Term
|
Definition
• Viruses are a heterogeneous intracellular group of microorganisms
• Vary in respect to size, morphology, and chemical composition that contains either DNA or RNA
• Acellular and metabolically inert outside the host cell
• Obligate intracellular parasites
• No ATP-generating system
• No ribosomes or means of protein synthesis
• Most viruses have a narrow host range
– Range determined by viruses’ ability to interact with host cell via binding and receptor sites |
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Term
| virus classification depends on? |
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Definition
– Nucleic acid
– Morphology – Replication |
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Term
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Definition
| Are the virus particles which consist of two or three parts: the genetic material made from either DNA or RNA, a protein coat that protects these genes, and in some cases an envelope of lipids that surrounds the protein coat when they are outside a cell |
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Term
| Nucleic acid viral structure |
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Definition
– The nucleic acid (DNA or RNA, never both) is the genome that contains the information needed for viral function and multiplication
– Composition of the protein shell called the viral “nucleocapsid” surrounding the genome |
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Term
| Capsid (coat protein) viral structure |
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Definition
– Protects viral genome from host endonucleases
– Consists of capsomeres, which are the structural units of the capsid
– Contains binding sites |
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Term
|
Definition
– Derived from the membrane of the host cell
– Contains binding sites
– Absence of the viral membrane gives the naked virus |
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Term
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Definition
|
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Term
|
Definition
The size of virions ranges from 20 nm (parvovirus) to –300 nm (poxvirus) in diameter
– So, too small to be seen with the light microscope
– Can be studied with the electron microscope |
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Term
|
Definition
– Meaningthecapsidisspiralinshape.
– Itsurroundsaspiral-shapedcoreof nucleic acid.
– Helicalcapsidsareusuallyflexibleand rod-like.
Nucleic acid
– Thelengthofthehelicalcapsidis usually determined by the length of the nucleic acids; that is, viruses having shorter nucleic acids will have a shorter helical nucleocapsid.
– Helical capsids can package only single-stranded RNA, but not double- stranded DNA or RNA, possibly because of the rigidity of the double- stranded nucleic acids. |
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Term
| Polyhedral (Icosahedral) virus |
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Definition
– The term cubic is used to describe icosahedral viruses.
– Viruses with icosahedral capsids possess a closed shell enclosing the nucleic acid inside. An icosahedron has 20 triangular faces, 30 edges.
– Unlike helical nucleocapsids that package only single-stranded nucleic acid, icosahedral capsids can be used to package either single- or double- stranded RNA and DNA molecules.
– An icosahedral virus can be either naked or enveloped, but, unlike the helical enveloped viruses, the icosahedron capsid structure is rather rigid |
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Term
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Definition
• Means the capsid symmetry is neither icosahedral nor helical.
• Only the poxviruses among the medically important viruses show complex symmetry.
• The overall shape of poxviruses is usually described as brick-shaped. |
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Term
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Definition
• Because viruses possess neither cellular structure nor organelles, they are unable to make their own proteins and essential enzymes. They are therefore completely dependent on their host cells for energy and multiplication.
• Outside of living cells, viruses are metabolically inactive.
• The information required for a virus to replicate is contained in its nucleic acid. This information is used by the host cell to produce new viruses. |
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Term
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Definition
• The virus leave the host cell by breaking the cytoplasmic membrane and is released out as viroins to attack other cells (enveloped viruses come out of the cells like budding without rupturing the cell).
