Microbiology Flashcards
1
Q
what are the types of herpes simplex virus
A
types 1 and 2
type 1 is acquired children
HSV2 more reactivations
2
Q
what does HSV1 cause
A
oral lesions, primary gingivostomatitis
3
Q
how does HSV infection spread
A
through saliva contact
4
Q
what are the features of primary gingivostomatitis
A
disease of pre school children primary infection systemic upset lips, buccal mucosa, hard palate vesicles, ulcers fever local lymphadenopathy
5
Q
do all people with HSV1 infection get primary gingivostomatitis
A
no, only severe end of the spectrum
6
Q
what is the treatment for primary gingivostomatitis
A
aciclovir treatment
7
Q
how long can primary gingivostomatitis take to recover
A
up to three weeks
8
Q
describe HSV latency
A
after primary infection virus becomes inaction in local ganglion (sensory nerve cells) usually trigeminal nerve
can reactivate and infect mucosal surfaces
9
Q
what is a cold sore
A
reactivation of HSV1 from nerves causes active infection
various stimuli
10
Q
what is the treatment for coldsores
A
aciclovir therapy or suppression (aciclovir doesn’t prevent latency)
11
Q
do all people with HSV1 get clinical recurrences of cold sores
A
no (about half do)
12
Q
what type of HSV causes oral herpetic lesions
A
HSV1
13
Q
does HSV usually cause recurrent intra-oral lesions
A
not usually
14
Q
what is herpetic wiplow
A
painful infection of the finger by HSV- an occupational hazard of dentistry and anaesthetics
15
Q
how is HSV diagnosed
A
swab of lesion (burst vesicle better for picking up live viruses)
PCR
16
Q
what causes herpangina
A
coxsackie viruses (enterovirus)
17
Q
what are the features of herpangina
A
vesicles/ ulcers on soft palate
pre school children
18
Q
how you diagnose herpangina
A
PCR
19
Q
what causes hand, foot and mouth disease
A
coxasckie viruses (enteroviruses)
20
Q
what are the features of hand food and mouth disease
A
family outbreaks common
gingival stomatitis around mouth
blisters on hands and mouth
21
Q
how do you diagnose hand foot and mouth disease
A
PCR
22
Q
what is a chancre
A
painless indurated ulcer that you get in primary syphllis at the site of entry of bacterium treponema pallidum
23
Q
where do you get chancre is syphillis
A
genital, oral
24
Q
what happens if primary syphillis is untreated
A
progresses to secondary and tertiary syphillis
25
is syphillis painful
no
26
what is the treatment for syphillis
penicillin
27
does syphillis have latency
no
28
what are apthous ulcers
non viral
self limiting
recurring painful ulcers of the mouth that are round or ovoid and have inflammatory halos
confined to mouth, absence of systemic disease
29
how long to apthous ulcers last
begin in childhood, usually go away by 3rd decade
| each ulcer lasts less than 3 weeks
30
what systemic diseases can you get recurrent ulcers in (non viral)
```
behects disease
gluten sensitive enteropathy/ IBD
reiters disease
drug reactions
skin diseases
```
31
what are the peaks in ages in acute throat infections
children aged 5-10 years
| then 15-25 years
32
what is acute pharyngitis
inflammation of the part of the throat behind the soft palate (oropharynx)
33
what causes throat infection
viral (most common) or bacterial
| common cold, influenza, streptococcal
34
what should you suspect in a patient aged 15-25 if sore throat persists into the second week
mononucleosis (glandular fever)
35
what causes mononucleosis
ebstein barr virus
36
what are the rare causes of throat infection
HIV, gonococcal pharyngitis, diptheria
37
what are the non infectious causes of a sore throat
```
physical irritation
-GORD
-chronic irritation from cigarette smoke
-alcohol
-hay fever
cancer look for red flags
```
38
when is a sore throat a medical emergency
when there is stridor or respiratory difficulty (dont examine throat)
39
what is the usual course of a sore throat
will resolve in 3 days (40%)- a week (85%)
40
what are the complications (rare) of a throat infection
otitis media (most common)
peri-tonsillar abscess (quinsy)
para-pharyngeal abscess
mastoiditis
41
what is the management for a sore throat
self care (analgesia- paracetamol/ ibruprofen, medicated lozenges, avoid hot drinks, drink lots)
prescribing antibiotics only where appropriate
identify and manage immunosuppressed people
42
what patients with a sore throat need admission/ referral
is suspected throat cancer (persistent sore throat, esp if neck mass)
sore or painful throat that lasts 3/4 weeks, pain on swallowing or dysphagia for more than 3 weeks
red/white patches or ulceration or swelling of the oral/pharyngeal mucosa persists for more than 3 weeks
stridor/ resp difficulty is an emergency
43
what causes the vast majority of sore throats
viruses- dont give antibiotics
44
what is the most common cause of a bacterial sore throat
strep pyogenes (group A or group B haemolytic strep)
45
what are the clinical features of strep pyogenes throat infection
acute follicular tonsillitis
46
what is the treatment for strep pyogenes throat infection
penicillin
47
describe the features of strep pyogenes
gram positive cocci chains
| beta haemolysis
48
what are the complications of strep pyogenes infection
