Yellow fever (also called yellow jack, or sometimes black vomit or American Plague) is an acute viral disease. It is an important cause of hemorrhagic illness in many African and South American countries despite existence of an effective vaccine. The yellow refers to the jaundice symptoms that affect some patients.
Yellow fever begins suddenly after an incubation period of three to five days in the human body. In mild cases only fever and headache may be present. Within 24 hours about 15% develop a more severe form, in which they enter the “toxic phase” characterized by fever, chills, bleeding into the skin, paradoxically slow heartbeat, headache, back pains, and extreme prostration. Nausea, vomiting, and constipation are common. Jaundice usually appears on the second or third day. After the third day the symptoms recede, only to return with increased severity in the final stage, during which there is a marked tendency to hemorrhage internally; the characteristic “coffee ground” vomitus contains blood. The patient then lapses into delirium and coma, followed by death in about 50% of those who enter the toxic phase.
There is no true cure for yellow fever, therefore vaccination is important. Treatment is symptomatic and supportive only. Fluid replacement, fighting hypotension and transfusion of blood derivates is generally needed only in severe cases. In cases that result in acute renal failure, dialysis may be necessary.
Yellow fever is preventable by a relatively safe, effective vaccine. For all eligible persons, a single injection of 0.5 mL of reconstituted vaccine should be administered subcutaneously.
Yellow fever vaccination must be given at a certified center in possession of an official “Uniform Stamp” which can be used to validate the ICVP. State health departments are responsible for designating nonfederal yellow fever vaccination centers and issuing Uniform Stamps to health-care providers. The ICVP must be validated by the center that administers the vaccine. Most city, county, and state health department’s immunization or travel clinics, as well as private travel clinics or individual health-care providers are designated sites. Information about the location and hours of yellow fever vaccination centers may be obtained by contacting local or state health departments or visiting CDC’s Travelers’ Health website. Health-care providers should emphasize to travelers that an ICVP must be validated to be acceptable to quarantine authorities. Failure to secure validations can cause a traveler to be revaccinated, quarantined, or denied entry.
The following section of the ICVP should be completed at the time of vaccination: