Lassa fever
An acute viral infection found in the tropics, especially in West Africa. Epidemics of Lassa fever have occurred in countries such as Sierra Leone, Congo (formerly Zaire), Liberia and Nigeria. The disease was discovered in 1969 when two missionary nurses died of it in the village of Lassa, Nigeria. The virus (a member of the virus family Arenaviridae) is a single-stranded RNA virus and is animal-borne (zoonotic). Lassa fever is a grave health concern because it can cause a very severe potentially fatal illness, is highly contagious and can spread like wildfire. The number of Lassa virus infections per year in West Africa has been roughly estimated at 100,000 to 300,000, with at least 5,000 deaths yearly. The Lassa virus has been found in a rodent known as the "multimammate rat" of the genus Mastomys. People can become infected by eating this infected rat or by eating food contaminated by rat excretions. Person-to-person transmission also occurs by direct contact, contamination of skin breaks with infected blood, and aerosol spreads (virus particles moving through the air). The first symptoms of the disease typically occur 1-3 weeks after the patient comes into contact with the virus and can include increasingly high fever, sore throat, cough, eye inflammation (conjunctivitis), facial swelling, retrosternal pain (behind the breastbone), back pain, {{}}abdominal pain, vomiting, diarrhea and general weakness lasting for several days. Neurological symptoms have also been described, including hearing loss, tremors, and encephalitis (brain inflammation). The most common long-term complication of Lassa fever is deafness. Because the symptoms are so varied and nonspecific, clinical diagnosis is often difficult. If the person has traveled to West Africa and has a severe fever within 3 weeks after returning (the incubation period of lassa virus is 1 to 3 weeks), the illness should be reported to a doctor. The key agent for treatment is Ribavirin (Rebetron, Virazole), an antiviral drug, which is most effective when given early in the course of the disease. Patients are also given supportive care with fluid balance, oxygen as needed, treatment of any other complicating infections, etc. Medical isolation procedures should be followed, due to the highly contagious nature of Lassa fever. These procedures are termed VHF isolation precautions or barrier nursing methods and include protective clothing such as masks, gloves, gowns, and goggles; infection control measures such as complete equipment sterilization; and isolating infected patients from contact with unprotected persons until the disease has run its course. Patients may excrete the virus weeks after recovery. Their bodily fluids should therefore be monitored for the virus before they leave the hospital. Cases of Lassa fever in such areas as the U.S., Canada, and Europe tend to make the news because of the fearsome and seemingly exotic nature of the disease. For example, in January, 2000 it was reported that a 23-year-old woman died of Lassa fever in Wuerzburg, Germany. An art student, she had been traveling in Africa where she contracted a new and especially aggressive strain of the Lassa virus. She died of massive internal bleeding. Cases in West Africa rarely, if ever, make news.

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Las·sa fever .las-ə- n a disease esp. of Africa that is caused by the Lassa virus and is characterized by a high fever, headaches, mouth ulcers, muscle aches, small hemorrhages under the skin, heart and kidney failure, and a high mortality rate

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a serious virus disease confined to Central West Africa. After an incubation period of 3-21 days, headache, high fever, and severe muscular pains develop; difficulty in swallowing often arises. Death from kidney or heart failure occurs in over 50% of cases. Treatment with plasma from recovered patients is the best therapy, and the causative virus is susceptible to ribavirin.

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an acute type of hemorrhagic fever caused by an arenavirus, endemic throughout West Africa but seen globally, usually transmitted via the multimammate mouse (Mastomys natalensis) or other Mastomys rodents but occasionally spread between persons. Most infections are subclinical or mild, although severe infection with multisystem involvement can be fatal. Clinical manifestations are variable, but may include fever, headache, dry cough, back pain, vomiting, diarrhea, pharyngitis, and occasionally a rash; some patients develop deafness that can be permanent. Hypotension, peripheral vasoconstriction, facial and pulmonary edema, and hemorrhage from mucosal surfaces, usually occurring in the second week of infection, are all associated with fatal infection.

Medical dictionary. 2011.

Look at other dictionaries:

  • Lassa fever — [läs′ə] n. [after Lassa, village in E Nigeria, where first detected] an acute viral disease endemic to W Africa, characterized by high fever and inflammation of various body parts …   English World dictionary

  • Lassa fever — ► NOUN ▪ an acute and often fatal disease transmitted by a virus and occurring chiefly in West Africa. ORIGIN named after the village of Lassa in Nigeria, where it was first reported …   English terms dictionary

  • Lassa fever — Taxobox | color = violet name = Lassa virus image width = 200 px image caption = TEM micrograph of Lassa virus virions. virus group = v familia = Arenaviridae genus = Arenavirus species = Lassa virus DiseaseDisorder infobox Name = Lassa Fever… …   Wikipedia

  • Lassa fever — n. an acute and often fatal febrile viral disease of tropical Africa. Etymology: Lassa in Nigeria, where first reported * * * lassa fever 7 [lassa fever] [ˈlæsə fiːvə(r)] [ˈlæsə fiːvər] noun uncountable a seri …   Useful english dictionary

  • Lassa fever — /læsə ˈfivə/ (say lasuh feevuh) noun an acute, often fatal, viral disease of central western Africa, causing progressive infection of the pharynx, lungs, heart and kidneys. Also, lassa fever. {named after Lassa, Nigerian village where the disease …   Australian English dictionary

  • Lassa fever — noun Etymology: Lassa, village in Nigeria Date: 1970 a disease especially of Africa that is caused by an arenavirus (species Lassa virus of the genus Arenavirus) and is characterized by a high fever, headaches, mouth ulcers, muscle aches, small… …   New Collegiate Dictionary

  • Lassa fever — noun An acute, and often fatal, viral infection endemic to West Africa. Symptoms include fever, sore throat, muscle aches, a skin rash, headache, abdominal pain, vomiting, diarrhoea, ulcers, heart and kidney failure. Syn: Lassa hemorrhagic fever …   Wiktionary

  • Lassa fever — /lah seuh/, Pathol. a highly contagious viral disease, largely confined to central West Africa, characterized by fever, difficulty in swallowing, and inflammation of the pharynx, often progressing to infect the lungs, heart, and kidneys, leading… …   Universalium

  • Lassa fever — Las′sa fe′ver [[t]ˈlɑ sə[/t]] n. pat an infectious, often fatal disease characterized by fever and pharyngitis, caused by an arenavirus • Etymology: 1965–70; after Lassa, Nigeria, village where it was first identified …   From formal English to slang

  • Lassa fever — See Lassa virus …   Dictionary of molecular biology

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