```
rheumatic fever (3 weeks post sore throat, fever, arthritis, pancarditis)
glomerulonephritis (1-3 weeks post sore throat, haematuria, albuminuria, oedema)
```
49
what are the scoring criteria for group A beta haemolytic strep infections that show whether you need to give antibiotics by showing the risk of the infection
centor and fever PAIN criteria
50
what should you do if someone is immunosuppressed an gets a throat infection
do FBC, referral, consider antibiotics
51
what can cause neutropenia
```
carbimazole
chemo
asplenia
leuaemia
aplastic anaemia
HIV
```
52
when in throat infections should you consider giving phenoxymethylpenicillin for a throat infection
if fever pain score of 4/5
| centor score of 3/4
53
what are the clinical signs of diptheria
severe sore throat with a grey white membrane across the pharynx (pseudomembrane)
54
what cause the majority of the disease in diptheria
the exotoxin produced by the bacteria is cardiotoxic and neurotoxic
55
what prevents diptheria
vaccine- toxoid vaccine
56
what is the treatment for diptheria
antitoxin (most important) and supportive (maintain the airway)
pencillin/ erythtomycin
57
what are the features of infective mononucleosis
```
fever
enlarged lymph nodes
sore throat
pharyngitis
tonsilitis
malaise
lethargy
```
can get post viral syndrome with fatigue lasting for up to 6 months
also can get jaundice/ hepatitis, rash, haematology, splenomegaly, palatal petechiae
58
what will there be presence of in mononucleosis on blood films
atypical lymphocytes
59
what are the complications of mononucleosis
```
anaemia
thrombocytopenia
splenic rupture (avoid contact sports)
upper airway obstruction
risk of lymphoma
```
60
what is the treatment for mononucleosis
```
self limiting
best rest
paracetamol
avoid sport
antivirals not effective
corticosteroids may have a role in some complicated cases
```
61
should you give steroids to help viruses
NO
62
how do you confirm mono
epstein barr virus IgM
heterophile antibody
blood count and film
liver function tests
63
what infections present similarly to mono
cytomegalovirus
toxoplasmosis
primary HIV infection
64
what are the clinical signs of candida/thrush
white patches on red, raw mucous membranes in throat/ mouth
65
what causes candida
candida albicans
| endogenous (post anitbiotics, immunosuppressed, smokers, inhaled steroids)
66
what is the treatment for candida
nystatin or fluconazole
67
when should you investigate candida
if recurrent (suggests somethings wrong with T cells)
68
what is acute otitis media
an upper resp infection involving the middle ear by extension of infection up the eustachian tube
69
how does acute otitis media present
with ear ache
70
what are common infections of the middle ear
often viral with bacterial secondary infection
most common bacterial= haemophilus influenzae, strep pneumoniae, strep pyogenes
71
can you get samples for diagnosis in otitis media
only if eardrum has been perforated
72
what is the treatment for infections of the middle ear
80% resolve without antibiotics
1st- amoxicillin
2nd-erthryomycin
73
what is malignant otitis externa
an extension of otitis externa into the bone surrounding the ear canal (i.e. the mastoid and temporal bones). Malignant otitis, without treatment, is a fatal condition. Osteomyelitis will progressively involve the skull and meninges
74
what are the symptoms and signs of malignant otitis
pain, headache, more severe than signs suggest
granulation tissue at the bone- cartilage junction of the ear canal= exposed bone in ear canal
facial nerve palsy
75
what are the risk factors for malignany otitis
diabetes, radiotherapy to head and neck
76
what investigations to diagnose malignant otitis
PV, CRP, imaging, biopsy
77
IMPORTANT what are the side effects of quinolones
tendonitis
Appetite decreased; arthralgia; asthenia; constipation; diarrhoea; dizziness; dyspnoea; eye discomfort; eye disorders; fever; gastrointestinal discomfort; headache; hearing impairment; hepatic disorders; myalgia; nausea; QT interval prolongation; rhabdomyolysis; skin reactions; sleep disorders; taste altered; vision disorders; vomiting
78
how do you treat malignant otitis
gentamicin 3x a day IV
79
what is otitis externa
inflammation of the outer ear canal
80
what are the clinical signs of otitis externa
redness, swelling of ear canal
itchy
sore
discharge/ increased amounts of ear wax- affects hearing
81
what commonly causes otitis externa
staph aureus
proteus spp
pseudomonas aeruginosa
associated with swimmers
fungal causes:
aspergillus niger
candida albicans
82
what is the management for otitis externa
topical aural toilet
swab in unresponsive/ severe cases
treatment depends on culture
83
what are the features acute sinusitis
mild discomfort over frontal/ maxillary sinuses due to congestion
seen in patients with URTI (viral)
84
what indicates a secondary bacterial infection in acute sinusitis
severe pain and tenderness with purulent nasal discharge
85
what is the treatment for acute sinusitis
usually lasts 2.5 weeks
antibiotics only for severe/ deteriorating cases
1st line phenomethylpenicillin
2nd line doxycycline (not in children)
