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Flashcards in Infectious Disease 1 Deck (127):
1

Particular food implicated in Hep A transmission?

Shellfish

2

Symptoms of Hep A?

Nausea, vomiting, malaise
Arthralgias
Rash

3

Signs of Hep A?

Jaundice
Fever
Lymphadenopathy
Hepatosplenomegaly

4

What test is diagnostic of Hep A?

anti-HAV IgM

5

What test can be used to investigate previous HAV infection?

anti-HAV IgG

6

3 preventative measures for Hep A?

Good sanitation in developing countries
Good hygiene practises
IgG vaccine

7

How is HBV transmitted?

Blood-borne, sexual/bodily fluids and vertically

8

Particular RFs for HBV infection?

Sexual contact with infected person
IVDU
Tattoos, particularly foreign countries
Medical treatment abroad
Blood transfusions before 1991

9

What 3 features are more prominent in HBV than HAV if present?

Rash
Jaundice
Arthralgia

10

How does HBV often present?

It's often asymptomatic; otherwise like a more severe HAV with prominent jaundice, rash and arthralgia

11

What blood tests indicate an acute HBV infection?

HBcIgM, HBcIgG
HBsAg
HBV DNA
Acutely deranged LFTs

12

What 2 blood markers are only found during the acute phase of HBV infection?

HBsAg
HBV DNA

13

What is HBV DNA used to monitor?

Treatment and infectivity

14

What unusual HBV marker is used to indicate high infectivity?

HBeAg

15

What blood tests indicate if someone has had a past HBV infection and recovered?

HBsAb
HBcIgG

16

What blood test indicates someone who has been vaccinated against HBV?

HBsAb (but no HBcIgG)

17

What blood test is used as a screening test for HBV?

HBsAg

18

Someone is HBV DNA, HBsAg positive as well as HBcIgM positive and has deranged LFTs. Diagnosis?

Acute infection

19

Someone is positive only for HBsIg. Diagnosis?

Vaccinated therefore immune

20

Someone is positive for HBsIg and HBcIgG. Diagnosis?

Immune due to previous infection

21

Someone is positive for HBsAg, HBcIgG and HBeAb but negative for HBcIgM and HBsIg. Diagnosis?

Chronic infection

22

What is the most likely outcome of HBV infection?

Complete recovery -

23

What LFT picture does Hep A give?

Hepatic damage + raised bilirubin

24

Apart from complete recovery and chronicity how else can HBV infection resolve?

Carrier state

25

What 3 blood tests indicate chronic HBV infection?

HBsAg
HBcIgG
HBeAb

26

How is HCV spread?

Bloodborne, sexual, vertical

27

If hep C presents symptomatically, how does it present?

Milder flu-like illness with fever +/- jaundice

28

How is HCV infection detected in the acute phase?

HCV RNA (PCR) + deranged LFTs

29

How is chronic HCV infection detected?

Anti-HCV Abs

30

What proportion of HCV goes on to become chronic? Future complications?

2/3 chronic
1/3 liver cirrhosis
1/10 HCC

31

Treatment of HCV? (Chronic)

PEG interferon alpha
Ribavirin

32

Prevention of HBV?

Vaccine (HBsAb)
Safe sex, clean needles, blood screening etc.

33

Is there a vaccine for HCV?

No

34

What is the role of Hep D virus infection?

Can only occur in context of HBV as it is an incomplete RNA virus

35

How is HDV spread?

In the blood

36

2 types of HDV infection?

Occurring at same time to make more severe infection (co-infection)
Causing flare up of chronic infection (superinfection)

37

Investigating HDV infection?

HDV RNA (PCR)

38

Treatment of HDV virus?

Alpha interferon (limited success)

39

Potential implications of HDV infection?

Increased risk of fulminant hepatitis and liver failure
But no chronic state

40

How is HDV prevented?

HBV vaccine!

41

How is HEV spread?

Fecal oral
But more like pork, deer, water supplies (and sexual)

42

Where is HEV common?

Indochina

43

Symptoms of HEV?

Similar to HAV - icterus, flu like Sx, pruritis, organomegally

44

What are the 2 phases of HAV infection?

Prodromal phase (non-specific, nausea vom headaches etc.)
Icteric phase (jaundice, fever, pruritis etc.)

45

How is HEV infection detected?

HEV RNA serology (PCR) via serum or stool

46

In whom does HEV infection carry particular significance?

Pregnant women - mega high mortality

47

What food is implicated in HEV infection?

Pork, deer

48

How is Hep A transmitted?

Fecal-oral route - contaminated food and water

49

Acute presentation of mastoiditis?

Often follows acute or recurrent OM, bulging erythematous TM
Otalgia, retroaural pain (swelling, redness, boggy)
Fever and malaise
Discharge and perforation

50

What CN and hearing findings might be consistent with mastoiditis?

CN5, 7, 8 involvement
Conductive deafness

51

Potential complications of mastoiditis?

Intracranial infection - meningitis, abscess

52

Subacute presentation of allergic extrinsic alveolitis?

Pneumonitis

53

Examples of allergic extrinsic alveolitis?

