yersinia pestis transmission

http://www.who.int/csr/disease/plague/en/. Gentamicin and fluoroquinolones are typically first-line treatments in the United States. Lymph node aspirate: An affected bubo should contain numerous organisms that can be evaluated microscopically and by culture. Plague ecology in the United States. Humans may contract plague through a flea bite or by handling an infected animal or breathing in an aerosolized form of the bacteria. Diagnosis. Septicemic and pneumonic plague may also be primary manifestations. The plague bacteria can be transmitted to humans in the following ways: Flea bites. Yersinia pestis can be transmitted to humans from the bites of inflected fleas or handling of plague-infected tissues. The pneumonic form is invariably fatal unless treated early. Humans are usually more at risk during, or shortly after, a plague epizootic. Sun et al. The regimens listed below are guidelines only and may need to be adjusted depending on a patient’s age, medical history, underlying health conditions, or allergies. These infected animals and their fleas serve as long-term reservoirs for the bacteria. Plague or black death is an infection of rodents caused by Yersinia pestis and accidentially transmitted to humans by the bite of infected fleas. The infection exists in three major plague forms: bubonic, septicemic, and pneumonic. Yersinia pestis, the causative agent of plague. Plague is a zoonotic disease affecting rodents and transmitted by fleasfrom rodents to other animals and to humans. Pneumonic plague occurs when Yersinia pestis infects the lungs. It is a zoonotic disease and exists in natural cycles involving transmission between rodent hosts and flea vectors. Remove brush, rock piles, junk, cluttered firewood, and possible rodent food supplies, such as pet and wild animal food. Y. pestis is evolved into a deadly pathogen and transmitted to mammals and/or human beings by i … The organism is transmitted to humans who are bitten by fleas that have fed on infected rodents or by humans handling infected animals. 8 mg/kg/dose every 12 hours (max 250 mg per dose). A downloadable version pdf icon [PDF – 1 page] is also available. Surveillance and control requires investigating animal and flea species implicated in the plague cycle in the region and developing environmental management programmes to understand the natural zoonosis of the disease cycle and to limit spread. The arthropod-borne transmission route of Yersinia pestis, the bacterial agent of plague, is a recent evolutionary adaptation.Yersinia pseudotuberculosis, the closely related food-and water-borne enteric species from which Y. pestis diverged less than 6,400 y ago, exhibits significant oral toxicity to the flea vectors of plague, whereas Y. pestis does not. It is caused by the bacterium, Yersinia pestis. Find and stop the source of infection. Yersinia pestis is a gram-negative bacterium that causes plague, a highly contagious and lethal disease and the cause of three disease pandemics throughout human history. Clin Infect Dis. Make your home and outbuildings rodent-proof. 1) bubonic and pneumoni plague 2) rodents (fleas) 3) flea bite; human to human 4) intra and extracellular. In the bubonic form there is also swelling of lymph nodes, while in the septicemic form tissues may turn black and die, and in the pneumonic form shortness of breath, cough and chest pain may occur. Mice 3. However, the diseases they cause and their patterns of transmission are very different. In the bubonic form there is also swelling of lymph nodes, while in the septicemic form tissues may turn black and die, and in the pneumonic form shortness of breath, cough and chest pain may occur. 2004 38(5):663-669. Duration of treatment is 10 to 14 days, or until 2 days after fever subsides. Specimens should be obtained from appropriate sites for isolating the bacteria, and depend on the clinical presentation: Yersinia pestis may be identified microscopically by examination of Gram, Wright, Giemsa, or Wayson’s stained smears of peripheral blood, sputum, or lymph node specimen.Visualization of bipolar-staining, ovoid, Gram-negative organisms with a “safety pin” appearance permits a rapid presumptive diagnosis of plague. Typically this requires direct and close contact with the person with pneumonic plague. The last urban outbreak of rat-associated plague in the United States occurred in Los Angeles in 1924-1925. September 19, 2009. Yersinia pestis, the plague bacteria can be transmitted to humans in the following ways: Yersinia pestis bacteria are most often transmitted by the bite of an infected flea. Plague can take different clinical forms, but the most common are bubonic, pneumonic, and septicemic. Prairie dogs 6. Humans may contract plague through a flea bite or by handling an infected animal or breathing in an aerosolized form of the bacteria. Generally people should be advised to avoid direct contact with infected body fluids and tissues. Plague was the cause of some of the most-devastating epidemics in history. Localization and adherence of the biofilm to the flea foregut is essential for transmission. Ecology and Transmission. Footnote: All recommended antibiotics for plague have relative contraindications