Infectious disease Flashcards

1
Q

What kind of cell walls do positive and negative bacteria have?

A

Positive - peptidoglycan call wall (stains purple)

Negative - no thick cell wall

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2
Q

What is unique about atypical bacteria?

A

Cannot be stained or cultured in the normal way

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3
Q

What are ribosomes?

A

Where bacterial proteins are synthesised

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4
Q

What are some gram positive cocci?

A

Staphylococcus

Streptococcus

Enterococcus

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5
Q

What are some gram positive rods?

A

corney Mike’s list of basic cars

Corneybacteria

Mycobacteria

Listeria

Bacillus

Nocardia

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6
Q

List some gram positive anaerobes?

A

CLAP

Clostridium

Lactobacillus

Actinomyces

Propionibacterium

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7
Q

What are some common gram negative bacteria?

A

Neisseria meningitis

Neisseria gonorrhoea

Haemophilia influenza

E. coli

Klebsiella

Pseudomonas aeruginosa

Moraxella catarrhalis

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8
Q

Name 5 organisms which can cause atypical pneumonia?

A

legions of psittaci MCQs

Legionella pneumophila

Chlamydia psittaci

Mycoplasma pneumoniae

Chlamydydophilia pneumoniae

Q fever (coxiella burneti)

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9
Q

What is Methicillin - RSA?

A

S. Aureus which has become resistant to beta-lactams e.g. penicillins, cephalosporins and carbapenems

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10
Q

How can MRSA be tackled?

A

Chlorhexidine body washes (if found on nasal / groin swabs)

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11
Q

What are the abx for MRSA?

A

Doxycycline

Clindamycin

Vancomycin

Teicoplanin

Linezolid

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12
Q

What are Extended Spectrum Beta Lactamase bacteria ?

A

Bacteria which is resistant to beta lactam abx

Tends to be E.Coli or Klebsiella

Normally sensitive to carbapenems e.g. meropenem imipenem

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13
Q

What is sepsis?

A

Immune response to infection which causes systemic inflammation and affects functioning of organs

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14
Q

Which cells recognise the bacteria in sepsis?

A

Macrophages

Lymphocytes

Mast Cells

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15
Q

What is released in a septic patient?

A

Cytokines

Interleukins

Tumour Necrosis Factor

to alert immune system

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16
Q

What causes the vaso dilation in sepsis?

A

Nitrous oxide

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17
Q

What is a result of the oedema in sepsis?

A

Space between the blood and the tissues - reducing amount of oxygen reaching the tissues

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18
Q

How can septic shock be measured?

A

Systolic blood pressure less than 90 despite fluid resus

Hyperlactaemia (lactate > 4 mmol/L)

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19
Q

What are some risk factors for sepsis?

A

Very old / young patients (<1 or >75)

Chronic conditions COPD/ Diabetes

Chemo, immunosuppressants, steroids

Pregnancy or peripartum

Indwelling catheters

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20
Q

What scoring system is used to pick up signs of sepsis?

A

NEWS (national early warning score):

  • Temp
  • HR
  • RR
  • O2 sats
  • BP
  • Consciousness level
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21
Q

What may be found on examination of a septic patient?

A

Potential sources of infection e.g. cellulitis, discharge from wound, cough / dysuria

Non-blanching rash

Reduced urine output

Mottled skin

Cyanosis

Arrhythmias e.g. new onset AF

Tachyopnoea = first sign

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22
Q

What can a non blanching rash a sign of?

A

Meningococcal septicaemia

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23
Q

When may a septic patient appear well?

A

If they’re neutropenic/immunosuppressed

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24
Q

What are the investigations for sepsis?

A

FBC (neutrophils/WCC)

U&E (kidney function)

LFTs (source of infection)

CRP (inflammation)

Clotting (DIC)

Blood cultures (bacteraemia)

Blood gas (lactate, pH and glucose)

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25
Q

What additional investigations can be used to source the infection in sepsis?

A

- Urine dipstick

- CXR

- CT for abscess

- Lumbar puncture for meningitis or encephalitis

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26
Q

What medications may causes neutropenic sepsis?

A

- Chemo

- Methotrexate

- Sulfasalazine

- Infliximab

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27
Q

Viral bronchitis presents similarly to pneumonia, does it requier abx?

A

No

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28
Q

What are the 5 causes of atypical pneumonia?

