U.S. Hantavirus Data
Hantavirus by the Numbers
Total U.S. Cases
890+
reported since surveillance began in 1993
Mortality Rate
38%
of those who develop respiratory symptoms
Western U.S.
94%
of cases occur west of the Mississippi River
Incubation Period
1-8 weeks
between exposure and symptoms
Source: CDC Hantavirus Surveillance Data
What Is Hantavirus?
Hantaviruses are a group of viruses carried by rodents, particularly mice and rats, transmitted to humans through contact with rodent droppings, urine, or saliva. According to the Centers for Disease Control and Prevention (CDC), more than 890 cases of hantavirus disease have been reported in the United States since national surveillance began in 1993, with the vast majority occurring in western states.
The virus causes two primary types of illness:
- Hantavirus Pulmonary Syndrome (HPS): The most common form in the United States, HPS is a severe respiratory disease that affects the lungs and heart. It is caused by hantavirus strains found in the Western Hemisphere, including Sin Nombre virus (the most common in the U.S.), Bayou virus, Black Creek Canal virus, and others.
- Hemorrhagic Fever with Renal Syndrome (HFRS): Caused by hantavirus strains found primarily in Europe and Asia, HFRS affects the kidneys. Seoul virus, which causes HFRS, is found worldwide, including in the United States.
The CDC reports that HPS has a mortality rate of about 38% among those who develop respiratory symptoms, making it one of the deadliest rodent-borne diseases in North America.
Where Hantavirus Is Found
Hantavirus cases have been reported in most U.S. states, but the disease is most common in the western United States. According to CDC surveillance data, approximately 94% of all U.S. hantavirus cases have occurred west of the Mississippi River, with New Mexico, Colorado, Arizona, and California accounting for the highest number of cases.
The virus was first identified in the United States in 1993 during an outbreak in the Four Corners region (where Arizona, Colorado, New Mexico, and Utah meet). Since then, cases have been documented across the country, though they remain relatively rare, averaging fewer than 30 cases per year nationally.
Deer mice are the primary carriers of Sin Nombre virus, the most common hantavirus strain in the United States. However, other rodent species can carry hantavirus, and recent research from the University of New Mexico found that more than 30 small mammal species in the state carry live hantavirus, including ground squirrels and chipmunks.
Transmission Methods
How Hantavirus Spreads to Humans
1
Breathing Contaminated Dust
Most common transmission method. Virus particles become airborne when rodent droppings or nesting materials are disturbed during cleaning, sweeping, or other activities.
2
Touching Contaminated Surfaces
Contact with rodent urine or droppings, then touching the mouth, nose, or eyes before washing hands.
3
Bites or Scratches
Rare transmission method. Direct bite or scratch from an infected rodent can spread the virus.
Person-to-person transmission is extremely rare. Only one strain (Andes virus) has shown limited human-to-human spread.
Research shows that approximately 90% of U.S. hantavirus infections are acquired through household or occupational exposures, making rodent control in both residential and workplace settings extremely important.
Symptoms of Hantavirus Infection
One of the most dangerous aspects of hantavirus is that early symptoms closely resemble the flu, often leading people to delay seeking medical care until the disease has progressed to a life-threatening stage.
Symptom Progression
How Hantavirus Develops
Initial Exposure
Contact with infected rodent droppings, urine, saliva, or contaminated dust.
1-8 Weeks Later
No symptoms; the virus incubates silently in the body.
Early Symptoms Begin
Initial symptoms appear and can easily be mistaken for influenza or other common viral illnesses:
Fever & Chills
Severe Muscle Aches
Headache
Fatigue
Nausea & Vomiting
Diarrhea
Dizziness
Abdominal Pain
Note: Severe muscle aches particularly affect thighs, hips, back, and shoulders.
4-10 Days Later: Critical Phase
If the infection progresses to Hantavirus Pulmonary Syndrome (HPS), patients develop severe respiratory symptoms that require immediate intensive medical care:
Coughing
Severe Shortness of Breath
Fluid in Lungs
Rapid Heartbeat
Drop in Blood Pressure
Respiratory Failure
Note: Once respiratory symptoms develop, the disease can progress extremely rapidly, sometimes within hours.
Treatment & Prevention
There is no cure or vaccine for hantavirus. Treatment is purely supportive, focusing on managing symptoms and supporting vital organ function while the body fights the infection.
Patients with HPS typically require:
- Hospitalization in intensive care units
- Oxygen therapy or mechanical ventilation
- IV fluids and medications to support blood pressure
- Close monitoring of heart and lung function
Early medical intervention significantly improves survival odds. According to medical experts, recognizing symptoms early and seeking immediate treatment is critical because the virus can progress to respiratory failure very quickly once lung symptoms begin.
Prevention Essentials
How to Reduce Hantavirus Risk
Seal entry points
Close gaps and holes in walls, foundations, and roofs to prevent rodents from entering buildings.
Set traps and control rodents
Use spring-loaded traps in and around buildings to reduce rodent populations.
