A private hospital here has reported the city’s first case of Covid-19 reinfection. Though not new, such instances are very rare, say doctors. The case was reported by Fortis Hospital when a 27-year-old woman with no history of comorbidities got re-infected. She had first tested positive in July and was discharged upon full recovery.
Doctors say that the first infection was very mild and the patient had not developed enough load of antibodies.
In a statement, Dr Pratik Patil, Consultant, Infectious Diseases, Fortis Hospital, said, “In the first week of July, the patient was symptomatic (fever, cough and sore throat) and was tested positive. She was admitted at the hospital and recovered. A repeat test was conducted on her, which turned out to be negative, post which she was discharged on July 24. However, nearly after one month, in the last week of August, she developed mild symptoms again and has tested positive yet again. Both the times she did not have severe disease. This is possibly the first reported case of Covid-19 reinfection in Bangalore.”
Explaining the case, Dr Patil said that Immunoglobulin G antibody lingers in the patient’s blood after two-three weeks of infection. However, the patient later tested negative for antibodies, suggesting she did not have immunity following the infection. “The other possibility is that the antibodies disappeared in nearly one month, leaving her susceptible to reinfection,” he said.
"A reinfection means that antibodies may not be produced by every individual, or, if they do develop, they may not last long enough, therefore allowing the virus to enter the body and cause the disease again," he added.
The case raises some fundamental questions about herd immunity, the duration that the pandemic would last and about the duration for which a vaccine would remain effective.
Researchers say re-infections are rare and there is no reason for alarm just yet. More studies are needed for a reliable inference. Cases of re-infection have also been reported from Telangana and Maharashtra and abroad, including Hong Kong, the US, the Netherlands and Belgium.