Disclaimer: We at Victor® are not medical professionals, and this article is not intended to provide medical advice. If you or someone you know is exhibiting symptoms of HPS, contact your nearest medical center immediately.
Hantavirus pulmonary syndrome (HPS) — known to the general public as hantavirus — is a disease marked by flu-like symptoms and respiratory deficiencies that often require patients to use breathing devices. Symptoms of hantavirus pulmonary syndrome include headaches, fever, nausea, chills, muscle aches and digestive problems. The disease is mainly transmitted to humans via physical contact and inhalation of infected, aerosolized rodent droppings.
Early detection can help with a patient's prognosis, but there is currently no vaccine or cure for HPS. For advanced symptoms, the best forms of Hantavirus pulmonary syndrome treatment include supportive therapy, mechanical ventilation and — for the most advanced cases — intensive care. HPS is fatal in roughly one in three cases.
History of Hantavirus Pulmonary Syndrome
Hantavirus pulmonary syndrome was first identified in the spring of 1993, when patients in the four-corners region — Arizona, New Mexico, Utah, Colorado — displayed symptoms that didn't match any previously known disease. The influenza-like symptoms of the infected individuals would quickly morph into extreme respiratory problems. Before long, the virus was identified as Sin Nombre Virus (SNV), which was ultimately traced to deer mice (Peromyscus maniculatus). Among infected humans, the virus was found to be the trigger for a newly identified syndrome that everyone was talking about: HPS. In the 20-plus years that have passed since it was first identified, HPS has been linked to more than 10 strains of hantavirus, each of which is attributed to a different species of rodent.
Areas Where HPS Is Found
In rural areas throughout the United States and Canada, cases and outbreaks of HPS have been reported at sporadic intervals over the past two decades. Some of the more familiar settings where infections have occurred include barns, sheds, farms, forests and other rural areas. The most common hantavirus known to trigger HPS is SNV.
Various other causes of HPS exist in certain parts of North America, such as the New York hantavirus, which is carried by the white-footed mouse. The cotton rat carries the Black Creek Canal hantavirus, which has been responsible for numerous HPS cases in the Deep South. Since that time, HPS has been reported in parts of Central and South America.
How HPS Spreads
Rodents are the only creatures known to spread HPS. Non-rodent household pets cannot contract hantavirus, though there are cases in which dogs or cats can put people into contact with the disease, such as when a cat carries an infected rodent onto a residential property as prey.
Carriers of HPS — such as deer mice and cotton rats — will leave active agents of the disease behind in their defecation. When human infections occur, it's usually through inhalation of air that has been saturated with tainted, airborne particles of rodent urine, saliva or feces. Other methods of rodent-to-human transmission include:
Bites –People can contract HPS through rodent bites, though this is one of the less frequent forms of transmission.
Touch –When a person touches an infected area or object — such as a spot on a floor or carpet that carries traces of rodent droppings, urine or saliva — and then touches a facial orifice, infection can occur.
Consumption –Food that has been contaminated with hantavirus-carrying rodent germs can also cause a person to become infected with the disease.
None of the HPS-causing hantaviruses known to occur in North America can be spread from person to person. For instance, physical contact with an infected individual, whether casual or intimate, will not cause you to catch the illness. It’s also worth noting that the disease cannot be contracted through transfusions of donated blood from infected individuals.
HPS Stats in the United States
As of 2016, the total number of reported HPS cases in the U.S. stands at 690. The vast majority of these cases (659) were diagnosed when the disease was first identified by science in 1993, whereas the remaining 31 were recognized in retrospect. In more than a third of these cases (36%) the disease has been fatal. Victims of HPS have ranged in age from 5 to 84, and nearly two-thirds of infected individuals have been male. In short, reported HPS cases have broken down along the following lines:
- 63% are male
- 37% are female
People affected by HPS by Race*:
- 78% are Caucasian
- 18% are Native American
- 1% are African American
- 1% are Asian
- (2% unknown)
*19% of HPS cases reported are among Hispanics (ethnicity considered separate from race).
The mean age among people diagnosed with HPS is 38. While 35 states have reported cases of the disease, an overwhelming majority (96%) of the infections have taken place in the Central, Mountain and Pacific regions. Though infections are known to occur in urban, suburban and rural settings, the last of these accounts for roughly three-quarters of all cases.
HPS Outside of North America
Beyond the United States and Canada, infections have been reported in South America. The following countries have seen HPS crop up among individuals and small groups of people:
Significant HPS outbreaks have been less frequent in Latin America, where the disease rarely persists during any given time beyond a few cases, except for when there's a natural cataclysm that causes hantavirus to spread. Viruses that resemble SNV have also been found among rodents in Central America and Mexico, but these have not shown to be infectious toward humans.
People at Risk of Contracting HPS
Anyone who encounters a rodent that's infected with one of the hantavirus strains that trigger HPS is at risk of contracting the disease. One of the most likely ways for urban dwellers and suburbanites to become infected is when deer mice or cotton rats make their way into houses and apartment buildings, leaving germs behind. Regardless of how healthy and physically robust a person might be, he or she can become infected if contact is made with strains of the virus.
Any area where infected deer mice and cotton rats are known to nest, scavenge or defecate could be an HPS-contagious area. Therefore, if you determine rodents have infested an area, it's important to avoid doing anything that may kick dust into the air. After all, if any of the dust particles contain hantavirus strains, you could be at risk of infection if those particles enter your lungs.
High-Risk Activities for HPS
People who stand the greatest risk of coming into contact with hantavirus are those who live, work or engage in activities in closed spaces that also attract rodents. The risks are even higher if the likely HPS carriers, such as the cotton rat, are actively nesting in the same location of human activity. Even if the HPS carriers are active at night and the human activity takes place during the day, the risk is higher.
Entering outbuildings – One activity that can open a potential Pandora's box of hantavirus is the opening of long-shut outbuildings and cabinets in which infected rodents have traveled. For that reason, it's advisable to proceed with caution when entering garages, sheds and barns for the first time after a lengthy winter break. Also, be careful to avoid kicking up dust when opening tool drawers and cupboards that haven't been accessed for many months.
Seasonal cleaning – When doing house-cleaning chores, you run the risk of coming into contact with HPS-causing agents if infected carriers have left their mark on the terrain. In particular, spring cleaning is a time for infections, because it's usually done just after winter, the period when rodents are likeliest to nest inside houses.
Blue-collar work –When it comes to HPS, the people who are among the most vulnerable to exposure are those who work in the fields of maintenance and construction, such as janitors and utility workers. Likewise, any job or task that involves entering basements, crawl spaces and attics — or emptying trash cans or dumpsters — could put you at risk for infection.
Camping and hiking – Hantavirus exposure can also occur during outdoor adventures, such as on trips that involve hikes in forests and sleep-outs at campsites that have been visited by infected rodents. Some of these sites could even fall within heavily infested areas, since rural stretches are the natural habitat of rodents.
In some cases, infection occurs after repeated contact with the rodents and their defecations, whether in the form of saliva, urine or droppings. A great number of people diagnosed with HPS are not even aware they have made contact with infected areas until the symptoms have become apparent.
After all, sightings of live rodents are a rare spectacle for humans. The critters usually come out when humans are away or asleep. Therefore, it's crucial to be cautious about spending time and setting up camp in areas known to sustain populations of hantavirus-hosting rodents, such as the deer mouse, cotton rat or white-footed mouse.
How to Protect Your Home from Rodents and Hantavirus
To keep rodents far enough away from your own personal space, it's crucial you ensure your environment isn’t rodent friendly. If rats or mice sense that your home or place of work is neither a hospitable nor opportune place to seek shelter, nest or scavenge for food, they'll go elsewhere.
You should seal with mesh wire or caulk any rooftop holes or gaps around the chimney or air vents that could allow rodents to make their way indoors. Likewise, you should tightly close any vents that could serve as openings into your basement or crawl space. After all, mice love dark places, and they can slip through gaps and cracks as small as a dime.
For further protection from rodent invasions, get the Victor® Ultra PestChaser® for your home. This ultrasonic device plugs into walls and emits ultrasonic sound waves — silent to human ears — that send rodents running as far away as possible. With a PestChaser® in both your attic and crawl space, rodents won't even want to know what kinds of goodies you have in the cupboard.
