Infections Flashcards
CNS infections are medical emergencies. True/False?
True
Brain and spinal cord do not regenerate once injured
List the main differential diagnoses for CNS infections causing fever and/or altered mental state
Meningitis Encephalitis Meningoencephalitis Encephalomyelitis Severe sepsis syndrome Abscess
When is the typical onset of viral meningitis?
Late summer/autumn
Which viruses are typically responsible for viral meningitis?
Enteroviruses most common e.g. ECHO
HSV and other microbes also
List investigations/diagnostic tools for viral meningitis
Viral stool culture
Throat swab
Lumbar puncture for CSF PCR
Outline treatment for viral meningitis
Supportive - paracetamol, fluids, rest, dark room
Which part of the brain does viral encephalitis affect?
Infection of brain parenchyma
List the main causes of viral encephalitis
Herpes simplex Varicella zoster CMV, HIV, measles Travel-viruses Rabies Non-infectious (autoimmune)
Which viruses are the only treatable causes of viral encephalitis?
HSV
Varicella zoster
List clinical features of viral encephalitis
Meningismus (rigidity, photophobia, headache) Comatose Seizures Paralysis Confusion, psychosis Speech and memory deficit
List investigations for viral encephalitis
Lumbar puncture
Electroencephalography (EEG)
MRI
What is the main treatment for viral encephalitis?
IV aciclovir
List the main causes of bacterial meningitis in neonates
Listeria monocytogenes
Group B Strep.
E. coli
Which antibiotic combats Listeria monocytogenes?
Ampicillin/amoxicillin
Which organism is the main causes of bacterial meningitis in children?
H. influenzae
Which organism is the main cause of bacterial meningitis in 10-21 year olds?
Neisseria meningitides from the throats of healthy carriers
List the main causes of bacterial meningitis in adults
Strep. pneumoniae
Neisseria meningitides
A fracture of the cribriform plate increases the risk of which bacterial meningitis?
Pneumococcal (Strep. pneumoniae)
List the main causes of bacterial meningitis in the immunocompromised
Strep. pneumonia Neisseria meningitides Staph aureus Listeria Aerobic Gram -ves Mycobacterium Cryptococcus neoformans
List clinical features of bacterial meningitis
Meningismus Vomiting Pyrexia Stiffness Confusion Rash
Signs of bacterial meningitis are often absent in the very young, very old and immunocompromised. True/False?
True
List investigations for bacterial meningitis
Blood cultures
Throat swab (meningococci)
Lumbar puncture for CSF
CSF must be interpreted in 5 tubes - list them and their contents
1: haematology- cell count, differential
2: microbiology- gram stain, cultures
3: biochemistry- glucose, protein
4: haematology- cell count, differential
5: PCR if necessary
A low ratio of blood sugar : CSF sugar is indicative of bacterial meningitis. True/False?
True
What is aseptic meningitis?
Non-pyogenic bacterial meningitis: low WBC count, normal glucose, small elevated protein
List indications for hospital admission for bacterial meningitis
Altered consciousness
Petechial rash
Febrile, headache
Which antibiotics are given for bacterial meningitis pre-hospital?
Penicillin
Ceftriaxone
A CT scan should delay treatment in bacterial meningitis. True/False?
False
An urgent CT scan should be requested but does not delay treatment
Why are steroids given to all patients suspected of bacterial meningitis?
Dampen down cerebral swelling caused by antibiotic treatment
If a patient is penicillin-allergic, what antibiotic is given for bacterial meningitis?
Chloramphenicol
