The risk that flies can spread MRSA and mink can infect humans with coronavirus demonstrates the need for a robust surveillance system for zoonoses, which also generates solid data on non-foodborne zoonoses. Read the annual report on the incidence of zoonoses in Denmark for 2020.
Zoonoses are diseases that can be transmitted from animals and food to humans. In order to prevent and control the occurrence of zoonotic disease in humans, it is important to know which animals and foods are the most significant causes of illness in humans.
Denmark has a well-developed surveillance system, which can monitor trends in the occurrence of foodborne zoonoses throughout the farm-to-fork chain. However, the surveillance system also generates solid data on non-foodborne zoonoses in Denmark.
Flies can carry MRSA over great distances
The National Food Institute in cooperation with Statens Serum Institut and the Danish Veterinary and Food Administration has just published the annual report on the occurrence of zoonoses in Denmark for 2020. It contains data from a Danish study conducted by the University of Copenhagen, which shows that flies can likely carry MRSA from an infected pig farm to other farms or residential addresses.
In total, 27% of the house flies and 7% of the stable flies that were caught by the researchers over the course of several weeks at one pig farm for the study, were carriers of MRSA. In many cases, they carried live MRSA for up to two days after they were caught.
Because flies can travel very far during that time, they could potentially carry MRSA to other farms—or even private homes given that two thirds of Danish residential addresses are located less than three kilometres from a pig farm.
The researchers did not study to what degree the flies are able to transmit MRSA to new pigs or to humans. As such, the study does not provide documentation that they can infect new hosts, even though it has shown that the flies can reach other animals or humans, while they are carrying MRSA.
Mink and humans
The report also describes the Danish efforts to monitor, contain and control the transfer of coronavirus between mink and humans during the epidemic.
During the autumn of 2020, it became evident that mink were susceptible to the SARS-CoV-2 virus. At the time, Denmark was the world’s largest producer of mink fur. The transfer of virus from mink to humans along with the possibility that the virus could mutate as it made its way through the mink population was assessed as being a threat to Danish public health.
Both the zoonotic aspect of the SARS-CoV-2 outbreak in mink and the way the outbreak progressed has created an increased focus in Denmark on the monitoring and handling of non-foodborne zoonoses.
Read more
The annual report presents a large amount of data collected by authorities and the industry in Denmark on the incidence of zoonoses in feed, animals, food and humans. Many of the tables include datasets that span more than ten years and as such provide an opportunity to follow trends over time.
Find the full report on the National Food Institute’s website: Annual Report on Zoonoses in Denmark 2020 (pdf). You can also have the printed report sent to you by contacting Vibeke Dybdahl Hammer, vdha@food.dtu.dk.
Read about the data presented in the report in a press release: Corona restrictions lead to fewer cases of foodborne illness.