What does one segment of the influenza virus correspond to?
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One polypeptide.
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What does one segment of the influenza virus correspond to?
One polypeptide.
What does the high error rate of viral RNA polymerases lead to?
Mutations.
Can people with mild or no symptoms infect others with influenza?
Yes, they can.
What defines a pandemic?
An epidemic over a very large area, affecting a large proportion of a population, often globally.
What is the significance of ACE2 Receptors in viral entry?
They facilitate the entry of the virus into host cells.
How does influenza spread?
It spreads rapidly in closed communities.
How long can the virus' genetic material be present after infection?
For weeks after a person is no longer infectious.
When do most influenza cases occur in the UK?
During an 8 to 10 week period in the winter.
What protein is responsible for the virus's envelope structure?
Envelope glycoprotein (E).
What is antigenic shift?
A major change in the influenza virus, resulting in new hemagglutinin and/or neuraminidase proteins.
What significant event occurred in 1968 related to influenza?
The H3 pandemic strain emerged.
What is the size of the genome for Coronaviridae?
28 - 32 kilobase pairs.
What acts as a receptor for the influenza virus?
Sialic acid (Neu5Ac) on a glycoprotein/glycolipid.
What are the dramatic changes in the antigenic properties of the influenza virus called?
Antigenic shift.
What receptor does the virus attach to for entry?
ACE2 Receptors.
What is the primary method for diagnosing influenza?
Usually diagnosis is made from symptoms and clinical assessment.
What type of RNA is associated with the influenza virus?
(-) ssRNA.
What are the main types of influenza viruses?
Influenza A, B, C, and D.
Where and when did COVID-19 originate?
It originated by zoonotic transfer in Wuhan, China in December 2019.
What are the three potential modes of transmission for influenza viruses?
What is assembled into nucleocapsids during influenza virus replication?
Viral proteins.
Which countries are mentioned in relation to flu deaths?
Mexico and China.
What is the number of deaths mentioned from an unspecified source?
15,000 deaths.
How many people are infected by influenza each year?
1 billion people (1,000,000,000).
What type of infection is influenza?
An acute viral infection of the respiratory tract.
What is the life cycle duration of the coronavirus?
Approximately 10 hours.
What is the result of antigenic shift?
The creation of a new subtype of the virus.
What is antigenic drift?
Genetic changes in the influenza virus.
What is the function of the Spike (S) glycoprotein?
Required for entry into cells.
Who contributed to the electron micrograph of the Coronavirus?
CDC/ Dr. Michael Shaw; Doug Jordan, M.A.
Who does the WHO recommend for annual influenza vaccination?
Pregnant women, children aged 6 months to 5 years, elderly individuals over 65, individuals with chronic medical conditions, and health-care workers.
What do PCR tests detect?
The virus’ genetic material.
How are influenza viruses primarily transmitted?
Via the respiratory route (coughing, sneezing, inhaling).
What role do host organisms play in virus classification?
Viruses can be classified based on the type of host they infect.
What role do ciliated respiratory epithelial cells play in defense against influenza?
They continually sweep mucus up from the lower respiratory tract.
Where do A viruses live and multiply?
In many different animals.
How long can small-particle aerosols remain suspended in the air?
For many hours.
What is an example of a current bird flu epidemic?
H5N1.
What are common symptoms of influenza A virus infection?
Sudden onset of fever, chills, headache, muscle/joint pain, extreme fatigue, dry cough, sore throat, stuffy nose.
What are antivirals used for treating influenza?
Rimantadine and amantadine, which inhibit viral uncoating.
When and where did SARS-CoV-2 emerge?
In Wuhan, China in 2019.
What is antigenic drift?
Minor changes (natural mutations) in the genes of flu viruses that occur gradually over time.
What type of virus is Coronaviridae?
Large, enveloped, pleomorphic particles.
What protein on the surface of the influenza virus facilitates entry into cells?
Hemagglutinin protein.
What type of cells does the influenza virus primarily infect?
Respiratory epithelial cells.
What are coronaviruses?
A family of viruses that can cause illness in animals and humans.
How does the influenza virus enter cells?
Via receptor-mediated endocytosis.
What is one alternative method of classifying viruses?
By their mode of transmission.
What immunologic defenses are present in the lung against influenza?
Secretory IgA, natural killer (NK) cells, and macrophages.
What is the incubation period for influenza A virus infection?
1 - 5 days (average 2 - 3 days).
What is the significance of understanding animal reservoirs in controlling outbreaks?
It helps in predicting and preventing potential zoonotic spillovers.
What type of contact can lead to infection from larger droplets?
