RNA Virus Flashcards
In RNA VIRUS, all are single stranded except:
Reovirus
In RNA VIRUS, all are enveloped Except:
Picornavirus, Calicivuris and Reovirus
In RNA VIRUS, they are generally helical except:
Picornavirus, Reovirus, Retrovirus, Flavivirus, Togavirus
In RNA VIRUS, all replicate in cytoplasm except:
Orthomyxovirus, Retrovirus
In RNA VIRUS the largest virus is ______, while the smallest is ______.
Largest: Paramyxovirus
Smallest: Picronavirus
Arthropod borne (insect borne):
▪️Bunyaviridae (except Hantavirus)
▪️Flaviviridae (except Hepatitis C virus)
▪️Togaviridae (except Rubella)
Just memorize this one.
This type of RNA VIRUS;
▪️Sand shape appearance in electron microscope
▪️Acquired through inhalation from infected rodent or direct contact
ARENAVIRUS
This type of ARENAVIRUS that manifest the following diseases;
Tacaribe, Guanarito, Junin and Machupo
New World Arena Virus
This type of ARENAVIRUS that manifest the following diseases;
Mus musculus, Mastomys natalensis
Old World Arena Virus
This disease is caused by ARENA VIRUS which is a rare case of aseptic meningitis
Lymphocytic Choriomeningitis
This is a virus that is under ARENA VIRUS which causes diseases like Hemorrhagic fever + influenza like
Lassa Virus
This type of RNA VIRUS;
▪️Star shaped appearance in EM
▪️Account to 2-9% of pediatric gastroenteritis in the world
ASTROVIRUS
This type of RNA VIRUS;
▪️Transmitted by mosquito, ticks and sandfly
BUNYAVIRUS
Type and Organ damage associated with Bunyavirus
▪️Phlebo virus - Rift Valley Fever Virus - Brain and Liver
▪️Orthobunya virus - LaCrosse & California Encephalitis – Brain
▪️Nairovirus - Crimean Congo Hemorrhagic Fever - Vascular Endothelium and
Liver
▪️Hantavirus – rodent borne bunyavirus
Disease caused is known as hemorrhagic fever with renal syndrome(HFRS)
Just memorize this one
This type of RNA VIRUS;
▪️ Small (30 to 38) nm rounded nonenveloped that cause gastroenteritis to humans
CALICIVIRUS
This type of CALICIVIRUS that is associated with 80% of nonbacterial acute gastroenteritis in undeveloped countries
Due to ingestion of contaminated Shellfish and water
Norovirus / Norwalk Virus
This type of CALICIVIRUS which is cup shaped in EM that is also associated with gastroenteritis
Sapovirus
This type of RNA VIRUS;
▪️Pleomorphic, roughly spherical
▪️Extremely fragile and difficult to
culture
▪️Resemble Halo/Crown on external
surface of the virus
CORONAVIRUS
▪️SARS-COV1: Acquired from civet cat that originated from Guangdong, China
▪️MERS-COV: Acquired from camel that originated in middle east
▪️SARS-COV2: Possibly acquired from pangolin that originated for Wuhan,China
SARS-COV2 DETECTION
▪️Direct: Microscopy / Viral nucleic acid
▪️Indirect: Serological Testing e.g. Antigen test
VARIANTS OF CONCERN
▪️Alpha – B117: United Kingdom
▪️Beta – B1351: South Africa
▪️Gamma P1: Brazil
▪️Delta B16172: India
Just memorize this one
This type of RNA VIRUS;
▪️Filo or threadlike due to long filamentous morphology in EM
▪️Most pathogenic of the hemorrhagic virus
FILOVIRUS
This type of FILOVIRUS that has 25% fatality rate and acquired from emerging virus due to eating of African Green Monkey in Africa is called?
Marburg hemorrhagic fever virus
This type of FILOVIRUS that has 80% fatality rate and acquired through direct contact with infected animal or human is called?
Ebola Virus
This type of RNA VIRUS;
▪️Derived from flavus which means Yellow – first type to be discovered is the Yellow Fever
FLAVIVIRUS
A. Yellow Fever
Three Cycles
1. Sylvatic: Monkey population transmitted by mosquitoes (Aedes aegypti)
2. Urban: Human
3. Intermediate: Human
B. Dengue Virus
▪️Dengue vectors: Aedes aegypti, Aedes albopictus and Aedes polynesiansis.
▪️It has four serotypes (1 to 4)
▪️Major protein in dengue virus, called ‘E’ for envelope protein
C. St. Louis Encephalitis (SCE)
▪️Is transmitted by Culex mosquitoes and mostly in summer months
D. Zika virus
▪️Spread by daytime Aedes aegypti and Albopictus
▪️There is preliminary evidence, that Zika is a cause of Guillain-Barré syndrome in adults.
F. West Nile Virus
▪️Vector is Culex mosquitos
▪️Maintained in bird-mosquito cycle such as crows, ravens
G. Hepatitis C virus
▪️Not an arthropod – Parenteral transmission
▪️Is associated with chronic liver disease
Just memorize this one
This type of RNA VIRUS;
• Previously under calicivirus
• High Case Fatality Rate in Pregnant Women (10-20%)
HEPEVIRUS
This type of RNA VIRUS;
▪️Pleomorphic single stranded with 8 segments.
