Influenza (4 types + avian )

Question 1

genome of influenza is …1… which allows a high rate of …..2..

Answer 1

1. single stranded RNA
2. mutation

Question 2

differences between the 3 major serotypes (A,B,C) of influenza are based on ?

Answer 2

antigens associated with the nucleoprotein

= influenza types can be distinguised by the specific proteins present inside the virus

Question 3

Type of virus that influenza virus is ?

Answer 3

enveloped negative-sense single stranded RNA

Question 4

influenza virus family ? what virus is it ?

Answer 4

orthomyxoviridae

orthomyxovirus

Question 5

Types of influenza virus responsible for seasonal flu in humans

Answer 5

Type B (infect only humans) , maybe A (infect animals + humans)

Question 6

Type A classified into subtypes based on ?

Answer 6

• hemagglutinin
• neuraminidase proteins
  e.g. Avian flu H5N1 , H9N2

Question 7

Influenza A viruses are responsible for …1… that usually cause higher …2… than seasonal …3..

Answer 7

1. sporadic pandemics
2. mortality rates
3. influenza epidemics

Question 8

Type B influenza virus classifed how ?

Answer 8

by lineage e.g. B/Victoria

Question 9

Influenza virus replication happens where ?

Answer 9

in host cell nucleus

Question 10

Pathogenesis of influenza ?

Answer 10

• prefers respiratory epithelium
• it multiplies in the ciliated cells of lower resp tract
• cellular synthesis of nucleic acids + proteins is shut down
• ciliated + mucus - producing epithelial cells are shed

Question 11

risk factors of influenza infection ?

Answer 11

• pregnancy
• age (< 5 yrs or >65 yrs)
• chronic medical conditions e.g. diabetes
• immunosuppressive conditions
• healthcare provision

Question 12

signs and symptoms of influenza ?

Answer 12

• sudden fever
• pharyngitis
• congestion
• cough
• myalgia

Question 13

Flu patients are susceptible to secondary infections due to virally produced damage to lung epithelium

3 bacteria that are common causes of superinfection ?

Answer 13

• streptococcus pneumoniae
• haemophilus influenzae
• staphylococcus aureus

Question 14

Influenza transmitted via how ?

Answer 14

• inhalation of airborne viruses
• self-inoculation

Question 15

complications of influenza occur most often in who ?

Answer 15

• elderly
• children
• those with chronic diseases

Question 16

Complications with influenza infection ?

Answer 16

• acute pneumonia in 30-40% hospitalised patients
• secondary bacterial infections
• acute respiratory distress syndrome

Question 17

Treatment for influenza infection ?

Answer 17

• uncomplicated = relief of symptoms (e.g. fever)
• severe / progressive clinical illness = antivirals , neuraminidase inhibitors (e.g. oseltamivir, zanamivir)

Question 18

Prevention for influenza infection ?

Answer 18

vaccination

Question 19

In infleunza infection virus replicates predominately in ….1…. cells because it’s the only site where ..2… is effectively cleaved

Answer 19

• respiratory epithelial cells
• HA (hemagglutinin )

Question 20

Cold symptoms

Answer 20

cold:
* low / no fever
* sometimes headache
* runny/ stuffy nose
* sneezing
* mild, hacking cough
* slight aches and pains
* normal energy level / may feel sluggish
* mild fatigue

Question 21

flu symptoms:

Answer 21

• high fever
• headache very common
• clear nose
• sometimes sneezing
• cough, often becoming severe
• often severe aches + pains
• several weeks of fatigue
• sometimes a sore throat
• extreme exhaustion

Question 22

What do the following influenza viruses infect ?
1. A
2. B
3. C
4. D

Answer 22

1. humans and many different animals + can cause influenza pandemic
2. amond humans + causes seasonal epidemics
3. humans + pigs , generally mild infections and rarely reported
4. primarily cattle not known to infect people

Question 23

How can influenza A virus cause an influenza pandemic ?

Answer 23

emergence of a new and very different INF A virus
with ability infect people and have sustained human to human transmission

Question 24

why are influenza type A viruses of most significance to public health ?

Answer 24

potential to cause an influenza pandemic

Question 25

Avian influenza is a ..1... disease caused by viruses that infect ..2..

Answer 25

1. contagious 2. birds

Question 26

How are avian influenza A virus strains classified ?

Answer 26

On basis of molecular + pathogenicity criteria * low pathogenic avian influenza (LPAI) * highly pathogenic avian influenza (HPAI)

Question 27

Most strains of Avian influenza are ...1... viruses and cause ..2... infection or ..3... disease in poultry

Answer 27

1.LPAI 2.asymptomatic 3.mild

Question 28

LPAI H6N1, H7N2, H7N3, H7N7, H7N9, H9N2, H10N7, and H10N8 virus strains have infected humans causing disease ranging from ?

Answer 28

from conjunctivitis to non-fatal upper respiratory and lower respiratory tract disease to severe lower respiratory tract disease and death (H7N9, H10N8)

Question 29

Rare,sporadic human cases of HPAI virus infection have been detected with which viruses ?

Answer 29

* H5N1 * H5N6 * H7N3 * H7N7

Question 30

Rare, sporadic human cases of HPAI viruses have caused a wide spectrum of illness from ...1.. to ..2..., ....3.., and ..4...

Answer 30

1. conjunctivitis 2. severe pneumonia 3. acute respiratory distress syndrome 4. fatal outcomes

Question 31

Avian flu presentation ?

Answer 31

* cough * influenza-like illness (non-specific symptoms e.g. headache, rhinorrhoea, sore throat, myalgia) * dyspnoea * fever * wheeze * tachypnoea

Question 32

Risk factors for avian infleunza A

Answer 32

* close contact with infected birds * recent travel to a virus infected country * visits to live poultry market in endemic countries * contact with infected humans (carers of family members) * healthcare personnel using inadequate PPE

Question 33

How to differentiate clinically between the following: Avian influenza A, influenza, TB, covid-19, bacterial pneumonia, SARS, MERS ?

Answer 33

* PCR for covid-19, avian influenza, SARS, MERS * sputum / blood culture for bacterial pneumonia (GAS/ S. pneumoniae) * acid fast stain + culture for TB * CXR (TB shows fibronodular opacities in upper lobes), also helpful for pneumonia (viral/ bacterial), lung cancer (can detect mass)

Question 34

Treatment for infleunza pharmacology aspect ?

Answer 34

* antivirals - neuarminidase inhibitors e.g. oseltamivir * antimicrobials if clinical suspicion of secondary bacterial infection

Question 35

2 basic approaches for treatment of influenza ?

Answer 35

* symptomatic care * anticipation of potential complications

Question 36

best treatments for influenza which aren't antimicrobials / antivirals ?

Answer 36

* rest + fluid intake * conservative use of analgesics for myalgia + headache * cough suppressants

Question 37

What are useful only if the infection if influenza diagnosed within 12-24 hours ?

Answer 37

* amantidine * rimantadine

Question 38

With treatment for infleunza what is important to consider ?

Answer 38

complications for those with severe, complicated or progressive illness, or those who require hospitalisation

Question 39

Apart from antiviral treatment for influenza the public health management includes personal protective measures like:

Answer 39

* Regular hand washing with proper drying of the hands * Good respiratory hygiene – covering mouth and nose when coughing or sneezing, using tissues and disposing of them correctly * Early self-isolation of those feeling unwell, feverish and having other symptoms of influenza * Avoiding close contact with sick people * Avoiding touching one’s eyes, nose or mouth