Lassa fever virus

Viremia is common to many viral illnesses, but it does not usually lead to the development of chnical sepsis. Hypotension and disseminated intravascular coagulation (DIG) may occur with unusual viruses, such as Ebola virus and Lassa fever virus, and may be seen occasionally with influenza A, arbovirus, and possibly severe measles. ... 

Yersinia pestis (pneumonic form) I Lassa fever virus... 

Arenavirus (Lassa fever virus, lymphocytic choriomeningitis virus, Machupo virus, and Junin virus). Enveloped, helical, ambisense, and ssRNA (two segments). Synthesis occurs in the host cell cytoplasm maturation involves budding from the host cell plasma membrane. Virions contain ribosomes. The human pathogens Lassa, Machuppo, and Junin viruses are Biosafety Level 4 pathogens - they must be handled in the laboratory under maximum containment conditions. 

Arenavirus (Lassa fever virus, lymphocytic choriomeningitis virus, Machupo virus, Junin virus)... 

Discovery of a potent anti-Lassa fever virus drug... 

Ebola virus, Marburg virus, Lassa fever, Argentine and Bolivian hemorrhagic fevers, Crimean Congo hemorrhagic fever, Rift Valley fever, dengue hemorrhagic fever,... 

Although ribavirin monotherapy is ineffective against HCV, oral ribavirin in combination with inter-feron-a (Rebatron) is approved for this indication and is effective in patients resistant to interferon therapy alone. Intravenous ribavirin may be useful in the therapy of Hantaan virus infection, Crimean or Congo virus hemorrhagic fever, Lassa fever, and severe adenovirus infection. 

Intravenous ribavirin decreases mortality in patients with Lassa fever and other viral hemorrhagic fevers if started early. High concentrations inhibit West Nile virus in vitro, but clinical data are lacking. Clinical benefit has been reported in cases of severe measles pneumonitis and certain encephalitides, and continuous infusion of ribavirin has decreased virus shedding in several patients with severe lower respiratory tract influenza or parainfluenza infections. At steady state, cerebrospinal fluid levels are about 70% of those in plasma. 

Antiviral spectrum Ribavirin is used in treating infants and young children infected with severe RSV infections. [Note It is not indicated for use in adults.] Favorable responses of acute hepatitis A virus and influenza A and B infections have also been reported. Ribavirin may reduce the mortality and viremia of Lassa fever. 

Hemorrhagic fever viruses (including Ebola, Marburg, Lassa, and the South American arenaviruses, such as Machupo, Junin, and Guanarito)... 

Frame, J.D., Baldwin, J.M., Gocke, D.J., Troup, J.M. Lassa fever, a new virus disease of man from West Africa. I. Clinical descriptions and pathological findings. Amer. J. Trop. Med. Hyg. 1970 19 670-676... 

Unlabeled u.ses of ribavirin include aerosol treatment of influenza types A and B and oral treatment of hepatitis, genital herpes, and Lassa fever. Ribavirin does not protect cells again.st the cytotoxic effects of the AIDS virus. 

Arenaviruses (Lassa (Lassa fever), Junin (Argentine hemorrhagic fever), and related viruses)... 

In West Africa, the arenavirus, Lassa Virus, causes Lassa Fever, responsible for 10-15% of adult febrile hospital admissions and up to 40% of nonsurgical deaths (48). The CDC estimates that Lassa virus infects 100,000-300,000 people annually, with approximately 5,000 deaths (50). Lassa causes pediatric disease as well as high mortality in pregnant women. Although nosocomial infections occur, most cases result from contact with the rodent species Mastomys natalensis (48). 

Uses include management of respiratory syncytial virus, influenza A and B, Lassa fever, Hantavirus, and as adjunct to alpha-interferons in hepatitis C. 

Amantadine blocks the attachment, penetration, and uncoating of influenza virus A zanamivir and oseltamivir inhibit influenza viruses A and B neuraminidase, promoting viral dumping and deceasing the chance of penetration. Ribavirin becomes phosphorylated and inhibits IMP dehydrogenase and RNA polymerase. It is used to treat respiratory syncytial virus, influenza A and B, Lassa fever,... 

FIGURE 3.9 Lassa fever. Liver from a patient with Lassa fever. Scattered hepatocytes and reticuloendothelial cells show reactivity with monoclonal antibody to Lassa virus. (Naphthol fast red substrate and hematoxylin counterstain original magnification x100.)... 

Who are these new adversaries They are led by viruses such as the human immunodeficiency virus (HIV) which causes AIDS, the hanta viruses, herpes, and the emerging viruses such as Ebola and Lassa fever. They are bacteria, such as Salmonella, Staphylococcus and Mycobacterium tuberculosis, that once were easily killed by a host of antibiotics and are now resistant to most drugs we develop. They are the insect-borne diseases such as Lyme s, Dengue, and West Nile. They are the prions, a lifeform less complex than viruses that can only survive in a host and cause debilitating, and presently noncurable, madness in animals and humans. They are the insects themselves that are resistant to many organic pesticides and which continue to cause destruction of plant life. Why are these threats emerging now ... 

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