Viral Diseases - YELLOW FEVER

(Black Vomit)

AGENT:

RNA virus, Family Togaviridae, (Group B Arbovirus)

RESERVOIR AND INCIDENCE:

All primates susceptible; major Public Health problem in Central and S. America and Africa.

TRANSMISSION:

Mosquito vector: Aedes and Hemagogues.

DISEASE IN NONHUMAN PRIMATES:

There is high fever and vomiting, with jaundice, oliguria (decreased urine output), and generalized hemorrhages. Microglobular fatty degeneration of liver cells occurs with disruption of the hepatic lobule and necrosis of midzonal liver cells, producing so called "Councilman" bodies. Degeneration and necrosis of the kidney tubules occurs. There are hemorrhages in tissues.

DISEASE IN MAN:

Most cases have fever, severe headache and backache, jaundice and albuminuria (more than the normal amount of albumin in the urine), followed by full recovery within a week, but in severe cases there is a second episode of fever, prostration, jaundice, renal failure and generalized hemorrhages. Microglobular fatty degeneration of liver cells occurs with disruption of the hepatic lobule and necrosis of midzonal liver cells, producing so called "Councilman" bodies. Degeneration and necrosis of the kidney tubules occurs. There are hemorrhages in tissues. The case fatality rate among indigenous populations of endemic regions is <5%, but may exceed 50% among nonindigenous groups and in epidemics.

DIAGNOSIS:

Virus isolation or serology.

TREATMENT:

Consists of limiting food to high-carbohydrate, high-protein liquids, IV glucose and saline, analgesics and sedatives, and saline enemas.

PREVENTION/CONTROL:

Monkeys should originate from a yellow fever free area, or be maintained in a double-screened mosquito-proof enclosure, or have been immunized against yellow fever. For humans, mosquito control, vaccination, and adherence to PHS quarantine standards.