Abstract

Every year, RIVM maps out the incidence of gastrointestinal infections in the Netherlands. For the first time, the information about all such infections has now been gathered in one overview. In 2020, the number of reported gastrointestinal infections fell sharply compared with the preceding years. This was probably due to the measures taken in the fight against coronavirus SARS-CoV-2.

The lockdown of cafes and restaurants, the decrease in the number of social events (including catering), international travel restrictions, social distancing and increased attention for hygiene (such as washing hands) reduced the contact between people and pathogens. Another reason is that due to the coronavirus crisis, people with a gastrointestinal infection were probably less likely to seek medical aid.

The number of norovirus and rotavirus infections in particular decreased during 2020 as compared to previous years. These viruses are spread mainly through human-to-human transmission. Food-related infections such as salmonellosis and campylobacteriosis also decreased significantly. The number of people who became ill with listeriosis, after infection with Listeria monocytogenes bacteria, remained unchanged. This bacterium is found especially in smoked fish, cheese and long-life meat products. The same applies to leptospirosis, an infection mainly transmitted through contact with water and mud.

Despite the overall sharp decline in gastrointestinal infections, a number of notable outbreaks were detected in 2020. In an outbreak, a single source of infection causes several individuals to fall ill. One example is the Salmonella Enteritidis outbreak in an institution for the disabled, where people were infected after eating a Turkish pizza delivered by a catering business. There was also a major norovirus outbreak related to a buffet on a boat. Finally, there were three minor listeriosis outbreaks linked to a food product (trout fillet, eel and soft cheese).