COVID-19 reinfection - An enigmatic public health threat.

To the Editor The COVID-19 pandemic has been consistently on the rise across the globe. The recovered patients getting long-term sequelae, especially lung fibrosis and residual neurological deficits, is an area of concern. Another extremely important conundrum is the risk of re-infection. It has been recently documented from Hong Kong  and puts an unpleasant question mark on long term immunity, sampling technique standardization, viral mutation and efficacy of herd immunity. There are definitions for COVID -19 infection and its severity, but unfortunately none for re-infection.