Filoviruses: Ebola, Marburg and Disease

Abstract

Abstract Ebola and Marburg viruses belong to the family of filoviruses and cause severe haemorrhagic fevers in humans and nonhuman primates. Since their discovery in 1967, during outbreaks in Germany and former Yugoslavia originating with nonhuman primates imported from Uganda, they have been responsible for numerous disease outbreaks in Africa. Ebola has also been implicated in massive die‐offs of great apes and in recent years there have been several cases of imported Marburg infections into Europe and North America. Filoviral haemorrhagic fevers (FHF) are severe diseases with case fatality rates of up to 90%. Currently, there is neither a licensed vaccine nor a specific therapy available. Although experimental vaccines and treatments have shown promise in nonhuman primates, at the present time supportive therapy and prevention of disease transmission through rigorous case management and patient isolation are the only means available to combat FHF. Key Concepts: Human pathogenic filoviruses (Ebola and Marburg viruses) are found in Africa, whereas Reston ebolavirus , which is nonpathogenic to humans, originates in the Philippines, where it is found in both nonhuman primates and pigs. Although the absolute number of filoviral haemorrhagic fever cases is low when compared to other diseases, the severe disease picture and high case fatality rates have led to a high public profile of filoviral haemorrhagic fevers. Imported nonhuman primates have been the cause of outbreaks of filoviral haemorrhagic fever in Europe and North America, both among humans and nonhuman primates. Tourism has also resulted in several imported infections during the last years. Bats represent the most likely reservoir for filoviruses. The pathophysiology of filoviral haemorrhagic fevers involves vascular dysfunction, impairment of the immune system and massive dysregulation of cytokine production. Death is caused by multiple organ failure as result of a syndrome resembling septic shock. Experimental treatments and vaccines in nonhuman primates exist, but are not licensed for use in humans. Currently the only measures to combat filovirus infections are supportive therapy and patient isolation.