About 14% of patients removed from nCoV and were discharged from hospital in Guangdong province for positive results with nCoV after the test.

There is no clear conclusion on the cause or whether these patients continue to spread the disease to others, said the deputy director of the Guangdong Province Centers for Disease Control and Prevention yesterday.

According to preliminary assessments, experts believe that patients are recovering from pneumonia and have not fully recovered, Tong said.

According to the latest Covid-19 treatment guidelines issued by the Chinese Health Commission, patients are considered cured and discharged when their throat and nose fluids are negative for nCoV after two tests, together with CT images showed no damage to the lungs, and no fever.

This guide requires patients who have recovered from their illness to monitor their health and limit outdoor activities for two weeks after being discharged from the hospital, and retest the following weeks.

Some patients who recovered from the disease showed positive results in subsequent examinations, said Li Nguyet Ping, leader of the intensive care unit at Guangzhou No. 8 People's Hospital.

People's Hospital No. 8 has 13 patients discharged with re-infection with nCoV, although there were no symptoms. Negative acid test with 104 close contacts with re-infected patients showed negative results.

Tai Wei Ping, head of the infectious disease department at People's Hospital No. 8, said that positive results for nCoV in cured patients were detected from faecal samples, which is rarely used in China.

National treatment guidelines only require testing of specimens from the throat or nose of patients with suspected nCoV infection, when the outbreak is thought to be spread through coughing or sneezing.

However, a study by Guangzhou Medical University found that nCoV appeared in the stool samples of patients, showing a new path of infection. A number of hospitals in Guangdong have begun using stool samples.

It is unclear whether nCoV was detected in the recovered patients. There is also the possibility of differences in patient samples, Cai said.

Tong said Guangdong Province will place nCoV re-infected patients under special surveillance. Health officials will also increase monitoring of patients discharged and health status during recovery.

Cases of patients recovering positive with nCoV were also recorded in many places in China. Last week, a patient was initially discharged after being cured in Chengdu City, Sichuan Province, and was hospitalized again after being found positive for nCoV in the follow-up examination.

Health authorities in Hainan province also confirmed a number of patients who recovered from the disease later tested positive for nCoV. Officials require patients to be discharged from hospital for 14 days at home, and are only allowed to leave the home after a negative throat and stool test.

The Covid-19 outbreak started in Wuhan, capital of Hubei province, China in December 2019, and appeared in 39 countries and territories. Worldwide there are more than 2,700 deaths and more than 80,000 infections, of which more than 30,000 are cured.