Direct contact with individuals.
What is the annual death toll from influenza?
500,000 deaths per year.
What is a characteristic of viral RNA polymerases in the flu virus?
They have a high error rate.
Why might the immune systems of individuals be unprepared for a new subtype of influenza virus?
Because it may not have been seen in circulation for many years.
What type of viruses cause outbreaks most years and are the usual cause of epidemics and pandemics?
A viruses.
When did the WHO declare COVID-19 a pandemic?
On 11 March 2020.
How can reassortment occur between influenza A viruses?
It can occur between viruses that infect different animal and avian species, such as pigs being infected by human- and avian-specific influenza viruses.
What type of RNA does the coronavirus have?
Positive-sense single-stranded RNA (ssRNA).
What potential does a reassortant virus have?
The potential to spread among humans, birds, and pigs.
What is the start codon for protein synthesis in coronaviruses?
AUG (Methionine).
How does the influenza virus leave infected cells?
Through the cleavage of sialic acid residues by neuraminidase.
What is the life cycle duration of the flu virus?
Approximately 6 hours.
What is antigenic shift?
Major changes in the genes of flu viruses that occur suddenly when two or more different strains combine.
What does 'A/Michigan/45/2015' refer to in influenza virus naming?
It indicates a specific strain of the influenza virus, including the type, location, and year of isolation.
What happens when the immune system overreacts to the flu virus?
T-cells attack and destroy the tissues where the virus is replicating, particularly in the lungs, leading to a cytokine storm.
What can antigenic shift cause?
Widespread epidemics or pandemics.
What was the cause of the deaths mentioned in the text?
Spanish flu.
What are the surface antigens of the influenza virus?
Hemagglutinin and neuraminidase.
What is the main animal reservoir for A viruses?
Birds, particularly wildfowl.
What was the recommended composition of virus vaccines for the 2023-2024 Northern Hemisphere influenza season?
What BMI classification indicates morbid obesity, which increases influenza risk?
BMI≥40.
How does coronavirus enter cells?
Through receptor-mediated endocytosis.
What are cleavage sites in the context of the influenza virus?
They are specific locations where neuraminidase acts to release the virus from host cells.
What is COVID-19?
An acute viral infection of the respiratory tract.
How does COVID-19 spread?
It spreads rapidly in communities, even from people with mild or no symptoms.
What is the primary genetic material of the Coronavirus?
Single-stranded positive-sense RNA (ss (+)RNA).
What complications may pregnant women face if they contract influenza?
Perinatal mortality, prematurity, smaller neonatal size, and lower birth weight.
What organization monitors influenza virus epidemiology worldwide?
World Health Organization (WHO).
What is an example of a variant in the coronavirus?
BA.2.86.
What type of influenza virus primarily affects animals, particularly pigs and cattle?
Influenza D.
How can influenza viruses infect others through surfaces?
By landing on surfaces where they remain infectious.
Is influenza A virus infection self-limiting?
Yes, it is self-limiting.
What is a live, attenuated vaccine for influenza?
A cold-adapted vaccine (quadrivalent) administered by nasal spray for influenza A & B (children).
Who is at higher risk for severe disease from SARS-CoV-2?
Older and immunocompromised individuals.
Who is the Infection Unit Lead?
Dr. Deborah Mitcheson.
Which gene segment is associated with the 1968 pandemic strain of H3?
PB1.
What does antigenic shift lead to?
A new subtype of influenza virus.
What is the result of genetic variation in the influenza virus?
Resistance.
What are the barriers to entry for the influenza virus via the respiratory route?
Thick glycocalyx and tracheobronchial mucus.
What type of secondary infection can occur after a flu infection?
Opportunistic bacterial infections, such as those caused by Streptococcus or Staphylococcus species, usually in the lungs.
In which animals can influenza type A viruses be found?
In many animals, including horses, pigs, and wild migrating waterfowl.
What is the function of the Spike glycoprotein (S) in Coronavirus?
It facilitates the virus's entry into host cells.
What is the significance of pigs coexisting with birds and humans?
It allows for a pig to be simultaneously infected with multiple influenza subtypes.
What is the role of the Spike glycoprotein in coronavirus?
It facilitates the entry of the virus into cells.
Where is ACE2 widely expressed?
In lung, heart, kidney, and gastrointestinal tissue.
How does influenza typically present in patients?
Sudden onset of symptoms, often including high fever and severe fatigue.
Name two examples of neuraminidase inhibitors.
Oseltamivir (Tamiflu) and Zanamivir (Relenza).
What is the function of Haemagglutinin (H) in the Influenza Virus?
