Infections Flashcards

1
Q

CNS infections are medical emergencies. True/False? Why?

A

True
Untreated infection can lead to brain herniation and death, and cord compression with paralysis
Brain and spinal cord do not regenerate once injured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List the main differential diagnoses for CNS infections causing fever and/or altered mental state

A

Meningitis (inflammation of the meninges)
Encephalitis (inflammation of brain)
Meningoencephalitis (inflammation of brain and meninges)
Encephalomyelitis (inflammation of brain and spinal cord)
Severe sepsis syndrome
Abscess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When is the typical onset of viral meningitis?

A

Late summer/autumn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which viruses are typically responsible for viral meningitis?

A

Enteroviruses most common e.g. ECHO, coxsacchie

HSV and other microbes also

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

List investigations/diagnostic tools for viral meningitis

A

Viral stool culture
Throat swab
Lumbar puncture for CSF
PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Outline treatment for viral meningitis

A

Supportive - paracetamol, fluids, rest, dark room

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which part of the brain does viral encephalitis affect?

A

Infection of brain parenchyma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the main causes of viral encephalitis

A
Herpes simplex
Varicella zoster
CMV, HIV, measles
Travel-viruses
Rabies
Non-infectious (autoimmune)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which viruses are the only treatable causes of viral encephalitis?

A

HSV

Varicella zoster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List clinical features of viral encephalitis

A

Insidious onset
Meningismus (rigidity, photophobia, headache)
Altered consciousness (comatose, seizures, paralysis)
Confusion, psychosis
Speech and memory deficit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List investigations for viral encephalitis

A

Lumbar puncture
Electroencephalography (EEG)
MRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the main treatment for viral encephalitis?

A

IV aciclovir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

List the main causes of bacterial meningitis in neonates

A

Listeria monocytogenes
Group B Strep. (pneumococcus)
E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which antibiotic combats Listeria monocytogenes?

A

Ampicillin/amoxicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which organism is the main causes of bacterial meningitis in children?

A

H. influenzae (type b)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which organism is the main cause of bacterial meningitis in 10-21 year olds?

A

Neisseria meningitides from the throats of healthy carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

List the main causes of bacterial meningitis in adults

A

Strep. pneumoniae

Neisseria meningitides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A fracture of the cribriform plate increases the risk of which bacterial meningitis?

A

Pneumococcal (Strep. pneumoniae)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

List the main causes of bacterial meningitis in the immunocompromised

A
Strep. pneumonia
Neisseria meningitides
Staph aureus
Listeria
Aerobic Gram -ves
Mycobacterium
Cryptococcus neoformans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

List clinical features of bacterial meningitis

A
Meningismus  (rigidity, photophobia, headache)
Nausea/ Vomiting
Pyrexia
Stiffness/ pain (particularly in neck)
Confusion (GCS <14)
Rash
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Signs of bacterial meningitis are often absent in the very young, very old and immunocompromised. True/False?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

List investigations for bacterial meningitis

A

Blood cultures
Throat swab (meningococci)
Lumbar puncture for CSF

23
Q

What CSF findings would you expect in bacterial meningitis?

A
High WBC (>2000)
High neutrophils (>1180)
High protein (>220)
Low glucose (<34) in blood
24
Q

A low ratio of blood sugar : CSF sugar is indicative of bacterial meningitis. True/False?

A

True

25
Q

What is aseptic meningitis? What are the findings of CSF analysis?

A

Non-pyogenic bacterial meningitis (includes viral meningitis): high WBC count, high lymphocytes, normal glucose, elevated protein

26
Q

List indications for hospital admission for bacterial meningitis

A

Altered consciousness
Petechial rash
Febrile, headache

27
Q

Which antibiotic is given for suspected meningitis 1st line? If the patient is over 60 yo add? If worried about resistance add?

A

Ceftoxamine/ ceftriaxone
Amoxicillin
Vancomycin + rifampicin

28
Q

A CT scan should delay treatment in bacterial meningitis. True/False?

A

False

An urgent CT scan should be requested but does not delay treatment

29
Q

Why are steroids given to all patients suspected of bacterial meningitis? What steroid is given?

A

Dampen down cerebral swelling caused by antibiotic treatment

Dexamethasone

30
Q

If a patient is penicillin-allergic, what antibiotics given for bacterial meningitis? If the patient is over 60 yo add?

A

Chloramphenicol

Co-trimoxazole

31
Q

What is the appearance of acute pyogenic meningitis in the brain?

A

Thick layer of suppurative exudate covers meninges over surface of brain
Neutrophils in sub-arachnoid space

32
Q

Which medication combats Haemophillus Influenza?

A

Dexamethasone

33
Q

What are some complications of bacterial meningitis?

A
Limb loss
Deafness
Blindness
Cerebral palsy
Quadriplegia
Mental impairment
Hydrocephalus
34
Q

What is the pathenogenesis of meningitis - how can the bacteria reach the brain?

A

Nasopharyngeal colonization
Direct extension of bacteria
From remote foci of infection (endocarditis, pneumonia, UTI)

35
Q

Outline the treatment for tuberculosis meningitis

A

Isoniazid + rifampicin —> + pyrazinamide + ethambutol

36
Q

Cryptococcal meningitis is a bacterial/viral/fungal infection

A

Fungal

37
Q

Cryptococcal meningitis is classically found in which immunocompromised group?

A

HIV sufferers (CD4 <100)

38
Q

Outline the treatment for cryptococcal meningitis

A

IV amphotericin B/ flucytosine

Fluconazole

39
Q

What are the warning signs to look out for in CNS infection?

A
Marked reduced consciousness (GCS <12) or fluctuating conscious level (fall >2)
Focal neurology
Seizure
Shock
Bradycardia and hypertension
Papilloedema
40
Q

What preventative strategies are used in CNS infection?

A

Report to public health

Give vaccines where appropriate - neisseria, HIb, strep pneumoniae

41
Q

When should a lumbar puncture not be performed before a CT?

A

Reduced consciousness
Seizures
Rapidly progressive rash (suspicious of VIC)

42
Q

Which organism is associated with gram negative diplococci?

A

Neisseria meningitis

43
Q

Which organism is associated with gram positive diplococci?

A

Strep pneumoniae

44
Q

Which antibiotic should be given as prophylaxis to people who have been in close contact with infectious meningitis?

A

Ciprofloxacin`

45
Q

What is the difference between petechia and purpura?

A

Petechia < 0.5cm

Purpura >0.5cm

46
Q

What is a complication of prescribing ceftriaxone?

A

C. diff infection

47
Q

How does a brain abscess appear on imaging?

A

Ring-enhancing lesion

48
Q

Outline the treatment for brain abcess

A

Ceftriaxone

Metronidazole

49
Q

Which organisms are mostly likely to trigger the formation of a brain abscess?

A

Streptococcoi
Bacteriodes (anaerobes)
G- bacilli (coliforms)

50
Q

Which organism is associated with gram positive flagellated rods? Who is at risk of infection?

A

Listeria

Neonates, pregnant woman, elderly

51
Q

Which organism is associated with gram negative coccobacillus?

A

Haemophillus influenzae

52
Q

HSV encephalitis has a preference towards affecting which lobes of the brain?

A

Temporal lobes

53
Q

What are the findings of CSF analysis in tuberculosis meningitis?

A
Opaque (if left to settle it forms a fibrin web)
Elevated opening pressure
Lymphocytes present
High protein
Low glucose