This article discusses the viral disease. is also another term for Asian Fetish .
(also called ''yellow jack'', ''black vomit'', or sometimes ''American Plague'') is an acute
Viral disease. It is an important cause of
Hemorrhagic illness in many
Africa n and
South America n countries despite existence of an effective
Vaccine .
Yellow fever has been a source of several devastating epidemics. During one of
Napoleon's campaigns to
Haiti in 1802, the troops were attacked by yellow fever. More than half of the army perished due to the disease. Outbreaks followed by thousands of fatalities occurred periodically in other Western Hemisphere locations until research which included human volunteers (some of whom died) led to an understanding of the method of transmission to humans (primarily by
Mosquito s) and development of a vaccine and other preventative efforts in the early 20th century.
Despite the costly and sacrificial breakthrough research by Cuban physician
Carlos Finlay , American physician
Walter Reed and many others, over 100 years later, unvaccinated populations in many developing nations in Africa and Central and South America continue to be at risk.
1 }} As of 2001, the
World Health Organization (WHO) estimates that yellow fever causes 200,000 illnesses and 30,000 deaths every year in unvaccinated populations.
2
'' mosquito on a human host, about to obtain a blood meal]]
Yellow fever is caused by an
Arbovirus of the family
Flaviviridae , and is one of the smallest
RNA Virus es isolated.
3 Human infection is begun after deposition of viral particles through the skin in infected
Arthropod saliva.
Mosquito s are the primary
Vector in transmission of the disease from forest
Monkey s to humans and in person-to-person transmission. The mosquitos involved are ''
Aedes Simpsoni '', ''
A. Africanus '', and ''
A. Aegypti '' in Africa, and the ''
Haemagogus '' and ''
Sabethes '' genera in South America.
Yellow fever infections are frequently severe; more moderate cases may occur as the result of previous infection by another flavivirus. After infection, the virus first replicates locally, followed by transportation to the rest of the body via the
Lymphatic System .
4 Following systemic lymphatic infection, the virus proceeds to establish itself throughout organ systems, including the heart, kidneys,
Adrenal Gland s, and the
Parenchyma of the live; high viral loads are also present in the blood. Necrotic masses (
Councilman Bodies ) appear in the
Cytoplasm of
Hepatocyte s.
,5 }}
After a 3 to 6 day
Incubation Period , the typical symptoms that arise are
Fever , muscle aches,
Headache , and backache. Other symptoms may include a red tongue, flushed face, and reddening of the eyes. In a proportion of cases there is also involvement of internal organs including the
Liver ,
Kidneys , and
Heart . There may be
Hemorrhage from the
Gastrointestinal Tract (bloody vomit). Later the disease is sometimes complicated by
Jaundice with liver failure (which causes yellow skin colour, hence the name "yellow fever") and/or kidney insufficiency with
Proteinuria . If the disease progresses,
Delirium ,
Seizure s and
Coma ensue.
Hypotension and
Dehydration are also common.
Mortality is around 5%; although historically it has been much higher
[http://etext.lib.virginia.edu/etcbin/fever-browse?id=N2659002 . Patients who die usually do so within six to seven days of onset.
There is a difference between disease outbreaks in rural or forest areas and in towns. Disease outbreaks in towns and non-native people are usually more serious.
Yellow fever occurs only in Africa, South and Central America, and the Caribbean
{Link without Title} . Most outbreaks in South America are to people who work within the tropical rain forests and have direct contact with the organisms within the rainforest.
The disease can remain locally unknown in humans for long periods of time and then suddenly break out in an epidemic fashion. In Central America and Trinidad, such epidemics has been due to a form of the disease (''jungle yellow fever'') that is kept alive in
Red Howler monkey populations and transmitted by ''Haemagogus'' mosquito species which live only in the canopy of rain forests. The virus is passed to humans when the tall rainforest trees are cut down. Infected woodcutters can then pass on the disease to others via species of ''Aedes'' mosquitoes that typically live at low altitudes, thus triggering an epidemic.
6
A
Vaccine for yellow fever was developed which gives a 10-year or more immunity from the disease and effectively protects people traveling to the affected areas whilst being a means to control the disease at the same time. Woodcutters working in jungle areas should be particularly targeted for vaccination.
Insecticide s, protective clothing and screening of houses are helpful but not always enough. In affected areas
Mosquito Control methods have proved effective in decreasing the number of cases.
Recent studies have noted the increase in areas affected by mosquito-borne viral infections and have called for further research and funding for vaccines.
7,8 }}
There is no specific cure for yellow fever; therefore vaccination is important. Treatment is symptomatic and supportive only. Fluid replacement, fighting hypotension and transfusion of blood derivates is mostly needed in severe cases. In severe cases resulting in
Acute Renal Failure , dialysis may be necessary. A fever victim needs to get lots of rest, fresh air, and drink plenty of fluids.
