Infection Flashcards
(197 cards)
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
what must you be cautious of in the elderly
a solitary arthritic joint, might be TB, never inject steroids into it
26
what are the more rarer presentation of TB (4)
pericardial (tamponade- fluid in the pericardium), renal (failure), septic arthritis (cold monoarthritis of large joints), adrenal (hypoadrenalism)
27
what are the tests for TB
ZN stain, AAFB, auramine, PCR, radiology
28
describe a ZN stain
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
what does 'smear positive, smear negative' mean
infected but not infectious due to low numbers of bacterium
30
how long does PCR takes and what does it reveal
2 hours, tells you if smear positive and whether its resistant to rifampicin
31
why might not infected people get a positive result from a PCR test
due to the lasting presence of the disease after treatment
32
describe the granulomas
multinucleate giant cell
33
what are the other histological features of TB
caseating necrosis, (sometimes visible) mycobacteria,
34
what has similar histological features to TB but lacks caseating necrosis and mycobacteria
sarcoidosis
35
describe the features seen in radiology of TB
upper lobe predominance, cavity formation, tissue destruction, scarring and shrinkage, heals with calcification
36
what causes miliary TB
massive seeding of mycobacteria through the bloodstream
37
where does TB in blood present in the chest
everywhere
38
what antibiotics are used in the first 2 months of treatment for TB
rifampicin, isoniazid, pyrazinamide, ethambutol
39
what antibiotics are used in the last 4 months of treatment for TB
rifampicin, isoniazid
40
when and why is directly observed therapy necessary
when not sure if patient taking medication, as have responsibility to protect public health.
41
what is a way of checking whether a patient is taking their medication
their urine goes pink/orange when taking rifampicin
42
why cant colourblind patients take ethambutol
as can cause optic neuritis- inflammation that damages optic nerve
43
what other side affects can rifampicin have
breakdown steroid molecules (hormonal contraception) and opiate analgesics
44
describe the presence of bacilli during treatment
rapid fall over first two weeks, some non dividing may remain
45
resistance to which drugs is most common for a single agent
isoniazid
46
what does MDR stand for and give two common examples
multidrug resistance
| rifampicin, isoniazid
47
what is XDR and give two examples
extensive drug resistance
| MDR + quinolone and injectable
48
TB is often the presenting disease of what condition
HIV
49
what does XDR mean
increased morbidity
50
describe latent TB
dormant, balance between organism and immune system
51
what symptoms are associated with latent TB
none
52
what culture results will a person with dormant TB receive
TB
53
how prevalent in latent TB
1/3 to 1/4 of worlds population
54
what test shows exposure to TB
BCG vaccine- reaction if exposed
55
what will an X-ray show for latent TB
no evidence
56
what are the tests for previous exposure to TB
interferon gamma release assay (blood test), Mantoux (tuberculin) (skin test) (detects previous exposure to TB and BCG as well)
57
how does the BCG vaccine affect TB testing
results in a positive skin test
58
describe the tuberculin skin test
intradermal injection, return 48 hours later to see if theres a reaction
59
what can the skin test not distinguish between
latent, cured. active or BCG
60
describe IGRA tests
performed on blood samples, if exposed body produces interferons (gamma specific to antigen), doesnt react with BCG
61
when will TST not work
in immunocompromised patients
62
which test is better. quicker and gives less false positives and negatives
IGRA
63
how is latent TNF treated
either left or treated with 6 months of isoniazid or 3 months of rifampicin + isoniazid
64
what are both drugs used to treat latent TB associated with
disturbance of liver function especially in women
65
what does anti TNF treatment aim to achieve
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
how is the reactivation of TB because of anti-TNF drugs clinically presented
a typical
67
how is TB prevented
contact tracing, screening of high risk subgroups, isolation of infectious cases, BCG immunisation, social measures (housing, nutrition),
68
describe the BCG vaccine
attenuated strain of mycobacterium bovis, intradermal injection
69
why does HIV medicine pose a risk for TB
as steroids and immunosuppressants can reactivate latent TB
70
what is empyema
collection of pus in the pleural cavity
71
what are some risk factors for pleural infections
diabetes mellitus, immunosuppressants (including corticosteroids), gastro-oesphageal reflux, alcohol misuse, intravenous drug abuse.