A

Lesions of psittaci MCQs

Legionella pneumophila

Chlamydia psittaci

Mycoplasma pneumoniae

Chlamydydophila pneumoniae

Q fever (coxiella burnetii)

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29
Q

What would be used to treat pneumonia in the community?

A

Amoxicillin

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30
Q

What are some alternative medications for CAP?

A

Erythromycin / clarithromycin

Doxycyclin

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31
Q

How do lower urinary tract infections present?

A

- Dysuria

- Suprapubic pain

- Frequency

- Urgency

- Incontinence

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32
Q

How does pyelonephritis present?

A

- Fever (more prominent than lower UTI)

- Vomiting

- Loss of appetite

- Back pain

- Haematuria

- Renal angle tenderness

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33
Q

What suggests an infection on urine dipstick?

A

- Nitrites (breakdown produce of nitrates by bacteria)

- Leucocytes (if only these are present then unlikely a UTI)

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34
Q

What are some organisms causing UTIs?

A

E.coli / Klebsiella pneumoniae (gram-negative anaerobic rods)

Enterococcus

Pseudomonas aeruginosa

Staphylococcus saprophyticus

Candida albicans

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35
Q

What length of abx for:

Simple UTI in women

Complex UTI (immunosuppressed, abnormal anatomy)

UTI in men / pregnant women or catheter related UTIs?

A

Simple UTI in women: 3 days

Complex UTI: 5-10 days

UTI in men?: 7 days

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36
Q

What abx for UTI?

A

Trimethoprim

Nitrofurantoin

Alternatives = cefalexin, pivmecillinam, amoxicillin

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37
Q

What can be used to treat pyelonephritis in the community?

A

Cefalexin

(or co-amoxiclav, trimethoprim, ciprofloxacin)

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38
Q

How does cellulitis present?

A

- Eythema

- Warm to touch

- Tense

- Thickened

- Oedematous

- Bullae (fluid-filled blisters)

  • Golden-yellow crust (indicates staphylococcus aureus infection)
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39
Q

What does cellulitis with a golden crust indicate?

A

Staphylococcus aureus infection

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40
Q

What are the most common causes of cellulitis

A

Staphylococcus aureus

Group A Streptococcus (mainly streptococcus pyogenes)

Group C strep (mainly streptococcus dysgalactiae)

MRSA

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41
Q

What medication is used for cellulitis?

A

Flucloxacillin (oral / IV)

Clarithromycin

Clindamycin

Co-amoxiclav

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42
Q

What ENT problems are commonly caused by viral infections?

A

Tonsillitis, otitis media and rhinosinusitis

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43
Q

What is bacterial tonisillitis commonly caused by (if not viral - which it usually is)?

A

Group A Streptococcus (GAS) infections, mainly streptococcus pyogenes

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44
Q

What are otitis media, sinusitis and tonsillitis not caused by GAS commonly caused by?

A

Streptococcus pneumoniae

(other causes = H. Influenzae, morazella catarrhalis, staphylococcus aureus)

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45
Q

What would suggest bacterial tonsilitis over viral (Centor Criteria)?

A

Fever > 38ºC

Tonsillar exudates

Absence of cough

Lymphadenopathy

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46
Q

What is the first line medication for bacterial tonsilitis?

What are some alternatives?

A

Penicillin V (phenoxymethylpenicillin)

Alternatives = co-amoxiclav, clarithromycin, doxycycline

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47
Q

How does otitis media usually present, what is it usually caused by?

A

Bulging tympanic membrane, difficult to distinguish viral or bacterial

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48
Q

What are the treatment options for otitis media?

A
  • Amoxicillin
  • Macrolide

(co-amoxiclav if not responding)

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49
Q

What can sinusitis be treated with in the community (usually lasts 2-3 weeks and resolves without treatment)?

A

Penicillin V (phenoxymethylpenicillin)

Macrolide (if penicillin allergy)

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50
Q

Name some possible intra-abdominal infections?

A

Acute diverticulitis

Cholecystitis (with secondary infection)

Ascending cholangitis

Appendicitis

Spontaneous bacterial peritonitis

Intra-abdo abscess

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51
Q

What are some common organisms in intra-abdominal infections?

A

Anaerobes (clostridium)

E. Coli

Klebsiella

Enterococcus

Streptococcus

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52
Q

What does co-amoxiclav protect against?

