Recovered patient has low viral load

April 21, 2020

Centre for Health Protection Communicable Disease Branch Head Dr Chuang Shuk-kwan:

For case number 496, after the patient was discharged from the hospital, he mainly stayed at home with food provided by his family or ordered to be delivered. His parents, they’re staying in a hotel. Because they’re worried and asked him to get tested again to see if he’s really clear of the virus, that’s why he was checked to be positive. Actually, he does not have many close contacts because all his family members are taking precautionary measures, but they had some minimal contact with him and also the domestic helper helped him to change the curtains and entered the room, so I think they are not really close contacts. And also, from our communication with the virologist, the numbers suggest it’s not a high viral load. But as a precautionary measure, we’ll provide some deep throat saliva bottles for his family members to check, just in case. 

Hospital Authority Chief Manager (Quality & Standards), Dr Lau Ka-hin:

As you all know, we are using a very sensitive polymerase chain reaction (PCR) test for the nucleic acid of the coronavirus. That means we can have positive results when there’s only a small amount of residual virus left in our bodies. In this case, the patient was admitted because of a weakly positive result of a PCR test. He was admitted after having the test (done) at a private doctor. After admission, he was seen by different experts, including a pediatrician, an infectious disease expert as well as a microbiologist. They all agreed that because of the very low value of the PCR test, it means there’s a very small amount of residual virus, which has a very low risk of infection. But in order to play safe, the patient was admitted to the ward and repeated tests will be done. Because of this phenomenon, we will have more discussions about the future management of this case in our Central Committee for Infectious Diseases & Emergency Response in the near future.

(To watch the full press briefing with sign language interpretation, click here.)

A patient who recovered from COVID-19 but tested positive for the virus again has a low viral load, the Centre for Health Protection said today.

The centre’s Communicable Disease Branch Head Dr Chuang Shuk-kwan told a media briefing this afternoon that the patient mainly stayed at home after he was discharged from the hospital.

Dr Chuang said the patient does not have many close contacts because his family members are taking precautionary measures.

“His parents, they’re staying in a hotel. Because they’re worried and asked him to get tested again to see if he’s really clear of the virus, that’s why he was checked to be positive.

“And also, from our communication with the virologist, the numbers suggest it’s not a high viral load.”

Dr Chuang added the patient’s family members have had minimal contact with him and will be tested for the virus as a precaution.

Additionally, the polymerase chain reaction (PCR) test used to check for the virus is very sensitive, the Hospital Authority said.

Its Chief Manager (Quality & Standards) Dr Lau Ka-hin told reporters at the media briefing that the test could show positive results if there is a small amount of residual virus.

Dr Lau said: “In this case, the patient was admitted because of a weakly positive result of a PCR test.

“After admission, he was seen by different experts, including a pediatrician, an infectious disease expert as well as a microbiologist.

“They all agreed that because of the very low value of the PCR test, it means there’s a very small amount of residual virus, which has a very low risk of infection.”

For information and health advice on COVID-19, visit the Government’s dedicated webpage.