Management of Common Infections Flashcards
How (and why) do you collect urine sample when investigating a UTI? [1]
Mid stream (avoid contamination of bacteria around urethra)
Describe how you would step up investigations for following UTIs:
- Asymptomatic bacterial infection
- Pyelonephritis
- Urosepsis
Asymptomatic bacterial infection:
- DIpstick
- MSU Culture
Pyelonephritis
- DIpstick
- MSU Culture
- Renal US or renal CT
Urosepsis
- DIpstick
- MSU Culture AND Blood culture
- Renal US or renal CT +/- abdomonal CT
Describe the overall managment plan for following:
- Asymptomatic bacterial infection
- Pyelonephritis
- Urosepsis
When would you treat asymptomatic bacteria? [4]
Normally - don’t, but do if:
- Immunosuppresed
- Abnormal anatomy
- Children
- Prenant
Which bacteria causing UTIs are strongly associated with renal calculi? [1]
Proteus mirabilis
Consider imaging
If you find S. aureus as a cause of UTI - what other pathology would you have a suspicion of? [1]
S. aureus isn’t usual uropathogen - have suspicion for endocarditis
- endocarditis -> renal abscess -> urine
What is important to think about nitrofurantoin when treating UTIs? [1]
- Need a eGFR > 60 otherwise won’t get into urine and effect
How long does usually fever last in pyelonephritis? [1]
3/4 days
Under what conditions would warrant further investigations w UTI? [5]
- UTI in child
- UTI in a man
- Recurrent UTIs
- Persistent symptoms
- Urinary catheter
Define:
- Cellulitis
- Erysipelas
- Impetigo
Cellulitis:
- Infection of dermis AND subcut tissue
- Typically indistinct edge
Erysipelas:
- Infection of dermins only
- Demarcated edge
Impetigo
- Infection usually of epidermis around mouth
Which organsims most commoly cause impetigo? [2]
Staph aureus
Streptococcus pyogenes
What is the usual treatment for skin & soft tissue infections? [1]
Flucoxacillin (high activity agaisnt staph aureus / strep pyogenes)
What is key to think about SSTIs? [1]
If pain is disproportinate to degree of skin change - if so: necrotising fascitis?
Fascia doesn’t have rich blood supply - so little lymphocytes
What is key to thing about cellulitis infection? [1]
Highly unlikely that is bilateral - think of a differential diagnosis
Bilateral cellulitis does not exist
Give three differentials for a hot red leg [3]
Cellulitis
DVT
Drug reaction
Gout
Insect bites
Exacerbation of lymphoedema
How do you assess for Mycoplasma pneumonia? [1]
PCR
Describe how atypical pneumonias present differently to typical resp infections
- Illness often milder
- WBC often less elevated
- May be associated with abnormal LFTs & hyponatraemia
-
Extra-pulmonary manifestations more common: at the time of resp. infection - e.g. myalgia; post-pulm. Infection -
e.g. mycoplasma and ADEM, deafness, skin rashes etc
Most atypical pneumonias are more mild - except for which one? [1]
Legionella infection
What are the general principles for CAP:
- Low severity [1]
- Moderate severity [2]
- High severity [3]
Low severity
- single antibiotic
Moderate severity:
- amoxicillin & a macrolide (azithromycin, clarithromycin, and erythromycin)
High severity
- β-lactamase stable β-lactam (e.g. co-amox) & a macrolide
A patient presents with CAP - under what conditions would you give pip-taz? [3]
If they have pseudomonas infection:
-CF; bronchiectasis
A patient comes back from the Gulf with a resp. infection - what should you consider? [1]
MERs
How do you test for infections for [3]
- Pneumococcal
- Legionella
- Mycoplasma
Pneumococcal
- Urinary antigen - if haven’t been able to isolate strep pneumonia from another site
Legionella:
- Urinary antigen
Mycoplasma:
- PCR
How do you differentiate between the symptoms of meningitis and encephaltiis?
