14 days before admission to Mount Sinai Hospital (New York, NY, USA), a 34-year-old man developed fever, cough, and dyspnoea due to influenza A, confirmed by an NP swab 2 days later at a walk-in urgent care facility of the Mount Sinai Health System. No radiograph was done. The patient was previously healthy with no past hospitalisations, and works as an anaesthesiologist in a large medical centre in New York City. His only medication was emtricitabine and tenofovir alafenamide for HIV pre-exposure prophylaxis, which he had been taking once a day for 5 months (and prior to that, tenofovir disoproxil fumarate and emtricitabine once a day for 3 years). He was treated for influenza with oseltamivir for 5 days; symptoms resolved after 5 days of illness. He felt fully recovered from influenza, and returned to work in the hospital 11 days after his symptoms had resolved.