During the summer there have been reports that people have been affected by the disease harpest. Above all, Dalarna, Hälsingland and southern Norrbotten are affected. For example, Region Gävleborg has received 33 reported cases since the beginning of July.

- There are also a number of cases that have not been reported yet because you want to wait for test answers. There are quite a few cases for us right now, says Signar Mäkitalo, infection control physician at Region Gävleborg, to TT.

Avoid mosquito bites

Above all, it is rodents and hares that carry the infectious disease caused by a bacterium. It is spread to humans mainly through mosquito bites, but the disease cannot be transmitted from person to person.

- The best way to protect yourself is to avoid mosquito bites and be careful when touching a dead animal. You can even get the bacteria if you breathe in infected dust. This year we have had a case where a person got the disease after a barn was cleaned, says Mäkitalo.

Sweden had a major outbreak of harpest in 2015. At that time, 859 people were affected throughout the country, of which 582 lived in Norrbotten and Västerbotten.

It's hard to say how big this year's outbreak is. Statistics from the Public Health Authority are lagging behind, but the Swedish National Veterinary Institute (SVA) receives many reports of dead animals from different parts of the country.

Many dead hares

- We are trying to bring in dead animals that are fresh, but not many have come in. So we do not yet have an increased number of positive cases, but there are definitely many dead hares in many places, says Erik Ågren, assistant state veterinarian and game pathologist at SVA.

Foremost are reports of suspected cases in Norrland. However, the prevalence - even though it is still a case of occasional cases - seems to be greater this year, Ågren says. Infected animals have been found in the Gothenburg area and outside Gislaved in Småland.

- But since the bacterium has been in the country for over 100 years, it can pop up anywhere, says Erik Ågren