Four healthcare workers at Government Rajaji Hospital (GRH) in Madurai have tested positive for COVID-19 for the 2nd time, thus indicating reinfection of coronavirus infection. Sources in the healthcare department said that there is no mechanism in Tamil Nadu to monitor cases of re-infection among the public. Experts have opined that re-infection is not a cause of concern because immunity which is developed against respiratory viral infections is usually short-lived.

As per the GRH sources, four healthcare workers at the hospital, i.e. two doctors and two nurses, were tested positive for COVID-19 for the 2nd time. Out of the four healthcare workers, three of them were posted on regular COVID duty whereas one doctor belonged to a non-COVID department. All the four staff were infected with coronavirus for the 1st time (positive during RT-PCR test) in June and July during the time the district has witnessed anupsurge in caseload. After an interval of 45 days to 2 and a half months since the 1st infection, the four staff were tested positive for COVID-19 again during RT-PCR test in the couple of months back. In between the first and second infection, one of the two nurses had tested negative for COVID-19 thrice, after completion of COVID duty.

All the four staff were symptomatic during the 1st infection period and during re-infection, they were asymptomatic having high concentration of antibodies. Among the two doctors, one is a postgraduate student and other one is an assistant professor aged 24 and 35, respectively and the two nurses are middle-aged.

Dr K Kolandaswamy, Public health expert and former Director of Public Health and Preventive Medicine, said that shedding of the virus takes place for one month maximum since the infection, after that the remnants of the virus could be considered to have disappeared completely from the body system. Therefore, turning positive for coronavirus after the one-month period of shedding of virus could be termed as re-infection.

Dr T S Selvavinayagam, the Director of Public Health and Preventive Medicine, said that Tamil Nadu has not documented any case of re-infection officially and the re-infection claims are subjected to careful study, if officially notified from the concerned districts.

Experts have however opined that re-infection should not be a cause of worry as the immunity developed against many respiratory tract infections is usually short-lived.

Renowned virologist, Dr T Jacob John said that the immunity developed against many respiratory viral infections are short-lived or incomplete, hence leading to re-infection, which is a common phenomenon. In these infections, the immunity does not prevent re-infection however prevents onset of diseases during re-infection. Re-infection is not a serious worry in COVID-19 treatment or vaccine development. In a scientific outlook, a study on re-infection is needed to learn about the pandemic from all angles.

Dr J Sangumani, Dean of GRH said that few samples of extracted coronavirus RNA of patients who were infected for the first and second time are sent to the King Institute of Preventive Medicine, Chennai for recording the viral strain for future reference. The results are still awaited.

Source: The New Indian Express