Rash reaction: outbreak of "mouse fever" recorded in Russia
A surge in hemorrhagic fever with renal syndrome (HFRS) has been recorded in Russia. This infection is also called "mouse infection" because rodents are its main carriers. In the first ten months of 2025, the number of people infected in the Urals has tripled compared to the same period last year. In the Saratov, Oryol regions and Bashkiria, the incidence doubled, in the Orenburg region and Udmurtia — almost tripled, Rospotrebnadzor reported. The outbreak occurred due to the warm autumn and winter, experts say. About the dangers of "mouse fever" and how to protect yourself from it, see the Izvestia article.
Send more cats.
From January to October 2025, more than 3.3 thousand Russians became infected with mouse fever, which is one and a half times more than in the same period last year. Such data was provided by the Kazan Scientific Research Institute of Epidemiology and Microbiology (KNIIEM) Rospotrebnadzor.
"In the first ten months of 2025, the incidence was registered in eight federal districts and 54 regions of Russia," the HFRS monitoring reference center noted. —The urban population prevailed among the cases — 86%, rural residents accounted for 13%."
They pointed out that the "unfavorable epizootological situation" has developed due to abnormally high temperatures for November and December.
In the Urals, the incidence of "mouse fever" has tripled, according to the CNIEM report. At the same time, more than 80% of all cases of infection registered in the country since the beginning of the year have been detected in the Volga region — an increase in the incidence is noted there "in all regions except Tatarstan and Chuvashia." In the Saratov region and Bashkiria, the number of people infected with HFRS doubled, and in the Orenburg region and Udmurtia — almost three times, the local departments of Rospotrebnadzor reported.
"No matter how strange it may seem, our rural population is less ill than the urban population," said Anastasia Sidorova, head of the Rospotrebnadzor Surveillance Department for the Udmurt Republic. — This is due to the fact that most of the patients are from Izhevsk and Zavyalovsky district. They go to their garden plots and get infected there."
A sharp rise in infection also occurred in Dimitrovgrad, Ulyanovsk region. According to the city administration, 50 local residents have been infected with mouse fever since the beginning of 2025. For comparison, 13 cases were registered last year. On social media, people complain about the invasion of field mice and ask to "send them more cats" to fight the rodents.
In the Orel region, the incidence of HFRS has almost doubled this year, and pensioners are most often diagnosed with the infection. A slight increase of 22% is also observed in the Far East. In Primorsky Krai, more than 35 cases of "mouse fever" were detected in 2025, which is the highest rate in the Far Eastern Federal District, the local department of the supervisory authority noted.
A seasonal increase in cases of HFRS was recorded in the fall of 2025, "due to the activation of natural foci in some regions of the Volga Federal District," Rospotrebnadzor told Izvestia.
"A full range of preventive and anti—epidemic measures has been carried out — the situation will not worsen," they noted.
However, over the years, there has been a steady decline in morbidity throughout Russia, the supervisory authority stressed.
"The figures are now three times lower than the last rise in 2019 and one and a half times lower than the average annual values. The seasonal increase in morbidity is associated with the autumn migrations of small mammals," the ministry noted.
Rospotrebnadzor pointed out that "mouse fever" is generally characterized by cyclical increases in morbidity — approximately every two to four years and seasonal — in summer and autumn.
What is the danger of "mouse fever"?
"Mouse fever" is not transmitted from person to person, and therefore there can be no epidemic — only outbreaks in certain regions that can be controlled, Vladimir Nikiforov, head of the Department of Infectious Diseases and Epidemiology at N.I. Pirogov Medical University and chief infectious disease specialist at the FMBA, told Izvestia.
— Rodents carry the infection, but they don't get sick themselves. Now they are attracted to human habitats, as there is no snow this year, but there are frosts. In Moscow, for example, the grass has withered and the mice have nothing to eat. The situation may be similar in other regions," he explained.
Hemorrhagic fever with renal syndrome is transmitted through food and drinking water contaminated with rodent secretions, Irina Volgina, associate professor of the Department of Therapy at the Medical Faculty of the State University of Education, reminded Izvestia.
— The disease got its name because the kidneys suffer the most from it. Delayed detection of HFRS can lead to kidney failure. But serious complications can be avoided if you start treatment on time," the expert said.
Infection also occurs when inhaling dust containing rodent excrement, while working in basements, cellars and dry cleaning of premises, added Vladimir Neronov, MD, Infectious diseases specialist at JSC "Medicine".
"The symptoms include headache, fever, back pain, and signs of kidney damage," he told Izvestia. — The disease is dangerous because the early stages of its manifestation may resemble the flu or other colds with severe febrile syndrome.
According to the infectious disease specialist, up to 8% of cases of infection with "mouse fever" are fatal.
At the same time, Irina Volgina noted, classic hemorrhagic fever with a temperature below 40 degrees and a rash that "looks like wounds after whiplash" is now extremely rare. The disease usually resolves in a mild form.
How to protect yourself from infection
There is no vaccine against hemorrhagic fever, the doctors interviewed by Izvestia emphasized. According to Vladimir Neronov, patients are treated in an infectious diseases hospital, affecting the main symptoms of the disease.
— Prevention is based on strict hygiene. It is necessary to wash hands and food thoroughly, use masks and respirators when working in rooms where mice or rats may live. In addition, protective measures include rodent control," the expert said.
Ekaterina Makarova, a doctor of integrative medicine, advised to be careful while working at the cottage, harvesting dead leaves and walking in the forest. In addition, lovers of hunting, fishing and other outdoor activities are at risk. Olga Goryacheva, Candidate of Medical Sciences, doctor at the Soft Medical Center clinic, said that wet cleaning and ventilation of rooms will help reduce the risk of infection. You should also keep food out of the reach of rodents, she concluded.
Переведено сервисом «Яндекс Переводчик»