Meningitis
- Symptoms of headache, neck stiffness & photophobia
Encephalitis:
- Symptoms associated with altered cerebral function (e..g Seizures, weakness, behaviour change, drop in GCS etc)
What are the implications of dinstinction betwen mengintis vs encephalitis with regards to treatment? [2]
Likely causes e.g. in UK encephalitis viral > bacterial
Treatment e.g. viral meningitis does NOT need treatment, enceph DOES
What are the different ways of classify infective endocarditis? [3]
Native vs. prosthetic valve
Indolent vs. acute
Culture positive vs. culture negative
Under what conditions would you suspect Streptococcus gallolyticus causing infective endocarditis? [1]
Due to GI malignancy
Under what conditions would you suspect Viridans streptococci causing infective endocarditis? [1]
Dental disease
Under what clinical picture would you suspect Salmonella typhi infection? [1]
What would you use to treat? [2]
Fever; malaise; abdominal pain; diarrhoea; constipation; travel history where there is poor sanitation
Treat early because can lead to septiciaemia and death :(
With a cephalosporin (e.g cefuroxime) or fluoroquinolone
What are the three most common causes of viral meningitis? [3]
Enteroviruses (e.g., coxsackievirus)
Herpes simplex virus (HSV)
Varicella zoster virus (VZV)
Viral meningitis is generally self-limiting. How do you treat HSV and VZV if needed? [1]
Viral PCR testing can be performed on a CSF sample. Aciclovir is used to treat HSV and VZV.
The causes of bacterial meningitis include: [5]
Neisseria meningitidis
Streptococcus pneumoniae (pneumococcus)
Haemophilus influenzae
Group B streptococcus (GBS) (particularly in neonates as GBS may colonise the vagina)
Listeria monocytogenes (particularly in neonates)
What does a non-blanching rash indicate with meningitis? [1]
Where there is meningococcal septicaemia, children can present with a non-blanching rash. Other causes of bacterial meningitis do not usually cause the non-blanching rash.
Children seen in the primary care setting with suspected meningitis and a non-blanching rash should receive an urgent dose of [] (IM or IV) while awaiting transfer to hospital (it should not delay transfer).
Children seen in the primary care setting with suspected meningitis and a non-blanching rash should receive an urgent dose of benzylpenicillin (IM or IV) while awaiting transfer to hospital (it should not delay transfer). Where there is a true penicillin allergy, transfer should be the priority rather than other antibiotics.
Typical antibiotics are to treat bacterial meningitis include
Under 3 months – [] plus [] ([] is to cover listeria)
Above 3 months – []
PLUS
[]
Typical antibiotics are:
Under 3 months – cefotaxime plus amoxicillin (amoxicillin is to cover listeria)
Above 3 months – ceftriaxone
PLUS
Steroids (e.g., dexamethasone) are also used in bacterial meningitis to reduce the frequency and severity of hearing loss and neurological complications.
When treating bacterial meningitis - what drug should be given if suspect penicillin-resistant pneumococcal infection? [1]
Vancomycin should be added if there is a risk of penicillin-resistant pneumococcal infection (e.g., recent foreign travel or prolonged antibiotic exposure).
Significant exposure to meningococcal infection puts contacts at risk. This risk is highest with close prolonged contact within 7 days before the onset of the illness. The risk to contacts decreases 7 days after the diagnosis.
Post-exposure prophylaxis is guided by the local health protection team when they are notified of the diagnosis. The usual choice is a single dose of [] given as soon as possible after the diagnosis.
Post-exposure prophylaxis is guided by the local health protection team when they are notified of the diagnosis. The usual choice is a single dose of ciprofloxacin given as soon as possible after the diagnosis.
Describe the Eron classification for the assessment of the severity of cellulitis [4]
The Eron classification assesses the severity of cellulitis:
Class 1 – no systemic toxicity or comorbidity
Class 2 – systemic toxicity or comorbidity
Class 3 – significant systemic toxicity or significant comorbidity
Class 4 – sepsis or life-threatening infection
Patients with cellulitis who are penicillin allergic can be given [3]
Patients with cellulitis who are penicillin allergic can be given clarithromycin, erythromycin (in pregnancy) or doxycyline
