"Nature": Over 40% of the earliest outbreak towns in Italy were asymptomatic
On June 30, a study published in "Nature" found that 42.5% of infections in Italy's earliest outbreak towns did not show any symptoms, indicating that asymptomatic infections may be a pandemic Important communicator and confirmed the importance of extensive testing.
On February 21, 78-year-old Adriano Trevisan (Adriano Trevisan) died and became Italy’s first victim of the new coronavirus. Three days later, the local government imposed a 14-day quarantine on Vo, a small town near Padua where he lived.
Scientists conducted swab tests on 3,275 residents of the town.
Studies have shown that at the beginning of quarantine, 73 Vo’ residents (2.6% of the total population) tested positive for viruses. Two weeks later, this number dropped to 29 people, 8 of which were new cases. But in two rounds of testing, 40% of the cases tested positive had no symptoms.
The study pointed out that if there are no strict social alienation measures or epidemiological monitoring, such as detection, tracking and isolation strategies, then in the case of many asymptomatic infections (without your knowledge), you will The risk of virus transmission to others has increased significantly, and it has also brought obvious challenges to control.
The study also found that "through the combination of early isolation of infected persons and community blockade", it is possible to control the outbreak of local epidemics. The paper points out that the testing and tracking methods in this area "have a huge impact on the epidemic process of the new coronavirus compared to other regions in Italy." "Vo's experience shows that although the new coronavirus can be spread silently and widely, the spread can be controlled. Of."