Viral Hemorrhagic Fevers Other than Ebola and Lassa

Abstract

Viral hemorrhagic fevers represent a group of diseases caused by enveloped RNA viruses belonging to four taxonomic families: filoviruses, arenaviruses, bunyaviruses, and flaviviruses.• Viral hemorrhagic fevers are severe febrile illnesses characterized by vascular abnormalities with plasma leakage and widespread bleeding in tissues and organs.• Rapid identification of the viruses causing hemorrhagic fevers is fundamental for patient management, outcome improvement and limitation of disease propagation, particularly in healthcare settings.• Treatment of viral hemorrhagic fevers is essentially supportive. Summary/synopsisViral hemorrhagic fevers (VHFs) represent a group of diseases caused by enveloped RNA viruses belonging to four taxonomic families: filoviruses, arenaviruses, bunyaviruses and flaviviruse. The epidemiology of VHFs is broadly variable, ranging from geographically localized infections causing sporadic outbreaks, such as Omsk hemorrhagic fever and Kyasanur Forest disease, to more diffuse infections, such as Lassa fever in West Africa, that cause not only sporadic outbreaks but also endemic diseases. VHF viruses are considered as possible biological weapons, and are classified as category A bioweapon agents by the Centers for Disease Control and Prevention (CDC). The main characteristic of VHF is represented by severe febrile illnesses with hemorrhagic phenomena.Laboratory diagnosis of VHF take place in highly specialized reference laboratories. Mobile laboratories are under implementation to improve field diagnosis and contact tracing. Treatment of VHF is essentially supportive. In this paper we focus the attention on yellow fever and VHFs other than Ebola and Lassa virus diseases that have been described elsewhere in this publication. Yellow fever and other Flaviviruses causing VHFs (dengue, Omsk hemorrhagic fever, Kyasanur Forest disease and Alkhumra viruses

Synanthropic rodents as virus reservoirs and transmitters

“…Mammarenaviruses are correlated to the geographical location where their hosts are found 147 ; currently classified as: (a) Old World (OW) (Lassa virus, Lujo virus, among others), and found mainly in Africa in rodents of the Murinae family as natural hosts 149 . Although Lymphocytic choriomeningitis virus (LCMV) belongs to this category, it circulates globally 146 .…”

Arenavirus as a potential etiological agent of odontogenic tumours in humans

“…A hallmark characteristic of arenavirus infection is its ability to establish life-long persistent infection avoiding to enter in a "latent phase" without adverse consequences such as retroviruses like HIV-1 or herpes viruses [6,9]. In humans, LF is usually characterized by general flu-like symptoms as fever, malaise and headache, but in severe cases it can develop hemorrhaging and/or neurologic involvement that may be fatal [6,9]. Viral evasion from the immune system is critical for productive replication and dissemination in the host.…”

“…Lassa virus, the causative agent of Lassa fever, is a member of the family Arenaviridae and it continues to be the most common cause of hemorrhagic fever in West-Est Africa, infecting roughly 400,000-500,000 individuals per year and yielding a yearly death rate of 30,000-40,000 [5,6]. The Arenaviridae family (Arenavirus) consists of two single stranded, ambisense RNAs.…”

“…Humans are infected most likely through mucosal exposure to aerosols or by direct contact between infectious materials as rat meat and abrasion of the skin and oral mucosa. Arenavirus can move through both the blood and the lymphatic system, thus reaching the major and minor salivary glands, and more human-to-human infection and the passage of the virus from the mother to the placenta have also been documented [5,6]. Arenaviruses are grouped in Old World as Lassa virus (LF) endemic in West Africa and in New World as Junin widespread in South America [5,6].…”

Emerging and Reemerging Infectious Diseases: Global Overview

“…Viral hemorrhagic fever can be caused by zoonotic viruses other than Ebola and LF viruses. 7 Viral hemorrhagic fevers represent a group of diseases caused by enveloped single-stranded RNA viruses belonging to 6 taxonomic families: Filoviruses (Ebola and Marburg); Arenaviruses (Lassa and other Old World arenaviruses and New World arenaviruses); Hantaviruses, Nairoviruses, Preface xv and Phenuiviruses (Congo-Crimean hemorrhagic fever, Rift Valley fever, Huaiyangshan virus, and Hantavirus); and Flaviviruses (Dengue, Yellow fever, Omsk hemorrhagic fever, Kyasanur Forest disease, and Alkhumra viruses). Chikungunya (CHIK) was first described in 1952 in southern Tanzania.…”