Marburg Hemorrhagic Fever :: essays research papers

Marburg Hemorrhagic Fever Marburg hemorrhagic fever is a rare, severe type of hemorrhagic fever that affects both humans and non-human primates. Marburg is the first member of the family Filoviridae (or "thread" viruses), which also includes the Ebola virus. Like Ebola, Marburg is an enveloped, single-stranded, unsegmented, negative-sense RNA virus. It has the same characteristic filamentous (thread-like) structure, can appear shaped like a U, a 6, or spiraled like a snail; and can sometimes be branched. The Marburg virus is identical to Ebola in form and structure; however, it is genically distinct from Ebola (meaning that it stimulates the production of different antibodies). Marburg virions are 80 nm (nanometers) in diameter and average approximately 800 nm in length, although length can vary up to 14,000 nm. The four species of Ebola virus are the only other known members of the filoviridae family. As with Ebola, the exact procedure of Marburg is unknown. However, virion surface spikes are made solely of large glycoprotein (compound consisting of carbohydrates and protein). It is assumed that, as with other negative-strand RNA viruses, these surface spikes bind to receptors on the host cell and act as a â€Å"go-between† entry into susceptible cells. Viral replication takes place in the cytoplasm, and envelopment is the result of budding preformed by nucleocapsids (viral protein coat and nucleic acid). Ultimately, the virus involves the liver, lymphoid organs, and kidneys. Marburg virus was first recognized in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia). A total of 37 people became ill; they included laboratory workers as well as several medical personnel and family members who had cared for them. The first people infected had been exposed to African green monkeys or their tissues. In Marburg, the monkeys had been imported for research and to prepare polio vaccine. Recorded cases of the disease are rare, and have appeared in only a few locations. While the 1967 outbreak occurred in Europe, the disease agent had arrived with imported monkeys from Uganda. No other case was recorded until 1975, when an Australian traveler most likely exposed in Zimbabwe became ill in Johannesburg, South Africa and passed the virus to his traveling companion and a nurse. The year 1980 saw two other cases, one in Western Kenya not far from the Ugandan source of the monkeys implicated in the 1967 outbreak.