シンガポール
両親がコロナウイルス感染で入院した際に、症状はないが一緒に入院していた6ヵ月の乳児の検査を行ったところ、鼻スワブからウイルスが検出された。
入院16日目でも、高いウイルス量が検出された。17日目に陰性となった。
入院2日目、血液にウイルス感染が検出された際、発熱が1時間だけあったが、その他には何も症状がなかった。血液が陽性の間でも、便と尿は陰性だった。
8日目に好中球減少、9日目尿はウイルス陰性、便は陽性だった。
A nasopharyngeal specimen taken on admission and tested by rRT-PCR confirmed the diagnosis of COVID-19 infection with low cycle threshold (N gene, 15.57; Orf1ab gene, 13.73), suggesting high viral load. Rapid multiplex respiratory pathogens nucleic acid amplification test (BioFire FilmArray RP2, BioFire Diagnostics, Salt Lake City, UT, USA) was negative for all pathogens, including influenza A and B and 4 human coronaviruses (OC43, 229E, NL63, HKU1). On day 2 of admission, he was found to be viremic with detection of SARS-CoV-2 in his blood sample via rRT-PCR. However, stool and urine samples from the same day were negative. During this viremic phase, he had 1 temperature record of 38.5°C which normalized within 1 hour. Otherwise, he was afebrile and remained asymptomatic throughout admission. Daily nasopharyngeal swabs continued to be positive for SARS-CoV-2 (Figure 1) and eventually became negative on day 17 of admission. Biochemical markers showed normal liver function tests on day 2 and day 8 of admission. His full blood count was normal on day 2 but neutropenia (absolute neutrophil count 0.9 x 109/L, normal range: 1.5-8.5 × 109/L) occurred on day 8 of admission. Repeat testing of his urine on day 9 of admission was negative, but his stool sample became positive for SARS-CoV-2. He did not have any gastrointestinal symptoms before or throughout this admission.