Hantavirus
* Hantavirus pulmonary syndrome [HAN-tuh-vi-rus PUL-mun-air-ee SIN-drome] (HPS) is a rare but serious, and often deadly, lung infection.
* HPS is caused by a type of virus called a hantavirus. The hantavirus that causes HPS is carried by rodents found throughout North America.
* People get HPS when they breathe in dust that is contaminated with saliva, urine, or droppings from infected rodents.
* No anti-virus drug is effective against HPS, and there is no vaccine.
* To prevent HPS, avoid contact with rodents, and avoid inhaling dust that might be contaminated with rodent urine, saliva, or droppings.
What is hantavirus pulmonary syndrome?
Hantavirus pulmonary syndrome (HPS) is a rare but serious, and often deadly, lung infection.
What is the infectious agent that causes hantavirus pulmonary syndrome?
Hantavirus pulmonary syndrome is caused by the Sin Nombre virus. This virus is a type of hantavirus. Most hantaviruses attack the kidneys, but the Sin
Nombre virus attacks the lungs. It infects the walls of the capillaries (tiny blood vessels in the lungs), making them leak and flooding the lungs with fluid.
Where is hantavirus pulmonary syndrome found?
Hantaviruses are found in rodents in different parts of the world. Each hantavirus has a preferred rodent host. The Sin Nombre virus is carried by the deer mouse, the cotton rat, and perhaps other rodents common throughout North America. These rodents live in semi-rural and rural areas and infest camps, old buildings, barns, and homes.
How do people get hantavirus pulmonary syndrome?
Wild rodents spread HPS to people. The Sin Nombre virus is passed in the saliva, urine, and droppings of infected rodents. The virus can live for a few days in contaminated dirt and dust. People are infected when they breathe in tiny particles of these materials in dust from places where rodents are living and active. People can also be infected by handling contaminated materials and then touching the mouth or nose.
HPS is not spread from person to person. Cats and dogs do not spread the illness either, although they can bring infected rodents into contact with humans.
What are the signs and symptoms of hantavirus pulmonary syndrome?
The first symptoms are general and flu-like: fever (101oF-104oF), headache, stomach pain, pain in the joints and lower back, coughing, and sometimes nausea and vomiting. The main symptom is difficulty breathing as the lungs fill with fluid. This can quickly lead to an inability to breathe and, in severe cases, death from suffocation.
How soon after exposure do symptoms appear?
Symptoms can appear from 3 days to 6 weeks after infection, but usually within 2 weeks.
How is hantavirus pulmonary syndrome diagnosed?
Because the early symptoms are not specific and vary from person to person, HPS is hard to identify in its early stages. It is usually detected only when it affects the lungs and causes breathing problems.
Who is at risk for hantavirus pulmonary syndrome?
Unlike many illnesses that mainly strike people with weakened immune systems, HPS has hit mostly strong, healthy persons. Those who work, play, or live in closed spaces with active rodent infestation are at risk, although the chances of infection are low. The risk to campers, hikers, and tourists is very small.
People who should take special precautions against HPS are: 1) people who often handle or are exposed to rodents, such as wildlife biologists and exterminators, 2) people who clean or work in attics or crawl spaces where rodents might be living and active, and 3) people who clean or renovate buildings that might be actively infested with rodents.
What complications can result from hantavirus pulmonary syndrome?
Infected persons can develop untreatable respiratory failure. HPS is fatal to more than half of those who become infected.
What is the treatment for hantavirus pulmonary syndrome?
No virus-killing drug is effective against HPS. Although there has been some experimental use of the anti-virus drug, ribavirin, mechanical ventilation (use of a respirator) is the main treatment. Most patients need to be hospitalized in intensive care. The sooner an infected person gets medical treatment, the better the chance of recovery.
How common is hantavirus pulmonary syndrome?
HPS is a rare disease. It was first recognized in 1993 after the investigation of an outbreak of sudden fatal respiratory illness in the southwestern United States. Since then, no more than 100 cases of HPS have been identified in 20 states, mostly in the western part of the country.
