Hantavirus is a rare but potentially deadly virus that can be transmitted to humans through contact with rodents or their waste material. The question of whether you can get hantavirus simply from touching a mouse comes up often, as mice infestations are common and contact is inevitable for many people.
The short answer is: yes, it is possible to contract hantavirus from touching an infected mouse, but the chances are very low. Hantavirus does not spread easily between people or between animals and people. Transmission almost always occurs through inhaling contaminated dust from rodent droppings, nests, or urine. However, the virus can also enter the body through breaks in the skin, so barehanded contact does pose a small risk.
What is hantavirus?
Hantavirus refers to a group of viruses that are found in wild rodents like mice, rats, voles, and chipmunks. Different strains of hantavirus occur across the Americas, Europe, and Asia, each named after the region where they were first discovered.
In North America, the strain that causes most human illness is the Sin Nombre virus, spread by deer mice. Other strains include the New York virus, found in white-footed mice, and the Bayou virus in the southern United States.
Hantaviruses do not appear to cause disease in their rodent hosts, who can be lifelong carriers of the virus. The viruses are shed in rodent urine, droppings, and saliva. Humans generally contract hantavirus when they breathe in tiny particles contaminated with the virus.
When hantaviruses do jump to humans, they can cause two diseases:
Hantavirus pulmonary syndrome (HPS) – Also called hantavirus cardiopulmonary syndrome, HPS is the most serious form of hantavirus disease. It causes severe respiratory problems and has up to 40% mortality rate.
Hemorrhagic fever with renal syndrome (HFRS) – Found in Europe and Asia, HFRS causes kidney damage and bleeding. Mortality ranges from less than 1% up to 15%.
There is no cure, vaccine, or specific treatment for hantavirus infections except mechanical ventilation to support breathing. However, if recognized early, patients have a better chance of recovery.
Can you get hantavirus directly from touching mice?
The primary route of hantavirus transmission to humans is through inhaling contaminated dust that is shed by infected rodents. This can happen when disturbing or cleaning up rodent nests, burrows, droppings, urine, or saliva. Activities like sweeping, vacuuming, and hiking can stir infected particles into the air where they can be breathed in.
Touching mice alone is unlikely to transmit hantavirus through intact skin. However, direct contact still poses some risk, which increases if the skin is broken or scratched. Bites from infected mice would also introduce virus particles into the wound and underlying tissue.
Here are some ways touching mice might lead to hantavirus transmission:
– Bite wounds – Mouse bites can break the skin barrier and introduce virus particles. All rodent bites should be thoroughly cleaned as they are prone to infection.
– Scratches – Scratches from mice claws or brushing against rough surfaces in nests may allow virus entry through damaged skin.
– Mucous membrane contact – Touching the eyes, nose or mouth after handling mice may transfer virus and provide an entry point.
– Cuts and abrasions – Any openings, sores or cuts on the hands and arms are potential routes for the virus to penetrate into the body.
– Indirect contamination – Touching objects contaminated with urine or droppings and then touching the face could transmit virus particles.
The overall risk is still low, as hantaviruses are not efficiently transmitted even with direct contact. But it is best to avoid touching mice and to take precautions that minimize exposure. Promptly washing hands with soap and water after contact can also reduce infection risk.
What are the symptoms of hantavirus?
Symptoms of hantavirus pulmonary syndrome (HPS) take 1-5 weeks to develop after exposure as the virus incubates. Initial symptoms include:
– Fever
– Fatigue
– Muscle aches
After a few days, affected individuals will suddenly develop severe respiratory distress:
– Shortness of breath
– Coughing
As fluid builds up in the lungs, symptoms rapidly worsen to:
– Difficulty breathing
– A sensation of “tightness” in the chest
– Rapid heart rate
Low blood pressure, fluid in the lungs, and oxygen levels that become dangerously low can lead to respiratory failure, shock, and death. The individual may feel better for a day or two but then decline again as fluid continues filling the lungs. Only about a third of patients survive once the pulmonary edema phase starts.
People with hemorrhagic fever may experience:
– Fever
– Back and abdominal pain
– Headaches
– Nausea
– Blurred vision
– Flushed skin
After a few days, increased bleeding occurs:
– Bleeding from the gums
– Bruises
– Bloody urine
– Bloodshot eyes
Low platelet counts and dissemintated intravascular coagulation lead to hemorrhages. Kidney function also declines. With proper medical care, fatality rates for HFRS are much lower than for HPS.
Who is at risk of hantavirus?
Anyone who comes into contact with infected rodents or their contaminated environments is at risk of hantavirus. However, activities that stir up dust and aerosolize the virus pose the greatest risk of inhaling it.
High risk groups include:
– People who work and play in infested environments like cabins and barns
– Pest control workers
– Field biologists
– Construction and utility workers
– Military personnel
– Farmers and ranchers
– People who clean up rodent infestations without protective gear
Rodent infestations are most common in rural settings at higher elevations. The majority of hantavirus cases in the United States occur west of the Mississippi River in states like New Mexico, Colorado, Arizona, California, Washington, and Montana. Cases peak in late spring and summer when outdoor activities increase.
Can you get hantavirus from pet rats or mice?
Pet rats, mice, gerbils, and other pocket pets sold in stores are not natural carriers of hantaviruses. They do not pose a risk for transmitting the virus to their owners. Wild rats and house mice can potentially carry hantavirus if they have come into contact with infected rodents in nature. But hantavirus transmission from wild rats to humans is extremely rare.
Can humans transmit hantavirus?
Hantaviruses cannot spread between humans or directly between rodents. Transmission requires infection through contact with contaminated materials from infected rodents.