• As the virus comes out of the cell, the host cell will rupture i.e., lyses (killed) and die. |
|
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Term
| viruses and Cell transformation |
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Definition
| A small group of viruses is able to change, or transform their host cells from normal cells into abnormal ones with properties of cancerous cells, where the cell is not dead. |
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Term
| viruses and Immune complex diseases |
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Definition
| Immune system of host cell produces antibodies to fight the virus. Antibodies will react with virus (antigen), and antigen-antibody complex is produced that deposit in different places of body, e.g., Hepatitis B deposit in glomeruli of kidney. |
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Term
| viruses and Asymptomatic disease |
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Definition
| – Some viruses after infecting cells do not replicate, or they become active for a time and then become inactive (latent). In response to certain stimuli, latent viruses can be reactivated and become active replicating particles, for example herpes viruses. |
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Term
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Definition
• The internationally agreed system of virus classification is based on the structure and composition of the virus particle (virion).
• In some cases, the mode of replication is also important in classification.
• Viruses are classified into various families on this basis. |
|
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Term
| virus classification chart |
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Definition
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Term
| Viral Replication Adsorption |
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Definition
– The first step in infection of a cell is attachment to the cell surface.
– The viral attachment protein recognizes specific receptors, which may be protein, carbohydrate, or lipid, on the outside of the cell.
– Cells without the appropriate receptors are not susceptible to the virus. |
|
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Term
|
Definition
– Penetration occurs almost rapidly after attachment and is a next
step for gaining entry into the cytoplasm by crossing the plasma
membrane.
– Thus, penetration allows the viruses to deliver their genome into
the host cells to initiate replication. |
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Term
| The penetration process differs for different viruses |
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Definition
– Penetration by the process of endocytosis is common to both enveloped and nonenveloped viruses.
– While some virus species can directly penetrate the plasma membrane and inject their genetic material into the cytoplasm, the majority of viruses enter cells via endocytosis.
– Direct penetration is observed only in nonenveloped viruses; membrane fusion is observed only in enveloped viruses. Some of the nonenveloped viruses like picornaviruses and phages are capable of directly injecting their genome into the host cell. |
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Term
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Definition
| Release of the viral genome from its protective capsid to enable the viral nucleic acid to replicate |
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Term
|
Definition
| – Synthesis of mRNA in host cell |
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Term
|
Definition
| – Viral mRNA is translated on cell ribosomes into structural and nonstructural proteins in host cell |
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Term
|
Definition
Endosome formation
pH drop due to H+ pump Fusion peptide to PM Conformational change Release of NA |
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Term
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Definition
| – New virus genomes and proteins are assembled to form new virus particles |
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Term
|
Definition
– Enveloped viruses are released by budding
– Unenveloped viruses are released by rupture and lysis of infected cells |
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Term
| antiviral Attachment antagonists |
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Definition
| – Block attachment molecule • Arildone |
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Term
| antivirals that Inhibit uncoating |
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Definition
– Neutralize acid environment • Amantadine
• Rimantadine |
|
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Term
| antivirals that Inhibit DNA/RNA synthesis |
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Definition
– Activation by phosphorylation of drug by viral kinases
• Acyclovir
• Ganciclovir |
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Term
| arthropod-borne viruses, or arboviruses, are |
|
Definition
a group of infectious agents that are transmitted by blood- sucking arthropods from one vertebrate host to another.
• They can multiply in the tissues of the arthropod without evidence of disease or damage.
• The vector acquires a lifelong infection through the ingestion of blood from a viremic vertebrate.
• All arboviruses have an RNA genome, and most have a lipid-containing envelope. |
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Term
Togaviridae
Genus Alphavirus arbovirus members |
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Definition
| Chikungunya, Western equine encephalitis |
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Term
Flaviviridae
Genus Flavivirus Arbovirus members |
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Definition
| Dengue, West Nile fever, yellow fever |
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Term
| Bunyaviridae genuses, Arbovirus |
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Definition
|
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Term
| Three Clinical Syndromes of arboviruses |
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Definition
• Fevers of an undifferentiated type with or without a maculopapular rash and usually benign
• Encephalitis, often with a high case fatality rate
• Hemorrhagic fevers, also frequently severe and fatal |
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Term
| Togaviridae Genera (arbovirus) |
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Definition
• Alphavirus(typicalvirus—Sindbisvirus) • Rubivirus
• Pestivirus |
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Term
|
Definition
| Eastern equine encephalitis (alphavirus) |
|
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Term
|
Definition
| Western equine encephalitis (alphavirus) |
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Term
| Febrile illness, encephalitis (VEE) virus |
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Definition
| Venezuelan equine encephalitis (alphavirus) |
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Term
| Febrile illness, rash, arthralgia alphavirus |
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Definition
|
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Term
|
Definition
|
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Term
| Pathogenesis of alphaviruses |
|
Definition
– Human illness exemplified by agents that produce
three markedly different disease patterns.
