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Flashcards in Infection Deck (197)
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1
Q

how is TB commonly shown on an chest X-ray

A

upper lobe consolidation

2
Q

what might be seen in a bronchoscopy of someone with tuberculosis

A

pus occluding the orifice of the upper lobe, tubercles in the lower trachea

3
Q

what may remain after treatment of tuberculosis

A

residual cavities and scarring

4
Q

describe TB in simple terms

A

infectious disease of the respiratory tract

5
Q

what organism and how is tuberculosis spread

A

airborne spread of mycobacterium tuberculosis

6
Q

can tuberculosis spread to other organs

A

yes

7
Q

where does TB usually present in the lungs and why

A

at the top as inhaled infection

8
Q

where do systemic infection present in the lungs

A

at the bottom

9
Q

in which countries is TN most prevalent

A

Indian sub continent, SE Asia, Africa and eastern Europe

10
Q

what is the role of the macrophages towards TB

A

intercepts it and turns in granuloma within which the bacteria grows

11
Q

when does a dormant TB colony become active

A

when the granuloma breaks open

12
Q

what percentage of people who are exposed to TB remain well

A

90%

13
Q

does infection guarantee immediate disease

A
  • no 10% with lifetime risk, half primary TB, half reactivation of latent disease
14
Q

what is the reservoir of TB in nature

A

humans, both pathogen and symbiont

15
Q

how would you describe the presentation of TB (not symptoms)

A

subacute (between acute and chronic) disease of gradual onset

16
Q

what are the general symptoms of TB

A

weight loss, malaise (weakness or discomfort), night sweats

17
Q

what are the respiratory symptoms of TB

A

cough, haemoptysis, breathlessness, upper zone crackles,

18
Q

what are the symptoms of meningeal TB

A

headache, drowsy, fits

19
Q

where does meningeal TB present

A

in the cerebrospinal fluid

20
Q

what are the symptoms of spinal TB and why

A

pain, deformity, paraplegia- infection starts in disc, spreads to adjacent vertebrae with subsequent anterior collapse of that spinal segment

21
Q

where does gastrointestinal TB present

A

in the cecum- intraperitoneal pouch considered to be the start of the large intestine

22
Q

what are the symptoms of gastrointestinal TB

A

bowl obstruction, pain, perforation, peritonitis

23
Q

what does TB in the lymph nodes present as

A

Lymphadenopathy- swelling of the lymph nodes

24
Q

what is a cold abscess in TB

A

a collection of dormant TB- lacks inflammation of infection

25
Q

what must you be cautious of in the elderly

A

a solitary arthritic joint, might be TB, never inject steroids into it

26
Q

what are the more rarer presentation of TB (4)

A

pericardial (tamponade- fluid in the pericardium), renal (failure), septic arthritis (cold monoarthritis of large joints), adrenal (hypoadrenalism)

27
Q

what are the tests for TB

A

ZN stain, AAFB, auramine, PCR, radiology

28
Q

describe a ZN stain

A

removes all bacteria but mycobacteria due to high wax content of cell wall and acid + alcohol of stain. Blue counter stain then colours them pink. infectious= smear positive. Takes long- sputum cultured for 12 weeks

29
Q

what does ‘smear positive, smear negative’ mean

A

infected but not infectious due to low numbers of bacterium

30
Q

how long does PCR takes and what does it reveal

A

2 hours, tells you if smear positive and whether its resistant to rifampicin

31
Q

why might not infected people get a positive result from a PCR test

A

due to the lasting presence of the disease after treatment

32
Q

describe the granulomas

A

multinucleate giant cell

33
Q

what are the other histological features of TB

A

caseating necrosis, (sometimes visible) mycobacteria,

34
Q

what has similar histological features to TB but lacks caseating necrosis and mycobacteria

A

sarcoidosis

35
Q

describe the features seen in radiology of TB

A

upper lobe predominance, cavity formation, tissue destruction, scarring and shrinkage, heals with calcification

36
Q

what causes miliary TB

A

massive seeding of mycobacteria through the bloodstream

37
Q

where does TB in blood present in the chest

A

everywhere

38
Q

what antibiotics are used in the first 2 months of treatment for TB

A

rifampicin, isoniazid, pyrazinamide, ethambutol

39
Q

what antibiotics are used in the last 4 months of treatment for TB

A

rifampicin, isoniazid

40
Q

when and why is directly observed therapy necessary

A

when not sure if patient taking medication, as have responsibility to protect public health.

