Prof., Dr. Nguyen Van Kinh, former Director of the National Hospital of Tropical Diseases, told reporters on Tuesday morning that the two relapse cases do not have contagious coronavirus, because the SARS-CoV-2 viral culture results on such patients show that they only carried the remnants of SARS-CoV-2, not the active coronavirus.
Among the 11 recoveries announced by the hospital this morning, there are two relapse cases, Patients 74 and 137, who were tested as re-positive for SARS-CoV-2 after their initial recoveries. Patient 74, a 23-year-old man from Phu Tho Province, tested re-positive after being declared recovered on April 10, while Patient 137, a 36-year-old man in Nghe An Province, was discharged on April 7 but then tested re-positive.
Prof. Kinh said that the duo were in good health. They were brought back into isolation and monitored to avoid any transmission risk to the community at the time they were confirmed re-positive.
During their second treatment phase at the hospital, they did not have any poor clinical signs. The duo were healthy and maintained their daily life activities normally. Therefore, the hospital’s doctors did not provide treatment to them but only performed viral cultures to see if the coronavirus was still active or not.
Kinh outlined that the nature of the current COVID-19 test is a Real Time-PCR technique; only taking a primer to detect the y gene segment of the SARS-CoV-2 virus. The accuracy of this test is as high as 98%, so it is only to detect the genetic code of the virus, not the existence of the whole virus.
“If we want to confirm whether the relapse patient is carrying the active coronavirus or not, we have to cultivate the virus,” Kinh said.
To date, Vietnam is the fourth country that can cultivate and isolate this virus; this being done at the National Institute of Hygiene and Epidemiology. All re-positive cases re-admitted to the hospital have undergone the viral culture and so far all the results have shown negative.
The culture results showed that SARS-CoV-2 was not active again. It did not develop but was just a chromosome fragment found via the high sensitivity of the test kit.
“These results show that the current tests have detected the virus’s DNA fragments which can be considered as discarded remnants,” Dr. Kinh affirmed.
Studies on re-positive in other countries has shown that until now, these cases have not infected any of their close contacts even after they returned to their self-isolation in the community. All these contact cases were completely negative.
“Re-positive patients following treatment is a phenomenon occurring in many countries, not only in Vietnam. This is among the components of the immune response that we need to research further. Regarding public health, we should not be too afraid of these re-positive cases," said Kinh.
