COVID-19 pneumonia suspected to be co-infection with Mycoplasma pneumoniae and improved by early administration of favipiravir and ciclesonide.

A female nurse in her 40s caring for a patient with severe coronavirus disease 2019 (COVID-19) pneumonia treated with a high-flow nasal cannula (HFNC) presented with fever, cough and dyspnoea. Based on imaging findings and a positive reverse transcription-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), COVID-19 pneumonia was diagnosed, although her cohabiting family had similar symptoms and their RT-PCR tests were negative. Laboratory results showed Mycoplasma antigen (+). She was started on ciclesonide 1200 µg/day and favipiravir (3600 mg/day on the first day and 1600 mg/day from Day 2). As Mycoplasma antigen was positive on admission and her family had similar symptoms, levofloxacin 500 mg/day was started. The patient recovered and was discharged on Day 10. The patient did not have Mycoplasma infection because the Mycoplasma antibody measured by particle agglutination (PA) method was increased only up to 80 times after 4 weeks. This case highlights that healthcare workers wearing full personal protective equipment can nevertheless acquire COVID-19 from patients treated with HFNCs.