Binds to cells of the infected person.
What is the zoonotic transfer source for SARS-CoV-2?
Horseshoe bats.
What do LFTs detect in relation to the virus?
Material from the surface proteins of the virus.
What is the genetic material of Coronaviridae?
(+) ssRNA.
What is a characteristic of viral RNA polymerases in coronaviruses?
They have a high error rate.
What does 'H1N1' signify in the context of influenza viruses?
It refers to a subtype of the influenza A virus, specifically the hemagglutinin (H) and neuraminidase (N) proteins.
What was the first major outbreak of type A influenza in the past 100 years?
The 1918 H1N1 pandemic.
What does genetic variation in coronaviruses contribute to?
Resistance to treatments and vaccines.
Which type of influenza virus is less common and usually causes mild respiratory illness?
Influenza C.
What is the role of the Membrane protein (M) in the Coronavirus structure?
It helps maintain the shape of the virus and is involved in the assembly of the viral envelope.
When did WHO recommend the vaccine composition for the 2023-2024 influenza season?
February 24, 2023.
How do A viruses spread between animals?
They may spread between different animal species.
What was the zoonotic transfer source for SARS-CoV-1?
Civets.
What type of sample is used for the diagnosis of Influenza?
A nasopharyngeal swab.
What is the primary basis for virus classification?
The structure and type of genetic material.
What type of sample is commonly used for influenza diagnosis?
A nasopharyngeal swab.
How can viruses be classified based on their structure?
By their shape, size, and presence of an envelope.
What is the major surface antigen of Coronaviridae?
Spike (S) glycoprotein.
What are reassortants in the context of influenza viruses?
Unique combinations of mRNAs encoding the H and N antigens produced within one host animal, such as a pig.
What type of imaging technique was used to capture the Coronavirus?
Electron micrograph.
What caused the 1957 H2N2 pandemic?
Reassortment of human and avian influenza.
Which pandemic occurred in 1968?
The H3N2 pandemic.
How long after childbirth are pregnant women at risk for influenza complications?
Up to 2 weeks postpartum.
What surrounds the Coronavirus structure?
A lipid bilayer.
What is the role of neuraminidase in the influenza virus?
Neuraminidase facilitates the release of the virus from infected cells.
What are the two surface antigens of the Influenza Virus?
Haemagglutinin (H) and Neuraminidase (N).
What was the zoonotic transfer source for MERS?
Camels.
What do antigenic drift changes in flu viruses cause?
Seasonal epidemics.
When are LFTs likely to give a positive result?
When someone is infectious.
What is the role of RdRp in the influenza virus?
It is RNA-dependent RNA polymerase from the infecting virus.
Which type of influenza virus is known to cause pandemics?
Influenza A.
What does 'pdm09' indicate in the naming of the H1N1 virus?
It denotes the pandemic strain of H1N1 that emerged in 2009.
What triggers the body's immune response to a viral invasion during the flu?
The production of antibodies and the movement of immune cells to the site of infection.
What role do cytokines play in the immune response to the flu?
Cytokines are released, leading to local inflammation as part of the immune response.
What is unique about the 2009 novel H1N1 outbreak?
It contains genes from a combination of human, swine, and avian reassortment.
What is assembled into nucleocapsids during the coronavirus replication process?
Viral proteins.
What is the general severity of disease caused by B viruses compared to A viruses?
B viruses cause less severe disease.
What are neuraminidase inhibitors used for treating influenza?
Oseltamivir (Tamiflu) and Zanamivir (Relenza), which inhibit viral release from infected cells.
How many types of Haemagglutinin are there?
18 types.
What type of influenza virus is H3 associated with?
Avian influenza.
What are the two main types of genetic material in viruses?
DNA and RNA.
What is an epidemic?
A widespread occurrence of an infectious disease in a community at a particular time.
How many deaths occurred in Britain due to the Spanish flu in 1918?
228,000 deaths.
What role do animal reservoirs play in the spread of coronaviruses?
They serve as sources of new strains that can infect humans.
What is the size of small-particle aerosols that can transmit influenza?
Less than 10 μm mass diameter.
What does WHO recommend regarding influenza strains?
Strains of influenza A & B predicted to circulate in the forthcoming winter.
What happens to larger droplets from an infected person?
They typically fall to the ground within 3 meters.
What type of viruses tend to cause less severe disease?
B viruses.
What is the codon for Tyrosine in the context of coronavirus replication?
UAC.
What protein does SARS-CoV-1 bind to?
Ace2 protein.
How many proteins does the Influenza Virus encode?
11 proteins.