Secure food and garbage
Store food in sealed containers and keep garbage in bins with tight-fitting lids.
Never sweep or vacuum rodent droppings
This can aerosolize the virus. Instead, spray with disinfectant, wait 5 minutes, then wipe with paper towels.
Wear gloves and masks when cleaning
Use rubber gloves and respirator masks when cleaning rodent-infested areas; ventilate for 30 minutes first.
Arnold & Itkin's $209 Million Hantavirus Verdict
Arnold & Itkin won a $209 million jury verdict in a hantavirus wrongful death case involving an employer's failure to warn workers or control rodent populations.
The case involved a drilling company operating in Western Colorado, an area with known hantavirus risk. Despite possessing written safety policies addressing hantavirus prevention and pest control, the company failed to implement those policies. Workers were never trained to recognize hantavirus symptoms, never warned about the virus despite working in an endemic area, and were housed in facilities where rodent infestations went uncontrolled.
When the worker developed symptoms, he assumed he had the flu—exactly the kind of misunderstanding that proper training would have prevented. By the time he sought emergency medical treatment, hantavirus had progressed to his lungs. He died that evening.
Attorneys Caj Boatright and Roland Christensen proved that the company's failures directly caused the worker's death. The jury awarded $103.6 million in compensatory damages to the family and added $105.6 million in punitive damages. This was a clear signal that the company's conduct was not just negligent but recklessly indifferent to worker safety.
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Hantavirus cases are rare, but we’ve learned what it takes to win. After litigating a serious hantavirus wrongful death case to verdict, we know many companies do not take adequate precautions and do not provide the care needed to save victims from the deadly virus.
This case established important precedent: companies operating in hantavirus-endemic regions cannot simply write safety policies and ignore them. They must actively warn workers, control rodent populations, and train employees to recognize potentially fatal symptoms early.
Legal Liability for Hantavirus Exposure
When hantavirus infections occur due to negligence, victims and their families may have legal claims against responsible parties. Liability can arise in multiple contexts:
Employer Liability
Employers who operate facilities in areas where hantavirus is known to occur have a duty to:
- Inform workers about hantavirus risks
- Provide training on recognizing symptoms
- Implement rodent control measures
- Maintain sanitary living and working conditions
- Supply appropriate protective equipment when needed
Failing to take these precautions, particularly when the employer is aware of hantavirus presence in the region, can constitute gross negligence. As the $209 million verdict demonstrated, juries may award substantial compensatory and punitive damages when employers knowingly expose workers to preventable hantavirus risks.
Property Owner Liability
Property owners, including landlords, hotels, campground operators, and vacation rental companies, may be liable for hantavirus exposure if they:
- Fail to control rodent infestations
- Do not warn guests or tenants about known rodent problems
- Neglect to maintain properties in a safe, sanitary condition
- Ignore complaints or evidence of rodent activity
A 2012 Yosemite National Park hantavirus outbreak, which killed three visitors who stayed in tent cabins at Curry Village, resulted in lawsuits against the concessionaire operating the facilities. Investigations revealed rodent infestations in the cabins where victims stayed.
Facilities & Institutions
Schools, warehouses, storage facilities, and other institutions where people may encounter rodent-infested areas also have duties to:
- Regularly inspect for rodent activity
- Implement pest control programs
- Clean and disinfect contaminated areas properly
- Warn occupants if rodent infestations are discovered
Legal Standards
Establishing Liability for Hantavirus
1
The defendant knew or should have known about rodent infestations or hantavirus risk.
2
The defendant failed to take reasonable precautions to control rodents or warn about the danger.
3
The victim was exposed to hantavirus as a result of the defendant’s negligence.
4
The exposure caused the victim’s illness or death.
Critical Evidence
Medical records, testing confirming hantavirus infection, evidence of rodent infestations, and proof that the defendant failed to implement proper pest control or warnings are all critical to these cases.
When to Contact an Attorney
If you or a loved one developed hantavirus after exposure in a workplace, rental property, hotel, or other facility where rodent control should have been maintained, you may have legal recourse.
Consider contacting an attorney if:
- Your employer knew about hantavirus risks but failed to warn you or control rodents
- You contracted hantavirus while staying at a hotel, rental property, or campground with rodent infestations
- A property owner ignored complaints about rodent problems
- You were not provided with proper training or protective equipment for work in rodent-infested areas
- A loved one died from hantavirus after preventable exposure
Hantavirus cases require attorneys who understand both the medical complexities of the disease and the legal standards for proving negligence. At Arnold & Itkin, we have extensive experience litigating a wide range of catastrophic injury and wrongful death claims involving preventable illnesses and injuries. We have recovered more than $25 billion for the injured and wronged, standing up against some of the biggest companies on the planet and holding them accountable for their wrongdoing.
We handle hantavirus cases on a contingency fee basis, meaning you pay nothing unless we win. Call (888) 493-1629 for a free, confidential consultation about your case.