A

Gram positive, gram negative and anaerobic (not pseudomonas or atypical pneumonia)

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53
Q

What do quinolones protect against? e.g. Ciprofloxacin and levofloxacin

A

Gram positive, gram negative and atypical (not anaerobes so usually given with metronidazole)

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54
Q

What does metronidazole protect against?

A

Anaerobes

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55
Q

What does gentamicin protect against?

A

Gram negative (and some staph) - bactericidal

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56
Q

What does vancomycin protect against?

A

Gram positive including MRSA (used in comb with gentamicin and metronidazole)

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57
Q

What are cephalosporins used for?

A

Gram negative and gram positive (no anaerobes and risk of C. difficile infection)

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58
Q

What are tazocin (piperacillin/tazobactam) and meropenem used against?

A

Gram positive/negative/anaerobes (not atypicals OR MRSA, tazocin not ESBLs)

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59
Q

What are some common abx regimes?

A

Co-amoxiclav alone

Amoxicillin plus gentamicin plus metronidazole

Ciprofloxacin plus metronidazole (penicillin allergy)

Vancomycin plus gentamicin plus metronidazole (penicillin allergy)

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60
Q

What is usually first line for spontaneous bacterial peritonitis (usually occurs in liver failure)?

A

Tazocin

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61
Q

How does septic arthritis usually present?

A

Hot, red, swollen, painful joint

Stiffness and reduced ROM

Fever, lethagy

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62
Q

What bacteria typically causes septic arthritis?

A

Staphylococcus aureus

Neisseria gonorrhoea

Streptococcus pyogenes (GAS)

Haemophilus influenza

E. coli

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63
Q

Diagnossi if a patient has urinary symptoms and swollen knee?

A

Septic arthritis (before reactive arthritis)

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64
Q

What are some differentials for a painful, swollen joint?

A

Gout (urate crystals = negatively birefringent of polarised light)

Pseudogout (calcium pyrophosphate crystals = postivelt birefringent)

Reactive arthritis (triggered by urethritis / gastroenteritis associated with conjunctivitis)

Haemarthrosis

Septic arthritis

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65
Q

What should the aspirate be tested for in joint swelling?

A

- Gram staining

- Crystal microscopy

- Culture

- Abx sensitivities

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66
Q

What are the empirical abx for septic arthritis?

A

Flucloxacillin plus rifampicin

Vancomycin plus rifampicin for penicillin allergy, MRSA or prosthetic joint

Clindamycin is alternative

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67
Q

Which patients are offered an annual flu jab?

A

Aged 65

Young children

Pregnant women

Asthma, COPD, heart failure and diabetes (chronic conditions)

HCW and carers

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68
Q

How does the flu present?

A

- Fever

- Coryzal symptoms

- Lethargy and fatigue

  • Anorexia (loss of appetite)
  • Muscle and joint aches

- Dry cough

- Muscle and joint aches

  • Sore throat
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69
Q

How is the flu diagnosed?

A

Viral nasal/throat swabs for PCR analysis

70
Q

What medication can be used for flu (usually resolves with just self care)?

A

Oseltamivir or inhaled zanamivir (needs to be started within 48 hours of onset of symptoms)

71
Q

What are some complications of the flu?

A
  • Otitis media, sinusitis and bronchitis
  • Febrile convulsions (young children)
  • Viral penumonia
  • Worsening COPD and heart failure
  • Encephalitis
72
Q

What is the most common cause of gastroenteritis?

A

Viral

73
Q

What viruses commonly cause gastroenteritis?

A

Rotavirus

Norovirus

Adenovirus (less common cause - presents with subacute diarrhoea)

74
Q

How does E.Coli (normal intestinal bacteria) cause gastroenteritis?

A

Certain strains (contact with infected faeces, unwashed salads or water)

75
Q

What does E. coli 0157 produce?

Why should abx not be used in E. coli gastroenteritis?

A

Produces shiga toxin causing abdo cramps, bloody diarrhoeaandvomiting- toxin also causeshaemolytic uraemic syndrome (abx increase this risk)

76
Q

What is the most common cause of travellers diarrhoea? How is it spread?

A

Campylobacter jejuni

Raw poultry, untreated water, unpasteurised milk

77
Q

What are the signs of campylobacter infection?

A

After 2-5 day incubation:

  • Abdo cramps
  • Diarrhoea with blood

- Vomiting

- Fever

78
Q

What are some abx for campylobacter jejuni? When might they be used?

