NEW DELHI: A recent study led by Kwok-Yung Yuen from the Department of Clinical Microbiology and Infection Control of the University of Hong Kong-Shenzhen Hospital suggests that the coronavirus (SARS CoV-2) that causes Covid-19 disease could easily spread in the early days of infection, even when symptoms are mild.The study looked at 23 patients admitted to Hong Kong hospitals and found that for most patients, the viral load of SARS-CoV-2 was very high when symptoms first presented themselves, but then declined steadily. This is in contrast to the SARS disease and MERS but similar to influenza, which also peaks at around the time of onset of symptoms.The study's conclusion is in line with observation by doctors elsewhere. Medical experts have observed that, in the early days, the virus is found in the upper respiratory tract (nose and throat), where the chances of it being transmitted are higher when the infected sneezes or coughs. The virus then spreads to the lower respiratory tract and towards lungs. At this stage, the infected patient is at higher risk, but the chances of transmission decrease.The findings help better understand the fast spread of the Covid-19 across the world, as the infected are more likely to slip under the radar when the symptoms are mild.