A Durban doctor has sounded the alarm about possible Covid-19 reinfection after dealing with patients who tested positive for the coronavirus more than once.

Dr Yuvan Maharaj, who is based in Prospecton, in the south of the city, told SowetanLIVE's sister publication TimesLIVE on Tuesday: "There are a few cases where patients tested positive, recovered and then became infected again.

"One patient tested positive twice in three months. These could be early reinfection cases in SA."

Maharaj said these patients were usually asymptomatic but still contagious.

"They still have to exercise quarantine protocols. They have to remain in isolation because they are contagious," said Maharaj.

According to media reports, a doctor at a hospital in Israel tested positive for Covid-19 three months after recovering from the disease.

A hospital spokesman told media the doctor tested positive again because she had remnants of the first virus "still floating around in her body".

The doctor suffered fevers, coughing and muscle pain when she tested positive for the coronavirus in April, but she recovered and tested negative in May and June.

She came into contact with a Covid-19 patient earlier this month, and subsequently tested positive for the coronavirus.