The question of why the number of cases of swine fever in humans varies so much between winters and why there was a major outbreak of swine fever with more than 2,000 cases in northern Sweden in 2007 has eluded researchers at the Swedish University of Agricultural Sciences (SLU) in Umeå for several years. .
By combining the time series on the degree to which forest mice hit the amount of precipitation, and whether the precipitation came as rain or snow, she has now revealed a clear pattern.
It seems almost no matter how the weather is the rest of the winter, if there is a lot of rain in November, the infection rate among rats increases, says Frauke Ecke, project manager and senior lecturer in the Department of Game, Fish and Environment at SLU in Umeå.
The most common in the north is sock fever
Forest rats are found almost throughout Sweden, but more than 90 percent of volcanic fever cases in humans are found in the country’s four northernmost counties.
If there is thin snow on the ground, it is easy to move the nozzles over large areas under the protective snow cover. If there is rain on the snow, there is no room for rodents to move, they gather in places where rain or snow does not inhabit and the spread of the virus among them increases.
Remember this winter
In order to increase the risk of people becoming infected, it is also necessary to have the so-called peak year for the forest eagle. About every three to four years the number of eagles is unusually large, then the breed collapses and the animals become much smaller before the breed gradually builds up again.
As global warming has made the temperate months of November in the north more common, the risk of it coinciding with a peak year for volcanic eruptions has increased.
– If there is heavy rain in November of this year, there is a risk of an outbreak of swine fever, says Frauke Ecke and continues:
There is talk about the consequences of climate change in the future, but what we see in this study is that it has already happened.
Healthcare has been warned
The new discovery could help prepare health care for the next time swine fever cases spike
The outbreak of the disease in 2007 came as a surprise to the regions. Much has been learned about the disease since then. Our volcanic forecasts are quite reliable, if you see that the increase in forest seasons continues in the fall and it will rain in November, it is time to go out with a warning and ask people to be careful, says Frauke Eke.
Facts: Sork Fever
Swine fever is a viral disease that spreads through cankers in forests.
Sork fever is in principle restricted to areas north of Dalvin, although isolated cases have been reported from other areas.
Spread of infection from woodland mice to humans occurs primarily through inhalation of dust contaminated with orifice urine and faeces or through direct contact with saliva, urine, or faeces.
Symptoms are high temperature, muscle aches, general malaise, and severe pain in the abdomen and back. The kidneys are affected and skin hemorrhages can sometimes occur. Almost everyone recovers without permanent damage.
Source: Swedish Public Health Agency
Facts: How to protect yourself
There is no vaccine against swine fever, but to prevent the spread of infection the following should be considered:
Avoid direct contact with rodents.
Avoid inhaling dust that may be contaminated with faeces.
When cleaning, do not vacuum or dry it. Instead, spray with a cleaner or disinfectant and then clean with a damp, disposable cloth. Put on gloves and wash your hands well afterwards with soap or hand sanitizer.
Use gloves when handling feces, dead nozzles, or objects that often have nozzles, such as firewood.
For added safety, respiratory masks used correctly can reduce the risk of transmitting airborne infections.
Source: Swedish Public Health Agency