– Chikungunya virus is the prototype for those causing an acute (3-to7-day) febrile illness with malaise, rash, severe arthralgias, and sometimes arthritis. |
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Term
| Epidemiology of alphaviruses |
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Definition
| – Diseases are maintained in natural ecologic cycles involving birds and, principally, bird-feeding mosquitoes such as Culex and Aedes. |
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Term
| host defenses of alphaviruses |
|
Definition
– Differences in susceptibility between individuals and species are not easily ascribed to specific immune responses, and a variety of nonspecific defense
mechanisms may be important.
– Alpha viruses are efficient inducers of interferon, the production of which probably plays a role in modulating or resolving infections.
– Antibodies are important in disease recovery and resistance. |
|
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Term
| Diagnosis/Control of alphaviruses |
|
Definition
• Blood, cerebrospinal fluid examination, section material, and blood serum to include viral cultures are critical in differentiating bacterial from viral infections.
• Laboratory diagnosis can be established by isolating virus from the blood during the viremic phase or by antibody determination
– Express-methods:ELISA
– Virological diagnosis: inoculation laboratory animals, cell cultures, eggs – Serology: paired sera
• Control of alphavirus diseases includes:
– Control of larvae and adult mosquitoes
– Inactivated vaccines
– A live attenuated chikungunya vaccine has proven safe and
immunogenic in investigational human trials |
|
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Term
|
Definition
German measles) is a common mild disease characterized by a rash.
• It affects children and adolescents worldwide and can also affect young adults.
• When rubella virus infects susceptible women early in pregnancy, it may be transmitted to the fetus and may cause birth defects.
– Therefore, accurate diagnosis is critical in pregnancy. |
|
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Term
| epidemiology of rubella viruses |
|
Definition
– Humansaretheonlyknownreservoirofrubellavirus. – Incubation16–18days.
– Mechanismoftransmission
• Postnatal person-to-person transmission occurring via direct or droplet contact with the respiratory secretions of infected persons
• Contact (formites) • Transplacental |
|
|
Term
| Clinical Manifestations of rubella viruses |
|
Definition
• Postnatal rubella is often asymptomatic but may result in a generally mild, self-limited illness characterized by rash, lymphadenopathy, and low-grade fever.
• As is the case for many viral diseases, adults often experience more severe symptoms than do children.
– In addition, adolescents and adults may experience a typical mild prodrome that is not seen in infected children; this occurs 1 to 5 days before the rash and is characterized by headache, malaise, and fever. |
|
|
Term
| Abnormalities Associated With Congenital Rubella Syndrome |
|
Definition
Ocular defects
Cataracts Microphthalmia Glaucoma Retinitis
Heart defects
Patent ductus arteriosus
Atrial septal defect
Ventricular septal defect
Peripheral pulmonic artery stenosis
Hearing impairment
Sensorineural deafness
Central nervous system
Mental retardation Meningoencephalitis
Progressive rubella panencephalitis (rare)
Microcephaly
Other
Growth retardation Radiolucent borne disease Hepatosplenomegaly Hemathologic abnormalities: Thrombocytopenia, purpura Pneumonitis
Endocrine dysfunction:
Insulin dependent diabetes mellitus, thyroiditis |
|
|
Term
|
Definition
• Postnatal infection rapidly induces a specific immune response which provides lifelong protection against the natural disease.
