Geo-Economics and Politics

COVID-19: Study shows 40% of cases in Italian town showed no symptoms

Life in Italy's original 'red zones': people take photographs of Italian President Sergio Mattarella as he visits Codogno, the small northern town where cases and deaths immediately surged after the country's first coronavirus disease (COVID-19) patient was diagnosed there on February 21, in this picture taken by schoolteacher Marzio Toniolo in Codogno, Italy, June 2, 2020. Toniolo has been documenting what life has been like for the small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country. REUTERS/Marzio Toniolo - RC211H982C9J

The Italian town of Vò has reported no symptoms in 40% of their coronavirus cases. Image: REUTERS/Marzio Toniolo - RC211H982C9J

Kate Kelland
Correspondent, Reuters
  • Wide-spread testing in the Italian town of Vò has shown that 40% of all its cases were asymptomatic.
  • These figures are important in understanding the 'silent' spread of COVID-19 throughout the world.
  • Vò was immediately put into quarantine for four days after suffering Italy’s first COVID-19 death, on February 21st.

A study of coronavirus infections that covered almost everyone in the quarantined north Italian town of Vò found that 40% of cases showed no symptoms - suggesting that asymptomatic cases are important in the spread of the pandemic.

The study, led by a scientist at Italy’s Padua University and Imperial College London, also produced evidence that mass testing combined with case isolation and community lockdowns can stop local outbreaks swiftly.

Life in Italy's original 'red zones': people gather in a square in front of town hall as Italian President Sergio Mattarella visits Codogno, the small northern town where cases and deaths immediately surged after the country's first coronavirus disease (COVID-19) patient was diagnosed there on February 21, in this picture taken by schoolteacher Marzio Toniolo in Codogno, Italy, June 2, 2020. Toniolo has been documenting what life has been like for the small cluster of northern Italian towns since they were put on lockdown weeks before the rest of the country. REUTERS/Marzio Toniolo REFILE - CORRECTING INFORMATION - RC211H9KA5RC
Image: REUTERS/Marzio Toniolo REFILE - CORRECTING INFORMATION - RC211H9KA5RC

“Despite ‘silent’ and widespread transmission, the disease can be controlled,” said Andrea Crisanti, a professor at Padua and Imperial who co-led the work. “Testing of all citizens, whether or not they have symptoms, provides a way to ... prevent outbreaks getting out of hand.”

Have you read?

Crisanti has become something of a celebrity in Italy for advocating widespread testing well before it became official World Health Organization guidance.

Vò, which has a population of nearly 3,200, was immediately put into quarantine for 14 days after suffering Italy’s first COVID-19 death, on Feb. 21.

During that fortnight, researchers tested most of the population for SARS-CoV-2, the coronavirus that causes COVID-19.

A analysis of the results, published in the journal Nature on Monday, showed that at the start of quarantine, 2.6% of Vo’s population - or 73 people - were positive. After two weeks, only 29 people were positive.

At both times, around 40% of positive cases showed no symptoms. But because all of the coronavirus cases found - whether symptomatic or not - were quarantined, the researchers said, this helped slow the spread of the disease, effectively suppressing it in a few weeks.

Crisanti said the success of Vo’s mass testing also guided wider public health policy in the wider Veneto Region, where it had “a tremendous impact on the course of the epidemic” there compared to other regions.

Loading...
Loading...
Don't miss any update on this topic

Create a free account and access your personalized content collection with our latest publications and analyses.

Sign up for free

License and Republishing

World Economic Forum articles may be republished in accordance with the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License, and in accordance with our Terms of Use.

The views expressed in this article are those of the author alone and not the World Economic Forum.

Stay up to date:

COVID-19

Related topics:
Geo-Economics and PoliticsHealth and Healthcare Systems
Share:
The Big Picture
Explore and monitor how COVID-19 is affecting economies, industries and global issues
World Economic Forum logo

Forum Stories newsletter

Bringing you weekly curated insights and analysis on the global issues that matter.

Subscribe today

What's 'bi-globalization' and could this be the near future for geo-economics and global trade?

Braz Baracuhy

December 19, 2024

Geopolitics and trade policy are becoming intertwined. Here's how it's impacting the global economy

About us

Engage with us

  • Sign in
  • Partner with us
  • Become a member
  • Sign up for our press releases
  • Subscribe to our newsletters
  • Contact us

Quick links

Language editions

Privacy Policy & Terms of Service

Sitemap

© 2024 World Economic Forum