Aerosols transmission

It is normally found in southern and Eastern Europe, Central Asia, the Mediterranean, northwestern China, Africa, and the Indian subcontinent. The natural reservoirs are ticks and numerous animal species. Animals (e.g., cattle, sheep, goats, horses, pigs, hares, hedgehogs) infected with this virus usually have no clinical symptoms or suffer only a mild illness. The hemorrhagic fever is highly pathogenic and notable for aerosol transmission. This is a biosafety level 4 agent. 

Routes of Entry to the Body Inhalation of aerosol, transmissible from horses to humans although the transmissibility rate is low. 

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. 

Aerosol transmission of certain VHP viruses has been theorized and has been seen in animal experiments. Case-fatality rates for VHP infections vary widely, ranging from less than 1% for Omsk hemorrhagic fever to up to 90 % for Ebola (subtype Zaire Borio etal., 2002). 

World Health Organization (WHO) identify Biosafety Levels 1,2, 3, and 4 and in the United Kingdom the Advisory Committee on Dangerous Pathogens (ACDP) categorizes Laboratory Containment Levels 1, 2, 3, and 4 (4-6). All share the same objective to identify biosafety or laboratory containment levels that minimize the risk to the laboratory worker, to the outside community, and to the environment. At Biosafety/Laboratory Containment Level 2, exposure risks to the laboratory worker arise mainly from contact through a contaminated work environment. As the risk of airborne infection increases, Biosafety/ Laboratory Containment Level 3 provides facilities to prevent aerosol transmission. Additional safeguards to protect the outside community and the environment are found at Biosafety/Laboratory Containment Level 4, which is... 

A smallpox attack wonld pose difficult problems for public health officials due to the ability of the virus to continue to spread unless stopped by isolation of patients and vaccination/isolation of their close contacts (26). Given the threat of aerosol transmission in hospitals, as the number of cases rises, physicians should isolate suspected patients in their homes or an alternative nonhospital facility. Such home care is reasonable, considering that supportive therapy is the only care available to smallpox victims (26). Chapter 6 discusses alternative treatment centers that public health authorities are likely to establish during large outbreaks. 

Human infection with arenaviru.ses is incidental to the natural cycle of the viruses and occurs when an individual comes into contact with the excretions or materials contaminated with the excretions of an infected rodent, such as ingestion of containinaied food, or by direct contact of abraded or broken skin with rodent excrement. Infection can also ixcur by inhalation of tiny particles soiled with rodent urine or saliva (aerosol transmission). The types of incidental contact depend on the habits of both humans and rodents. For example, where the infected rodent species prefers a field habitat, human infection is associated with agricultural work. In areas where the rodent species habitat includes human homes or other buildings, infection occurs in domestic settings. 

Safety professionals should also be aware that OSHA has announced an airborne infectious disease rule that may impact a substantial number of workplaces. This proposed rule is modeled after the Cal-OSHA aerosol transmissible disease rule, which required respiratory protection, fit testing, disease exposure control plans, medical surveillance, and communication procedures, among other requirements. 

Dinimick, R.L., VogI, W.F., and Chatigny, M.A., Potential fcr accidental mio obial aerosol transmission in the biological laboratory, in Biohazards in Biological Reseanch, Heilman, A., et al., Eds.,... 

Li genous or exotic agents with potential for aerosol transmission low disease may have serious or lethal consequences... 

It is extremely difficult to prevent aerosol transmission of microorganisms or their products if one is unaware of the importance of this hazard. Aerosols are unseen and can persist in the indoor atmosphere for... 

The history of laboratory infection has been covered by various authors over the years " and has formed the topic of an excellent book by Collins. In the early days of medical microbiology, the risk of infection was perhaps regarded as part of the job, with ill health normally arising as a consequence of careless or thoughtless laboratory practice. Bad practice possibly arose partly from a belief in the glamour of medical martyrdom and partly from the under-recognised importance of aerosol transmission. 

McKissick, G.E., R.A. Griesemer, and R.L. Farrell. 1970. Aerosol transmission of Rauscher murine leukemia virus. J. Nat. Cancer Inst. 45 625-636. 

Oster, C.N., D.S. Burke, R.H. Kenyon, M.S. Ascher, P. Harber, and C.E. Pedersen, Jr. 1977. Laboratory-acquired Rocky Mountain spotted fever. The hazard of aerosol transmission. N. Engl J. Med. 297 859-863. 

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