• Neutralizing and hemagglutination-inhibiting antibodies appear shortly after the onset of rash and reach maximum levels in 1 to 4 weeks.
• Specific antibodies persist after infection.
– Cell-mediated immunity also develops in convalescence and can be detected for years following infection. |
|
|
Term
|
Definition
• Serologic studies
– Detection of IgM and/or fourfold antibody rises
– Presence of specific IgM antibodies indicates recent rubella infection
– Specific IgG antibodies in healthy individuals demonstrate immunity to rubella
• Antibodies are detectible by a variety of methods including: – Neutralization test
– Hemagglutination inhibition
– ELISA
– Indirect immunofluorescent immunoassay
• Virologic studies
– Virus can be readily recovered in cell cultures from respiratory tract
secretions and, in infants with congenital infection, from urine, cerebrospinal
fluid, and blood
– Presence of virus in inoculated cultures can be recognized by viral interference or immunoperoxidase staining assays
– Seldom used except for the diagnosis of congenital rubella |
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Term
|
Definition
• Classification within the genus is based upon antigenic relationships.
• Flaviviruses vary widely in their pathogenic potential and mechanisms for producing human disease. It is useful to consider them in three major categories: those associated
primarily with:
– Theencephalitissyndrome(prototype:St.Louisencephalitis) – Fever-arthralgia-rash(prototype:denguefever)
– Hemorrhagic fever (prototype:yellowfever) |
|
|
Term
|
Definition
– Themosquito-borneencephalitisvirusesexistprimarilyasvirusesof
birds and are transmitted by Culex mosquitoes that feed readily on
birds.
– Humaninfectionwithbothmosquito-borneandtick-borneflavivirusesis
initiated by deposition of virus through the skin via the saliva of an infected arthropod. |
|
|
Term
| causes Febrile illness, rash, hemorrhagic fever, shock syndrome |
|
Definition
| Dengue (DEN) (Flavivirus), Tropics, worldwide |
|
|
Term
| causes Hemorrhagic fever, hepatitis |
|
Definition
| Yellow fever (YF) (flavivirus), Africa, South America |
|
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Term
|
Definition
| St. Louis encephalitis (SLE)-Americas , Japanese encephalitis (JE) (flaviviruses)- India, China, Japan, South- East Asia |
|
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Term
|
Definition
| West Nile (flavivirus)- Africa, Middle East, Europe |
|
|
Term
| Yellow Fever general info |
|
Definition
– Spherical viruses
• Capsid, membrane protein, and envelope protein
– Capsid (C protein)
• Structural protein
• Houses the RNA and the viral RNA polymerase
– Membrane protein (prM/M)
• Helps the capsid pass through the cell membrane |
|
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Term
| Yellow Fever transmission |
|
Definition
• Vertical and horizontal transmission
– Vertical transmission is mosquito to mosquito
– Horizontal transmission is when an infected mosquito bites
a noninfected human or monkey |
|
|
Term
|
Definition
– Jungle fever
• Spread from monkeys to people by mosquitoes – Urban fever
• Spread person to person by mosquitoes |
|
|
Term
|
Definition
– Acute phase
• Fever, muscle pains(LBP), headaches, nausea, vomiting
• Usually recovers in 3–4days
– Toxic phase
• Fever, jaundice, abdominal pain, vomiting, bleeding (nose, eyes, stomach), kidney failure
• Mortality rate 50% within 10–14days |
|
|
Term
|
Definition
|
|
Term
|
Definition
• Single-strand RNA arbovirus
• Four serotypes based on envelop glycoprotein
– Infection with any serotype confers specific lifelong immunity – Transient cross-protection to other serotypes
– Any serotype can cause severe, fatal disease
• Generally an animal virus, but man accidentally infected
