“No symptoms” means nothing
Preliminary recent data on COVID-19 confirms that infected asymptomatic patients shed the virus at the same rate as people who show symptoms.
In Vo municipality of Province Padua in Italy, 78 years old retired man has died on February 21, 2020. Adriano Trevisan spent most of his time at home and sometimes at a local bar to play cards. Vo is a small town, one hour from Venezia, Italy, with a low population density of 160 people per sq. km. He enjoyed playing cards with a 67 years old friend from Vo, who also became infected and tested positive for the COVID-19 virus. His friend was admitted to the hospital but survived the disease.
A day after his death, another victim died of pneumonia and was tested positive for the COVID19 virus. A 77-year-old woman from the small town of Codogno in Lombardy, her infection was traced back to 38 years old man from Lodi, who believed to be patient 1 in Italy. He has never traveled to China but had dinner with one single traveler from China. This young man infected his pregnant wife, his running buddy, and three other Lodi residents who have never met him in person.
The recent and preliminary data was just published by Italian scientists, highlighting the importance of asymptomatic COVID-19 patients. Since the first confirmed fatality in Vo, the town was on 14 days lockdown. During that lockdown, almost every single resident of Vo was tested for active infection, not once but twice. At first, out of 2834 tests, 74 came back positive for the virus. In seventy-four positive people, only 42 had symptoms of the disease.
Approximately 14 days later the population of town Vo was tested again, this time out of 2360 tests, 28 came back positive for infection. In twenty-eight positive people, only 16 had symptoms of the disease.
The scientists believe that up to 43 % of infected cases are completely asymptomatic but as highly contagious as people who experience symptoms.
The viral load of people with no symptoms was the same as the people who had signs of infection. Another study originated from Italy, which confirms that the droplets spread theory can not fully explain the high number of cases in Lombardy, Italy. The samples of outdoor air were tested to determine whether the particular matter (a mixture of solid particles or liquid droplets that remain suspended in the atmosphere for considerable periods) exceeds the legal limit of 50 µg/m3. The testing provided a possible explanation for COVID-19 clusters in Italy, where the legal limit of particles in the air is 50 µg/m3. Research carried out by the Harvard School of Public Health seems to confirm an association between increases in particulate matter concentration above the legal limit and mortality rates due to COVID-19.
Ample evidence exists that particulate matter ( airborne) may carry the viral droplet and boost the spreading of the viral infection. As many as 43 % of people tested positive for the COVID19 virus have not experienced any symptoms of coronavirus. At least not yet.