Coronavirus: why do ‘recovered’ patients test positive again?
- Despite the hospital release criteria set by Beijing, doctors say some people are being allowed home while still infected with the disease
- But new tests are in development that could make the diagnostic process more effective
As of Tuesday, the virus had infected more than 80,000 people in mainland China, of whom more than 47,000 had been released from hospital, official data showed.
They were released after being getting a negative result in a reverse transcriptase-polymerase chain reaction (PCR) test – the most commonly used when testing for infection – but then tested positive again days or even weeks later.
On Monday, two people in the northern port city of Tianjin, where more than 130 cases have been confirmed, were sent back to hospital after testing positive for Covid-19 about a week after being told they had recovered from it. An earlier case involved a patient who tested positive for the disease two weeks after being sent home, the local health authority said.
In south China’s Guangdong province, 14 per cent of coronavirus patients released from hospital were later found to still be infected, the provincial disease control centre said last week.
Similar cases have been reported in other parts of the country, including Jiangsu and Sichuan provinces.