Hantavirus is a rare disease transmitted from rodents to people with only 864 cases reported in the U.S. since 1993, following an outbreak on the border of New Mexico and Arizona that if gets into the lung can be fatal. It falls under the category of viral hemorrhagic fever that interferes with the body’s ability to clot.
What is Hantavirus and are there different types?
Hantavirus is a zoonotic virus meaning its spread from animals mostly rats and mice to humans with over 30 virus types found globally that can make people sick by targeting special cells (endothelial) in the body that lines the blood vessels. Each Hantavirus type is unique to a certain animal or species of rodent, geographic region in the world, and attacks the lung or kidney depending on the strain.
It may cause Hantavirus pulmonary syndrome (HPS) by attacking the lungs or Hemorrhagic fever with renal (kidney) syndrome (HFRS) that damages the kidney and blood cells.
In the United States (U.S.) the most common rodent that carries Hantavirus is the deer mouse, named because of its fur and agility, and may carry what is called the Sin Nombre Virus (SNV) strain. SNV can be deadly in 40 % of people who are infected especially if leads to Hantaviral pulmonary or lung syndrome (HPS) where the lungs fill up with fluid and the heart weakens.
In Asia and Europe, Norway rats and field mice carry a less deadly strain of Hantavirus causing hemorrhagic fever with renal (kidney) syndrome (HFRS). Symptoms are high fever, headaches, low platelets (blood cells important in clotting), abnormal kidney function, flushed face and redness of the eyes.
Hantavirus is spread by inhaling or breathing in droplets of virus found in feces, urine, and saliva of rodents as very few people have symptoms after being bitten or scratched. Most describe encounters with living or dead rodents in rooms with visible evidence of rodent infestation 2-3 weeks before symptoms start. Virtually all people infected with Hantavirus Sin Nombre Virus (SNV) in the U.S. had indoor exposure inside rodent infested buildings. Person to person spread is very rare and is confined to one species, Andes found in Argentina.
What are the symptoms of Hantavirus?
The symptoms depend on the strain and may cause either Hantavirus pulmonary syndrome (HPS) found in North and South America including the U.S. or Hemorrhagic fever with renal (kidney) syndrome or (HFRS) found in Asia and Europe. The risk of death is the highest with full blown Hantavirus pulmonary syndrome (HPS) with the highest risk in people whose lungs fill with fluid and cannot get enough oxygen to the body.
Symptoms of HPS starts 1 to 8 weeks after contact with rodent droppings, saliva, or urine with high fever, weakness, muscle aches similar to any viral illness with some people experiencing headache, chills, abdominal pain and diarrhea. Four to ten days later, people may get sicker with cough, chest pain and difficulty breathing, and lungs may start filling with fluid. If the lung symptoms start, it can be rapidly fatal. Unfortunately, there are no medications that have shown to be beneficial although IV Ribavirin, an antiviral has been tried. Treatment is mostly supportive including hospitalization usually in the intensive care setting (ICU), and if needed a machine to help with breathing and keeping oxygen levels up.
Testing for the virus is possible per the CDC (Center for Disease Control and Prevention) using special antibody testing but takes 72 hours before tests positive. Early symptoms may seem like a common cold, flu, or COVID-19 so important if you live in a region of the U.S. especially Arizona, New Mexico, Colorado, or California and exposed to rodents important to seek medical attention immediately.
How common is Hantavirus?
Hantavirus has been around for centuries with China having the highest number and Russia likely close behind with a vaccination available in China for a specific strain and the number infected may have improved but is thought to be anywhere from 16,000 to 100,000 cases per year depending on the reference.
In the U.S. there has only been 864 cases over that past 20 years since tracking started in 1993 however is now reported in over 30 states with 90% of the cases found west of the Mississippi river. In the U.S. is rare to have Hemorrhagic fever with renal syndrome (HFRS) as is found only in Asia and Europe unless exposed to rodent species from these areas. The states with the highest total number of cases during this time included New Mexico with 122 cases.
Europe in 2023, reported a decline in Hantavirus cases with Finland and Germany having the most, and the reason for improvement is better rodent control, avoiding contact with rodent droppings, saliva, and urine, and disinfecting areas with known mice and rats.
The first outbreak in the spring of 1993 in the U.S., at the Four Corners where Utah, Colorado, New Mexico and Arizona meets was one of the deadliest, and scientists say the increase in mouse density and coming in closer contact with people may have contributed as part of changes in the ecosystem with El Nino and heavy rains happening around that time.
How do I stop from getting Hantavirus?
The CDC says to reduce risk minimize contact with rodents including mice and rats. Important to seal holes or gaps in your home to keep rodents from getting in. Place traps and clean up food that might attract rodents. If you are outdoors, say camping keep food out of your tent and properly secure it. Hantavirus has been found in fish and reptiles but to date no cases of infecting people.
In 2012, there was an outbreak in ten people who visited Yosemite National Park with 9 of whom stayed overnight in an insulated tent, and 8 got Hantavirus pulmonary syndrome (HPS) and 3 died. Rodent nests and tunnels were found in the foam insulation of the cabin walls and thought to be the cause of the outbreak.
Another case in 2016, a woman in Tennessee who had a pet rat got a high fever, and blood in her urine infected with a different strain of Hantavirus causing Hemorrhagic fever with renal (kidney) syndrome (HFRS) and recovered. There have been multiple reports of getting the Seoul variant (from Asia and Europe) with infected pet rats notably Norway rats in the U.S. In 2017, there was also an outbreak of the same Seoul virus in rat breeders and pet rat owners in Wisconsin where 24 people were infected.
Any final advice on Hantavirus?
Hantavirus is a rare but deadly disease especially in the U.S. where the most common variant transmitted by deer mice and can cause severe Hantavirus pulmonary syndrome (HPS) with a 40 % risk of death says the CDC and higher by other sources. The majority of cases are transmitted by breathing in the droplets of excrement of rodents including feces, saliva, and urine but also can be spread by touching objects and then touching the nose or mouth, or eating food contaminated with virus.
The number one risk for infection is indoor rodent infestation and even healthy people are at risk if they have contact with the virus. How serious or deadly the infection depends on the strain. The first signs of the infection include high fevers, headaches, and muscle pain so if you are in an area of the U.S. known for Hantavirus, had recent exposure to deer mice or other rodents important to be tested and seek medical care immediately for best chances at recovery.
Unfortunately, the recent death of Gene Hackman’s wife, Betsy Arakawa from Hantavirus pulmonary syndrome (HPS) at their home in Sante Fe, New Mexico, where the largest number of cases have been reported, has increased public awareness to this rare but potentially fatal disease. It’s difficult to speculate where she had contact with rodents but likely in an indoor area. Gene Hackman’s death was not due to Hantavirus and their dog who also passed away was not from Hantavirus as the virus is not found in dogs. Our thoughts and prayers go out to the family and loved ones for their tragic loss.
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