Hantavirus is a virus that can cause severe respiratory disease. It is spread through accidentally breathing in virus particles in dust from dry rodent urine or through contact with rodents or their droppings or nests.
Early signs in people include fever, headache, muscle aches, vomiting, diarrhea, abdominal pain, dizziness, and chills.
Follow CDC’s cleaning guidelines for cleaning areas that may have a rodent infestation, and air out unused buildings before entering.
Infection with hantavirus can progress to Hantavirus Pulmonary Syndrome (HPS), which can be fatal. People become infected through contact with hantavirus-infected rodents or their urine and droppings. The Sin Nombre hantavirus, first recognized in 1993, is one of several New World hantaviruses circulating in the US. Old World hantaviruses, found in Asia, can cause Hemorrhagic Fever with Renal Syndrome (HFRS). Rodent control in and around the home remains the primary strategy for preventing hantavirus infection. All cases of Hantavirus infection are reported to the CDC.
Signs & Symptoms for Hantavirus Pulmonary Syndrome (HPS)
Due to the small number of HPS cases, the “incubation time” is not positively known. However, on the basis of limited information, it appears that symptoms may develop between 1 and 8 weeks after exposure to fresh urine, droppings, or saliva of infected rodents.
Early symptoms include fatigue, fever and muscle aches, especially in the large muscle groups—thighs, hips, back, and sometimes shoulders. These symptoms are universal.
There may also be headaches, dizziness, chills, and abdominal problems, such as nausea, vomiting, diarrhea, and abdominal pain. About half of all HPS patients experience these symptoms.
Four to 10 days after the initial phase of illness, the late symptoms of HPS appear. These include coughing and shortness of breath, with the sensation of, as one survivor put it, a “…tight band around my chest and a pillow over my face” as the lungs fill with fluid.
Is the Disease Fatal?
Yes. HPS can be fatal. It has a mortality rate of 38%.
Diagnosing HPS in an individual who has only been infected a few days is difficult, because early symptoms such as fever, muscle aches, and fatigue are easily confused with influenza. However, if the individual is experiencing fever and fatigue and has a history of potential rural rodent exposure, together with shortness of breath, would be strongly suggestive of HPS. If the individual is experiencing these symptoms they should see their physician immediately and mention their potential rodent exposure.
Are there any complications?
Previous observations of patients that develop HPS from New World Hantaviruses recover completely. No chronic infection has been detected in humans. Some patients have experienced longer than expected recovery times, but the virus has not been shown to leave lasting effects on the patient.
There is no specific treatment, cure, or vaccine for hantavirus infection. However, we do know that if infected individuals are recognized early and receive medical care in an intensive care unit, they may do better. In intensive care, patients are intubated and given oxygen therapy to help them through the period of severe respiratory distress.
The earlier the patient is brought in to intensive care, the better. If a patient is experiencing full distress, it is less likely the treatment will be effective.
Therefore, if you have been around rodents and have symptoms of fever, deep muscle aches, and severe shortness of breath, see your doctor immediately. Be sure to tell your doctor that you have been around rodents—this will alert your physician to look closely for any rodent-carried disease, such as HPS.
How People Get Hantavirus Pulmonary Syndrome (HPS)
Where HPS is Found
Cases of HPS occur sporadically, usually in rural areas where forests, fields, and farms offer suitable habitat for the virus’s rodent hosts. The peridomestic setting (for example, barns, outbuildings, and sheds) are potential sites where people may be exposed to the virus. In the US and Canada, the Sin Nombre hantavirus is responsible for the majority of cases of HPS. The host of the Sin Nombre virus is the deer mouse (Peromyscus maniculatus), present throughout the western and central US and Canada.
Several other hantaviruses are capable of causing HPS in the US. The New York hantavirus, hosted by the white-footed mouse, is associated with HPS cases in the northeastern US. The Black Creek hantavirus, hosted by the cotton rat, is found in the southeastern US.
Cases of HPS have been confirmed elsewhere in the Americas, including Canada, Argentina, Bolivia, Brazil, Chile, Panama, Paraguay, and Uruguay.