Who is at higher risk for serious complications from influenza?
Children under six months, older people (over 65), those with underlying health conditions, pregnant women, and individuals with morbid obesity (BMI≥40).
What is the consequence of the high error rate in coronavirus replication?
It leads to mutations.
Which proteins are involved in the antigenic shift of influenza viruses?
Hemagglutinin (H) and neuraminidase (N) proteins.
What underlying health conditions increase the risk of serious influenza complications?
Respiratory disease, cardiac disease, long-term neurological conditions, and immunosuppression.
What is the age group that is particularly vulnerable to influenza complications?
Older people, specifically those over 65 years old.
Can people with mild or no symptoms of influenza A still infect others?
Yes, they can still infect others.
What is an example of a subtype change in influenza?
From H1N1 to H3N2.
What does the term 'mRNA' refer to in the context of coronavirus?
It refers to the positive-sense ssRNA that serves as messenger RNA.
What is the function of Neuraminidase (N) in the Influenza Virus?
Releases the virus from the host cell surface.
What type of influenza virus primarily affects humans and is responsible for seasonal flu?
Influenza B.
What does AUG code for in the context of influenza virus proteins?
Methionine (Met).
Which type of influenza viruses show antigenic shift?
Only influenza type A viruses.
What is the function of RNA-dependent RNA polymerase (RdRp) in coronaviruses?
It replicates the viral RNA from the infecting virus.
What is the recovery time for influenza A virus infection?
2 - 7 days.
What type of vaccine is used for influenza prevention?
Formalin-inactivated vaccine (quadrivalent/trivalent) by injection for influenza A & B.
What effect do neuraminidase inhibitors have on viral particles?
They cause aggregation of viral particles.
What is the genetic material of the Influenza Virus?
( - ) ssRNA with 8 genes.
What protein does SARS-CoV-2 bind to?
Ace2 protein.
Which animals are known to be reservoirs for coronaviruses?
Bats and pangolins are among the primary reservoirs.
How do coronaviruses typically jump from animals to humans?
Through direct contact or via intermediate hosts.
What type of RNA is produced during the replication of the influenza virus?
(+) ssRNA.
What is ACE2?
A transmembrane protein that acts as a receptor for coronavirus.
What are the H and N in HN glycoproteins?
H stands for hemagglutinin and N stands for neuraminidase.
What type of vaccine is used for influenza prevention?
Formalin-inactivated vaccine (quadrivalent/trivalent) by injection for influenza A & B.
What are neuraminidase inhibitors used for?
They inhibit viral release from the infected cell and cause aggregation of viral particles.
How many types of Neuraminidase are there?
11 types.
How often does antigenic shift occur in influenza viruses?
Infrequently, maybe every 10 or 20 years.
What does UAC code for in the context of influenza virus proteins?
Tyrosine (Tyr).
What is the function of the Nucleocapsid protein (N) in Coronavirus?
It protects the viral RNA and is involved in the replication process.
How do rimantadine and amantadine work?
They inhibit viral uncoating after uptake, probably through the M2 protein in influenza A.
When and where did SARS-CoV-1 emerge?
In Asia in 2002.
What protein does MERS bind to?
DDP4.
What is the origin of coronaviruses?
Possibly all originated in bats.
What does antigenic shift involve in terms of genetic changes?
Genetic changes in the influenza A virus surface antigens from different species.
In which population is the burden of disease mostly found for B viruses?
Children.
What complications can arise from influenza?
Pneumonia, bronchitis, sinus infections, and worsening of chronic conditions.
What is notable about the RNA polymerases in the Influenza Virus?
They have high error rates.
What are common symptoms of influenza?
Fever, cough, sore throat, body aches, and fatigue.
How do rimantadine and amantadine work?
They inhibit viral uncoating after uptake, probably through the M2 protein in influenza A.
What type of viruses are Orthomyxoviruses?
Spherical, enveloped viruses containing a segmented, negative strand RNA genome.
What percentage of winter colds were caused by coronaviruses before 2002?
10-30%.
Who is at higher risk for complications from influenza?
Young children, elderly adults, pregnant women, and individuals with chronic health conditions.
What are antivirals used for treating influenza?
Rimantadine and amantadine, which inhibit viral uncoating.
When and where did MERS emerge?
In the Middle East in 2012.
What is a live, attenuated vaccine for influenza?
A cold-adapted vaccine (quadrivalent) administered by nasal spray for influenza A & B in children.
What type of disease does MERS cause?
Severe disease.
What year is associated with the Infection Unit?
What is the cause of Severe Acute Respiratory Syndrome (SARS)?
Coronavirus.