41
Q

what is a way of checking whether a patient is taking their medication

A

their urine goes pink/orange when taking rifampicin

42
Q

why cant colourblind patients take ethambutol

A

as can cause optic neuritis- inflammation that damages optic nerve

43
Q

what other side affects can rifampicin have

A

breakdown steroid molecules (hormonal contraception) and opiate analgesics

44
Q

describe the presence of bacilli during treatment

A

rapid fall over first two weeks, some non dividing may remain

45
Q

resistance to which drugs is most common for a single agent

A

isoniazid

46
Q

what does MDR stand for and give two common examples

A

multidrug resistance

rifampicin, isoniazid

47
Q

what is XDR and give two examples

A

extensive drug resistance

MDR + quinolone and injectable

48
Q

TB is often the presenting disease of what condition

A

HIV

49
Q

what does XDR mean

A

increased morbidity

50
Q

describe latent TB

A

dormant, balance between organism and immune system

51
Q

what symptoms are associated with latent TB

A

none

52
Q

what culture results will a person with dormant TB receive

A

TB

53
Q

how prevalent in latent TB

A

1/3 to 1/4 of worlds population

54
Q

what test shows exposure to TB

A

BCG vaccine- reaction if exposed

55
Q

what will an X-ray show for latent TB

A

no evidence

56
Q

what are the tests for previous exposure to TB

A

interferon gamma release assay (blood test), Mantoux (tuberculin) (skin test) (detects previous exposure to TB and BCG as well)

57
Q

how does the BCG vaccine affect TB testing

A

results in a positive skin test

58
Q

describe the tuberculin skin test

A

intradermal injection, return 48 hours later to see if theres a reaction

59
Q

what can the skin test not distinguish between

A

latent, cured. active or BCG

60
Q

describe IGRA tests

A

performed on blood samples, if exposed body produces interferons (gamma specific to antigen), doesnt react with BCG

61
Q

when will TST not work

A

in immunocompromised patients

62
Q

which test is better. quicker and gives less false positives and negatives

A

IGRA

63
Q

how is latent TNF treated

A

either left or treated with 6 months of isoniazid or 3 months of rifampicin + isoniazid

64
Q

what are both drugs used to treat latent TB associated with

A

disturbance of liver function especially in women

65
Q

what does anti TNF treatment aim to achieve

A

Rheumatoid arthritis associated with latent TB. Anti-TNF therapy strongly associated with latent TB activation in patients with RA. Anti-TNF aims to avoid complications such as RA, crohns, Psoriasis

66
Q

how is the reactivation of TB because of anti-TNF drugs clinically presented

A

a typical

67
Q

how is TB prevented

A

contact tracing, screening of high risk subgroups, isolation of infectious cases, BCG immunisation, social measures (housing, nutrition),

68
Q

describe the BCG vaccine

A

attenuated strain of mycobacterium bovis, intradermal injection

69
Q

why does HIV medicine pose a risk for TB

A

as steroids and immunosuppressants can reactivate latent TB

70
Q

what is empyema

A

collection of pus in the pleural cavity

71
Q

what are some risk factors for pleural infections

A

diabetes mellitus, immunosuppressants (including corticosteroids), gastro-oesphageal reflux, alcohol misuse, intravenous drug abuse.