for use in children and pregnant women; however, use is justified in life-threatening situations. Wear gloves if you are handling or skinning potentially infected animals to prevent contact between your skin and the plague bacteria. The disease can also result by inhaling contaminated aerosols or from direct contact with infected animal tissue. If the patient has pneumonic signs, he/she should also be isolated and placed on droplet precautions. In the case of plague pneumonia, transmission can occur via inhalation of the cough droplets from another infected individual. Yersinia pestis is a zoonotic bacteria that causes plague or the Black Death during medieval times, that is most commonly transmitted through fleas that feed on infected rodents. How they produce a transmissible infection in their arthropod host is just as critical to their life cycle, however. Ensure correct treatment: Verify that patients are being given appropriate antibiotic treatment and that local supplies of antibiotics are adequate. Reduce rodent habitat around your home, work place, and recreational areas. However, recovery rates are high if detected and treated in time (within 24 hours of onset of symptoms). Typically this requires direct and close contact with the person with pneumonic plague. Routine hand-washing is recommended with soap and water or use of alcohol hand rub. This page of the eMedTV Web site offers related statistics and discusses symptoms of infection, transmission methods, treatment options, and preventive measures. agent of bubonic plague. Antibiotic treatment is effective against plague bacteria, so early diagnosis and early treatment can save lives. Plague is a highly virulent disease believed to have killed millions during three historic human pandemics. Yersinia pestis can be transmitted by fleas within a few days after taking a blood meal from a highly bacteremic host, termed early-phase or mass transmission; and again after it forms a dense biofilm in the foregut of its vector that can eventually block blood feeding. The three most endemic countries are the Democratic Republic of Congo, Madagascar, and Peru. During plague epizootics, many rodents die, causing hungry fleas to seek other sources of blood. The bubonic plague is the most common form of infection and targets the victim’s lymphatic system. Gross L. How the plague bacillus and its transmission through fleas were discovered: reminiscences from my years at the Pasteur Institute in Paris. The conclusions from studies comparing how efficiently fleas transmit plague after becoming infected have been inconsistent, possibly because a variety of rodent blood sources have been used. If cultures yield negative results, and plague is still suspected, serologic testing is possible to confirm the diagnosis. Yersinia pestis can be transmitted by fleas within a few days after taking a blood meal from a highly bacteremic host, termed early-phase or mass transmission; and again after it forms a dense biofilm in the foregut of its vector that can eventually block blood feeding. A bubo usually occurs in the groin, armpit or cervical lymph nodes. The septicemic plague courses through the body via the bloodstream, disseminating from infected lymph nodes. Septicemic plague can occur as the first symptom of plague, or may develop from untreated bubonic plague. This dosing regimen is based on the levofloxacin package insert and is recommended for pediatric patients <50 kg and ≥6 months of age. The researcher studied the genetics of harmful bacteria, including a … Biofilm development is positively regulated by hmsT , encoding a diguanylate cyclase that synthesizes the bacterial second messenger cyclic-di-GMP. Sputum: Culture is possible from sputum of very ill pneumonic patients; however, blood is usually culture-positive at this time as well. Without proper antibiotic treatment, infection by Yersinia pestis led to death within a few days. Do not allow dogs or cats that roam free in endemic areas to sleep on your bed. Buboes are often so painful that patients are generally guarded and have restricted movement in the affected region. When handling potentially infected patients and collecting specimens, standard precautions should apply. Bubonic plague is the most common primary manifestation of Yersinia pestis infection with patients developing sudden onset of fever, headache, chills, and weakness and one or more swollen, tender and painful lymph nodes (called buboes). Between 2010 and 2015, there were 3,248 cases reported worldwide. Identify the most likely source of infection in the area where the human case(s) was exposed, typically looking for clustered areas with large numbers of small animal deaths. Usually this begins one to seven days after exposure. CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. First, fleas get infected with Yersinia pestis by feeding on a bacteremic … Yersinia pestis, the etiologic agent of plague, is endemic in the western United States; 105 cases were reported between 1970 and 1979. http://www.who.int/en/news-room/fact-sheets/detail/plague, Institute of Medicine (US) Forum on Microbial Threats. Epizootics are most likely in areas with multiple types of rodents living in high densities and in diverse