sensitivity for diagnosing pertussis; the diagnosis is confirmed by measuring serum anti-pertussis toxin (anti-PT) or anti-filamentous hemagglutinin antibody titers, and by genetic testing (polymerase chain reaction/loop-mediated isothermal amplification). Isolation of B. pertussis in adults is difficult, resulting in a delayed diagnosis, as a delayed cough may present ≥3 months after onset. Differentiation from bronchial asthma is also important. We encountered an adult patient in whom B. pertussis was isolated by culture who previously received rituximab for mucosa-associated lymphoid tissue (MALT) lymphoma and steroids for prolonged cough. No elevation of anti-PT antibody titers was observed in the patient.