72
Q

what is a pleural effusion

A

build up of fluid in the pleural space

73
Q

what are the three types of pleural effusion

A

simple and complicated parapneumonic, empyema

74
Q

how do you distinguish between the three types of pleural effusion

A

acidic pH= simple
cloudy, pos G stain, low glucose, septations, loculations, pH >7.2= complicated
clear puss= empyema

75
Q

how is empyema treated

A

aggressively cleaned out + antibiotics

76
Q

what are the two types of pneumonia

A

community and hospital acquired

77
Q

how is a large effusion treated

A

chest drainage

78
Q

can v small effusions be left untapped

A

yes

79
Q

how is an effusion treated

A

drainage when necessary, antibiotics,

80
Q

what antibiotic cannot treat hospital acquired pneumonia/ empyema and why

A

gentomiosin as cant get into pleural space

81
Q

what antibiotics used for empyema cover staff

A

vancomycin

82
Q

describe the antibiotic treatment for an effusion

A

two weeks IV, 6 weeks comoxiclav

83
Q

what do fibrinolytics do

A

break down clots + structures

84
Q

what do DNAse do

A

with firbinolytics can break down clots

85
Q

are pleural infections common

A

no

86
Q

what are the risk factors for developing chronic pulmonary

A

abnormal host response (immunodeficiency/suppression), abnormal innate host defence (mucosa, cillia, secretions), repeated insult (aspiration, indwelling material)

87
Q

what are 4 types of immunodeficiency

A

immunoglobulin deficiency (IgA deficiency, CVID), hypo-splenism, immune paresis (cancer), HIV

88
Q

what can damage bronchial mucosa

A

smoking, recent pneumonia, malignancy

89
Q

what can make cilia abnormal

A

kartenager’s and youngs syndrome

90
Q

what can affect secretions

A

CF, channelopathies

91
Q

what other than aspiration can cause repeated insult

A

NG tube, chest drain, inhaled foreign body

92
Q

what can cause aspiration

A

NG feeding, poor swallow, pharyngeal pouch, vomiting

93
Q

what are 5 forms of chronic infection

A

intrapulmonary abscess, empyema, chronic bronchial sepsis, bronchiectasis, CF

94
Q

describe the presentation of a intrapulmonary abscess

A

indolent- causing little or no pain

95
Q

what symptoms does a intrapulmonary abscess cause

A

weight loss, lethergy, tiredness, weakness, cough +/- sputum

96
Q

what does an intrapulmonary abscess often follow

A

an illness e.g pneumonic infection, viral, foreign body

97
Q

describe the steps that leads to an abscess forming from flu

A

flu-> pneumonia-> cavitating pneumonia-> abscess

98
Q

what is hypogammaglobulinaemia

A

immune disorder

99
Q

what can a septic emboli cause

A

right sided endocarditis, septicaemia

100
Q

in what group of people are septic embolis common

A

IVDU

101
Q

what is empyema

A

pus in the pleural space

102
Q

what intervension does a complicated parapneumonic effusion require

A

chest tube drainage

103
Q

how is an empyema differentiated from a effusion

A

empyema has frank pus

104
Q

how is empyema differentiated from an abscess clinically

A

CT scan

105
Q

what do you look for in a CXR when diagnosis a empyema

A

D sign

106
Q

what are treatments for empyema

A

Iv (broad spectrum amoxicillin and metronidazole) and oral antibodies

107
Q

what does detection of complicated pleural effusion require

A

sampling of the effusion

108
Q

what drain types are preferred initially

A

small bore seldinger

109
Q

what is bronchiectasis

A

localised irreversible dilation of the bronchial tree

110
Q

describe the bronchi when affected with bronchiectasis

A

dilated, inflamed and easily collapsible

111
Q

what are the pathological results of dilated and inflames airways

A

airflow obstruction, impaired clearance of secretions

112
Q

how is bronchiectasis clinically presented

A

recurrent infections with no/short lived response to antibiotics and persistent sputum production, chest pain

113
Q

what has all the hallmarks of bronchiectasis except the CXR

A

chronic bronchial sepsis

114
Q

how is chronic bronchial sepsis confirmed

A

positive sputum results

115
Q

who does chronic bronchial sepsis usually affect

A

younger women working in childcare- or older with COPD/airway disease

116
Q

what are the sinuses a reservoir for

A

infection

117
Q

how is bronchiectasis treated

A

smoking cessation, flu/pneumococcal vaccine, reactive antibiotics

118
Q

when colonised with persistent bacteria what treatments should be used

A

prophylactic antibiotics, nebulised gentamicin and colomycin, alternating oral antibiotics

119
Q

what has been shown to reduce exacerbation rate in bronchiectasis (anti-inflammatory)