habitats. Duration of post-exposure prophylaxis to prevent plague is 7 days. After being taken up by macrophages, the bacteria proliferate in the affected lymph nodes, causing inflammation and swelling to occur, i.e., buboes. Global distribution of natural plague foci as of March 2016, Figure 3. Yersinia pestis est une bactérie résistante dans le milieu extérieur dans certaines conditions (basse température, humidité, absence de lumière), ce qui maintient des foyers naturels de peste dans le monde. Transmission to humans is usually through the bite of infected fleas. Humans are usually more at risk during, or shortly after, a plague epizootic. People and animals that visit places where rodents have recently died from plague are at risk of being infected from flea bites. Bactericidal. To the Editor: Yersinia pestis (family Enterobacteriaceae) is a bacterium that can cause high rates of death in susceptible mammals and can provoke septicemic, pneumonic, and bubonic plague in humans ( 1 ). This type of spread has not been documented in the United States since 1924, but still occurs with some frequency in developing countries. Scientific studies have suggested that epizootics in the southwestern United States are more likely during cooler summers that follow wet winters. Not widely available in the United States. Epidemic. Yersinia pestis is an arthropod-borne bacterial pathogen that evolved recently from Yersinia pseudotuberculosis, an enteric pathogen transmitted via the fecal-oral route.This radical ecological transition can be attributed to a few discrete genetic changes from a still-extant recent ancestor, thus providing a tractable case study in pathogen evolution and emergence. Transmission Fleas are natural vectors (carriers) of Y. pestis , and the bacteria are typically transmitted to and among rodents via flea bite. Rabbits 5. pestis is closely related to Y. pseudotuberculosis genetically but became highly virulent. Available from: https://www.ncbi.nlm.nih.gov/books/NBK45744, Human Plague – Four States, 2006. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5534a4.htm. Figure 5. Prompt treatment with the correct medications is critical to prevent complications or death. Todd SR, Dahlgren FS, Traeger MS, Beltrán-Aguilar ED, Marianos DW, Hamilton C, McQuiston JH, Regan JJ. Bronchial/tracheal washing may be taken from suspected pneumonic plague patients; throat specimens are not ideal for isolation of plague since they often contain many other bacteria that can mask the presence of plague. The patient, a researcher in a university laboratory, had been working along with other members of the laboratory group with a pigmentation-negative (pgm-) attenuated . Plague is a serious illness. CDC twenty four seven. The organism that causes plague, Yersinia pestis, lives in small rodents found most commonly in rural and semirural areas of Africa, Asia and the United States. Transmission Fleas are natural vectors (carriers) of Y. pestis , and the bacteria are typically transmitted to and among rodents via flea bite. Many types of animals, such as rock squirrels, wood rats, ground squirrels, prairie dogs, chipmunks, mice, voles, and rabbits can be affected by plague. FDA approved based on animal studies but limited clinical experience treating human plague. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website. The last urban outbreak of rat-associated plague in the United States occurred in Los Angeles in 1924-1925. See WHO map of global cases. Being that a rat is a bigger organism and can mobilize itself and the flea. Wild carnivores can become infected by eating other infected animals. The plague bacteria, Yersinia pestis, is transmitted to humans through the bites of fleas that have previously fed on infected animals, such as: 1. Contact with contaminated fluid or tissue. Yersinia pestis is an obligate parasite, meaning that it cannot reproduce without a host. Author summary Yersinia pestis, the bacterial agent of plague, is transmitted by fleas that feed on blood from rodents that carry this disease. Yersinia pestis, the etiological agent of the zoonosis plague, is transmitted from diseased rodents to humans by the bite of infected fleas. The flea draws viable Y. pestis organisms into its intestinal tract. No visible dental staining in children treated with doxycycline for suspected Rocky Mountain spotted fever. During plague epizootics, many rodents die, causing hungry fleas to seek other sources of blood. Surveillance: identify and monitor close contacts of pneumonic plague patients and give them a seven-day chemoprophylaxis. The incubation period for bubonic plague is usually 2 to 6 days. