Plague
- 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), septicemia 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 another animals by infected fleas. In people, plague has three forms: Bubonic plague, infection of the lymph glands; septicemia 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?
Perinea pests cause plague, 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 oxblood.
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, wood rats, wild mice, and voles -- suffer plague outbreaks and are occasional sources of human infection. Domesticates 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 (septicemia plague), severe blood infection. Signs and symptoms are fever, chills, tiredness, abdominal pain, shock, and bleeding into the skin another organs. Untreated septicemia 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 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 15per 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 toad 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 contacts 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.
Where can I find more information about plague?
CDC
http://www.cdc.gov/ncidod/dvbid/dvbid.html
This fact sheet is for information only and is not meant to bemuse for self-diagnosis or as a substitute for consultation with health-care provider. If you have any questions about the disease described above, consult a health-care provider.