A

Azithromycin or ciprofloxacin

Other risk factors e.g. HIV / heart failure

79
Q

How is Shigella transmitted?

A

Faeces in contaminated drinking water, swimming pools and food

80
Q

How does Shigella infection present?

A

Bloody diarrhoea

Abdo cramps

Fever

81
Q

What does shigella produce?

How can severe cases be treated?

A

Shiga toxin - risk of haemolytic uraemic syndrome

Azithromycin / ciprofloxacin

82
Q

What are the features of a salmonella diarrhoea?

A

Watery diarrhoea associated with mucus or blood

83
Q

What is bacillus cereus?

A

Gram positive rod spread through inadequately cooked food

84
Q

How does bacillus cereus develop?

A

On food which has not been refridgerated immediately after cooking allowing a toxin called cereulide to develop causing vomiting (5 hours after ingestion) and watery diarrhoea (8 hours after ingesting)

85
Q

When does gastroenteritis caused by bacillus cereus usually resolve?

A

Within 24 hours

86
Q

Where does the bacteria yersinia enterocolitica come from? (causing gastroenteritis)

A

Gram negative bacillus from undercooked pork causes mestenteric lymphadenitis (inflammation of the intestinal lymph nodes) and D&V

87
Q

What is Yersinia Enterococolitica?

Who are carriers?

Who norally is affected?

How does it present?

How long can symptoms last?

A

Gram negative bacillus

Pigs (eating undercooked pork can cause infection)

Children causing watery / bloody diarrhoea fever and lymphadenopathy (can also cause right sided abdo pain due to mesenteric lymphadenitis - inflammation of intestinal lymph nodes - appendicitis impression)

Lasts up to 3 weeks

88
Q

When can staph aureus cause gastroenteritis?

How does the infection progress?

A

Produce enterotoxins when growing in foods e.g. eggs, dairy, meat

Small intestine inflammation causing diarrhoea / vomiting / abdo cramps and fever - start within hours and settle within 12-24 hours (toxin causes enteritis)

89
Q

What is giardia lamblia?

How does it present?

How is it diagnosed?

What is the treatment?

A

Microscopic parasite living in small intestine of mammals (may be pets, farmyard animals or humans) releasing cysts in stools of infected mammals (spread faecal-oral)

Asymptomatic or chronic diarrhoea

Diagnosed with stool microscopy

Treated with metronidazole

90
Q

What is the management of gastroenteritis?

A
  • Good hygiene (barrier nursing)
  • Faeces tested with microscopy, culture and sensitivities

- Dioralyte if tolerating oral fluids

  • Off work / school until 48 hrs after symptoms resolved
  • Antidiarrhoeal e.g. loperamide and anti-emetic e.g. metoclopramide for MILD SYMPTOMS not for bloody diarrhoea / e.coli 0157 / shigella

Anti

91
Q

What are some post gastroenteritis complications?

A
  • Lactose intolerance
  • IBS
  • Reactive arthritis
  • Guillain-Barre syndrome
92
Q

What type of bacteria is neisseria meningitis?

What is meningococcal septicaemia?

What is meningococcal meningitis?

A

Gram negative diplococcus (commonly known as meningococcus)

Meningococcal septicaemia = mengococcal bacterial infection in the bloodstream

Meningococcal meningitis = bacteria is infecting the meninges and CSF

93
Q

What does the non-blanching rash in meningococcal meningitis indicate?

A

DIC and subcutaneous haemorrhages

94
Q

Which bacteria commonly causes bacterial meningitis?

A

Children and adults = neisseria meningitidis, streptococcus pneumoniae

Neonate = Group B Streptococcus

95
Q

How does meningitis present?

A

Fever

Neck stiffness

Vomiting

Headache

Photophobia

Altered consciousness

Seizures

Non blanching rash (meningococcal septicaemia)

Neonates = non specific: hypotonia, poor feeding, lethargy, hypothermia, bulging fontanelle

96
Q

When to peform a lumbar puncture for suspected meningitis?

A

Under 1 month with fever

1-3 month with fever and unwell

Under 1 year with unexplained fever and other features of serious illness

97
Q

What is Kernig’s test?

A

Lie patient on their back, with hip and knee flexed to 90 degrees then slowly straighten the leg and look for spinal pain

98
Q

How to perform Brudzinski’s test?

