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Yellow fever

Mosquito borne viral disease.

An acute viral hemorrhagic disease caused by the yellow fever virus.

Transmitted by Aedes aegypti mosquitos.

Largely controlled by vaccine.

A zoonotic infection in Sub-Saharan Africa.

The disease is endemic to tropical and subtropical regions in Africa and the Americas.

Single stranded RNA virus of the family Flaviviridae.

Can result in a sub clinical to severe illness, characterized by fever, jaundice, and hemorrhage.

In 2013 in Africa it was estimated 51-380,000 severe cases of yellow fever and 19,000-180,000 deaths.

In 2020 there will be an estimated 20,000 cases.

Lethal disease.

Incubation period of about seven days

A hemorrhagic disease caused by a mosquito-borne virus related to dengue and Zika viruses.

Patients present with fever, malaise, headache, photophobia, and generalized muscle ache.

Symptoms can progress to include hemorrhagic manifestations, relative bradycardia, epigastric distress with transaminase elevation usually 48-72 hours after onset of symptoms.

The virus can be transmitted by multiple routes.

Mosquitoes can infect nonhuman primates, which become a reservoir to infect more mosquitoes and subsequently humans, who spend time near forested areas.

Urban transmission occurs directly between humans and mosquitoes.

Endemic to and epidemic in tropical areas of South America and Africa.

Maintained in nature by transmission to human by monkeys and mosquitoes that breed in tree holes.

17D vaccine may cause visceral and neurotropic adverse events and anaphylaxis.

Yellow fever a live attenuated viral vaccine can result in fulminant 17D virus infection of the liver and visceral organ and resembles the naturally acquired yellow fever.

Yellow fever vaccine is a live, attenuated vaccine that replicates within the body and produces long duration immunity, which is probably lifelong.

Yellow fever vaccine studies have revealed that one dose induces seroconversion in 98% of recipients, and protection is believed to be lifelong.

Neurotropic disease refers to brain viral replication in the brain.

Approximately 400,000 doses of 17D vaccine administered in the US each year.

Rates of viscerotropic disease from vaccine 0.4 cases per 100,000 population(Lindsey LP et al).

Rates of neutropic disease 0.8 cases per 100,000 population from yellow fever vaccine.

Rates of anaphylaxis 1.8 cases per 100,000 population from yellow fever vaccine.

Yellow fever outbreaks have case fatality of 75% in hospitalized patients.

Yellow fever vaccination indication is to prevent infection in individuals at risk.

All healthy adult travelers to areas with a risk of yellow fever transmission should be vaccinated.

because of rare but serious vaccine associated adverse affects persons who are not at any risk of exposure should not be vaccinated.

The risk of fatal adverse events to yellow fever vaccine are one per 334,000 doses, and can occur most frequently in persons older than 60 years and any individual with a thymus disorder.

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