72
what is a pleural effusion
build up of fluid in the pleural space
73
what are the three types of pleural effusion
simple and complicated parapneumonic, empyema
74
how do you distinguish between the three types of pleural effusion
acidic pH= simple
cloudy, pos G stain, low glucose, septations, loculations, pH >7.2= complicated
clear puss= empyema
75
how is empyema treated
aggressively cleaned out + antibiotics
76
what are the two types of pneumonia
community and hospital acquired
77
how is a large effusion treated
chest drainage
78
can v small effusions be left untapped
yes
79
how is an effusion treated
drainage when necessary, antibiotics,
80
what antibiotic cannot treat hospital acquired pneumonia/ empyema and why
gentomiosin as cant get into pleural space
81
what antibiotics used for empyema cover staff
vancomycin
82
describe the antibiotic treatment for an effusion
two weeks IV, 6 weeks comoxiclav
83
what do fibrinolytics do
break down clots + structures
84
what do DNAse do
with firbinolytics can break down clots
85
are pleural infections common
no
86
what are the risk factors for developing chronic pulmonary
abnormal host response (immunodeficiency/suppression), abnormal innate host defence (mucosa, cillia, secretions), repeated insult (aspiration, indwelling material)
87
what are 4 types of immunodeficiency
immunoglobulin deficiency (IgA deficiency, CVID), hypo-splenism, immune paresis (cancer), HIV
88
what can damage bronchial mucosa
smoking, recent pneumonia, malignancy
89
what can make cilia abnormal
kartenager's and youngs syndrome
90
what can affect secretions
CF, channelopathies
91
what other than aspiration can cause repeated insult
NG tube, chest drain, inhaled foreign body
92
what can cause aspiration
NG feeding, poor swallow, pharyngeal pouch, vomiting
93
what are 5 forms of chronic infection
intrapulmonary abscess, empyema, chronic bronchial sepsis, bronchiectasis, CF
94
describe the presentation of a intrapulmonary abscess
indolent- causing little or no pain
95
what symptoms does a intrapulmonary abscess cause
weight loss, lethergy, tiredness, weakness, cough +/- sputum
96
what does an intrapulmonary abscess often follow
an illness e.g pneumonic infection, viral, foreign body
97
describe the steps that leads to an abscess forming from flu
flu-> pneumonia-> cavitating pneumonia-> abscess
98
what is hypogammaglobulinaemia
immune disorder
99
what can a septic emboli cause
right sided endocarditis, septicaemia
100
in what group of people are septic embolis common
IVDU
101
what is empyema
pus in the pleural space
102
what intervension does a complicated parapneumonic effusion require
chest tube drainage
103
how is an empyema differentiated from a effusion
empyema has frank pus
104
how is empyema differentiated from an abscess clinically
CT scan
105
what do you look for in a CXR when diagnosis a empyema
D sign
106
what are treatments for empyema
Iv (broad spectrum amoxicillin and metronidazole) and oral antibodies
107
what does detection of complicated pleural effusion require
sampling of the effusion
108
what drain types are preferred initially
small bore seldinger
109
what is bronchiectasis
localised irreversible dilation of the bronchial tree
110
describe the bronchi when affected with bronchiectasis
dilated, inflamed and easily collapsible
111
what are the pathological results of dilated and inflames airways
airflow obstruction, impaired clearance of secretions
112
how is bronchiectasis clinically presented
recurrent infections with no/short lived response to antibiotics and persistent sputum production, chest pain
113
what has all the hallmarks of bronchiectasis except the CXR
chronic bronchial sepsis
114
how is chronic bronchial sepsis confirmed
positive sputum results
115
who does chronic bronchial sepsis usually affect
younger women working in childcare- or older with COPD/airway disease
116
