- It is an acute viral hemorrhagic disease.
- The virus is a 40 to 50 nm enveloped RNA virus with positive sense of the Flaviviridae family.
- The yellow fever virus is transmitted by the bite of female mosquitos (the yellow fever mosquito, Aedes aegypti, and other species)
- It can be found in tropical and subtropical areas in South America and Africa, but not in Asia.
- The only known hosts of the virus are primates and several species of mosquito.
- The origin of the disease is most likely to be Africa, from where it was introduced to South America through the slave trade in the 16th century.
- Since the 17th century, several major epidemics of the disease have been recorded in the Americas, Africa and Europe.
- In the 19th century, yellow fever was deemed one of the most dangerous infectious diseases.
- In Africa on the other hand, virus eradication programs have mostly used vaccination, but have been unsuccessful since the sylvatic cycle could not be eradicated.
- After the measures to fight yellow fever were abandoned since few countries have established regular vaccination programs, the virus could spread again.
- Clinically, yellow fever presents in most cases with fever, nausea, and pain and it generally subsides after several days.
- In some patients, a toxic phase follows, in which liver damage with jaundice (giving the name of the disease) can occur and lead to death.
- Because of the increased bleeding tendency (bleeding diathesis), yellow fever belongs to the group of hemorrhagic fevers.
- The WHO estimates that yellow fever causes 200,000 illnesses and 30,000 deaths every year in unvaccinated populations around 90% of the infections occur in Africa.
- A safe and effective vaccine against yellow fever has existed since the middle of the 20th century and some countries require vaccinations for travelers.
- Since no therapy is known, vaccination programs are, along with measures to reduce the population of the transmitting mosquito, of great importance in affected areas.
- Since the 1980s, the number of cases of yellow fever has been increasing, making it a reemerging disease.
- 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.
- Ribavirin treatment during the first five days after virus infection improved survival rates, reduced tissue damage in target organs (liver and spleen)
- The results of this study suggest that ribavirin may be effective in the early treatment of yellow fever
- In the past, yellow fever has been researched by several countries as a potential biological weapon.
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Yellow fever (YF) has remained a disease of public health importance since it was first described in the fifteenth century. At different periods in human history, YF has caused untold hardship and indescribable misery among populations in the Americas, Europe, and Africa. It brought economic disaster in its wake, constituting a stumbling block to development. Yellow fever is an arboviral infection with three epidemiological transmission cycles between monkeys, mosquitoes, and humans. It is an acute infectious disease characterized by sudden onset, with two phases of development separated by a short period of remission. The clinical spectrum of YF varies from a very mild, nonspecific, febrile illness to a fulminating, sometimes fatal disease with pathognomonic features. In severe cases, jaundice and bleeding diathesis with hepatorenal involvement are common. The fatality rate of severe YF is 50% or higher. Despite landmark achievements in the understanding of the epidemiology of YF and the availability of a safe, efficacious vaccine, YF remains a major public health problem in both Africa and South America, where annually the disease affects an estimated 200,000 persons, causing an estimated 30,000 deaths. Since the 1980s epidemics of YF in Africa have affected predominantly children under the age of 15 years. The failure to control YF arises from a misapplication of public health strategies and insufficient political commitment by governments in YF endemic areas, especially in Africa, to control the disease.
I researched where the disease is modernly epidemic I found this video
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