New Delhi, July 13:

A student from Kerala’s Thrissur enrolled at a medical college in China, who was the first Indian to test positive for Covid-19 after returning to India with the outbreak of the pandemic in January 2020, has been infected again, a health official said on Tuesday. She is, however, asymptomatic, the official added.

The student was found to have been reinfected after she was retested as she planned to travel to Delhi. She has been put under home quarantine, her family said. The family added said she is showing no visible symptoms and that she has also been administered the first Covid-19 vaccine dose.

The student spent almost a month in the hospital while undergoing treatment for Covid-19 in 2020. Later two of her friends, who travelled with her from Wuhan in China, were also tested positive.

The student last year told HT she never thought she will be infected but once she was diagnosed with the infection, her main concern was her family members and others who she met after returning home. She spent 24 days at an isolation ward from January 27 to February 20, wearing personal protective equipment. She said her medical background helped her to overcome the trauma.

An Indian Council of Medical Research study from January to October last year estimated 4.5% re-infection. Researchers at New Delhi’s Institute of Genomics and Integrative Biology (IGIB) found over 10% of the people were likely exposed to the virus again during the April wave of infections in Delhi. The findings were based on the sequential analysis of samples from 1,000 people across 10 locations part of the study. The study also found that the antibodies in them were mostly declining before they shot up again. It found that 80% of the participants with antibodies against Sars-CoV-2 virus, which causes Covid-19, in June, after the fourth wave of infections (and the second nationwide) in Delhi.