Les fièvres hémorragiques virales

Viral hemorrhagic fevers (VHF) include a variety of infections which associated usually high fever with hemorrhages more or less intense with a high fatality rate. The viruses belong to different families: the Flaviviridae (dengue, Yellow fever, Omsk, Kyasanur, Alkhurma), and Bunyaviridae (Crimean-Congo, Rift Valley fever) transmitted by mosquitoes or ticks, the Arenaviridae (Lassa, Junin…) and hantaviruses transmitted by excretas from rodents, and finally the Filoviridae (Ebola, Marburg) with bats as possible natural reservoir. Human to human transmission which may occur for some viruses requires an appropriate management of the patients with isolation measures and a rapid diagnosis. Due to the large variety of infectious agents potentially responsible for hemorrhagic fever, epidemiological informations are needed for the biological investigation. Transportation of biological specimens to the reference laboratory for diagnosis must follow specific regulations. Ribavirin is the unique antiviral treatment available for Crimean-Congo and Arenavirus infections. Rapid diagnosis must be initiated in a P4 lab with direct detection of viral genome by means of RT-PCR or detection of viral antigen and IgM/IgG antibodies by ELISA.