Rabies :: Biology Medical Disease Rabies

Rabies Rabies virus belongs to the Lyssavirus family in which all the members are animal viruses mainly found in bats and are of a bullet-like shape. The virus is usually spread through bites or scratches. Rabies was first suspected in bats in Brazil during the 1910s. In 1931, it was diagnosed for the first time in Trinidad. Rabies is most common in Asia and found more in wild animals than in domestic animals or humans. There has only been one person who miraculously survived rabies even though she had never been previously exposed to it. Rabies virus belongs to the order Mononegavirales, and within this group, it falls into the Rhabdoviridae family because of its shape. This family includes three genera of animal viruses: Lyssavirus, Ephemerovirus, and Vesiculovirus. The genus Lyssavirus includes the rabies virus and other viruses that are mainly found in bats. The Rabies virus has a distinct bullet-like shape. The length of the virus structure is of about 180 nm with a cross-sectional diameter of about 75nm. Like a bullet, one end of the virus is rounded and the other end is planar or concave. The genome encodes 5-proteins: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G), and polymerase (L). The two major structural components of viruses like rabies that fall under the rhabdoviruses family are: a helical ribonucleoprotein core (RNP) and a surrounding envelope. Rabies is an RNA virus. The arrangements of the five proteins and the RNA genome determine the structure of the rabies virus. The genome is a single-stranded, non-segmented, RNA of about 12kb that is followed by the five proteins. The rabies virus is usually spread through bites or scratches, abrasions, or through open wounds in the skin when saliva (and in certain conditions, the urine) from an infected animal that makes contact with the open flesh. The virus-induced, aggressive biting-behavior in the infected animal, along with the viral budding into the salivary glands, maximize the chances of viral infection to a new host. Rabies has been around for many years causing the deaths of animals as well as humans. During the 1910s, rabies in bats was suspected in Brazil. In 1931, it was definitively diagnosed for the first time in Trinidad in Latin America. Since 1985, bats have been the main rabies reservoirs identified. Bats are, and have been, the number one source of infection for the cases diagnosed in domestic animals every year. Recently in 2001, forty-nine U.S.