A

Lying patient on back and gently using hands to lift head and neck off bed, flexing chin to chest

Positive = involuntary flex of hips and knees

99
Q

What are the investigations for suspected meningitis?

A

Lumbar puncture for CSF

Blook cultures

100
Q

What are the abx for meningitis?

A

In primary care with suspected meningitis and non blanching rash = stat IM / IV benzylpenicillin (if true penicillin allergy then prioritise transfer)

In hospital (first send bloods for meningococcal PCR - tests directly for meningococcal DNA and gives quicker result than blood cultures)

  • < 3 months = cefotaxime plus amoxicillin (amx to cover listeria cibtracted during pregnancy from mother)
  • > 3 months = ceftriaxone

Vancomycin added if risk of penicillin resistant pneumococcal infection e.g. recent foreign travel / prolonged abx exposure

Steroids = bacterial meningitis to reduce frequency and severity of hearing loss and neurological damage

Dexamethasone = 4 times daily for 4 days to children over 3 months if LP suggests bacterial meningitis

Bacterial meningitis and meingococcal infection = notifiable disease so PH need informing

Ceftriaxone

Vancomycin

Steroids (reduce hearing loss)

101
Q

What is typically given as post exposure prophylaxis for meingococcal infection?

A

Single dose of ciprofloxacin (only if within 7 days of exposure)

102
Q

What are the common causes of viral meningitis?

What is the treatment of HSV meningitis

A

Herpes Simplex Virus (treated with aciclovir)

Enterovirus

Varicella zoster virus

(viral PCR testing)

103
Q

Where is a needle inserted for a lumbar puncture?

A

L3/L4 (after spinal cord ends at L1/L2)

104
Q

What are CSF samples tested for?

A

Bacterial culture

Viral PCR

White cell count

Protein

Glucose

105
Q

How do bacterial and viral CSF samples test?

A

Bacterial = cloudy, high protein, low glucose, high neutrophils

Viral = clear, normal protein, normal glucose, high lymphocytes

106
Q

What are some complications of meningitis?

A

Hearing loss

Seizures and epilepsy

Learning disability

Memory loss

Focal neurological deficits e.g. limb weakness / spasticity

107
Q

What kind of bacteria causes meningitis? Does it gram stain?

A

Mycobacterium Tuberculosis (rod shaped)

Waxy coating so doesn’t stain (acid fastness)

108
Q

Why is TB called acid-fast?

A

Resistant to the acids in the staining process of gram staining

109
Q

What staining is used instead for bacteria?

A

Zeihl-Neelsen stain (turning bacteria bright red against blue background)

110
Q

What is latent TB?

What is secondary TB?

What is disseminated TB?

A

Latent TB = immune system encapsulates sites of infection and stops progression of disease

When latent TB reactivates

Disseminated = immune system is unable to control disease

111
Q

Where else does TB affect?

A

Lymph nodes (causes “cold abscesses” in neck - no inflammation, redness or pain)

Pleura

CNS

Pericardium

GI system

GU system

Bones and joints

Cutaneous TB

112
Q

What are some risk factors for TB?

A

Known contact with active TB

Immigrants from high TB prevalence

Immunosuppression

Homeless

113
Q

What type of vaccine is BCG?

A

Live attenuated intradermal injection (prior to vaccination patients are given the mantoux test and assessed for immunosuppression / HIV)

114
Q

Who is at risk from a live vaccine?

A

Immunosuppressed and HIV

115
Q

Who is offered a BCG vaccine?

A

Neonates born in areas of UK / other countries with high rates of TB / FH of TB

Healthcare workers

Unvaccinated older children who have close contact with TB

116
Q

What are some signs of TB infection?

A
  • Lethargy
  • Fever
  • Weight loss
  • Cough with or without haemoptysis
  • Lymphadenopathy
  • Erythema nodosum
  • Spinal pain (potts)
117
Q

What tests can be used to see if a patient has ever had TB?

A
  • Mantoux
  • Interferon-gamma release assay
118
Q

What can be used if active disease is suspected?

A

CXR

Cultures

119
Q

What can a postive Mantoux test indicate?

A

Previous vaccination

Latent

Active TB

120
Q

What does the Mantoux test involve?

A

Injecting some tuberculin (TB proteins isolated from bacteria - not live bacteria) into intradermal and examining for a reation after 72 hours (induration of 5mm / more = positive result)

121
Q

What is involved in the interferon gamma release assay?