• Transmitted by the mosquito Aedes aegypti |
|
|
Term
| Presentation: Nonbleeding Form of dengue fever |
|
Definition
• Incubation period 2–7 days after the mosquito bite;
sudden onset of fever, chills, headache
• Back pain with severe muscle and joint pains
• Pain behind the eyes and on moving the eyes
• Red patches or spots on the skin
• Mild nose bleeds |
|
|
Term
| Presentation: Bleeding Form of dengue fever |
|
Definition
• Blood vessels are affected
• There is severe oozing into tissues
• Bleeding into all possible parts of body
• Blood clotting mechanism is disrupted
• Blood pressure falls and many end in collapse and death |
|
|
Term
| Diagnosis of dengue fever |
|
Definition
• Routine blood test
• Clotting profile
• Urinalysis
• Dengue:ELISA |
|
|
Term
| prevention of dengue fever |
|
Definition
– No vaccine
– Prevent mosquito bites |
|
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Term
|
Definition
| Rhinoviruses, coronaviruses (respiratory viruses) |
|
|
Term
|
Definition
| Influenza viruses (respiratory viruses) |
|
|
Term
|
Definition
| parainfluenza virus (respiratory virus) |
|
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Term
|
Definition
|
|
Term
| Bronchopneumonia caused by |
|
Definition
| Influenza virus, RSV, adenoviruses (respiratory viruses) |
|
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Term
|
Definition
• RNA virus, genome consists of eight segments
• Enveloped virus, with hemagglutinin and neuraminidase spikes
• Three types
– A,B,andC
– Type A undergoes antigenic shift and drift
– Type B undergoes antigenic drift only, and Type C is relatively stable |
|
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Term
|
Definition
• Undergoes antigenic shifts and antigenic drifts with the hemagglutinin and neuraminidase proteins.
• Antigenic shifts of the hemagglutinin results in pandemics. Antigenic drifts in the H and N proteins result in epidemics.
• Usually causes a mild febrile illness.
• Death may result from complications such as viral/bacterial pneumonia. |
|
|
Term
| Epidemiology of influenza A |
|
Definition
– Pandemics: Influenza A pandemics arise when a virus with a new hemagglutinin subtype emerges as a result of antigenic shift. As a result, the population has no immunity against the new strain. Antigenic shifts have occurred three times in the 20th century.
– Epidemics: Epidemics of influenza A and B arise through more minor antigenic drifts as a result of mutation |
|
|
Term
| Past Antigenic Shifts for flu |
|
Definition
1918 H1N1 “Spanish Influenza”
1957 H2N2 “Asian Flu”
1968 H3N2 “Hong Kong Flu”
1977 H1N1 Re-emergence 2009
H1N1 “Swine Flu” |
|
|
Term
| Theories Behind Antigenic Shift |
|
Definition
• Reassortment
– Reassortment of the H and N genes between human and avian influenza viruses through a third host.
• There is good evidence that this occurred in the 1957 H2N2 and the 1968 H3N2 pandemics.
• The 2009 pandemic virus was thought to be a novel virus that was a triple reassortant involving human, bird, North American pig, and Eurasian pig viruses.
– Recycling of pre-existing strains—this probably occurred in 1977 when H1N1 resurfaced.
– Gradual adaptation of avian influenza viruses to human transmission. There is some evidence that this occurred in the 1918 H1N1 pandemic. |
|
|
Term
|
Definition
• An outbreak of Avian Influenza H5N1 occurred in Hong Kong in 1997 where 18 persons were infected, of which six died.
• The source of the virus was probably infected chickens, and the outbreak was controlled by a mass slaughter of chickens in the territory.
• All strains of the infecting virus were totally avian in origin and there was no evidence of reassortment. |
|
|
Term
|
Definition
• Several cases of human infection with avian H9N2 virus occurred in Hong Kong and Southern China in 1999.