Repel Rodents — Clean Up and Store Away Food
Never leave food out in the open, because it can serve as bait, which rodents will likely find and feast upon if they make their way into your house. With the following tips, you can deny rodents what they like most about human households:
- Seal food in glass jars or plastic/metal containers and ensure the lids are tight.
- If food drops or spills, pick it up and rinse it away before leaving the area.
- Don't fill up sinks with used dishes. Wash dirty plates, cups and utensils on the same day of use.
- After barbecues and backyard parties, pick up and put away any unconsumed food, clean off the grills and throw away any paper plates or plastic utensils.
- Keep pet food tightly stored between servings. Never leave cat or dog food or water bowls out in the open when not being actively consumed by your pet.
- Place bird feeders at a safe distance from the house. Cover them with squirrel guards to prevent rodents from gaining access to bird feed.
- Place garbage only in tightly lidded containers. If your garbage container develops a hole, throw it out, too.
- Build compost piles at the farthest point of your property from the house itself, preferably at a distance of 100 ft plus.
- For outdoor animals, store unconsumed grains and feed in tightly sealed metal/plastic containers during nighttime.
You should tightly seal indoor and outdoor garbage containers at all times. Containers should be cleaned on a regular basis.
If you've found evidence of rodent activity in the living quarters or insulated spaces of your house, assume an HPS-exposed population of rodents is active there and take steps to clean the area. Wear work clothes and prepare a cleaning formula of 10 percent bleach and 90 percent water. With rubber gloves, wipe the infected area using paper towels. For best results, repeat the process in each area where rodent prints and defecations are evident.
Put the paper towels in Ziploc bags and throw them away in a tightly sealed garbage can. Clean the gloves in the bleach and water solution before removing. Throw work clothes into the washing machine and wash hands with soap repeatedly until thoroughly cleaned. Finally, take a shower.
Rodent-Proof Your House, Seal Off Openings
Clear away anything that could serve as nesting grounds around your house, such as foliage clusters, stick piles and mounds of raked leaves. Anything stored in the backyard — such as hay stacks, wood piles, recycling bins — should be elevated no less than 12 in above the ground. Firewood should be stored at least 100 ft from the house.
Keep any tree growth on your property at least 12 ft away from the house. Tree overhangs often serve as a bridge for rodents to crawl right onto rooftops, so keep all branches trimmed well away from your roof. Keep your lawn mowed on a weekly basis during the warm weather months and regularly trim bushes and shrubbery around your yard, house and fences.
Mice can slip through tiny holes, while rats can fit their bodies through openings the size of a nickel. Consequently, there are virtually dozens of potential entryways on any given house. All a HPS-infected rodent has to do is find a way into one of these infrequently used areas — attic, crawl space, wall cavities — and from there forge a pathway to the kitchen. Openings can even appear undetected in areas normally in plain sight, such as:
- Behind, beneath and within kitchen cupboards, under-sinks, refrigerators and ranges
- Along the corner trimmings of floors on the insides of closets
- At the ceiling and floor around the masonry of a fireplace
- Within and around door trim
- Around the holes of drains and furnace pipes
- Around the screens of vents on floors, walls and in laundry rooms
- Along the trimming where floors and walls connect
Aside from the more obvious openings — doors, windows, chimneys, vents — there are also plenty of spots on the outside of a house where holes, cracks and tiny little entryways can form, including:
- Along the eaves, gables and rafters on rooftops
- Around the entry holes for power lines and phone, television and internet cables
Check all of these spots for holes or gaps and seal them as needed. For small holes, use steel wool reinforced with caulk. For big holes, use lath screen or sheet metal to seal the opening.
Scare Rodents with Ultrasonic Traps from Victor®
If infestations of HPS-hosting rodents have been happening in your area, the best anti-rodent products keep the critters from entering your house in the first place. Out of all the products on the market today, the best rodent repellent device is the Victor® Ultra PestChaser®, which plugs into walls and emits ultrasonic signals rodents cannot bear to be around. Best of all, the device is clean, poison-free, and its pulses are undetectable by human ears.
When it comes to repellents and traps for rats, mice and other rodents, Victor® carries a full range of products for indoor and outdoor use, as well as urban, rural and residential settings. Watch some demonstration videos and learn more about how our products can make your home happily rodent free.