Last updated: November 3, 2026. Medical disclaimer: This article is for general information only and is not medical advice. The Russia mouse fever situation is a developing story and reported figures may change — always follow official health guidance and your doctor's advice. If urination drops sharply, bleeding appears, or a patient becomes unusually weak, seek medical care promptly.

Mouse Fever Symptoms: Russia Hantavirus Outbreak & Home Care Guide

Written by Fatima Nursing Care

More than 1,500 people in Russia have been diagnosed with "mouse fever" in 2026 — a rodent-borne viral illness that causes high fever and, in severe cases, kidney damage. Cases are concentrated in five regions, and health experts link the autumn rise to rodents moving from fields into homes as the weather cools. Here is what is confirmed, what the symptoms look like, and how families can protect themselves.

Russia mouse fever outbreak: what happened

• The scale: A total of 1,512 cases of hemorrhagic fever with renal syndrome (HFRS), known as "mouse fever", were identified in Russia during 2026, according to a November 3, 2026 report by UNN citing The Moscow Times.
• The worst-hit regions: Udmurtia recorded the most cases at 656, followed by Bashkortostan with 367 and Nizhny Novgorod Oblast with 278. Cases are also spreading in Tatarstan and Saratov Oblast, with isolated cases reported in Pskov Oblast and the Moscow region.
• Sharply above average: The 1,512 cases are about 2.2 times higher than the long-term average for these regions, according to a November 2 report. In Nizhny Novgorod Oblast alone, cases rose 1.5-fold compared with last year.
• Why now: The outbreak coincided with autumn, when rodents migrate from fields closer to human settlements in search of warmth. Medical experts quoted in the reports say people can be infected while raking leaves at summer cottages, cleaning outbuildings, or even in cities where traces of mice — saliva or droppings — are present.
• Official position: Russia's consumer protection watchdog, Rospotrebnadzor, says the epidemiological situation remains stable and under control despite the increase in cases.

What is mouse fever?

Mouse fever is the common name for hemorrhagic fever with renal syndrome (HFRS), an acute infectious disease caused by hantaviruses carried by rodents, particularly field mice and gray rats. It is not a new virus, and it is not the same illness as rat-bite fever. The virus does not spread from person to person — every human infection starts with rodent contact.

People are usually infected by inhaling dust contaminated with rodent urine, droppings or saliva, for example while sweeping a dusty barn, cottage or storage room. Infection can also occur through contaminated food or through broken skin. Because the virus travels in dust, dry sweeping and shaking out old bedding or stored items are the riskiest everyday activities.

Mouse fever symptoms: what to watch for

Symptoms reported in the current outbreak and in medical guidance for HFRS include:

• Sudden high fever of 38–40 degrees Celsius, with chills
• Headache, muscle pain and lower back pain
• Abdominal pain and nausea
• Unusual redness of the face and upper body
• In severe cases, kidney damage and sharply reduced urination

The incubation period ranges from 4 to 49 days, most commonly 2 to 3 weeks — so a fever that appears weeks after cleaning a cottage or handling stored items can still be linked to rodent exposure. Tell the doctor about any rodent or dusty-storage exposure: mouse fever symptoms overlap with seasonal flu and other infections, and the exposure history is what points doctors toward the right diagnosis.

Warning signs that need urgent care

Most patients recover with supportive hospital care, but mouse fever can turn serious when the kidneys are affected. Seek medical care urgently for:

• Sharply reduced urination or no urine at all
• Severe lower back or abdominal pain
• Vomiting that will not stop, or any bleeding
• Confusion, extreme weakness or difficulty breathing

Do not wait these symptoms out at home. Kidney complications need hospital assessment, and early care gives the best outcome — especially for elderly patients and people with chronic illness.

How to prevent mouse fever at home

• Rodent-proof your home: Seal gaps around doors, pipes and vents, and keep food in sealed containers so rodents are not drawn indoors as temperatures fall.
• Clean dusty spaces safely: Ventilate sheds, barns and cottages before cleaning, wear a mask and gloves, and use a damp cloth or mop instead of dry sweeping, which throws contaminated dust into the air.
• Handle droppings with care: Do not sweep or vacuum rodent droppings dry. Dampen them first, wear gloves, and wash hands thoroughly with soap and water afterwards.
• Protect stored items: Store bedding, clothing and food in closed containers in outbuildings, and air and shake out stored items outdoors rather than inside a closed room.
• Keep yards tidy: Clear leaf piles, woodpiles and clutter near the house, where rodents shelter close to homes in autumn.

Home care for fever illness: practical guidance

Most mild fever illnesses can be managed at home with rest, plenty of fluids and regular symptom checks — but a fever after rodent exposure deserves a prompt call to a doctor, not watchful waiting alone, because kidney warning signs can develop after the fever phase. Watch urine output closely: a patient who stops passing urine normally, or who develops severe back pain or bleeding, needs urgent hospital care.

For elderly patients and people with chronic conditions, close monitoring matters most. A home nurse can check temperature and fluid intake daily, watch urine output and warning signs, help with hydration and meals, and support the family in following the doctor's advice — so a vulnerable patient is never left unmonitored at home.