Is hantavirus pulmonary syndrome a new or emerging infectious disease?
Yes. The Sin Nombre virus is a newly recognized virus, and HPS is a newly recognized disease. Scientists are working to learn more about it and to develop diagnostic tests and treatments.
How can hantavirus pulmonary syndrome be prevented?
* The best way to prevent HPS is to avoid contact with rodents and to avoid inhaling dust that might be contaminated with rodent saliva, urine, or droppings.
* Control mice inside. Keep the kitchen clean, and store food and trash in containers with tight lids. Carefully dispose of dead rodents trapped indoors or brought inside by pets. Rodent-proof the house by sealing cracks and clearing brush from around foundations.
* Control mice outside. Eliminate possible nesting sites. Elevate hay, woodpiles, and garbage cans, and place them away from the house. Store animal food in closed containers.
* Use safety precautions when cleaning indoor or outdoor areas that might be contaminated with rodent saliva, urine, or droppings. Do not stir up and breathe dust. Before cleaning, wet down potentially contaminated areas with a household disinfectant (such as bleach or alcohol). While cleaning, wear rubber gloves, and disinfect them after use. Dust masks that cover the nose and mouth can also help.
* When participating in outside activities, stay clear of rodents and their burrows and nests. Keep campsites clean and food tightly sealed. Open up and air out outbuildings and rural or wilderness cabins before entering or cleaning. Remove garbage and trash before leaving.
Where can I find more information about hantavirus pulmonary syndrome?
Center for Disease Control at http://www.cdc.gov/ncidod/diseases/hanta/hps/index.htm
This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above, consult a health-care provider.
Lyme Disease
Though much more common in the Eastern U.S., Lyme Disease is found in the Sierra Nevada Range. It is serious enough for every hiker and backpacker to be familiar with this disease and its avoidance.
* Lyme disease is a rapidly emerging bacterial infection that is spread to people by the bite of infected ticks.
* Lyme disease can cause a rash, flu-like symptoms, and aching joints.
* Lyme disease can be treated with antibiotics. Without treatment, Lyme disease can cause serious, long-term health problems.
* To prevent Lyme disease: 1) protect yourself from tick bites, 2) remove attached ticks promptly, and 3) get early diagnosis and treatment.
What is Lyme disease?
Lyme disease is an infection transmitted by the bite of certain, very small, infected ticks. Lyme disease gets its name from the town of Lyme, Connecticut, where the illness was first identified in the United States in 1975.
What is the infectious agent that causes Lyme disease?
Lyme disease is caused by a corkscrew-shaped bacterium, or spirochete, called Borrelia burgdorferi. Ticks infected with the bacterium spread the disease to humans.
Where is Lyme disease found?
Cases of Lyme disease have been reported by nearly every state in the United States, but the disease is concentrated in the east coastal states, the north central states, and northern California. Connecticut, Rhode Island, New York, New Jersey, Delaware, Pennsylvania, Maryland, and Wisconsin account for about 90% of all cases.
In the Northeast and Great Lakes region, Lyme disease is spread by the black-legged tick, which lives in wooded areas, grasslands, and yards. In the Pacific Northwest, the disease is spread by the western black-legged tick. In the Southeast, the disease is thought to be spread by the black-legged tick.
How do people get Lyme disease?
Ticks become infected with the Lyme disease bacterium by feeding on infected animals, such as mice, chipmunks, and other wild rodents. Lyme disease is passed to humans and other animals when a tick infected with the bacterium bites the person or animal and stays attached long enough (usually more than 36 hours) to take a meal.
The tick that spreads Lyme disease has a 2-year life cycle, and feeds once in each of its three life stages -- larvae, nymph, and . In the tick's larvae stage, it is tan, the size of a pinhead, and feeds on small animals like mice. During the nymph stage, the tick is the size of a poppy seed, beige or partially transparent, and feeds on larger animals such as cats, dogs, and humans. ticks are black and/or reddish and feed on large mammals such as deer, dogs, and humans.
What are the signs and symptoms of Lyme disease?
The early stage of Lyme disease is usually marked by one or more of these signs and symptoms:
* Tiredness
* Chills and fever
* Headache
* Muscle and/or joint pain
* Swollen lymph glands
* A characteristic skin rash, called erythema migrans
The skin rash is a red circular patch about 2 inches in diameter that appears and expands around the site of the tick bite. The center may clear as it enlarges, resulting in a "bulls-eye" appearance. The rash may be warm, but it usually is not painful or itchy.
Some infected people do not recognize the early symptoms and are diagnosed only after complications occur.
What complications can result from Lyme disease?
Persons who did not have or did not recognize the early symptoms and who did not receive treatment can end up with serious complications:
* Arthritis (swelling and pain) in the large joints, which can recur over many years
* Nervous system problems, such as numbness, meningitis (fever, stiff neck, and severe headache), and Bell's palsy (paralysis of the facial muscles, usually on one side)
* Irregularities of the heart rhythm
How soon after exposure do symptoms appear?
Early symptoms can develop within a week to a few weeks of the tick bite. Other symptoms can appear weeks, months, or years later.
How is Lyme disease diagnosed?
Lyme disease is diagnosed by a physical examination and medical history. The clinical diagnosis is supported by laboratory testing.
Diagnosis of Lyme disease can be difficult. Current tests are not completely accurate, and the symptoms can mimic those of other diseases. Diagnosis is easiest when there is a skin rash.
Who is at risk for Lyme disease?
Lyme disease can affect anyone. Persons who spend time in brushy and wooded areas are at increased risk of exposure. The chances of being bitten by a tick are greatest during times of the year when ticks are most active. Deer ticks in the nymph stage are active from mid-May to mid-August. ticks are most active in mid- to late fall and early spring.
What is the treatment for Lyme disease?
Lyme disease is treatable with antibiotics taken for 3 to 4 weeks. More difficult cases may require longer treatment and combinations of . Re-infection from tick bites is possible after treatment.
How common is Lyme disease?
Lyme disease is the most common disease spread by ticks in the United States. More than 16,000 cases were reported by 45 states in 1996. However, because of considerable under-reporting and misdiagnosis, the actual number of cases is probably several times higher.
Is Lyme disease an emerging infectious disease?
Yes. Lyme disease is a rapidly emerging infectious disease. Since it was first recognized in the United States in 1975, reports of Lyme disease have increased substantially, and the disease is now found in several regions of the country. Factors contributing to the rise in Lyme disease in humans is a thriving tick population and the expansion of suburbs into formerly wooded areas, which increases people's exposure to infected ticks.
How can Lyme disease be prevented?
A Lyme disease vaccine is under development but is not yet available. The only sure way to prevent the disease is to avoid exposure to infected ticks. Especially avoid areas where wild mice might live, such as the edges of yards, fields, and woods with low, dense groundcover.
If this is not possible, you can reduce your risk by taking these precautions:
* During outside activities, wear long sleeves and long pants tucked into socks. Wear a hat, and tie hair back.
* Use insecticides to repel or kill ticks. Repellents containing the compound DEET can be used on exposed skin except for the face, but they do not kill ticks and are not 100% effective in discouraging ticks from biting. Products containing permethrin kill ticks, but they cannot be used on the skin -- only on clothing. When using any of these chemicals, follow label directions carefully. Be especially cautious when using them on children.
* After outdoor activities, check yourself for ticks, and have a "buddy" check you, too. Check body areas where ticks are commonly found: behind the knees, between the fingers and toes, under the arms, in and behind the ears, and on the neck, hairline, and top of the head. Check places where clothing presses on the skin.
