Initial symptoms of patients with coronavirus disease 2019 in Japan.

Abstract Background: Fever, cough, malaise, and throat pain are the most common initial symptoms of coronavirus disease 2019 (COVID-19). However, no studies have ever been conducted to investigate the initial symptoms of COVID-19 in Japan. Methods: We investigated 707 consecutive COVID-19 patients who were diagnosed in ten prefectures of Japan until May 16, 2020 by using publicly available data. The primary outcome was initial symptoms on the day of symptom onset. The proportion of patients with individual symptoms among symptomatic patients was calculated.Results: Of all the patients, 79 (11.2%) were asymptomatic. Among the 628 symptomatic patients, the most common initial symptom was fever (65.9%), followed by cough (23.5%), malaise (23.5%), and throat pain (12.9%). At least one of these four symptoms was reported in 88.2% of all symptomatic patients. Nineteen patients (3.0%) reported gastrointestinal symptoms without respiratory symptoms, while six patients (1.0%) reported only loss of smell or taste as the initial symptom. Conclusions: Like other countries, the most common initial symptoms of COVID-19 patients in Japan are fever, cough, malaise, or throat pain. Gastrointestinal symptoms without respiratory symptoms and loss of smell and taste are uncommon initial symptoms in Japan.