what are the sinuses a reservoir for
infection
117
how is bronchiectasis treated
smoking cessation, flu/pneumococcal vaccine, reactive antibiotics
118
when colonised with persistent bacteria what treatments should be used
prophylactic antibiotics, nebulised gentamicin and colomycin, alternating oral antibiotics
119
what has been shown to reduce exacerbation rate in bronchiectasis (anti-inflammatory)
macrolide antibiotics
120
what is the prognosis of bronchiectasis
recurrent infection, abscesses and infection, colonisation
121
what is a congenital cause of bronchiectasis
cystic fibrosis
122
what is the mortality from abscess
10%
123
what is the mortality from empyema
20%
124
what drugs cause immunosuppression
steroids
125
what is SPAD
inability to develop antibodies against monosaccharide sugars
126
what is hypo-splenism
when spleen is taken out, susceptible to streptococci
127
how does myeloma cause immunodeficiency
produces too much of one immunoglobulin that wipes out all other antibodies
128
how does chemotherapy cause immunosuppression
wipes out neutrophils
129
what are multiple abscesses a result of
infection in the blood, bacteremia
130
what is radiological bronchiectasis
bronchus bigger in diameter than accompanying pulmonary artery
131
what is clinical bronchiectasis
symptoms without radiological features
132
how can bronchiectasis be determined by an x ray
as position shouldn't be able to get that far into the lungs, has to be dilated
133
what is traction bronchiectasis
radiology but no symptoms
134
what is the pathophysiology of more than 50% of bronchiectasis cases
idiopathic
135
what is the range of infections that affect the upper respiratory tract (4)
coryza-common cold, pharyngitis- sore throat, sinusitis, epiglottitis
136
what is the range of infections that affect the lower respiratory tract (below the chords) (4)
acute bronchitis, acute exacerbation of chronic bronchitis, pneumonia, influenza
137
what is the common cold
acute viral infection of the nasal passages
138
how does a common cold spread
droplets and fomites (objects that carry infection)
139
what are 2 complications of a common cold
sinusitis and acute bronchitis
140
what viruses cause the common cold
adenovirus, rhinovirus, respiratory syncytial virus
141
what is the main symptom of acute sinusitis
purulent nasal discharge
142
how is acute sinusitis treated
usually left limiting and resolves within 10 days, if not antibiotics
143
why is diptheria so dangerous
life threatening due to toxin production
144
what is diptheria characterised by
pseudo-membrane
145
what are the symptoms of acute tonsillitis
swollen tonsils, erythematous, dysphagia (difficulty), dysphonia (difficulty speaking)
146
what is quincy/quinsy
a complication of tonsilitis- tonsilar abscess
147
what are the symptoms of strep throat
dysphagia and dysphonia
148
what is strep throat
an infection of the tonsils
149
who is acute epiglottis most dangerous to and why
children- life threatening due to obstruction
150
what are the symptoms of acute bronchitis
productive cough, fever (not common), normal chest exam and CXR, may have transient wheeze
151
what does acute bronchitis precede
common cold 'cold which goes to the chest'
152
what is not used to treat acute bronchitis
antibiotics
153
in what patients is acute bronchitis dangerous
in COPD patients
154
what is the incubation period
period of time after exposure to a infection to when symptoms start to show
155
how is epiglottis treated
IV antibiotics and anaesthetic
156
what are the features of COPD
chronic sputum production, bronchoconstriction, inflammation of the airways
157
what are the clinical features of an acute exacerbation of COPD
increased sputum production and purulence, more wheezy, breathless
158
what does an acute exacerbation of COPD usually follow
upper respiratory tract infection
159
what is found on examination of a patient with an acute exacerbation of COPD