• The disease was mild and all patients made a complete recovery
• Again, there was no evidence of reassortment |
|
|
Term
| avian influenza symptoms and complications |
|
Definition
• Fever
• Headache
• Myalgia
• Cough
• Rhinitis
• Ocular symptoms
• Pulmonary
– Croup (young children)
– Primary influenza pneumonia
– Secondary bacterial infection
• Nonpulmonary
– Myositis (rare, Type B, children)
– Cardiac complications
– Reyes syndrome
– Peripheral nervous system |
|
|
Term
|
Definition
|
|
Term
| Laboratory Diagnosis of flu |
|
Definition
• Rapid diagnosis
– Nasopharyngeal aspirates, throat, and nasal swabs are
normally used.
• Antigen detection can be done by IFT or EIA
• RNA detection: RT-PCR assays give the best sensitivity and specificity. It is the only method that can differentiate the 2009 pandemic H1N1 strain from the seasonal H1N1 strain. How• Virus isolation
– Virus may be readily isolated from nasopharyngeal
aspirates and throat swabs. • Serology
– Retrospective diagnosis may be made by serology.
– CFT most widely used.
– HAI and EIA may be used to give a type-specific diagnosis.ever, is expensive and technically demanding. |
|
|
Term
|
Definition
• Neuraminidase inhibitors
– Are highly effective and have fewer side effects than
amantidine.
– Oseltamivir (Tamiflu) and zanamivir (Relenza).
– The resistance to different types varies year to year.
– H3N2 strains were mainly sensitive, whereas seasonal H1N1 were almost totally resistant.
– More than 98% of the 2009 pandemic influenza H1N1 tested were sensitive.
• Amantadine
– Effective against influenza A if given early in the illness – However, resistance to amantadine emerges rapidly
• Rimantadine
– Similar to amantadine but fewer neurological side effects
• Ribavirin
– Thought to be effective against both influenza A and B |
|
|
Term
|
Definition
• Inactivated split/subunit vaccines are available against influenza A and B.
– The vaccine is normally trivalent, consisting of one A H3N2 strain, one A H1N1 strain, and one B strain.
• Vaccines at best give about 70% protection.
– They may sometimes not be effective against the most recently evolved strains because the rate of evolution outpaces the rate at which new vaccines can be manufactured.
• This constant antigenic change down the years means that new vaccines have to be made on a regular basis.
– The strains used are reviewed by the WHO each year.
• Everyone should be vaccinated yearly. |
|
|
Term
| optimal time for flu vaccine |
|
Definition
| oct-nov (but still get during flu season) |
|
|
Term
|
Definition
| flu a most severe, flu a has shift and drift changes, flu b just drift changes, flu a sensitive to Amantadine, rimantadine, and Zanamivir, flu b only sensitive to Zanamivir. flu c does not cause severe illness |
|
|
Term
| Parainfluenza Virus general info |
|
Definition
– ssRNA virus, enveloped, pleomorphic morphology
– Five serotypes: 1, 2, 3, 4a, and 4b
– No common group antigen, closely related to Mumps virus |
|
|
Term
| parainfluenza virus clinical manifestations |
|
Definition
– Croup (laryngotracheobronchitis): most common manifestation of parainfluenza virus infection. However, other viruses may induce croup, e.g., influenza and RSV.
– Other conditions that may be caused by parainfluenza viruses include bronchiolitis, pneumonia, flu-like tracheobronchitis, and corza-like illnesses. |
|
|
Term
| Parainfluenza Virus lab diagnosis |
|
Definition
– Detection of antigen: a rapid diagnosis can be made by the detection of parainfluenza antigen from nasopharyngeal aspirates and throat washings.
– Virus isolation: virus may be readily isolated from nasopharyngeal aspirates and throat swabs.
– Serology: a retrospective diagnosis may be made by serology. CFT most widely used. |
|
|
Term
| parainfluenza virus management |
|
Definition
– No specific antiviral chemotherapy available.
– Severe cases of croup should be admitted to hospital and placed in oxygen tents.
