Infectious diseases Flashcards
How do you screen for atypical pneumonia?
Blood for serology- looks for antibiotics
How do you screen for mycoplasma and influenza?
Nasal swab PCR
How do you screen for pneumocystis (atypical pneumonia)?
Sputum PCR (or bronchial lavage PCR)
Key/first test for infective endocarditis?
blood cultures 3 sets from different venepuncture sites over a period of time
Likely pathogen of infective endocarditis in an IVDU?
staph aureus
What is onchomycosis?
Fungal nail infection
Key test in febrile illness on return from sub-saharan africa?
Malaria blood film
Myalgia, headache, high fever, sometimes rash on return from SE asia- what key test?
Dengue serology (IgM and IgG)
Dengue incubation period?
1w
What time of day does the dengue mosquito bite?
Day time
What is Q fever?
Coxiella burnetii
from infected farm animals such as sheep, cattle and goats- breathing in the bacteria
Risk in pregnant, immune-suppressed, heart valve disease
Can lead to atypical pneumonia
Chronic- endocarditis - fatal if untreated
Serology and Abx
What should you do if you think the source of sepsis is an indwelling line?
PAIRED cultures- one peripheral (normal) and one from the line.
What to do in a pt presenting with fever post operatively?
Find source- it may not be wound/perforation- could also be catheter, lines, HAP etc.
How do you screen for latent TB
IGRA- interferon gamma release assay
Pathogens of bac meningitis
N meningitidis S pneumoniae Hib Listeria Group B strep (neonates)
Which babies should get an LP?
<1m and fever
1-3m fever and unwell
<1y unexplained fever and features of serious illness
C/Is to LP
- sepsis/rapidly evolving rash
- severe resp/CV compromise
- sig bleeding risk
- signs of shifting brain compartments e.g. FND/papilloedema/seizures/GCS <12 –> CT head first as long as stable!!
In Rx bac meningitis when do you add amoxicillin to the cephalosporin?
Immune comp/>50yo
In Rx bac meningitis when do you add vancomycin to the cephalosporin?
If there is a risk of penicillin resistant pneumococcal infection e.g. recent travel or prolonged Abx exposure
What do you give as well as Abx in Rx bacterial meningitis?
IV dex 10mg AT THE SAME TIME AS THE ANTOIBIOTICS to reduce neuro complications particularly in pneumococcal
When do you avoid giving Dex in bacterial meningitis
Septic shock
Meningococcal septicaemia
Immune compromised
Meningitis following surgery
Public health implications of bac meninigitis
Notifiable
Contacts should get prophylaxis cipro or rifampicin
Risk factors for pneumococcal meningitis?
Immune compromise
Splenectomy
Smoking
Pneumococcus infection at another site e.g. lung/otitis media/sinusitis
Skull injuries
Spinal level of an LP
L3-L4
Viral causes of meningitis
Enteroviruses (echovirus and coxsackie)
HSVII
VZV
mumps
Which type of meningitis is less acutely unwell
viral
Treatment of viral meningitis
Supportive
Is there evidence for aciclovir in viral meningitis?
No as HSVII not I
How do you distinguish meningitis and encephalitis
clinical
How do the clinical signs differ in encephalitis compared to meningitis?
Enceph- fever/behav. changes/confusion/seizure
Meningitis- neck stiff/photophobia/headache
What might mimic enceph in elderly
derlirium from infection
Cause of encephalitis
HSV1 majority
rarer= EBV, VZV, HIV, HHV6, rabies, japanese enceph, tick borne, zika
What is the classical MRI finding in encephalitis?
temporal lobe inflammation
Why might you do a CT head in ?encephalitis?
Rules out important differentials e.g. brain abscess, stroke, SOL
Does a normal CSF r/o encephalitis?
yes
Rx encephalitis?
IV aciclovir 10mg/kg TDS for 14-21 days.
Start empirically and continue if confirmed
Can you get non-infective encephalitis?
Yes- autoimmune/paraneoplastic/acute disseminated encephalomyelitis
