Viral infections of the lower respiratory tract Flashcards

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1
Q

Lower respiratory tract infection (LRTI) is a significant cause of morbidity and mortality in (children or adults?)

A

Children

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2
Q

_________ account for a significant proportion of LRTI especially in children

A

Viruses

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3
Q

Types of lower respiratory tract infection

Mention 3

A

Pneumonia
Acute Broncholitis
Acute Bronchitis

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4
Q

Types of lower respiratory tract infection

Pneumonia

Infection of the ________ .

Symptoms include fever, respiratory distress and _______.

Often not much clinical “_________”.

RSV, Adenovirus, Influenza

A

lung tissue itself

cyanosis

consolidation

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5
Q

Types of lower respiratory tract infection

Acute Broncholitis

___________ and _______ of ____________

Complete plugging of ———— with ___________ leads to _________

fever and coryzal symptoms, respiratory distress and wheezing.

Can be life-threatening in______ and _______

Respiratory Syncitial virus, Parainfluenza viruses

A

Inflammation and narrowing of terminal bronchioles

bronchioles; air resorption ; patchy collapse

babies and small children.

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6
Q

Bronchiole diameter is (smaller or larger?) during inspiration than during expiration and this leads to _____________ (proximal or distal?) to bronchiole.

A

Larger

hyperinflation of air sacs

Distal

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7
Q

Types of lower respiratory tract infection

Acute Bronchitis

Inflammation of _____, accompanied by fever, cough, wheezing and “________ “.

RSV, Para-influenza viruses, Adenovirus

A

bronchi

noisy chest

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8
Q

Epidemiology

_______ account for the largest proportion of childhood pneumonia.

A

Viruses

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9
Q

Epidemiology

______ is the most frequent cause of lower respiratory tract infection in infants and children

A

RSV

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10
Q

Epidemiology

The ______ viruses are the most common viral cause of pneumonia in adults

A

influenza

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11
Q

Epidemiology

___________ is second in importance only to RSV as a cause of lower respiratory tract disease in children and pneumonia and bronchiolitis in infants younger than 6 months

A

Parainfluenza virus (PIV)

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12
Q

Host defence

Mechanical barriers are _____ from the nostrils that filter particles larger than _______, and ______ clearance,

_______ branching of the central airways that helps the ______-micron particles to become impacted in the mucosa.

Humoral immunity is represented by mucosal immunoglobulin _______

Phagocytic cells consist of polymorphonuclear (PMN) cells;

A

hairs; 10 microns; mucociliary

Sharp-angle; 5- to 10

A (IgA),

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13
Q

Host defence

Phagocytic cells consist of polymorphonuclear (PMN) cells;

Alveolar, interstitial, and intravascular _______; and respiratory ________ cells.

_____________ provide the first defense involved in internalizing and degrading the viral pathogens.
They act as _________ and ________ cells.

A

macrophages; dendritic

Alveolar macrophages

antigen-presenting and opsonin-producing

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14
Q

Pathogenesis

Transmission is by _________ nuclei during _____,________

Touching _______ which are contaminated with the virus

A

droplet; coughing, sneezing

formites

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15
Q

Pathogenesis

Viral multiplication in the ________ of the upper airway

Secondarily infect the lung by means of ________ or _______ spread.

A

epithelium

airway secretions or hematogenous

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16
Q

Pathogenesis

Severe pneumonias may result in extensive ________ of the lungs with varying degrees of _________

Some patients developing _________ and diffuse _____________

A

consolidation; hemorrhage

bloody pleural effusions

alveolar damage

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17
Q

Pathogenesis

Respiratory viruses damage the respiratory tract and stimulate the host to release multiple __________ such as:

histamine, leukotriene C4, and virus-specific _____ in RSV infection and bradykinin, interleukin (IL)–1, IL-6, and IL-8 in _________ infections.

A

humoral factors

IgE

rhinovirus

18
Q

Pathogenesis

RSV infections can also alter __________ _____ease bacterial adherence to respiratory epithelium, reduce ___________, and alter bacterial phagocytosis by host cells

A

bacterial colonization patterns,

incr

mucociliary clearance

19
Q

Orthomyxovirus

Influenza virus ___,___,__

_______, pleomorphic, 80–120 nm in diameter (______ nucleocapsid, 9 nm)

______ stranded segmented (___)

______ sense RNA, 13.6 kb overall size

A

A, B, C

Spherical; helical

Single; 8

negative

20
Q

Orthomyxovirus

______ structural proteins, ____ nonstructural

Envelope contains viral _______, and _________ proteins

A

Nine; one

hemagglutinin and neuraminidase

21
Q

Orthomyxovirus

The 2 glycoproteins are the important antigens that determine _________ of influenza viruses and _______

A

antigenic variation

host immunity

22
Q

Influenza virus

Influenza A virus consist of _____ and ______ strains

The ______ and ______ proteins, are used to divide influenza viruses into types A, B, and C.

