Yellow+Fever+Biology

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From book- Yellow Fever, Black Goddess. By Christopher Wills. Copyright date : 1996, //HarperCollinsPublishers//

'acute viral disease'

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[] - good basic facts.

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 * Look in bookshelf for the __Fever: 1793__**[[image:file:///C:/DOCUME%7E1/sara/LOCALS%7E1/Temp/moz-screenshot-4.jpg]]


 * http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/yellow_fever.jsp

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[] - history

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Symptoms of Yellow Fever**: The virus remains silent in the body during an incubation period of three to six days. There are then two disease phases. While some infections have no symptoms whatsoever, the first, "acute", phase is normally characterized by fever, muscle pain (with prominent backache), headache, shivers, loss of appetite, nausea and/or vomiting. Often, the high fever is paradoxically associated with a slow pulse. After three to four days most patients improve and their symptoms disappear.However, 15% enter a "toxic phase" within 24 hours. Fever reappears and several body systems are affected. The patient rapidly develops jaundice and complains of abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes and/or stomach. Once this happens, blood appears in the vomit and faeces. Kidney function deteriorates; this can range from abnormal protein levels in the urine (albuminuria) to complete kidney failure with no urine production (anuria). Half of the patients in the "toxic phase" die within 10-14 days. The remainder recover without significant organ damage.Yellow fever is difficult to recognize, especially during the early stages. It can easily be confused with malaria, typhoid, rickettsial diseases, haemorrhagic viral fevers (e.g. Lassa), arboviral infections (e.g. dengue), leptospirosis, viral hepatitis and poisoning (e.g. carbon tetrachloride). A laboratory analysis is required to confirm a suspect case. Blood tests (serology assays) can detect yellow fever antibodies that are produced in response to the infection. Several other techniques are used to identify the virus itself in blood specimens or liver tissue collected after death. These tests require highly trained laboratory staff using specialized equipment and materials.**

Common-
 * //Stage 1: early symptoms with sudden onset lasting about 2-5 days://
 * High fever
 * Rapid pulse (briefly)
 * Slow pulse
 * Facial flushing
 * Bloodshot eyes
 * Furry tongue
 * Nausea
 * Vomiting
 * Constipation
 * Irritability
 * Headache
 * Muscle pains
 * Kidney inflammation
 * Reduced urine
 * Proteinurea
 * //Stage 2: brief remission stage lasting hours or days//
 * //Stage 3: yellow phase lasting 3 to 9 days//:
 * Liver inflammation
 * Jaundice - see symptoms of jaundice
 * Yellow eyes
 * Yellow skin
 * Vomiting blood
 * Black vomit
 * Slow heartbeat
 * High fever
 * General weakness
 * Kidney inflammation
 * Renal damage
 * Lack of urine
 * Proteinurea
 * Hemorrhage
 * Mucous membrane bleeding
 * Bleeding into the skin
 * Gastrointestinal inflammation
 * Gastrointestinal bleeding
 * Tiredness
 * Confusion
 * Convulsions
 * Coma
 * Death
 * Fever
 * Jaundice
 * Yellow discoloured skin
 * Bleeding
 * Bruising
 * Diarrhoea
 * Abdominal pain
 * Chest pain
 * Haematuria
 * Sudden fever
 * Yellow skin
 * Hemorrhage

History of Yellow Fever From 1793 to 1822 yellow fever was one of the most dreaded diseases in the port cities of the United States. Statistically, one can dismiss it as inconsequential in comparison to tuberculosis and smallpox. Yellow fever did not kill that many people, but during that period, it struck with such ferocity in principal cities that it spread gloom and fear throughout the country. Doctors were uncertain of the cause of yellow fever and the factors that led it to reach epidemic proportions. That uncertainty was not unique. The causes of other diseases were also unknown. But doctors and patients then had an acute understanding of fever. Today, fever is a symptom that can usually be controlled with over-the-counter medicines. Then, fever was tantamount to disease itself. Fever was far more than a question of body temperature and discomfort. It was a state in which a person's whole being was reordered. Two hundred years ago it was conceived in much the same way that we conceive of cancers. Just as today, when one discusses cancer, death is assumed to be a likely consequence, then when one discussed fever, death was assumed to be a likely consequence. It was this view of morbidity that made yellow fever so feared simply because in the experience of these people who were so sensitive to fevers, yellow fever was most powerful and horrible.

Pathogen:
 * Acute Viral Infection**

Treatment: The only treatments for yellow fever are given to relieve its symptoms. Fevers and pain should be relieved with acetaminophen, not aspirin or ibuprofen, both of which could increase the already-present risk of bleeding. Dehydration (due to fluid loss both from fever and bleeding) needs to be carefully avoided. This can be accomplished by increasing fluids. The risk of bleeding into the stomach can be decreased through the administration of antacids and other medications. Hemorrhage may require blood transfusions. Kidney failure may require dialysis (a process that allows the work of the kidneys in clearing the blood of potentially toxic substances to be taken over by a machine, outside of the body).
 * There is no specific treatment for Yellow Fever found yet.**

Epidemiology: The urban form is transmitted between humans by the Aedes aegypti mosquito and thus the potential distribution of urban YF is in any areas where infestation with Aedes aegypti occurs, including Africa, S and N America and Asia. Although the urban vector is present in Asia, yellow fever has never been established there. The majority of reported human YF cases come from Africa (Angola, Cameroon, Gambia, Ghana, Nigeria, Sudan, and Zaire) and S America (Brazil, Bolivia, Columbia, Peru, Ecuador and Venezuela). Both of these continents have jungle yellow fever transmitted in a monkey-mosquito-monkey cycle. In these areas, YF is reintroduced into urban populations from time to time as a result of contact with jungle areas. YF cases occur more frequently at times of the year when there are high temperatures ad high rainfall, conditions which are most conducive to mosquito reproduction. Once infected, the mosquito vector remains infectious for life. transovarial transmission of Aedes aegypti had been demonstrated and may provide a mechanism for the continuation of the jungle or urban cycle. Once the virus is inoculated into human skin, local replication occurs with eventual spread to the local lymph nodes and viraemia occurs. The target organs are the lymph nodes, liver, spleen, heart, kidney and foregut.**
 * Yellow fever, once a scourge of the port cities of North America and Europe, remains an important endemic and epidemic disease of Africa and South America. Yellow fever occurs in 2 major forms: urban and jungle (sylvatic) yellow fever. Jungle YF is the natural reservoir of the disease in a cycle involving nonhuman primates and forest mosquitoes. Man may become incidentally infected on venturing into jungle areas. The S American monkeys are more prone to mortality once infected with YF than the old world monkeys, suggesting that American YF probably originated from the old world as a result of sailing ships.