INFECTIONS - Medicine for Mountaineering and Other Wilderness Activities - page 316

30,000 individuals a year in Africa even though most infections are mild and the mortality
rate is only about 15 percent. Only two infections each by Ebola Tai and Ebola Sabia (or
Brazilian hemorrhagic fever) have been recognized.
These infections share the feature of frequent, although not universal, bleeding into the
skin, into the gastrointestinal tract, and from body orifices. However, the unfortunate indi-
viduals who contract hemorrhagic fever die as the result of organ failure, usually liver or
kidney failure; they do not bleed to death.
The viruses that cause these infections have highly specific animal reservoirs, and the
infections are limited to areas where those animals are found. For instance, the reservoir
for Argentine hemorrhagic fever is two species of rat found only in cornfields in northern
Argentina, and the infection is limited to that area. However, hemorrhagic fevers of one
type or another are found over most of the globe, and the reservoir for one such infection,
Seoul hemorrhagic fever, is the common rat or Norwegian rat, which is found everywhere.
Dengue, which can produce dengue hemorrhagic fever, is found throughout the tropical
world.

Table 22-1 Viral Hemorrhagic Fevers

VIRUS FAMILY CLINICAL DISORDER METHOD OF SPREAD

Bunyaviruses

Hantavirus Hemorrhagic Fever with Renal
Syndrome

Rodent contact

Hantavirus Pulmonary Syndrome Rodent contact

Crimean-Congo Hemorrhagic Fever Direct contact or tick borne

Rift Valley Fever Mosquito borne

Flaviviruses

Yellow Fever Mosquito borne

Dengue Hemorrhagic Fever Mosquito borne

Kyasanur Forest Disease Tick borne

Tick-borne Encephalitis Tick borne

Omsk Hemorrhagic Fever Tick borne

Filoviruses

Marburg Disease Bats and direct contact

Ebola Sudan Bats and direct contact