_________ in HA and NA, are used to subtype the viruses.

A

human and animal

nucleocapsid (NP) and matrix (M)

Antigenic variations

23
Q

Influenza virus

Only type ___ has designated subtypes.

_____ subtypes of HA (_______) and ___ subtypes of NA (_______), in different combinations.

A

A

15; H1–H15

9; N1–N9

24
Q

Influenza virus

_______ HA ( _________ ) and ___ NA (_______) subtypes have been recovered from humans.

A

Four

H1–H3, H5

two; N1, N2

25
Q

Influenza virus

Influenza A(_____) and A(______) subtypes are currently circulating among humans

A

H1N1; H3N2

26
Q

Influenza virus

Antigenic drift

Accumulation of _______ in the gene, resulting in _________ in the protein.

Sequence changes can alter __________ on the molecule such that a virion can escape _______ by the host’s immune system

A

point mutations; amino acid changes

antigenic sites ; recognition

27
Q

Influenza virus

Antigenic shift

_______ changes in the sequence of a viral surface protein, changes
That are ______ to ____________

The ________ genomes of influenza viruses reassort readily in ______________ cells.

A

Drastic; too extreme; be explained by mutation.

segmented

doubly infected

28
Q

Influenza virus

Antigenic shift

The mechanism for shift is ________ between ______ and _____ influenza viruses.

Can result in a _________

A

genetic reassortment

human and avian

pandemic

29
Q

Influenza B and C viruses exhibit antigenic shift

T/F

A

F

Influenza B and C viruses do not exhibit antigenic shift

30
Q

Influenza

Is a/an (acute or chronic ?) viral infection that spreads easily from person to person.

Viruses circulate ______ and can affect ____ age group.

Annual epidemics peak during ______ in ________ regions.

A

Acute ; worldwide; any

winter; temperate

31
Q

Influenza

Serious public health problem that causes severe illness and death in high risk populations.

children younger than age ____ years,
adults aged _____ years or older

_________ women,

certain medical conditions, such as chronic heart, lung, kidney, liver, blood or metabolic diseases (such as diabetes), or ————- immune systems.

A

2; 65

pregnant

weakened

32
Q

Influenza

Influenza virus spreads from person to person by ____________ or by _______ with contaminated hands or surfaces

A

airborne droplets

contact

33
Q

Epidemiology of influenza

Influenza occurs ______ with an annual attack rate estimated at __%–__% in adults and __%–__% in children.

A

globally; 5–10; 20-30

34
Q

Epidemiology of influenza

Illnesses can result in hospitalization and death mainly among high-risk groups (the very young, elderly or chronically ill).

T/F

A

T

35
Q

Epidemiology of influenza.

Worldwide, these annual epidemics are estimated to result in about ___________ cases of severe illness, and about __________ to ________ deaths.

A

3 to 5 million

250 000 to 500 000

36
Q

Clinical features of Upper respiratory tract infection

chills, headache, and dry cough followed closely by high fever, generalized muscular aches, malaise, and anorexia.

T/F

A

T😂

37
Q

Clinical features of Pneumonia

May be complicated by secondary bacterial infection

Eg ________ and _______

A

S. aureus, H. influenzae

38
Q

Treatment of influenza

May reduce severe complications and deaths.

Ideally they need to be administered early (within ______ of onset of symptoms)

A

48 hours

39
Q

Treatment of influenza

Neuraminidase inhibitor

oselta_____ and zana_____ , pera_____ and lanina____

Adamantanes
aman______ and riman_____

A

mivir; mivir; mivir; mivir

tadine; tadine

40
Q

Prevention and control

___________ viral vaccines

A

Inactivated

41
Q

Prevention and control

Vaccine composition ———- that targets the _________ most representative virus types in circulation

_____ subtypes of influenza A viruses and ——- B virus.

Hand hygiene

A

biannually

3 (trivalent)

two; one