* Remove attached ticks promptly. Removing a tick before it has been attached for more than 24 hours greatly reduces the risk of infection. Use tweezers, and grab as closely to the skin as possible. Do not try to remove ticks by squeezing them, coating them with petroleum jelly, or burning them with a match.
* Large brown ticks that are commonly found on dogs and cattle do not carry the Lyme disease bacterium. If you remove a very small tick and want to have it tested for Lyme disease, place it in a clean pill vial or tight-sealed plastic storage bag with a moistened cotton swab. Contact your health-care provider and local health department.
Where can I find more information about lyme disease?
Center for Disease Control at http://www.cdc.gov/ncidod/dvbid/index.htm
This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above, consult a health-care provider.
Plague
Ever see the posted warnings about feeding squirrels? Here's one reason why.....
* Plague is a bacterial disease of rodents that can be spread to humans and other animals by infected fleas.
* Plague has three forms: bubonic plague (infection of the lymph glands), septicemic plague (infection of the blood), and pneumonic plague (infection of the lungs). Pneumonic plague can spread from person to person.
* People can get plague: by the bites of infected fleas; by direct contact with the tissues or body fluids of a plague-infected animal; by inhaling infectious airborne droplets from persons or animals with plague pneumonia; or by laboratory exposure to plague bacteria.
* Plague is treatable with antibiotics if detected early.
* Prevention consists of controlling rodent fleas, educating the public and the medical community in places where plague occurs, and using preventive medicines and vaccines as appropriate.
What is plague?
Plague is a disease of rodents that can be spread to humans and other animals by infected fleas. In people, plague has three forms: Bubonic plague, infection of the lymph glands; septicemic plague, infection of the blood; and pneumonic plague, infection of the lungs. Pneumonic plague is the most contagious form because it can spread from person to person in airborne droplets.
What is the infectious agent that causes plague?
Plague is caused by Yersinia pestis, a bacterium that is spread from rodent to rodent by infected fleas. Periodic outbreaks of plague kill large numbers of rodents (called a "die-off"). The risk of infection to humans and other animals in the area increases when the rodent hosts die and infected fleas look for other sources of blood.
Where is plague found?
Plague is found in some semi-arid areas in Asia, Eastern Europe, Africa, South America, and North America. In the United States, most cases in humans occur in two regions: 1) northern New Mexico, northern Arizona, and southern Colorado, and 2) California, southern Oregon, and far western Nevada.
In the southwestern United States, rock squirrel fleas are the most common source of infection in people. In the Pacific states, California ground squirrel fleas are the most common source. Many other types of rodents -- including other ground squirrels, prairie dogs, chipmunks, woodrats, wild mice, and voles -- suffer plague outbreaks and are occasional sources of human infection. Domestic cats can be infected by fleas or by eating infected wild rodents and can be a direct source of infection to people.
Dogs rarely suffer severe illness and have yet to be shown to be sources of infection for humans.
How do people get plague?
* By the bites of infected fleas
* By direct contact with the tissues or body fluids of a plague-infected animal
* By inhaling infectious airborne droplets from persons or animals, especially cats, with plague pneumonia
* By laboratory exposure to plague bacteria
What are the signs and symptoms of plague?
When a person is bitten by an infected flea or is infected by handling an infected animal, the plague bacteria move through the bloodstream to the lymph nodes. The lymph nodes swell, causing the painful lumps ("buboes") that are characteristic of bubonic plague. Other symptoms are fever, headache, chills, and extreme tiredness. Some people have gastrointestinal symptoms.
If bubonic plague goes untreated, the bacteria can multiply in the bloodstream and produce plague septicemia (septicemic plague), a severe blood infection. Signs and symptoms are fever, chills, tiredness, abdominal pain, shock, and bleeding into the skin and other organs. Untreated septicemic plague is usually fatal.
Pneumonic plague, or plague pneumonia, develops when the bacteria infect the lungs. People with plague pneumonia have high fever, chills, difficulty breathing, a cough, and bloody sputum. Plague pneumonia is considered a public health emergency because a cough can quickly spread the disease to others. Untreated pneumonic plague is usually fatal.