A

macrolide antibiotics

120
Q

what is the prognosis of bronchiectasis

A

recurrent infection, abscesses and infection, colonisation

121
Q

what is a congenital cause of bronchiectasis

A

cystic fibrosis

122
Q

what is the mortality from abscess

A

10%

123
Q

what is the mortality from empyema

A

20%

124
Q

what drugs cause immunosuppression

A

steroids

125
Q

what is SPAD

A

inability to develop antibodies against monosaccharide sugars

126
Q

what is hypo-splenism

A

when spleen is taken out, susceptible to streptococci

127
Q

how does myeloma cause immunodeficiency

A

produces too much of one immunoglobulin that wipes out all other antibodies

128
Q

how does chemotherapy cause immunosuppression

A

wipes out neutrophils

129
Q

what are multiple abscesses a result of

A

infection in the blood, bacteremia

130
Q

what is radiological bronchiectasis

A

bronchus bigger in diameter than accompanying pulmonary artery

131
Q

what is clinical bronchiectasis

A

symptoms without radiological features

132
Q

how can bronchiectasis be determined by an x ray

A

as position shouldn’t be able to get that far into the lungs, has to be dilated

133
Q

what is traction bronchiectasis

A

radiology but no symptoms

134
Q

what is the pathophysiology of more than 50% of bronchiectasis cases

A

idiopathic

135
Q

what is the range of infections that affect the upper respiratory tract (4)

A

coryza-common cold, pharyngitis- sore throat, sinusitis, epiglottitis

136
Q

what is the range of infections that affect the lower respiratory tract (below the chords) (4)

A

acute bronchitis, acute exacerbation of chronic bronchitis, pneumonia, influenza

137
Q

what is the common cold

A

acute viral infection of the nasal passages

138
Q

how does a common cold spread

A

droplets and fomites (objects that carry infection)

139
Q

what are 2 complications of a common cold

A

sinusitis and acute bronchitis

140
Q

what viruses cause the common cold

A

adenovirus, rhinovirus, respiratory syncytial virus

141
Q

what is the main symptom of acute sinusitis

A

purulent nasal discharge

142
Q

how is acute sinusitis treated

A

usually left limiting and resolves within 10 days, if not antibiotics

143
Q

why is diptheria so dangerous

A

life threatening due to toxin production

144
Q

what is diptheria characterised by

A

pseudo-membrane

145
Q

what are the symptoms of acute tonsillitis

A

swollen tonsils, erythematous, dysphagia (difficulty), dysphonia (difficulty speaking)

146
Q

what is quincy/quinsy

A

a complication of tonsilitis- tonsilar abscess

147
Q

what are the symptoms of strep throat

A

dysphagia and dysphonia

148
Q

what is strep throat

A

an infection of the tonsils

149
Q

who is acute epiglottis most dangerous to and why

A

children- life threatening due to obstruction

150
Q

what are the symptoms of acute bronchitis

A

productive cough, fever (not common), normal chest exam and CXR, may have transient wheeze

151
Q

what does acute bronchitis precede

A

common cold ‘cold which goes to the chest’

152
Q

what is not used to treat acute bronchitis

A

antibiotics

153
Q

in what patients is acute bronchitis dangerous

A

in COPD patients

154
Q

what is the incubation period

A

period of time after exposure to a infection to when symptoms start to show

155
Q

how is epiglottis treated

A

IV antibiotics and anaesthetic

156
Q

what are the features of COPD

A

chronic sputum production, bronchoconstriction, inflammation of the airways

157
Q

what are the clinical features of an acute exacerbation of COPD

A

increased sputum production and purulence, more wheezy, breathless

158
Q

what does an acute exacerbation of COPD usually follow

A

upper respiratory tract infection

159
Q

what is found on examination of a patient with an acute exacerbation of COPD

A

respiratory distress, wheeze, coarse crackles, maybe cyanosed, when advanced- ankle oedema

160
Q

how is an acute exacerbation of COPD managed in primary care

A

antibiotics (doxycycline or amoxicillin), bronchodilator inhalers, short course or steroids (in some cases)