Three Serotypes:
▪️A - naturally infects animals
▪️B, C - human
Transmitted through respiratory secretions
ORTHOMYXOVIRUS
This is under ORTHOMYXOVIRUS
Influenza is further subdivided based on Hemagglutinin(HA) and neuraminidase(NA):
▪️Hemagglutinins are rod shaped spikes
▪️Neuraminidase are mushroom shaped spikes
Antigenic drift refers to alteration of Influenza HA and NA antigens
Antigenic shift occurs after having a completely new novel type ONLY H1 H2 H3 N1 N2 found in human population
▪️H1N1 - Spanish Flu
▪️H2N2 - Asian Flu
▪️H3N2 - Hongkong Flu
▪️H5N1 - Avian Flu
Just memorize this one
This type of RNA VIRUS;
▪️Do not have segments that’s why they don’t undergo antigenic shift
PARAMYXOVIRUS
This is under PARAMYXOVIRUS;
A. Mumps or Rubulavirus
▪️Characterized by inflamed salivary gland accompanied by high temperature and fatigue;
B. Parainfluenza virus
▪️Second cause of pneumonia and bronchiolitis in children after RSV 4 serotypes
▪️Parainfluenza 1 is associated with croup (larygeotracheobronchitis)
▪️Parainfluenza 3 is severe and fatal associated
C. Respiratory Synctial Virus (RSV) or Pneumovirus
▪️Most significant cause of acute RTI in children under 5 years of age worldwide.
▪️Contains a surface F protein (Fusion)
▪️Leads to Giant Multinucleated Cells
D. Measles or Morbilivirus
▪️Highly contagious accompanied by maculopapular rash and fever
E. Metapneumovirus
▪️Associated with winter epidemics bronchiolitis and pneumonia which is common in children
F. Nipah virus
▪️Can cause encephalitis in human
Just memorize
This type of RNA VIRUS;
▪️Simplest of RNA viruses with highly structured capsid but limited surface elaboration
▪️Consists of 30% RNA and 70% Protein
PICORNAVIRUS
This is under PICORNAVIRUS;
A. Enterovirus
▪️The most common cause of aseptic meningitis or inflammation of brain parenchyma.
◾️Primary MOT: Respiratory or gastrointestinal
Enteroviruses are subdivided into:
▪️Poliovirus (1-3):
Associated with Paralytic Poleomyelitis or Flaccid Paralysis
▪️Coxsackie A (1-23):
Associated with Herpangina or Severe Febrile Pharyngitis with small blisters in mouth
▪️Coxsackie B (1-6):
Associated with Epidemic Myalgia or Chronic Fatigue Syndrome; Pleurodynia or pain upon breathing; and Borneholm Disease
▪️Enterovirus (68-72):
▪️Echovirus (1-32):
Characterized by cough, rash, and influenza like syndrome
▪️Parechovirus (1-4):
B. Rhinovirus
▪️It is the major cause of Cold virus
▪️Resistant to detergents, lipid solvents, and temperature extremes but
sensitive to pH less than 6.
Just memorize
This type of RNA VIRUS;
(Respiratory Enteric Orphan)
REOVIRUS
This type of REOVIRUS which is the most common cause of Viral Gastroenteritis in infants and children worldwide
Rotavirus
This type of REOVIRUS which is associated with Colorado tick fever and has 12 RNA segments.
Coltivirus
This type of RNA VIRUS;
▪️Requires RNA-dependent DNA polymerase
RETROVIRUS
This is under RETROVIRUS;
A. Oncovirus
▪️HTLV-1, HTLV-2 and HTLV-5 are oncovirus but not cytolytic HTLV-1 is known as T cell leukemia
▪️HTLV-2 is known as Hairy Cell Leukemia
B. Lentivirus
▪️HIV: It is the causative agent of AIDS
▪️HIV antigens are p24, gp41, gp120 and gp 160. ▪️Screening: ELISA
▪️Confirmatory: WB
HIV has 2 groups:
▪️HIV 1: Worldwide prevalence,
▪️HIV-2: West Africa
HIV -1 main groups are M,N and O whereas A-K are subgroup
Memorize
This type of RNA VIRUS;
▪️Rabies is caused by several strains of viruses belonging to the genus Lyssavirus.
RHABDOVIRUS
This type of RHABDOVIRUS;
▪️Bullet shaped appearance
▪️It is characterized by saliva frothing with painful spasm
▪️May lead to coma or death
▪️Associated with negri bodies in brain tissues of infected animals and
humans
Lyssavirus/ Rabies
This type of RNA VIRUS;
This kind of virus which contains the genera Alphavirus, Rubivi- rus, and Arterivirus.
TOGAVIRUS
This type of TOGAVIRUS is associated with equine encephalitis and transmitted by mosquitos, usually Aedes
Alphavirus
This type of TOGAVIRUS is;
▪️Non arthropod type
▪️German measles or 3 day measles – may lead to congenital defect if pregnant women is infected
Rubella or Rubivirus
This type of TOGAVIRUS is associated with myositis and arthritis which is transmitted by Aedes aegypti
Chikungunya virus