How soon after exposure do symptoms appear?
Symptoms usually begin within 2 to 6 days after exposure to the plague bacteria.
How is plague diagnosed?
U.S. health-care providers should suspect plague in anyone with a large, painful, very tender lymph gland accompanied by fever, extreme tiredness, and a history of exposure to possibly infected rodents and their fleas in the western United States. Plague should also be suspected in a person with plague symptoms plus a history of handling sick or dead cats, or wild animals such as rabbits.
Patients with suspected plague should be hospitalized, placed in isolation, have specimens obtained for plague diagnosis, and immediately treated. All suspected plague cases must also be reported to local and state health departments.
What is the treatment for plague?
If diagnosed in time, plague is treatable with antibiotics. Treatment of suspected plague cases should start as soon as possible after the laboratory specimens are taken. The drug of choice is streptomycin, but several other antibiotics are also effective.
How common is plague?
In the United States, human plague cases average about 10 to 15 per year. Worldwide, there are 1,000 to 2,000 cases each year.
Who is at risk for plague?
* People who live in rural areas where plague occurs in wild rodents
* People, such as biologists, trappers, and hunters, who handle potentially infected animals
* Campers, hikers, travelers, and others in areas where plague is known to exist
* People in close contact with pneumonic plague patients
Is plague a new or emerging infectious disease?
Plague is an ancient disease that occurs in irregular cycles and remains a public health hazard in parts of Asia, the Middle East, Eastern Europe, Africa, and South America, as well as the United States. Epidemics of plague in humans usually involve house rats and their fleas. Rat-borne epidemics continue to occur in some developing countries, particularly in rural areas. Highly publicized outbreaks of bubonic and pneumonic plague occurred in 1994 in India, leading to a heightened international reaction.
The last rat-borne epidemic in the United States occurred in Los Angeles in 1924-1925. Since then, all human plague cases in the United States have been associated with plague outbreaks in wild rodents and their fleas.
How can plague be prevented?
1. People who live, work, or play in areas with active plague infection in wild rodents should take these precautions:
* Eliminate food and shelter for rodents around homes, work places, and certain recreation areas, such as picnic sites or campgrounds where people congregate. Remove brush, rock piles, junk, and food sources, including pet food.
* Allow health authorities to use appropriate and licensed insecticides to kill fleas during plague outbreaks in wild animals.
* Treat pets (cats and dogs) for flea control regularly.
* Avoid sick or dead animals, and report such animals to the health department. Hunters and trappers should wear rubber gloves when skinning animals.
* Use insect repellents when outdoors in areas where there is a risk of flea exposure.
2. Preventive treatment with antibiotics is recommended for: 1) people who are bitten by fleas during a local outbreak or who are exposed to tissues or fluids from a plague-infected animal; 2) people living in a household with a bubonic plague patient, since they may also be exposed to infected fleas; and 3) people in close contact with a person or pet with suspected plague pneumonia. Close contact is defined as face-to-face contact or being in the same closed space, such as a room or vehicle.
3. People who travel to countries where plague occurs should take these additional precautions:
* Avoid exposure to fleas from diseased rats. The risk of being bitten by infected fleas is especially high after large numbers of plague-infected rats have died. Therefore, avoid places that are infested with rats or where large numbers of rats have reportedly died.
* If travel to such areas is essential, apply insect repellent containing DEET to legs and ankles. Also apply repellents and insecticides to clothes and outer bedding according to manufacturers' instructions.
* Take preventive antibiotics if the risk of exposure is high.
4. Plague vaccine is available for: 1) persons who work with the plague bacterium in the laboratory or in the field, and 2) persons who work in areas where human plague outbreaks occur or who handle potentially infected animals.
Where can I find more information about plague?
Center for Diease Control at http://www.cdc.gov/ncidod/dvbid/index.htm
This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above, consult a health-care provider.
This page revised September 15, 2007