What is hantavirus pulmonary syndrome (HPS)?
Hantavirus is a rare viral disease that can damage the heart, lungs and other organs so they cannot function properly. It is also called hantavirus cardiopulmonary syndrome (HCPS).
People get this illness when they inhale or come into contact with infected rodent droppings, urine or saliva. HPS progresses quickly. It can be life-threatening.
What does the hantavirus do to the body?
Once the hantavirus enters the human body, it replicates and spreads. In the lungs, the virus causes blood vessels to become weak and leak, which fills air sacs with blood and makes breathing difficult. In the heart, damage to the heart muscle itself plus weak and leaky blood vessels reduce the heart’s ability to pump oxygen-filled blood to organs and cells of the body. Without oxygen and adequate blood pressure, the body can go into shock, which in turn can result in organ failure followed rapidly by death.
How common is hantavirus pulmonary syndrome (HPS)?
Hantavirus is extremely rare. The total number of cases that have ever been reported in the U.S. as of the beginning of 2017 was 728. Most cases of HPS in the U.S. have occurred west of the Mississippi.
HPS is not limited to those with a weak immune system. It can infect anyone who has inhaled or come into contact with infected rodent droppings, urine or saliva. According to the Centers for Disease Control and Prevention, some 36 percent of all reported cases of HPS have resulted in death.
Symptoms and Causes
What causes hantavirus pulmonary syndrome (HPS)?
Hantavirus is caused by a group of viruses called hantaviruses. Wild rodents such as mice and rats carry these viruses.
In most cases, people get HPS after inhaling particles of mouse droppings infected with these viruses. The deer mouse is the most common carrier of HPS.
The HPS virus can also spread to people after they:
- Are bitten by a rodent carrying the virus
- Touch a surface contaminated with rodent secretions (feces, urine, or saliva) and then touch their mouth or nose
- Eat food contaminated with infected rodent secretions
What are the symptoms of hantavirus pulmonary syndrome (HPS)?
Hantavirus causes different phases of symptoms as the infection progresses.
The first stage of the disease is the incubation phase. It produces no outward signs. This phase can last up to 8 weeks after exposure to the virus.
The second phase of early HPS symptoms develops quickly. It lasts from 2 to 8 days. Symptoms include:
- Fever above 101 degrees Fahrenheit
- Muscle aches, especially to thighs, hips, and back
- Stomach pain, nausea, vomiting, and diarrhea
- Rash (red spots on skin)
- Dry cough and trouble breathing
About 4 to 10 days after early symptoms start, the third phase of symptoms begins. This stage can be very serious. It may involve internal bleeding and the lungs filling with fluid.
These developments can cause life-threatening organ and respiratory problems. Signs that you are entering this phase of HPS include:
- Trouble breathing
- Rapid heartbeat
- Chest tightness
Diagnosis and Tests
How is hantavirus pulmonary syndrome (HPS) diagnosed?
Doctors diagnose hantavirus with several tests. Blood tests identify proteins (antibodies) associated with the virus.
Blood tests can also reveal signs of the disease. These signs may include larger-than-normal white blood cells and an abnormally low amount of platelets (a substance that helps blood clot). Your doctor may also check the oxygen levels in your blood.
Be sure to tell your physician if you have had recent contact with rodents or their droppings. This information will let your doctor know to test for HPS and other diseases carried by rodents.
Management and Treatment
How is hantavirus pulmonary syndrome (HPS) treated?
It is important to receive treatment for hantavirus as soon as possible. People who have flu-like symptoms after being around rodent droppings should go to a hospital right away for immediate treatment.
Treatment for the disease nearly always involves intensive care. Your care team will monitor your needs and may provide treatments including:
- Oxygen therapy to help you breathe
- Fluid replacement
- Medication to raise blood pressure
- Use of a ventilator (your body is hooked up to a machine that moves air through your lungs)
- Kidney dialysis (a machine that removes waste products from the blood)
In extremely severe cases, doctors use a procedure called extracorporeal membrane oxygenation (ECMO) to add oxygen to your blood by running it through a machine.
What complications are associated with hantavirus pulmonary syndrome (HPS)?
Hantavirus rarely causes lasting problems for people after successful treatment.
What are the risk factors for hantavirus pulmonary syndrome (HPS)?
The biggest risk factor for hantavirus infection is exposure to infected rodents. HPS does not spread from human to human. It is most common in rural areas with sizable wild rodent populations.
Can hantavirus pulmonary syndrome (HPS) be prevented?
There isn’t a vaccine for hantavirus. Steps you can take to reduce your risk of HPS include:
- Stay away from places where rodents leave droppings
- Wear rubber gloves and a mask that covers your nose and face during exposure to mouse droppings
- Use disinfectant to sanitize areas containing mouse droppings so infected dust does not spread in the air
- Seal holes in and around your home so rodents cannot get in
- Trap rodents in and around your home to decrease the population
- Avoid leaving food out in your home and when camping
- Before entering spaces known to have rodents in them, air out the area
Outlook / Prognosis
What is the prognosis (outlook) for people with hantavirus pulmonary syndrome (HPS)?
Prompt treatment is necessary for people with hantavirus. If not treated soon enough, HPS can be fatal.
Most people successfully treated for HPS recover fully with no lasting effects.
When should I call the doctor?
The symptoms of hantavirus are common to other illnesses, including pneumonia and the flu. If you develop symptoms of HPS and have been around rodents or their droppings, contact your doctor. It is essential to seek treatment. The disease can get worse very quickly.
When can I go back to my regular activities?
People successfully treated for HPS often recover within a few days. Some lung functions may take a month or more to return to normal. Your doctor will tell you when you can return to normal activities.