Yellow+Fever

=__Introduction__=

Yellow Fever (//Coquillettidia fuscopennata)// (1), an acute viral hemorrhagic disease is found primarily in South and sub-Saharan Africa, along with much of South America. Transmitted by the bite of //Aedes aegypti// mosquitoes, it is a potentially life threatening disease that can cause liver and kidney complications, internal bleeding, and can eventually result in death. Yellow Fever is hard to diagnose in its early stages, is often mistaken for typhoid, @dengue fever, or malaria, an estimated 30,000 people each year are killed by Yellow Fever and resulting complications (3).

toc



=__Mode of Infection/Transmission__= = = Yellow fever is an arbovirus, thus its sole viral vector are arthropods. This illness is transmitted by the bite of certain species of female mosquites, such as the notorious yellow fever mosquitos (//Aedes aegypti//) and other mosquitos in the //Haemogogus// species. These mosquitos carry the virus from humans to humans, monkeys to humans, and most commonly from monkeys to monkeys. The risk of obtaining yellow fever can be decreased by controlling the mosquitos through the application of insecticides; this is a popular method of delaying the inevitable during periods of vaccination in urban epidemics. Relatively simple blood tests can confirm whether or not one is infected with yellow fever, and the World Health Organization (WHO) considers one confirmed case in an unvaccinated population to be an outbreak due to the rapid rate at which the virus can be transferred (4).

=__Replication__=

The yellow fever virus is just as deadly in monkeys as in humans. In addition to transferring it from infected humans to healthy humans and infected apes to healthy apes, mosquitos also transfer the pathogen from infected primates to healthy humans (and vice versa). The viral illness maintains itself in a lysogenic state while within the mosquito. This attribute allows the virus to stay within the mosquito without causing the carrier harm. After the pathogen is transmitted to the mammal, the virus switches gears and enters the lytic cycle, quickly reproducing and eventually causing serious harm to its host. In humans, the virus will replicate in the sweat glands, later traveling down through antibodies to the liver. As a result of mass replication and travel throughout the body, many detrimental symptoms occur.(2)

=__Symptoms__=

Symptoms of yellow fever usually develop three to six days subsequent to the day of the mosquito biting. The progression of yellow fever can be broken down into three primary stages: infection, remission, and intoxication. In the first stage, the infected person starts showing the following common symptoms of yellow fever.
 * Seizures
 * Red eyes, face and tongue
 * Headache
 * Yellow skin and eyes
 * Irregular heart beats
 * Bleeding
 * Coma
 * Decreased urination
 * Delirium
 * Fever
 * Vomiting

These symptoms generally disappear after three to four days.

The second stage in the progression of yellow fever is remission, in which the symptoms briefly dissipate. Eighty five percent of people will recover at this stage, but the remaining fifteen percent (of those who do not recover) will progress to the third stage.

The third stage of yellow fever is essentially intoxication. In this stage, serious organ damage can occur. Symptoms include but are not limited to liver and kidney damage, internal bleeding, delirium, seizures, and comas (3).

=__List of Treatments__=

There is no specific treatment for yellow fever. The purpose of any and all available treatments is not to cure the illness, but to alleviate the severity of symptoms to assuage pain and suffering. Ways to treat significant symptoms are as follows (1):
 * Severe bleeding can be countered by receiving more blood.
 * Kidney failure is often followed by dialysis.
 * Physical conditions are stabilized by injecting basic and essential fluids with an intravenous line.

There are many ways to prevent obtaining yellow fever. Major methods of prevention are as follows.
 * Screens indoors and around the bed to prevent contact with mosquitoes.
 * Mosquito repellents and insecticide to ward off insects and/or kill them.
 * Dress fully clothed in thick layers (as mosquito carriers can often pierce through thin layers of clothing).

=__Vaccine__=

However there is not a cure for yellow fever, there is a vaccine. As stated by the World Health Organization (WHO), vaccination is the most important measure against yellow fever. "The vaccine is safe, affordable, and highly effective, and appears to provide protection for 30 - 35 years or more. The vaccine provides effective immunity within one week for 95% of persons vaccinated," (4). It is suggested that persons 9 months of age to 60 years of age receive the vaccine if they live or are going to a place where the virus is common. It is recommended that the a booster shot be taken every 10 years for people who are in the areas that Yellow Fever is found (2).



=__Works Cited__=

(1). (2).  (3). (4).   (5).