Hantavirus Pulmonary Syndrome # HPS

What is Hantavirus Pulmonary Syndrome?

Hantaviruses are single-stranded, enveloped, negative sense RNA viruses in the Bunyaviridae family. They normally infect rodents and don’t cause disease in these hosts. Humans may become infected with hantaviruses through contact with rodent urine, saliva, or feces. Some strains of hantaviruses cause potentially fatal diseases in humans, such as Hantavirus hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), while others have not been associated with known human disease.

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).

Hantavirus Pulmonary Syndrome (HPS) is a severe, sometimes fatal, respiratory disease in humans caused by infection with a hantavirus. 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.

Hantavirus is a life-threatening disease spread to humans by rodents. It has symptoms similar to influenza.

Hantavirus pulmonary syndrome (HPS) facts

• Hantaviruses are RNA viruses that are transmitted to human by rodents.
• Hantavirus pulmonary syndrome (HPS) is a disease in which in the late stage of infection with a hantavirus subtype, patients experience lung congestion, fluid accumulation in the lungs, and shortness of breath. Death occurs in about 38% of patients. Early symptoms (fatigue, fever, muscle aches) are nonspecific.
• Hantavirus was first identified in an outbreak in 1993 in the “Four Corners” area of the southwestern U.S. and found to be transmitted to humans by rodent urine, feces, saliva, and by airborne particles containing these items. The 2012 outbreak at Yosemite National Park was due to hantavirus transfer to humans by deer mice. Human-to-human transmission of hantavirus in the Americas has not been documented.
• HPS is caused by hantaviruses that cause lung capillaries to leak fluid into the lung tissue.
• HPS is usually diagnosed presumptively by the patient’s lung symptoms or the patient’s association with rodents, or the patient’s probable contact with rodent-contaminated airborne dust; chest X-rays provide additional evidence, but definitive diagnosis is usually done at a specialized lab or the CDC.
• There is no specific treatment of HPS; patients are usually treated in an intensive-care facility and often require respiratory support (intubation).
• Risk factors are any association with rodents and their airborne body excretions.
• Complications of HPS are death in about 38% of patients; if the HPS patient survives, there are usually no long-term complications.
• For patients who survive HPS, the prognosis is very good without complications.
• Prevention of HPS centers on avoidance of rodent contamination; there is no vaccine available to prevent hantavirus infection or HPS.

Causes of Hantavirus

Hantavirus is carried by rodents, especially deer mice. The virus is found in their urine and feces, but it does not make the animal sick.

It is believed that humans can get sick with this virus if they come in contact with contaminated dust from mice nests or droppings. You may come in contact with such dust when cleaning homes, sheds, or other enclosed areas that have been empty for a long time.

Hantavirus does not spread between humans.

Rodents carrying the hantavirus have been found in many U.S. national parks. As of November 1, 2012, the National Park Service (NPS) has announced a total of 10 confirmed cases of hantavirus infection in people who recently visited Yosemite National Parks. Campers and hikers may be more likely to catch the disease than most people. This is because they pitch tents on the forest floor and lay their sleeping bags down in musty cabins.

However, only a couple of cases have been directly linked to camping or hiking. Most people who are exposed to the virus have come in contact with rodent droppings in their own homes.

Hantavirus Infections

Hantavirus pulmonary syndrome (HPS) is a rare but deadly viral infection. It is spread by mice and rats. They shed the virus in their urine, droppings, and saliva. Tiny droplets with the virus can enter the air. People can get the disease if they breathe infected air or come into contact with rodents or their urine or droppings. You cannot catch it from people.

Early symptoms of HPS include

• Fatigue
• Fever
• Muscle aches, especially in the thighs, hips and back
• Headaches
• Chills
• Dizziness
• Nausea, vomiting, diarrhea or abdominal pain

Later symptoms include coughing and shortness of breath.

Controlling rodents in and around your house is the best way to prevent infection. If you have been around rodents and have symptoms of fever, deep muscle aches, and severe shortness of breath, see your doctor immediately.

There is no specific treatment, cure, or vaccine for HPS. Patients may do better if it is recognized early and they get medical care in an intensive care unit. They often need to use a breathing machine and have oxygen therapy.

Preventing Hantavirus Pulmonary Syndrome (HPS)

Avoid exposure to rodents and their excreta. Adventure travellers, backpackers, campers and travellers with occupational exposure to rodents in countries or areas at risk for hantaviruses should take precautions to exclude rodents from tents or other accommodation and to protect all food from contamination by rodents.

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.