On 24 March 2020, local center for disease control and prevention (cdc) performed routine RT-PCR test for COVID-19 nucleic acid in nasopharyngeal swab samples among quarantined abroad people, and a positive result was identified. The patient is a 19 years-old Chinese female with underlying disease of myocarditis. She has become an oversea student in England since September 2019. On March 19, 2020 she came back to China by taking plane and self-reported a man sitting next to her on the plane experienced serious cough during the journey. However, we can’t determine whether this man was COVID-19 case because he got off plane in Singapore. On March 21 she arrived in China and quarantined in single hotel room. The patient was initially asymptomatic with normal CT imaging and routine blood examination before March 26. On March 27 the patient developed fever (37.5℃), slight cough and running nose and CT imaging showed scattered mottling opacity in the left lung. On April 1, the patient was diagnosed as COVID-19 confirmed case and the severity of disease was normal.
On admission, antiviral treatment including interferon α 5 million units of taken aerosol inhalation every 12 hours and ribavirin 300 mg of taken orally every 8 hours, was provided for the patient, and the treatment procedure lasted for 12 days. Other adjunctive therapy such as oxygen supplemented and traditional Chinese medicine therapy were also provided. The patient’s body temperature persistently normal since hospitalization, and respiratory symptoms (cough) were significantly relieved and completely disappeared on April 13, and CT imaging abnormalities had resolved since April 3. Results from routine blood examination and biochemical tests were normal throughout disease course and normal vital signs with oxygen saturation of 98% while the patient was breathing ambient air. IgM test for influenza A and B, parainfluenza, respiratory syncytial virus, adenovirus, coxsackievirus, Mycoplasma pneumoniae, and Chlamydia pneumoniae was negative. IgM and IgG colloidal gold test for COVID-19 was negative on April 2, while the IgG turned positive on April 7. Four times of RT-PCR test were performed during hospitalization including 2 positive results (March 29 and April 9) and 3 negative results (April 1, April 11 and April 12), she discharged on April 13. The time from symptom onset to negative result of nucleic acid test was 16 days and the length of hospital stay was 21 days.
After hospital discharge, the patient continued to be quarantined at designated hospital for 14 days (April 13- April 26). She experienced asymptomatic and normal CT imaging throughout the quarantined period, and the routine blood examination and biochemical tests were also normal. RT-PCR tests for nasopharyngeal swab and stool were performed in 10th and 14th days of quarantine and all were negative. After discontinuation of quarantine at hospital, the patient was asked to continue the quarantine protocol at home for 14 days (April 27 – May 11). Positive RT-PCR test results were identified in respiratory sample on May 11 and May 12 while the results in stool was negative. The patient continued to be asymptomatic by clinician examination and chest CT findings showed no change from previous images. However, routine blood examination revealed abnormal white blood cell count (10.85 × 109, reference range: 4–10 × 109). Two following RT-PCR tests were performed on May 13 and May 15, and negative result were identified in both respiratory and stool samples. Two household contacts (the patient’s family member) were traced and sampled and none of them was infected.