161
Q

when would you refer someone having an acute exacerbation of

A

if there is evidence of resp failure, patient not coping at home,

162
Q

how is an acute exacerbation of COPD manged in hospital

A

(antibiotics, bronchodilator inhalers, short course of steroids) AND; ABGs, CXR to look for other diseases, oxygen if resp failure

163
Q

what is red hepatisation

A

when lung tissue is consolidated and resembles liver tissue

164
Q

what is consolidation

A

when an area contains liquid rather than gas

165
Q

what are some symptoms of pneumonia

A

malaise, anorexia, rigors, myalgia, headache, confusion, cough, pleurisy, haemoptysis, dyspnoea, abdominal pain, diarrhoea

166
Q

what is pleurisy

A

inflammation of the pleura

167
Q

what can a pneumonia follow

A

an URTI

168
Q

what are the clinical signs of pneumonia

A

fevers, rigor, herpes labialis, tachypnoea, crackles, rub, cyanosis, hypotension

169
Q

why is reactivation of herpes simplex virus common in pneumonia

A

due to alteration in the immune system

170
Q

how is a pneumonia investigated (7)

A

blood culture, serology, ABGs, full blood count, urea, liver function, VXR

171
Q

what scoring system is used to measure the severity of a pneumonia

A
CURB 65 
C-onfusion
U-rea >7
R-espiratory rate > 30
B-lood pressure systolic < 90 or diastolic < 61
65- y/o or older
172
Q

does COPD increase the mortality of a pneumonia

A

yes

173
Q

what increases as CURB65 increases

A

mortality

174
Q

what are other severity markers for pneumonia

A

temperature, cyanosis PaO2, WBC, multi-lobar involvement

175
Q

what is the pathogen that most commonly causes pneumonia

A

strep pneumoniae

176
Q

who can die from chicken pox pneumonia

A

adult smokers

177
Q

what pathogen should you think of when a patient keeps birds

A

chlamydia psitacci

178
Q

what pathogen causes a peak in pneumonia every 4 years

A

mycoplasma pneumonia

179
Q

how is community acquired pneumonia managed

A

antibiotics (amoxicillin, doxyxcycline), oxygen, fluids, bed rest, no smoking

180
Q

what are 4 possible complications of pneumonia

A

resp failure, pleural effusion, empyema, death

181
Q

what antibiotics does hospital acquired pneumonia require

A

extended gram negative cover

182
Q

what antibiotic cover does aspiration pneumonia require

A

anaerobic cover

183
Q

what symptoms are common with legionella pneumonia

A

chest symptoms may be minimal, GI disturbance, confusion

184
Q

how is pneumonia prevented

A

influenza and pneumococcal vaccine

185
Q

in what group of people is a fungal infection most likely

A

immuno supressed

186
Q

what are the symptoms of acute sinusitis

A

frontal sinusitis, retro-abdominal pain, maxillary sinus pain, tooth ache, disharge

187
Q

how is mycoplasma pneumonia resistant to beta-lactam antibiotics

A

as it has no cell wall

188
Q

what does mycoplasma pneumonia causes

A

protracted paroxysmal cough- cillial dysfunction, H2O2 production which damaged resp membranes

189
Q

when should IV antibiotics be given to treat pneumonia

A

oral route not available (NPO). sensitivities, deep seated infections, first dose

190
Q

when is sputum important

A

resistant organism suspected, TB or NTM (non tuberculosis mycobacteria) suspected, failure to improve, high risk indivuals

191
Q

what pathogen commonly causes pneumonia in people with HIV

A

PCP- pneumocystis pneumonia

192
Q

what pathogen commonly causes pneumonia in PWID

A

staph aureus

193
Q

what pathogen commonly causes pneumonia in homeless/alcoholic people

A

TB, klebsiella

194
Q

what pathogen commonly causes pneumonia in the frequently hospitalised

A

pseudomonas

195
Q

what pathogen commonly causes pneumonia in a returning traveller

A

legionella, TB

196
Q

what pathogen commonly causes pneumonia in people from the indian sub continent

A

TB (not always)

197
Q

what pathogen commonly causes pneumonia in eastern europe

A

MDR TB (XDR TB)