Among all the recovered and isolated, there are 182 of them has been re-tested for at least one time, 84 (46.2%) of the 182 were males and 98 (53.8%) were females, the average age was 46.4±17.1 (median 49, ranges 1-81); 39 (21.4%) had severe symptoms, 143 (78.6%) mild and moderate (Table 1). Few of them had shown different symptom during the medical isolation, and was eliminated from COVID-19 recur.
There are 20 (10.99 %) patients out of the 182 re-tested has found positive results, this rate is slightly lower than 14%, which is officially announced by Guangdong province9. Thirteen of the re-positive cases are females, much more than males (7 cases). Thirteen of them tested to be re-positive on the 7th day, and another 7 on the 14th day; 14 were tested as nasopharyngeal swabs positive, and 6 were anal swabs positive, none has found both swabs positive (Table2).
All the re-positives were suggested an antibody detection and laboratory testing by taking their blood, 14 out of the 20 re-positives were collected. Total immunoglobulin, IgA, IgG shown a positive result for all 14 re-positives, 4 of them shown IgM negative，meanwhile all 14 re-positives were SARS-CoV-2 antibody carrier. And there was no clear abnormality was found in blood routine laboratory test (Table 3).
The re-positives are transferred to designated infectious hospital for quarantine treatments, and again their RT-PCR testing results of blood, nasopharyngeal swabs and anal swabs were collected on the 1st, 4th and 7th day (some were taken on 2nd and 6th), we got results of the 14 cases, 5 of them was positive, and 1 of the 5 (case 8) were found positive in all three testing days. And also, there are 3 (case 2, case 4 and case 15) of the 14 were negative in all three testing days, none have found positive in blood tests (Figure 1A).
Meanwhile, we have noticed a particular case of an 8-year-old boy who has Hubei exposure history during 10-26 Jan and was tested to be re-positive for repeated times (Case 19). He returned from Hubei Journey to Shenzhen on January 26th, the grandpa of him confirmed with COVID-19 on 31st. As a close contact, a throat swab was performed to the whole families and the boy was confirmed to get COVID-19 on February 1st, then hospitalized. During his hospitalization, no fever or other symptoms was found. He reached the hospital discharge criteria (according to the 4th Trail edition) on February 15th, and was transferred to isolation hotel for further 14 days (15th-28th Feb), due to the positive result of anal swab test on February 14th. During hotel isolation, results on two test days (21st and 28th Feb) are negative, and thus he was allowed to go home. And on his return visit to hospital on March 2nd, anal swab test showed positive result again, and he was requested hospitalization for a second time, during the second hospitalization, test results on the two test days (5th and 7th Mar) were negative, then he was transferred to isolation observation for the second 14 days from March 8th, and in the routine tests on March 15th (Day 7 of second isolation observation), the anal swab test result showed positive again (Figure 1B). two followed tests had been collected, there was a positive result again (anal swab) on 4th day after transferred to designated infectious hospital (Figure 1A, case 19). It has been 35 days since his first recovery and discharge from hospital, we can still observe viral RNA positive in him although there’s no clinical symptom.