Answer To: Foundation Studies Biology (BIOL 2414) Research Assignment (worth 25%) Due: before 11.59pm on...
Anju Lata answered on Oct 17 2021
Marburg Virus
Assignment
Topic: Research Report on Marburg Virus
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1. Structure and Function of Virus
Marburg Virus (MARV) is enveloped, filamentous, negative sense, single stranded RNA virus having crystal structure (Zhang, Bornholdt, Abelson, and Saphire, 2014). The virus is from Filoviridae family and is responsible for delirium, rash, hemorrhagic fever in humans and other primates. The virus encodes seven structural proteins or genes: Nucleocapsid (VP35), Nucleoprotein, Matrix (VP40), transcription factor (VP30) and RNA Polymerase. VP 40 and VP35 are immunosuppressive. It appears like U in shape, coiled or branched. They are generally 80 nm wide with median particle length between 795 to 828 nm. The negative stranded linear RNA genome is 19 KB in size (Viral Zone, 2014). Core part of the virus is helical ribonucleocapsid, with RNA wrapped around Nucleoprotein polymer. RNA Polymerase is associated with Ribonucleoprotein with VP35 and VP30. The Ribonucleoprotein remains embedded in the matrix which is composed of VP24 and VP40 proteins. The matrix is surrounded by the cell membrane of host.
Source: Viral Zone(2014)
2. Virus Transmission
Viral RNA enters the host cell through cytoplasmic replication or endocytosis into the vesicles of host cells. The viral membrane fuses with that of vesicles and ribonucleocapsid gets released into the cytoplasm. The RNA polymerase attaches to the genome through the 3’ Region. Polyadenylation of viral mRNAs takes place through polymerase stuttering inside the cytoplasm. The replication begins when adequate nucleoprotein is available to encapsulate newly synthesized genome and antigenome. The ribonucleocapsid associates with the plasma membrane or matrix and leads to host assisted viral budding through the plasma membrane’s ESCRT (Endosomal Sorting Complex Required for Transport) while setting free the virions (Viral Zone, 2014). The entry of virus in the host cell essentially requires NPC1 Cholesterol Transporter Protein.
The viral transmission occurs due to exposure at caves or mines where the colonies of Rousettus bats inhabit (Public Health England, 2017). Further human to human transmission requires close contact with the person already infected. The virus is found in high concentration in urine, faeces, respiratory secretions, vomit and saliva. Contact with any of these fluids causes viral transmission. The virus may transmit through cytoplasmic replication and sexual transmission. It may survive in semen until 7 weeks post clinical recovery. The Virus also spreads through contaminated needles or laboratory apparatus.
The sexual transmission of MARV virus also takes place through infected semen.
3. Effects of Virus in Humans
The incubation period of Haemorrhagic fever due to Marburg Virus lasts upto 5 to 21 days. The fever occurs suddenly with the symptoms of malaise, rapid debilitation, high fever and severe headache. At third day the person my develop symptoms like cramping, abdominal pain, vomiting, nausea and diarrhea. Within one week, the symptoms get severe with bleeding from the body. At initial stage, the symptoms of...