Yellow Fever

Zoonotic viral infection transmitted by the bite of the Aedes mosquito

Found in tropical and subtropical South America and Africa

Incubation period is typically 3–6 days

Adults and children equally susceptible

Mild form (85%)

• Fevers

• Malaise

• Retro-orbital pain

• Nausea

• Photophobia

• Bradycardia

Severe form (15%)

• Begins with the same symptoms as the mild form of the disease

• Then, after initial remission of symptoms, a toxic phase ensues with fever, bradycardia, hypotension, jaundice, delirium, hemorrhage

Leukopenia, elevated liver enzymes, and bilirubin can occur

Proteinuria is present and usually disappears completely with recovery

Bleeding dyscrasias with elevated prothrombin and partial thromboplastin times, decreased platelet count, and presence of fibrin-split products, can also occur

In the early stages of the disease (up to 10 days), diagnosis is confirmed if yellow fever virus RNA is detected by (RT-PCR) in blood from a person with no history of recent yellow fever vaccination

Presence of yellow fever virus-specific IgM antibody and negative ELISA panel for other relevant flaviviruses confirm the diagnosis

If ELISA is positive for other flaviviruses, plaque reduction neutralization assay, which measures the titer of the neutralizing antibodies in the serum towards the infecting virus, should be done

Supportive measures, including analgesia and hydration

No specific antiviral therapy

Prevention: a highly effective and safe vaccine is available and should be used when living or traveling to endemic areas

Prevention: mosquito control measures