Viral Hemorrhagic Fever

Abstract

Viral hemorrhagic fever is a zoonotic viral infection that can result in a serious bleeding disorder in humans. The signs and symptoms of VHF differ according to the causative agent, but the most common ones include fever, weakness, myalgia, vomiting and dizziness. In severe conditions symptoms such as shock, coma, hemorrhage, delirium and death may result. Five major families including Arenaviridae, Bunyaviridae, Filoviridae, Flaviviridae and Rhabdoviridae contain several RNA enveloped viruses that can produce multiple types of VHFs such as Alkhurma hemorrhagic fever, Ebola hemorrhagic fever, Marburg hemorrhagic fever, Lassa fever and many others. The virus can be transmitted from its natural host to human via bites, vectors such as ticks and mosquitos and contaminated dust particles. Human-human transmission can happen with some viruses such as Ebola. The geographic distribution of the disease depends on the distribution of the virus natural host. However, imported cases to non-endemic areas can occur. The diagnosis of these viruses relies on molecular techniques, PCR in particular. Advances in the diagnostic methods and methods for predicting future epidemics are being developed and tested for their efficacy such as multiplex-PCR and genome sequencing. Currently, treatments and vaccine for most of the VHFs are not available and treatment rely on supportive therapy only. Ribavirin has been effective in treating some cases of VHF such as Lassa fever. Several clinical trials are conducted to 10 discover safe and effective antiviral drugs and other therapies. Human vaccines against this disease are also under developing; the focus nowadays is on Ebola and Marburg due to their recent major outbreaks.