Rinderpest

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A Viral Biorealm page on the family Rinderpest


Baltimore Classification

Group V: (-) sense single-stranded RNA viruses

Higher order categories

Order: Mononegavirales
Family: Dicistroviridae
Genus: Cripavirus

Description and Significance

Rinderpest Virus (RPV), a term derived from German, meaning cattle-plague, is the cause of gastrointestinal illness most commonly seen in cattle and buffalo, but occurs less frequently and with less conspicuity in sheep, goats, camels, and some species of Sus. Among livestock plagues, Rinderpest is one of the oldest on record, dating back 9000 years, and was the subject of several pioneering insights in agricultural medicine (Broad, 1983). It is also believed that all other members of the Morbillivirus genus evolved from RPV (Norrby, E; 1985). The virus has recently been made to recombine to aid in the production of a more effective vaccine (Baron, Foster-Cuevas, et al.1999). RPV cannot infect humans, but the high mortality rate it exhibits in immunologically-naïve populations of cornerstone livestock, it is devastating to international trade, rural incomes, and the survivability of local populations alike (Shaila, 2006).

Genome Structure

The RPV genome is 15,881 base pairs long, and consists of a single molecule (nonsegmented) of negative-sense single-stranded RNA. This contains six genes that code for structural proteins, and two that code for non-structural proteins (Shaila, 2006) that are transcribed in order form a single promoter and the 3’ terminus of the molecule (Baron; Barrett;1999).

Virion Structure of a Rinderpest virus

The Rinderpest virion is characterized by a semispherical-pleomorphic capsid surrounded by an envelope of host-derived lipids (ICTV Db, 2006). Enveloped capsids range from 150-250 nm in diameter, depending on the individual virus and the technique used. Projections of glycoproteins through channels in the lipous envelope are roughly 9-15 nm in length (ICTV Db, 2006).

Reproductive Cycle of a Rinderpest virus in a Host Cell

Very little is known regarding the specific endocellular activities of RPV, and much attention has been recently paid the production of a model. It has been strongly suggested that the plus sense leader RNA of RPV, transcribed from 3’ end of genomic RNA, specifically interacts with cellular La protein, stimulating RNA synthesis (Raha et al. 2004). Further evidence was given that interaction is made with the host cell protein striatin (Sleeman; Baron; 2004). RPV has an incubation period of 3-15 days, and will die if not transmitted to a living host before the death of the present host, as it cannot survive for any time worth consideration outside of a living organism (Shaila, 2006).

Viral Ecology & Pathology

Rinderpest symptoms include an pyrexia, depression, loss of appetite, reduced milk production, nasal and eye discharges, and labored breathing. In advanced stages, erosions appear in the mucous membranes. This is followed by acute diarrhea and death, which occurs 6-12 days after initial observation of symptoms (Baron; Barrett; 2000). RPV infection occurs via the epithelium of the upper and lower respiratory tract. Shedding of the virus begins 24-48 hours prior to pyrexia. At this point, all bodily fluids are infectious, regardless of symptoms. RPV has no carrier state (Shaila, 2006). Although it formerly occurred worldwide (save Australia), the vast majority of developed and developed and developing countries have completely eradicated RPV through vaccination. Today, the virus only presents symptoms in herds in select regions of Africa and the Middle East, Nepal, Pakistan, Russia, and India (Shaila, 2006).

References

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Page authored for BIOL 375 Virology, September 2008