Can pets transmit HPS to humans?
The hantaviruses that cause HPS in the United States are not known to be transmitted by any types of animals other than certain species of rodents. Dogs and cats are not known to carry hantavirus; however, they may bring infected rodents into contact with people if they catch such animals and carry them home. Guinea pigs, hamsters, gerbils, and rodents from pet stores are not known to carry hantavirus.
How Humans Become Infected with HPS
In the United States, deer mice (along with cotton rats and rice rats in the southeastern states and the white-footed mouse in the Northeast) are the reservoir of the virus. The rodents shed the virus in their urine, droppings, and saliva. The virus is mainly transmitted to people when they breathe in air contaminated with the virus.
When fresh rodent urine, droppings, or nesting materials are stirred up, tiny droplets containing the virus get into the air. This process is known as “airborne transmission“.
There are several other ways rodents may spread hantavirus to people:
- If a rodent with the virus bites someone, the virus may be spread to that person, but this type of transmission is rare.
- Researchers believe that people may be able to get the virus if they touch something that has been contaminated with rodent urine, droppings, or saliva, and then touch their nose or mouth.
- Researchers also suspect people can become sick if they eat food contaminated by urine, droppings, or saliva from an infected rodent.
The types of hantavirus that cause HPS in the United States cannot be transmitted from one person to another. For example, you cannot get the virus from touching or kissing a person who has HPS or from a health care worker who has treated someone with the disease. You also cannot get the virus from a blood transfusion in which the blood came from a person who became ill with HPS and survived.
People at Risk for HPS
Anyone who comes into contact with rodents that carry hantavirus is at risk of HPS. Rodent infestation in and around the home remains the primary risk for hantavirus exposure. Even healthy individuals are at risk for HPS infection if exposed to the virus.
Any activity that puts you in contact with rodent droppings, urine, saliva, or nesting materials can place you at risk for infection. Hantavirus is spread when virus-containing particles from rodent urine, droppings, or saliva are stirred into the air. It is important to avoid actions that raise dust, such as sweeping or vacuuming. Infection occurs when you breathe in virus particles.
Potential Risk Activities for HPS
Opening and Cleaning Previously Unused Buildings
Opening or cleaning cabins, sheds, and outbuildings, including barns, garages and storage facilities, that have been closed during the winter is a potential risk for hantavirus infections, especially in rural settings.
Cleaning in and around your own home can put you at risk if rodents have made it their home too. Many homes can expect to shelter rodents, especially as the weather turns cold. Please see our prevention information on how to properly clean rodent-infested areas.
Construction, utility and pest control workers can be exposed when they work in crawl spaces, under houses, or in vacant buildings that may have a rodent population.
Campers and Hikers
Campers and hikers can also be exposed when they use infested trail shelters or camp in other rodent habitats.
The chance of being exposed to hantavirus is greatest when people work, play, or live in closed spaces where rodents are actively living. However, recent research results show that many people who have become ill with HPS were infected with the disease after continued contact with rodents and/or their droppings. In addition, many people who have contracted HPS reported that they had not seen rodents or their droppings before becoming ill. Therefore, if you live in an area where the carrier rodents, such as the deer mouse, are known to live, take sensible precautions-even if you do not see rodents or their droppings.
Preventing Hantavirus Pulmonary Syndrome (HPS)
Eliminate or minimize contact with rodents in your home, workplace, or campsite. If rodents don’t find that where you are is a good place for them to be, then you’re less likely to come into contact with them. Seal up holes and gaps in your home or garage. Place traps in and around your home to decrease rodent infestation. Clean up any easy-to-get food.
Recent research results show that many people who became ill with HPS developed the disease after having been in frequent contact with rodents and/or their droppings around a home or a workplace. On the other hand, many people who became ill reported that they had not seen rodents or rodent droppings at all. Therefore, if you live in an area where the carrier rodents are known to live, try to keep your home, vacation place, workplace, or campsite clean.
For more information on how you can prevent rodent infestations, the following information is available on the CDC Rodents site.