A recently published study suggests 11% of the population aged 20-64 in the Swiss canton of Ticino has come into contact with the SARS-CoV-2 virus.
The first results of the Corona Immunitas Ticino project, conducted by the Institute of Public Health of Università della Svizzera italiana and the Department of Business Administration, Health and Social Affairs of SUPSI, were published this week.
Randomly selected people aged 20-64 in the Italian-speaking canton of Ticino were tested for antibodies using a test developed by scientists at the CHUV hospital in Lausanne. Overall, 11% of this group tested positive for SARS-CoV-2 antibodies.
The researchers estimate that around 23,000 of the roughly 210,000 people in this age group in the canton have been exposed to the virus.
Currently, 3,661 cases have been recorded in the canton, representing a little over 1% of the population, so this study suggests real infection rates might be more than 10 times the recorded number.
The Ticino study mirrors a similar study run in the canton Geneva that found a 10.8% antibody positivity among a random sample of the population.
Geneva and Ticino had Switzerland’s highest per capita infection rates based on recorded case numbers. That Ticino’s antibody rates are as high as Geneva’s is no surprise.
Similar antibody studies across Switzerland reveal a wide range of infection rates. Vaud showed a seroprevalence of 7%, Basel 4% and Zurich 3%.
The next phase of antibody research in Ticino will focus on those under 20 and over 64. Research in Geneva revealed disproportionately low antibody positivity among those over 64 suggesting that many more in this group might have managed to avoid contact with the virus, something that might help to explain the relatively low mortality in Switzerland compared to some other nations in Europe. Phase 3 of the Ticino might reveal a similar pattern.
SUPSI press release (in Italian)