We report the case of an 83-year-old woman with acute, febrile respiratory failure resulting from interstitial pneumonia that required high-flow oxygen therapy. This clinical picture, associated with the ongoing epidemiological situation, initially guided us toward a diagnosis of COVID-19. Based on SARS-CoV-2 reverse transcription-polymerase chain reaction negativity and the absence of anti-SARS-CoV-2 antibodies, a search for a differential diagnosis was conducted that led us to conclude a diagnosis of severe pulmonary leptospirosis This case highlights the need to engage in early discussions about differential diagnoses, including neglected tropical and subtropical diseases, during the COVID-19 era.