respiratory distress, wheeze, coarse crackles, maybe cyanosed, when advanced- ankle oedema
160
how is an acute exacerbation of COPD managed in primary care
antibiotics (doxycycline or amoxicillin), bronchodilator inhalers, short course or steroids (in some cases)
161
when would you refer someone having an acute exacerbation of
if there is evidence of resp failure, patient not coping at home,
162
how is an acute exacerbation of COPD manged in hospital
(antibiotics, bronchodilator inhalers, short course of steroids) AND; ABGs, CXR to look for other diseases, oxygen if resp failure
163
what is red hepatisation
when lung tissue is consolidated and resembles liver tissue
164
what is consolidation
when an area contains liquid rather than gas
165
what are some symptoms of pneumonia
malaise, anorexia, rigors, myalgia, headache, confusion, cough, pleurisy, haemoptysis, dyspnoea, abdominal pain, diarrhoea
166
what is pleurisy
inflammation of the pleura
167
what can a pneumonia follow
an URTI
168
what are the clinical signs of pneumonia
fevers, rigor, herpes labialis, tachypnoea, crackles, rub, cyanosis, hypotension
169
why is reactivation of herpes simplex virus common in pneumonia
due to alteration in the immune system
170
how is a pneumonia investigated (7)
blood culture, serology, ABGs, full blood count, urea, liver function, VXR
171
what scoring system is used to measure the severity of a pneumonia
```
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
does COPD increase the mortality of a pneumonia
yes
173
what increases as CURB65 increases
mortality
174
what are other severity markers for pneumonia
temperature, cyanosis PaO2, WBC, multi-lobar involvement
175
what is the pathogen that most commonly causes pneumonia
strep pneumoniae
176
who can die from chicken pox pneumonia
adult smokers
177
what pathogen should you think of when a patient keeps birds
chlamydia psitacci
178
what pathogen causes a peak in pneumonia every 4 years
mycoplasma pneumonia
179
how is community acquired pneumonia managed
antibiotics (amoxicillin, doxyxcycline), oxygen, fluids, bed rest, no smoking
180
what are 4 possible complications of pneumonia
resp failure, pleural effusion, empyema, death
181
what antibiotics does hospital acquired pneumonia require
extended gram negative cover
182
what antibiotic cover does aspiration pneumonia require
anaerobic cover
183
what symptoms are common with legionella pneumonia
chest symptoms may be minimal, GI disturbance, confusion
184
how is pneumonia prevented
influenza and pneumococcal vaccine
185
in what group of people is a fungal infection most likely
immuno supressed
186
what are the symptoms of acute sinusitis
frontal sinusitis, retro-abdominal pain, maxillary sinus pain, tooth ache, disharge
187
how is mycoplasma pneumonia resistant to beta-lactam antibiotics
as it has no cell wall
188
what does mycoplasma pneumonia causes
protracted paroxysmal cough- cillial dysfunction, H2O2 production which damaged resp membranes
189
when should IV antibiotics be given to treat pneumonia
oral route not available (NPO). sensitivities, deep seated infections, first dose
190
when is sputum important
resistant organism suspected, TB or NTM (non tuberculosis mycobacteria) suspected, failure to improve, high risk indivuals
191
what pathogen commonly causes pneumonia in people with HIV
PCP- pneumocystis pneumonia
192
what pathogen commonly causes pneumonia in PWID
staph aureus
193
what pathogen commonly causes pneumonia in homeless/alcoholic people
TB, klebsiella
194
what pathogen commonly causes pneumonia in the frequently hospitalised
pseudomonas
195
what pathogen commonly causes pneumonia in a returning traveller
legionella, TB
196
what pathogen commonly causes pneumonia in people from the indian sub continent
TB (not always)
197
what pathogen commonly causes pneumonia in eastern europe
MDR TB (XDR TB)