In the hamster model of yellow fever, early administration of the antiviral
Ribavirin is an effective early treatment of many pathological features of the disease.
9 }} Ribavirin treatment during the first five days after virus infection improved survival, reduced tissue damage in target organs (liver and spleen), prevented hepatocellular steatosis, and normalized alanine aminotransferase (a liver damage marker) levels. The results of this study suggest that ribavirin may be effective in the early treatment of yellow fever, and that its mechanism of action in reducing liver pathology in yellow fever virus infection may be similar to that observed with ribavirin in the treatment of hepatitis C, a virus related to yellow fever. Because ribavirin had failed to improve survival in a virulent primate (rhesus) model of yellow fever infection, it had been previously discounted as a possible therapy.
10 }}. However, the rhesus model may have been too severe to correctly model moderately severe infections in humans.
'' eradication program in
Miami ,
Florida ]]
Yellow fever has had an important role in the history of
Africa , the
Americas , and the
Caribbean .
English and American colonial troops died by the thousands in
Havana between 1762-1763. Epidemics struck coastal and island communities throughout the area during the next 140 years.
In 1793, the largest yellow fever epidemic in American history killed as many as 5,000 people or 10% in
Philadelphia, Pennsylvania .
11 At the time, the port city was the largest in the United States and
Seat of the U.S. Government (prior to establishment of the
District Of Columbia ). The city had recently seen arrival of political refugees from the Caribbean. The summer that year was especially hot and dry, leaving many stagnant water areas ideal breading grounds for mosquitos.
The outbreak began in July and continued through November, when the cold weather eliminated the breeding ground for mosquitos, although the connection had not yet then been established.
Thousands of Philadelphians, including prominent government officials like
George Washington and
Alexander Hamilton fled the national capital.
Benjamin Rush , the city's leading physician and a signer of the
Declaration Of Independence , advocated the
Bloodletting of patients to combat the disease, but the treatment was controversial.
Stephen Girard also helped supervise a hospital established at Bush Hill, a mansion just outside Philadelphia. Though many high-ranking people of Philadelphia fled, a few officials stayed. Mayor
Matthew Clarkson as well as the mayor's committee tried to hold the city together as the death toll increased.
12
Matthew Carey published a fast-selling chronicle of the yellow fever crisis, ''A short account of the Malignant Fever, Lately Prevalent in Philadelphia'' that went through four editions. Although other ethnic groups were included, Carey's account failed to include the involvement of the city's
African American s in the community's response and relief efforts, despite the fact that African American leaders
Richard Allen and
Absalom Jones had rallied their church community to assist victims. Allen and Jones subsequently wrote a pamphlet, ''Narrative of the Proceedings of the Black People, During the Late Awful Calamity in Philadelphia'', which detailed the contributions of the African Americans during to the epidemic.
13
In
1802 , an army of forty thousand sent by First Consul
Napoleon Bonaparte of
France to
Haiti to suppress the
Haitian Revolution was wiped out by an epidemic of Yellow Fever (including the expedition's commander and Bonaparte's brother-in-law,
Charles Leclerc ). Some historians believe Haiti was to be a staging point for an invasion of the
United States through
Louisiana (then still under French control).
A ship carrying persons infected with the virus arrived in
Hampton Roads in southeastern
Virginia in June of
1855 . The disease spread quickly through the community, eventually killing over 3,000 people, mostly residents of
Norfolk and
Portsmouth . The
Howard Association , a benevolent organization, was formed to help coordinate assistance in the form of funds, supplies, and medical professionals and volunteers which poured in from many other areas, particularly the
Atlantic and
Gulf Coast areas of the
United States .
hi
On August 13th, the first official victim of yellow fever died, sparking an exodus of over half of the city's population. When it was over, 5,150 would die, and 17,600 would suffer the effects of the disease.
Yellow fever severely hampered early Spanish and American efforts to settle
California , which lacks the frosts that normally control the mosquitos.
In addition the first failed attempts to build the
Panama Canal (by a French company) were thwarted in part due to the huge number of deaths amongst workers caused by yellow fever. The vaccination for the fever was first formulated during the second attempt to build the canal.
Walter Reed , M.D., (1851-1902) was an
American Army surgeon who led the team which confirmed the theory first set forth in
1881 and proven by the Cuban doctor and scientist Dr.
Carlos Finlay that yellow fever is transmitted by
Mosquito es rather than direct contact.
14 }} The risky but fruitful research work was done with human volunteers, including some of the medical personnel such as
Clara Maass and
Walter Reed Medal winner surgeon
Jesse W. Lazear who allowed themselves to be deliberately infected and died of the virus.
15 By applying methods first suugested by Finlay, the elimination of Yellow Fever from Cuba was completed, as well as the completion of the Panama Canal. Lamentably, almost 20 years passed while the scientific community ignored Finlay's methods of mosquito control; the acceptance of Finlay's work was one of the most important and far-reaching effects of the Walter Reed Commission of 1900.
16
