Prolonged period of acute bronchitis with late progression to acute respiratory distress syndrome as possible result of influenza A (H1N1) virus infection.

Young adults with underlying medical conditions who are infected with the H1N1 virus are at risk of quickly progressing from mild upper airways infection to severe ARDS within 4 to 5 days after the onset of the illness. Here, we report the case of a 46-year-old morbidly obese and diabetic woman infected with the H1N1 virus who developed acute bronchitis that lasted for 4 weeks and then progressed to ARDS. We discuss the month-long persistence of the H1N1 viral bronchitis and its late progression to ARDS which may reflect prolonged viral activity. Such a prolonged, rather than quick, course of deterioration can cause clinicians to misdiagnose the etiology of the ARDS and may cause the patient to receive a prolonged treatment with steroids to treat bronchitis symptoms. These steroids may cause increased viral replication and promote parenchymal involvement and the development of ARDS.