– No vaccine is available. |
|
|
Term
| Respiratory Syncytial Virus (RSV) |
|
Definition
• ssRNA eveloped virus
• Belong to the genus Pneumovirus of the Paramyxovirus family
• Considerable strain variation exists; may be classified into subgroups A and B by monoclonal sera
• Both subgroups circulate in the community at any one time
• Causes a sizable epidemic each year |
|
|
Term
| Clinical Manifestations of RSV |
|
Definition
• Most common cause of severe lower respiratory tract disease in infants, responsible for 50–90% of bronchiolitis and 5–40% of bronchopneumonia.
• Other manifestations include croup (10% of all cases).
• In older children and adults, the symptoms are much milder: it may cause a corza-like illness or bronchitis. |
|
|
Term
| Infant at risk of severe infections with RSV |
|
Definition
– Infants with congenital heart disease: infants who were hospitalized within the first few days of life with congenital disease are particularly at risk.
– Infants with underlying pulmonary disease: infants with underlying pulmonary disease, especially bronchopulmonary dysplasia, are at risk of developing prolonged infection
with RSV.
– Immunocompromized infants: children who are immunosuppressed or have a congenital immunodeficiency disease may develop lower respiratory tract disease at
any age. |
|
|
Term
| laboratory diagnosis of RSV |
|
Definition
• Detection of antigen: a rapid diagnosis can be made by the detection of RSV antigen from nasopharyngeal aspirates. A rapid diagnosis is important because of the availability of therapy.
• Virus isolation: virus may be readily isolated from nasopharyngeal aspirates. However, this will take several days.
• Serology: a retrospective diagnosis may be made by serology. CFT most widely used. |
|
|
Term
| treatment and prevention of RSV |
|
Definition
• Aerosolised ribavirin can be used for infants with severe infection and for those at risk of severe disease.
• There is no vaccine available.
• immunoglobulin can be used to protect infants at risk of severe disease. |
|
|
Term
|
Definition
• ds DNA virus
• Nonenveloped
• At least 47 serotypes are known
• Classified into six subgenera: A to F
• Most Adenovirus infections involve either the respiratory or gastrointestinal tracts or the eye.
• Adenovirus infections are very common, most are asymptomatic. Most people have been infected with at least one type by age 15 |
|
|
Term
| Laboratory Diagnosis of adenovirus |
|
Definition
• Detection of antigen: a rapid diagnosis can be made by the detection of adenovirus antigen from nasopharyngeal aspirates and throat washings.
• Virus isolation: virus may be readily isolated from nasopharyngeal aspirates, throat swabs, and feces.
• Serology: a retrospective diagnosis may be made by serology. CFT most widely used. |
|
|
Term
| Treatment and Prevention of adenovirus |
|
Definition
• There is no specific antiviral therapy.
• A vaccine is available against adult respiratory distress syndrome. It consists of live adenovirus 4, 7, and 21 in enterically coated capsules. It is given to new recruits into various armed forces around the world. |
|
|
Term
|
Definition
account for one-third to one-half of all acute respiratory infections in humans.
• Rhinoviruses are responsible for 30–50% of common colds, coronaviruses 10–30%.
• The rest are due to adenoviruses, enteroviruses, RSV, influenza, and parainfluenza viruses, which may cause symptoms indistinguishable to those of rhinoviruses and coronaviruses. |
|
|
Term
|
Definition
• ssRNA virus
– Belong to the picornavirus family
• Acid-labile
– At least 100 serotypes are known
• Rhinoviruses are picornaviruses similar to enteroviruses
• Rhinoviruses are isolated commonly from the nose and throat but very rarely from feces
• These viruses cause upper respiratory tract infections, including the common cold |
|
|
Term
|
Definition
• ssRNA virus
• Enveloped, pleomorphic morphology
• Two serogroups: OC43 and 229E |
|
|
