Where is yersinia pestis most commonly found

Between and , confirmed or probable human plague cases occurred in the United States. In recent decades, an average of 7 human plague cases are reported each year range: cases per year. Worldwide, between 1, and 2, cases each year are reported to the World Health Organization external icon WHO , though the true number is likely much higher. Plague can still be fatal despite effective antibiotics, though it is lower for bubonic plague cases than for septicemic or pneumonic plague cases.

It is hard to assess the mortality rate of plague in developing countries, as relatively few cases are reliably diagnosed and reported to health authorities. Plague can be successfully treated with antibiotics. Once a patient is diagnosed with suspected plague they should be hospitalized and, in the case of pneumonic plague, medically isolated. Laboratory tests should be done, including blood cultures for plague bacteria and microscopic examination of lymph node, blood, and sputum samples.

Antibiotic treatment should begin as soon as possible after laboratory specimens are taken. To prevent a high risk of death in patients with pneumonic plague, antibiotics should be given as soon as possible, preferably within 24 hours of the first symptoms. Although cases can occur any time of the year, most cases in the United States are acquired from late spring to early fall.

Plague occurs in rural and semi-rural areas of the western United States. Plague is most common in the southwestern states, particularly New Mexico, Arizona, and Colorado. Human plague occurs in areas where the bacteria are present in wild rodent populations. The risks are generally highest in rural and semi-rural areas, including homes that provide food and shelter for various ground squirrels, chipmunks and wood rats, or other areas where you may encounter rodents.

A plague vaccine is not available. New plague vaccines are in development but are not expected to be commercially available in the immediate future. Ecology and Transmission.

Diagnosis and Treatment. Information for Healthcare Professionals. Maps and Statistics. Frequently Asked Questions. Related Links. The bacteria can also enter your body if a break in your skin comes into contact with an infected animal's blood.

Domestic cats and dogs can become infected with plague from flea bites or from eating infected rodents.

Pneumonic plague, which affects the lungs, is spread by inhaling infectious droplets coughed into the air by a sick animal or person. The risk of developing plague is very low. Worldwide, only a few thousand people develop plague each year. However, your plague risk can be increased depending on the area where you live and travel, your job, and your hobbies.

Plague outbreaks are most common in rural and semirural areas that are overcrowded, have poor sanitation and have a high rodent population. The greatest number of human plague infections occur in Africa, especially the African island of Madagascar.

Plague has also been transmitted to humans in parts of Asia and South America. In the United States, plague is rare, but it has been known to occur in several western and southwestern states — primarily New Mexico, Arizona, California and Colorado. Veterinarians and their assistants have a higher risk of coming into contact with domestic cats and dogs that may have become infected with plague.

People who work outdoors in areas where plague-infected animals are common are also at higher risk of getting plague. Camping, hunting or hiking in areas where plague-infected animals reside can increase your risk of being bitten by an infected flea. No effective vaccine is available, but scientists are working to develop one. A plague epidemic in the 14th century killed more than one-third of the population of Europe within a few years.

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