Covid precautions led to a drop in other infectious diseases

The closure of recreation centers and the consequent increase in outdoor pursuits was partly responsible for the decline Keystone / Laurent Gillieron

Switzerland saw a 20% drop in known cases of highly infectious diseases in 2020 as a result of government and individual measures taken to contain the spread of Covid-19. 

On Monday, the Federal Office of Public Health (FOPH) revealed that around 65,000 cases of highly infectious diseases were reported last year. These fall under a list of 16 diseases such as tuberculosis, salmonella or Legionnaires’ disease that must be notified to the health authorities.  

The decline in cases ranged from 15% to 90% compared to the expected values based on the years 2015-2019. Only the number of cases of tick-borne meningoencephalitis increased (13%) in 2020. 

The closure of recreation centers and the consequent increase in outdoor pursuits was partly responsible for the decline, according to FOPH. Wearing a mask, keeping a safe distance and limiting travel, also reduced transmission from person to person by water droplets.  

Four categories 

The 16 diseases are grouped into four categories. Among the respiratory diseases, the decrease was 26% for tuberculosis, 58% for pneumococcal infection and 32% for Legionnaires’ disease, a kind of pneumonia. The closure of leisure centers and the decrease in hotel stays led to a lower exposure to water installations that may contain legionella, a type of bacteria that causes lung infections, according to the FOPH. 

With regards to fecal-oral route of disease transmission, the decline ranged from 24% for campylobacteriosis to 82% for shigellosis, two types of bacterial infections that cause diarrhea. Among vector-borne diseases, malaria and dengue fever also declined significantly, 72% and 90% respectively. There were fewer travel-related infections as international and domestic travel plummeted.   

Reported cases of sexually transmitted diseases were below the normal curve with a decline in 15% for chlamydia and 36% for syphilis. The reduction in personal contacts due to Covid restrictions could have led to a reduction in sexual contacts outside fixed relationships, particularly with the closure of brothels imposed by many cantons, the FOPH noted, even if it has no data to confirm the hypothesis.