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website. Bubonic plague is the most common form and is characterized by painful swollen lymph nodes or ‘buboes’. The acquisition of flea-borne transmission is a recent event in the evolution of Yersinia pestis. pestis is closely related to Y. pseudotuberculosis genetically but became highly virulent. A known flea bite or the presence of a bubo may help a doctor to consider plague as a cause of the illness. In cases where live organisms are unculturable (such as postmortem), lymphoid, spleen, lung, and liver tissue or bone marrow samples may yield evidence of plague infection by direct detection methods such as direct fluorescent antibody (DFA) or polymerase chain reaction (PCR). Scientists think that plague bacteria circulate at low rates within populations of certain rodents without causing excessive rodent die-off. Cats are particularly susceptible to plague, and can be infected by eating infected rodents. Appropriate diagnostic samples include blood cultures, lymph node aspirates if possible, and/or sputum, if indicated. Pneumonic plague, or lung-based plague, is the most virulent form of plague. (adsbygoogle = window.adsbygoogle || []).push({}); (adsbygoogle = window.adsbygoogle || []).push({ Rodents are the primary hosts of the bacteria, which is spread through fleas. In many cases, particularly in septicemic and pneumonic plague, there are no obvious signs that indicate plague. The flea lives on a rat and gives the rat the sickness, but it doesn't affect the rat. report that only four genetic changes in the progenitor species, Yersinia pseudotuberculosis, enabled transmission by flea vectors. Plague symptoms depend on how the patient was exposed to the plague bacteria. Interest in arthropod-borne pathogens focuses primarily on how they cause disease in humans. If pneumonic plague patients are not given specific antibiotic therapy, the disease can progress rapidly to death. Pneumonic plague is the most serious form of the disease and is the only form of plague that can be spread from person to person (by infectious droplets). When a person has plague pneumonia, they may cough droplets containing the Yersinia pestis bacteria into air. Note: A plague vaccine is no longer available in the United States. Cats are particularly susceptible to plague, and can be infected by eating infected rodents. The bacteria that cause plague, Yersinia pestis, maintain their existence in a cycle involving rodents and their fleas. Plague occurs in rural and semi-rural areas of the western United States, primarily in semi-arid upland forests and grasslands where many types of rodent species can be involved. A specific Yersinia pestis antigen can be detected by different techniques. VolesThe bacteria can also enter your body if a break in your skin comes into contact with an infected animal's blood. If the patient is not treated with the appropriate antibiotics, the bacteria can spread to other parts of the body. }); 5 mg/kg once daily, or 2 mg/kg loading dose followed by 1.7 mg/kg every 8 hours, Not FDA approved but considered an effective alternative to streptomycin. Annually, most human cases occur in Africa, with Madagascar considered to be the most highly endemic country. It is also possible to be infected through the respiratory droplets of infected hosts. Plague is a very severe disease in people, particularly in its septicaemic (systemic infection caused by circulating bacteria in bloodstream) and pneumonic forms, with a case-fatality ratio of 30% to 100% if left untreated. In Madagascar cases of bubonic plague are reported nearly every year, during the epidemic season (between September and April) 4). Human infections with the bacterium Yersinia pestis are often secondary sequelae to expansion phases of sylvatic rodent plague foci (17, 24).Expansion events occur in response to conditions that facilitate the dispersal of the infectious agent or to the population dynamics of animal reservoirs (), the flea vector (), and human hosts (8, 52). Rodents are the primary hosts of the bacteria, which is spread through fleas. Yersinia pestis bacteria can cause plague, which is an acute, infectious disease. edited August 2015 The Yersinia pestis infection guidelines were first published in the J Feline Med Surg 2013; 15: 582-584 by Maria Grazia Pennisi. Since that time, plague has occurred in rural and semi-rural areas of the western United States, primarily in semi-arid upland forests and grasslands where many types of rodent species can be involved. Blood cultures: Organisms may be seen in blood smears if the patient is septicemic. Yersinia pestis is transmitted to humans by the bite of rodent fleas or more rarely from infected domestic cats, handling of infected animal tissue, inhalation of aerosolized droplets, or from laboratory exposure. J Pediatr. It is a facultative anaerobic organism that can infect humans via the Oriental rat flea (Xenopsylla cheopis). The last urban plague epidemic in the United States occurred in Los Angeles from 1924 through 1925. Man to man transmission. Prairie dogs 6. Dissemination of Yersinia pestis , the etiological agent of plague, by blocked fleas has been the accepted paradigm for flea-borne transmission. Centers for Disease Control and Prevention. Spraying of face/chest area of suspected pneumonic plague deaths should be discouraged. VolesThe bacteria can also enter your body if a break in your skin comes into contact with an infected animal's blood. Disinfection. Yersinia pestis is a Gram-negative, non-motile, non-spore-forming coccobacillus that is also a facultative anaerobe 1). Yersinia pestis, responsible for causing fulminant plague, has evolved clonally from the enteric pathogen, Y. pseudotuberculosis, which in contrast, causes a relatively benign enteric illness.