Plague transmission

Primary pneumonic plague occurs after inhalation of organisms, which may occur by aerosol transmission from a person or animal with secondary or primary pneumonic plague. Septicemic plague may evolve from any form of plague. It features the acute onset of bacteremia, septic shock, and thrombosis with or without antecedent lymphadenitis. Prognosis for both pneumonic and septicemic pneumonic plague is poor the fatality rate is 100 percent for untreated cases. 

Pneumonic) Plague 1. Aerosol 2. Infected vectors High High 2-3 days 1-2 days Very high Less important because of high transmissibility Yes Moderately effective No... 

Plagne remains a rare but reportable disease in the United States, with 390 cases reported from 1947 to 1996. Of these cases, 84% were bubonic, 13% septicemic, and 2% were pneumonic (23). Most hnman cases in the United States occur in two regions northern New Mexico, northern Arizona, and southern Colorado and California, southern Oregon, and far western Nevada (http //www.cdc.gov/ncidod/ dvbid/plague/epi.htm). Modes of transmission are known for 284 of 341 cases reported between 1970 and 1995 Flea bites were responsible for 222 (78%) cases, direct contact with an infected animal was responsible for 56 (20%) cases and inhalation of airborne materials snch as respiratory droplets from infected animals was responsible for 7 (2%) cases. Los Angeles was the site of the last person-to-person transmission in the United States in 1924 (23). 

Hayes (5) has also reviewed the contribution of pesticides to the control of human diseases spread by arthropods and other vectors. Outbreaks of malaria, louse-borne typhus, plague, and urban yellow fever, four of the most important epidemic diseases of history, have been controlled by use of the organochlorine insecticides, especially DDT. In fact, the single most significant benefit from pesticides has been the protection from malaria. Today malaria eradication is an accomplished fact for 619 million people who live in areas once malarious. Where eradication has been achieved it has stood the test of time. An additional 334 million people live in areas where transmission of the parasite is no longer a major problem. Thus, about 1 billion people, or approximately one-fourth of the population of the world, no longer live under the threat of malaria. 

Eisen, R.J., Bearden, S.W., Wilder, A.P., Montenieri, J.A., Antolin, M.F., Gage, K.L. 2006. Early-phase transmission of Yersinia pestis by unblocked fleas as a mechanism explaining rapidly spreading plague epizootics. Proc. Natl. Acad. Sci. USA 103 15380—15385. 

Human-to-human transmission of plague can occur from patients with pulmonary infection. However, understanding of the epidemiology of pneumonic plague is incomplete. Most epidemics have occurred in cool climates with moderate humidity and close contact between susceptible individuals. Outbreaks of pneumonic plague have been rare in tropical climates even during epidemics of bubonic disease. Respiratory transmission may occur more efficiently via larger droplets or fomites rather than via small-particle aerosols.48... 

None, no evidence of person to person transmission pneumonic plague For 72 hrs, following initiation of appropriate antimicrobial therapy or unUl sputum culture is negative Smallpox approximately 3 weeks, usually corresponds with the initial appearance of skin-lesions to their final disappearance, most infectious during the first week of rash via inhalation of virus released from oropharyngeal-lesion secretions of the index case VHF varies with virus, but at minimum, all for the duration of illness and for Ebola Marburg transmission through semen may occur up to 7 weeks after clinical recoverv. 

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