VIRAL HEMORRHAGIC FEVERS
Viral hemorrhagic fevers are a diverse group of illnesses caused by a number of different RNA viruses. VHF are zoonoses, transmitted from animal hosts to humans.
Humans become infected with VHF when they come in contact with an animal host—or another infected human (dead or alive). Ebola and Lassa fever have spread via contaminated syringes in hospitals. Marburg, Lassa, and Crimean-Congo VHF have spread through close contact with infected people and their body fluids. Rates of nosocomial infection have been high, and hospital workers are at great risk of acquiring VHF if strict barrier nursing techniques and standard precautions for disposing of wastes and fluids are not observed.
In general, VHF cause severe multi-system illness often accompanied by bleeding—thus the group name “viral hemorrhagic fevers.” Some VHF are more lethal than others, but all have the potential to cause death
Varies by disease, but early warning signs include fever, fatigue, muscle ache, and dizziness. Patients with severe disease progress to bleeding (under the skin, internal organs, from the mouth, eyes or ears). Severely ill people may experience kidney failure, shock, delirium, coma, and seizures. For information about disease specific symptoms, go to The World Health Organization Web site factsheets.
There is no cure for VHF. Intensive supportive therapy for symptoms is the only course of treatment at present though the antiviral drug ribavirion has been used in treatment of Crimean-Congo Hemorrhagic fever with some success. Modern supportive therapy can lower mortality rates for most of the VHF.
Vaccines have been developed for yellow fever and Argentine hemorrhagic fever. Prevention efforts focus on preventing contact with the host species.
Maximum precautions are required for all VHF. Barrier nursing and other infection control strategies are mandatory, as is careful use and disposal of instruments used in the treatment of VHF patients, and standard precautions in the handling and disposal of blood and body wastes.