A

Mix a sample of blood with antigens from TB (if they have had previous exposure WBC will release interferon-gamma as part of immune response

Used after a postive mantoux to confim latent TB if no symptoms

122
Q

What may primary TB show on CXR?

A

Patchy consolidation, pleural effusion, hilar lymphadenopathy

123
Q

What may reactivated TB show on CXR?

A

Patchy / nodular consolidation with caviation (gas filled spaces in lungs) typically in upper zones

124
Q

What may disseminated miliary TB show on CXR?

A

Millet seeds - uniformly distributed thoughout lung fields

125
Q

How can cultures for TB be collected?

A

3 sputum samples (hypertonic saline to induce or bronchoscopy lavage)

Mycobacterium blood cultures (special bottles)

Lymph node aspiration / biopsy

126
Q

When in Nucleic Acid Amplification Testing used for TB?

A

Results come back quicker than traditional bacterial culture so used when it would affect treatment, tested on sputum sample

127
Q

What is the management of latent TB?

A

Isoniazid and rifampicin for 3 months

or

Isoniazid for 6 months

(if otherwise healthy then may not need treatment)

128
Q

What is the drug treatment for TB?

A

R – Rifampicin for 6 months

I – Isoniazid for 6 months

P – Pyrazinamide for 2 months

E – Ethambutol for 2 months

129
Q

What is co-prescribed with TB medication?

A

Pyroxidine (vit B6) as isoniazid causes peripheral neuropathy

130
Q

What are other management concerns for TB?

A

Test for HIV hep B and C

Test contacts

Notify Public Health

Treat in negative pressure room (isolated)

Treatment is different for extrapulmonary disease (often involves corticosteroids)

131
Q

What are side effects of each of the drugs?

A

Rifampicin = red/orange discolouration in urine / tears (also induces cytochrome P450 so reduces effect of drugs metabolised by P450)

Isoniazid = peripheral neuropathy

Pyrazinamide = hyperuricaemia - gout

Ethambutol = colour blindness and reduced visual acuity

All are hepatotoxic bar ethambutol

132
Q

What type of virus is HIV?

A

RNA retrovirus - entering and destroying CD4 T helper cells

133
Q

How is HIV spread?

A

Unprotected sex (anal , vaginal or oral)

Mother to child (pregnancy, birth, breastfeeding)

Sharing needles

134
Q

What are some AIDs defining illnesses?

A

Kaposi’s sarcoma

Pneumocystis jirovecii pneumonia

Cytomegalovirus infection

Candidiasis

Lymphomas

Tuberculosis

135
Q

How long can antibody testing be negative for HIV?

A

3 months (with verbal consent documented)

136
Q

What is the testing for HIV?

A

Antibody blood test (normal hospital test)

Testing for p24 antigen (can give positive result earlier in infection)

137
Q

What PCR testing can be done for HIV?

A

HIV RNA virus (gives viral load)

138
Q

What CD4 count (cells destroyed by HIV virus) is considered end stage?

A

Under 200

139
Q

What is the treatment for HIV?

A

Antiretroviral therapy (irrespective of viral load CD4 count)

140
Q

What are some classes of HAART medications (highly active anti-retrovirus therapy)?

A
  • Protease inhibitors
  • Integrase inhibitors
  • Nucleoside reverse transcriptase inhibitors
141
Q

What is given to HIV patients to prevent PCP (pneumocystis jirovecii penumonia)?

A

Co-trimoxazole (septrin) if CD4 < 200

142
Q

What are women with HIV at an increased risk of ?

A

Human papillomavirus and cervical cancer

143
Q

What vaccinations should patients with HIV have?

A

Annual influenza

Pneumococcal

Hep A and B

Tetanus

Diptheria

Polio

Avoid live vaccines

144
Q

What is the advise for sex with HIV?

Can patients safely concieve?

Can HIV mothers breastfeed?

A

Condoms for vaginal / anal sex and dams for oral sex even if both positive (if viral load undetectable then transmission is unlikely but possible)

Sperm washing can help to conceive safely

C-section should be used unless undetectable viral load

Breastfeeding only considered if viral load undetectable but still a risk of contracting

145
Q

What is given as post-exposure prophylaxis for HIV?

A

Truvada (emtricitabine / tenofovir)

Raltegravir for 28 days

HIV test does initially but also 3 months after and should abstain from unprotected sex for 3 months after

146
Q

How is malaria spread?