Farmers lung (hay)
Pigeon fanciers lung (feathers and avian proteins)
Cheese workers lung (penicillium casei)
Malt workers lung
Hot tub lung (mycobacterium Avium)

54

Signs of chronic allergic extrinsic alveolitis?

SOB and weight loss over time
Cyanosis, clubbing
Can lead to cor pulmonale

55

What are the most common viral meningitides?

HHV meningitis
Enterovirus associated
Complications of childhood disease
HIV-associated

56

3 most common causes of bacterial meningitis?

Neisseria meningitidis
Haemophilus influenzae B
Pneumococcus

57

Bacterial meningitis with particular relevance in pregnancy?

Listeria monocytogenes

58

Bacterial meningitis with particular relevance in neonates?

GBS (strep viridans)

59

Aseptic meningitis causes?

Viral or partially treated bacterial
Fungal - cryptococcus, aspergillus etc.
Parasitic e.g. Toxoplasma

60

Differentiating between meningitis and encephalitis signs and symptoms?

Encephalitis typically has more reduction in consciousness level +/- focal neurological signs, meningitis is more about the meningism

61

Features of cerebral abscess?

Swinging fever and signs
Signs of raised ICP - Papilloedema, postural headache, reduced consciousness
Focal signs - visual fields?

62

Quad of acute bacterial meningitis?

Fever
Headache
Neck stiffness and photophobia
Altered mental state

63

4 contraindications to LP for meningitis?

Any signs of ICP - risk of coning
Acutely reduced consciousness
Focal neurological signs
Immunodeficiency

64

What LP findings does bacterial meningitis provide?

Neutrophilia
High exudative protein count
Low glucose

65

What LP findings does viral meningitis provide?

Lymphocytosis
Slightly raised protein if at all
Normal glucose

66

What LP findings does fungal or TB meningitis demonstrate?

Lymphocytosis
Very high protein - chronicity
Normal or lowered glucose

67

Is LP is contraindicated acutely, what investigation should be done instead?

CT/MRI

68

Urgent treatment if suspecting meningococcal sepsis?

Benpen IM ASAP before transfer etc.
Then start on ceftriaxone/cefotaxime

69

What prophylaxis is used for contacts of bacterial meningitis? Why?

Ciprofloxacin/Rifampicin - don't want to breed resistance to ceftriaxone

70

What is the most common viral encephalitis and what is its specific treatment?

HSV - IV aciclovir

71

What intracranial infection can result from childhood measles infection?

Subacute sclerosing panencephalitis

72

Differentiating between cellulitis and erysipelas?

Cellulitis goes deeper (down to deep subcut tissue) and has poorly demarcated borders; erysipelas typically has well demarcated borders and looks like a fiery red rash

73

RFs for cellulitis?

Immunosuppression
Prev cellulitis
Skin lesions incl insect bites and athletes foot
Old age, venous insufficiency, obesity
Alcohol, IVDU
Lymphoedema

74

Differentials for cellulitis/erysipelas?

Necrotising fasciitis
Compartment syndrome
Septic arthritis/osteomyelitis
DVT
Varicose eczema, venous insufficiency
Vasculitis/thrombophlebitis

75

Usual management of SSTIs?

Flucloxacillin to cover GAS, staph

76

What triad is suggestive of primary HIV infection?

Fever
Pharyngitis
Rash (palmar plantar?)

77

Pathophysiology behind HIV?

Retrovirus which binds to cells with CD4 receptors (T lymphocytes, macrophages, monocytes etc) spread by bloodborne contact (sex, needles etc.)

78

What diagnostic can be used in the acute HIV illness before Ab detection?

HIV RNA and p24 antigen

79

What diagnostic screen can be used for established HIV?

anti-HIV Abs

80

What is the first stage of illness in HIV?

Seroconversion illness few weeks post-infection - may be glandular fever like, with classic triad of fever rash and pharyngitis

81

What follows seroconversion in HIV illness?

Asymptomatic infection - slow replication with low viral load, cd4 count relatively unaffected

82

What follows completely asymptomatic infection in HIV and how is it defined?

Persistent generalised lymphadenopathy PGL
LNs >1cm in at least 2 non-inguinal sites persistent for at least 3 months with no other cause

83

What symptoms might be experienced in HIV as cd4 count starts to drop, alongside PGL?

Constitutional Sx - diarrhoea, weight loss, fever, night sweats
Opportunistic infections - oral hairy leukoplakia, oral thrush, VZV, recurrent HZV, seborrhoeic dermatitis

84

What 2 components are used to stage HIV in the CDC classification?

CD4 count and clinical category

85

CD4 divisions used in HIV staging? When is treatment generally started?

>500/mm3 = stage 1
200-499 = stage 2 (treatment when under 350)
Less than 200 = stage 3

86

What is category A in HIV staging?

Asymptomatic infection, including seroconversion or PGL

87

What is category B in HIV testing?

Symptomatic infection (incl constitutional Sx diarrhoea, fever) or opportunistic infections not meeting category C criteria, incl oral thrush and oral hairy leukoplakia and VZV, ITP

88

What is category C in HIV staging?

Presence of at least 1 AIDS defining condition

89

Which CDC classifications of HIV are indicative of AIDS?