The only exception is Andes virus, a rare hantavirus strain found in South America. Documented cases of human-to-human transmission have occurred from close contact with infected individuals. But even for Andes virus, the risk of transmission apart from the rodent host appears very low. There is no evidence for any other hantavirus strains being passed from person to person.
Can you get hantavirus from food contaminated by mice?
Rodent droppings and urine sometimes contaminate food supplies, especially grains. Eating food contaminated with hantavirus would not transmit the virus and cause disease. Hantaviruses are not foodborne illnesses.
Swallowing hantavirus does not lead to infection. The virus would be killed by stomach acid. Inhaling contaminated dust into the lungs is required for the virus to enter the body and cause illness.
However, food contaminated by mice should not be consumed for other reasons:
– May contain disease-causing bacteria like salmonella
– Mouse droppings and urine can cause other illnesses
– Carry a risk of biting into sharp objects like bone fragments
Proper food storage and handling hygiene helps avoid indirect hantavirus exposure by reducing mouse infestations. But the disease cannot be caught just by eating infected food.
How to prevent hantavirus infection
The most effective ways to lower hantavirus risk are to avoid coming into contact with infected rodents and eliminate any infestations. Prevention recommendations include:
– Use rodent traps and keep homes, garages, sheds rodent-proofed
– Clear brush, grass, and junk piles around the home to remove nesting sites
– Seal holes, cracks, and gaps in walls, floors, roofs, doors, and windows
– Store food, pet food, and garbage securely in rodent-proof containers
– Ventilate areas like barns, cabins, and crawlspaces before cleaning to allow virus particles to disperse
If rodent infestation is present:
– Do not sweep, vacuum, or disturb nests – this stirs up contaminated dust
– Ventilate the area first, then spray nests, droppings etc with disinfectant or bleach solution before removing
– Wear protective gloves, goggles, mask, coveralls – avoid bare skin contact
– Mop or sponge-clean contaminated areas rather than sweeping
– Disinfect or dispose of items that cannot be washed like mattresses or stuffed furniture
What should you do if you touch a mouse?
While the odds of contracting hantavirus from simply touching a mouse are exceedingly slim, it is smart to take precautions following contact. Here are steps to help reduce infection risk:
– Wash hands immediately – Use soap and warm water; scrub well for 20 seconds
– Avoid touching eyes, nose or mouth before washing up
– Wash arms past elbows if exposed skin had contact
– Apply antiseptic to any bites, cuts or scratches
– Seek medical care for rodent bites to lower bacterial infection risk
– Monitor for symptoms like fever or muscle aches in the following 6 weeks
Diagnosing hantavirus
Hantavirus is challenging to diagnose, especially early on when symptoms mimic other common illnesses like influenza. Doctors may suspect hantavirus based on potential exposure history and a rapid progression to respiratory distress.
Blood tests can detect hantavirus antibodies but results take time to confirm. Testing for viral RNA by PCR offers faster results. Imaging exams like x-rays and CT scans may reveal characteristic findings like fluid in the lungs.
Lab tests to help diagnose hantavirus include:
– Serologic assays – Antibody blood tests taken at two points in time to look for a rise in antibody levels against hantaviruses. Results confirm recent infection but are retrospective.
– Immunohistochemistry – Detects viral antigens in tissue samples from lung biopsy or autopsy.
– Reverse transcriptase polymerase chain reaction (RT-PCR) – Detects viral RNA from blood, tissues, or fluids. Provides faster results than antibody tests.
– Viral culture isolation – Growing the virus in cell culture from blood or tissues. Difficult and limited availability.
Treatment relies on managing symptoms and complications. There are no antiviral drugs proven effective for hantaviruses. Patients with HPS need ventilator support and intensive care to improve the chances of recovery. Dialysis may be required for kidney injury from HFRS. Preventing exposure remains key, as prognosis is poor once severe symptoms arise.
Hantavirus infection statistics and facts
Here are some key statistics and facts about hantavirus epidemiology in the United States:
– Average of 17-48 cases per year for the past decade
– Over 700 cases reported since tracking began in 1993
– 36% case fatality rate for hantavirus pulmonary syndrome
– Majority of cases in western and southwestern states
– 90% of cases associated with exposure in rural areas
– Peak incidence in May, June, and July
– Most common in adults aged 30-50 years
– 2 times more common in males than females
– Outbreaks of up to 15 associated cases can occur
– Deer mice (Peromyscus maniculatus) responsible for most cases
– Sin Nombre virus strain causes 95% of cases
– No documented cases from pet rats or mice
– Rare disease but can have high mortality if infected
While incidence remains low overall, hantavirus should be considered as a potential diagnosis in cases of unexplained respiratory illness with known rodent exposure. Public education and precautions when handling rodents or cleaning infested spaces is crucial to avoid this life-threatening yet preventable zoonotic disease.
Hantavirus cases maps
| State | 1993-2015 Cases |
|---|---|
| New Mexico | 110 |
| Colorado | 101 |
| Arizona | 90 |
| California | 84 |
| Washington | 50 |
| Utah | 29 |
| Oregon | 24 |
| Idaho | 23 |
| Texas | 21 |
This table shows the top 9 states for reported hantavirus cases from 1993 through 2015. The majority occurred in southwestern states like New Mexico, Colorado, Arizona, and California where the primary carrier (the deer mouse) is abundant. However, cases have occurred in 30 different states over this time period.
Conclusion
Hantaviruses can cause severe and potentially fatal respiratory disease but are uncommon. Transmission almost always occurs by inhaling dust contaminated by infected rodents – not through direct contact. So while touching mice does carry a small degree of risk, especially if skin is broken, this type of contact alone is extremely unlikely to transmit hantavirus. Far greater risks come from exposure to aerosolized virus when cleaning or occupying rodent infested areas. By controlling rodent populations, avoiding contact with droppings, and proper hygiene, hantavirus infections can be prevented.