A

Female anophele mosquitos carrying plasmodium falciparum (from family of protozoan parasites)

147
Q

What are the other types of parasites causing malaria?

A

Plasmodium falciparum

Plasmodium vivax

Plasmodium ovale

Plasmodium malariae

148
Q

What is the pathophysiology of malaria?

A

Sporozoites (spores produced in mosquito gut as it digests infected blood) are injected into the human - travel to the liver (here can lie dormant for many years ar P. vivax and P. ovale)- mature to merozoites which then infect RBCs and reproduce over 48 hours - RBC ruptures every 48 hrs releasing more merozoites (spike in temp every 48 hours)

149
Q

What is the incubation period of malaria?

A
  • Fever, sweats and rigors
  • Malaise
  • Myalgia
  • Headache
  • Vomiting
  • Pallor due to anaemia
  • Hepatosplenomegaly
  • Jaundice
150
Q

How is a diagnosis of malaria made?

A

3 malaria blood films (sent in EDTA bottle - RBC bottle) over 3 consecutive days (due to 48 hr lifecycle)

151
Q

What are the medication options for uncomplicated malaria?

A

Riamet

Malarone

Quinine sulphate

Doxycycline

152
Q

What is the IV treatment for severe malaria?

A

Artesunate

Quinine dihydrochloride

153
Q

What are some complications for Plasmodium Falciparum (most severe form)?

A
  • Cerebral malaria
  • Seizures
  • Reduced consciousness
  • AKI
  • Pulmonary oedema
  • DIC
  • Severe haemolytic anaemia
  • Multi-organ failure and death
154
Q

What general prophylaxis is there against malaria?

A
  • Use mosquito sprays (e.g. 50% DEET spray) / nets
  • Use antimalarials
155
Q

Name an antimalarial? When is it taken?

A

Malarone (proguanil and atovaquone) - daily 2 days before, during and 1 week after being in endemic area, most expensive (£1 per tablet)

Mefloquine - taken once weekly 2 weeks before, during and 4 weeks after (causes bad dreams / psychotic disorders)

Doxycycline - taken daily 2 days before, during and 4 weeks after being in endemic area (broad spectrum = diarrhoea and thrush, sensitivity to sun = rash / sunburn)

156
Q

Which abx inhibit cell wall synthesis?

A

Antibiotics with a beta-lactam ring

  • Penicillin
  • Carbapenems such as meropenem
  • Cephalosporins

Antibiotics without a beta-lactam ring

  • Vancomycin
  • Teicoplanin
157
Q

How do bacteria make their own folic acid?

A

Para-aminobenzoic acid (PABA) is directly absorbed across cell membrane, then converted to dihydrofolic acid (DHFA) then tetrahydrofolic acid (THFA) and finally folic acid

158
Q

Which abx inhibit production of folic acid?

A

Sulfamethoxazole blocks the conversion of PABA to DHFA

Trimethoprim blocks the conversion of DHFA to THFA

Co-trimoxazole is a combination of sulfamethoxazole and trimethoprim

159
Q

What is metronidazole effective against?

A

Anaerobes

160
Q

Which abx inhibit protein synthesis by targettting the ribosome?

A

Macrolides such as erythromycin, clarithromycin and azithromycin

Clindamycin

Tetracyclines such as doxycycline

Gentamicin

Chloramphenicol

161
Q

What bacteria does amoxicillin cover?

A

Streptococcus

Listeria

Enterococcus

162
Q

Which bacteria does co-amoxiclav cover?

A

Staphylococcus, haemophilus and E.Colo

163
Q

What does tazocin cover?

A

Pseudomonas

164
Q

What covers ESBLs?

A

Meropenem

165
Q

What covers MRSA?

A

Teicoplanin

Vancomycin

166
Q

What covers atypical bacteria?

A

Clarithromycin or doxycycline

167
Q

Why are UTIs risky in pregnancy?

A

Increased risk of pyelonephritis, premature ROM, pre-term labour

168
Q

How to manage UTI in pregnancy?

A

7 days of abx (even with asymptomatic bacteruria)

Urine culture and sensitivities

First line: nitrofurantoin

Second line: cefalexin or amoxicillin

169
Q

When are nitrofurantoin / trimethoprim avoided in pregnancy?

A
170
Q
A