A3, B3 and C1, C2 and C3

90

Common AIDS defining infections?

Oesophageal candidiasis
TB and other mycobacterium infections incl MAC
Cryptococcal meningitis
Cryptosporidium infection
Pneumocystis jirovecii pneumonia
Histoplasmosis infection
Toxoplasmosis infection (cerebral)
CMV retinitis, unusual EBV or HSV infections
PML

91

Common AIDS defining cancers?

Invasive cervical carcinoma
Burkitts lymphoma (EBV)
Non-hodgkins lymphoma
Neurolymphoma
Kaposi sarcoma

92

Under what 3 circumstances can ART for HIV be started?

CD4 under 350
Nervous system involvement
AIDS defining condition

93

Under what circumstances may ART be started for HIV CD4 count between 350-500/mm3?

Present or likely CV disease

94

What vaccinations should be given in HIV? What should be avoided?

Generally everything possible apart from BCG and VZV

95

6 classes of ART?

Nucleoside reverse transcriptase inhibitors
Non-nucleoside reverse transcriptase inhibitors
CCR5 inhibitors
Fusion inhibitors
Protease inhibitors
Integrase inhibitors

96

What type of ART is majorly associated with lipodystrophy syndrome?

Protease inhibitors

97

What complication can arise from ART? What is it?

Lipodystrophy syndrome - redistribution of fat from subcutaneous to central, increased insulin resistance and dislipidaemia

98

What type of ART should be avoided in concurrent hepatitis?

Nucleoside reverse transcriptase inhibitors

99

5 methods for preventing HIV spread?

Safe sexual practises
Needle exchange programmes
Blood screenings for transfusions
Screening during pregnancy
Post exposure prophylaxis

100

What is often implicated in acute infective COPD exacerbations? First line Rx?

Haemophilus - doxycycline

101

MARRFAW of infectious disease symptoms screen?

Malaise
Arthralgias/myalgias
Rigors
Rash
Fever and night sweats
Appetite
Weight loss

102

TINVAPPS of broad areas of infectious disease RFs to ask about?

Travel - ask first and explore where when what who
Infectious contacts/food related
Needles - IVDU, blood transfusion, tattoos, medical Rx abroad
Vaccinations
Previous major infection - BBVs and TB
Sexual Hx if appropriate
Previous hospital admission or indwelling devices
Animals

103

3 criteria for defining PUO?

Fever over 38.3 on several occasions over duration of illness
At least 3 weeks of illness
Failure to reach diagnosis after proper investigation at 2 OP visits or 3 days inpatient

104

Common cancers causing PUO?

Lymphoma
Leukaemia
Renal cell carcinoma

105

What might be the cause of PUO (and arthralgia, spinal tenderness) in a patient with Hx of cattle/sheep exposure and raw milk products?

Brucellosis

106

What characterises oral thrush vs hairy oral leukoplakia?

Oral thrush comes off with scraping

107

What causes HIV associated retinitis at CD4 less than 50?

CMV

108

Cause of insidious fungal meningitis in HIV patient?

Cryptococcus

109

What virus causes HIV associated neurolymphoma?

EBV

110

Most common cerebral infection in HIV?

Toxoplasmosis

111

How does PCP pneumonia present?

Dry cough, SOBOE, night sweats - looks a bit like TB

112

What is the incubation period of gonorrhoea?

Up to 2 weeks

113

Rx for HPV?

Podophyllotoxin (podophyllin), cryotherapy, electrocautery or excision

114

When does secondary Syphillis infection occur?

1-2 months after primary chancre

115

2 features of congenital Syphillis?

Saber tibia
Hutchinsons teeth (have little half moons in them)

116

What criteria is used in defining BV?

Amsel criteria 3/4 of:
Thin white discharge
Clue cells
KOH sniff test
pH over 4.5

117

Incubation and presentation of cholera?

3-4 days then abrupt onset severe diarrhoea, going from brown and water to Mucoid fluid alongside dehydration

118

What microscopy findings indicate cholera infection?

Comma shaped highly motile gram negative bacteria

119

What is yellow fever?

Another flavivirus a bit like dengue but slightly longer incubation
VACCINE!

120

Early Sx of schistosomiasis?

Swimmers ish - skin irritation and rash

121

Second stage of schistosomiasis infection?

Invasive stage - dry cough, abdo pain, splenomegaly with eosinophilia

122

Chronic schistosomiasis infection?

Chronic diarrhoea and hepatomegaly, portal HTN etc.

123

Diagnosis schistosomiasis?

PCR serodiagnosis
Ova found in faeces

124

Rx for schistosomiasis?

Single dose praziquantel

125

Classical Sx of diphtheria?

Grey tough pseudomembrane on pharynx/tonsils
Fever, pharyngitis, mega cervical lymphadenopathy/oedema (Bulls neck sign), stridor, airway compromise

126

Defining features of giardiasis?

More common in well sanitised areas
Acute diarrhoea or chronic flatulence, grumbly intestinal Sx and early morning greasy/loose stools

127

3 things that can cause Asplenism?

Iatrogenic
SCD
Coeliacs