Infectious Disease 1 Flashcards
(127 cards)
1
Q
Particular food implicated in Hep A transmission?
A
Shellfish
2
Q
Symptoms of Hep A?
A
Nausea, vomiting, malaise
Arthralgias
Rash
3
Q
Signs of Hep A?
A
Jaundice
Fever
Lymphadenopathy
Hepatosplenomegaly
4
Q
What test is diagnostic of Hep A?
A
anti-HAV IgM
5
Q
What test can be used to investigate previous HAV infection?
A
anti-HAV IgG
6
Q
3 preventative measures for Hep A?
A
Good sanitation in developing countries
Good hygiene practises
IgG vaccine
7
Q
How is HBV transmitted?
A
Blood-borne, sexual/bodily fluids and vertically
8
Q
Particular RFs for HBV infection?
A
Sexual contact with infected person IVDU Tattoos, particularly foreign countries Medical treatment abroad Blood transfusions before 1991
9
Q
What 3 features are more prominent in HBV than HAV if present?
A
Rash
Jaundice
Arthralgia
10
Q
How does HBV often present?
A
It’s often asymptomatic; otherwise like a more severe HAV with prominent jaundice, rash and arthralgia
11
Q
What blood tests indicate an acute HBV infection?
A
HBcIgM, HBcIgG
HBsAg
HBV DNA
Acutely deranged LFTs
12
Q
What 2 blood markers are only found during the acute phase of HBV infection?
A
HBsAg
HBV DNA
13
Q
What is HBV DNA used to monitor?
A
Treatment and infectivity
14
Q
What unusual HBV marker is used to indicate high infectivity?
A
HBeAg
15
Q
What blood tests indicate if someone has had a past HBV infection and recovered?
A
HBsAb
HBcIgG
16
Q
What blood test indicates someone who has been vaccinated against HBV?
A
HBsAb (but no HBcIgG)
17
Q
What blood test is used as a screening test for HBV?
A
HBsAg
18
Q
Someone is HBV DNA, HBsAg positive as well as HBcIgM positive and has deranged LFTs. Diagnosis?
A
Acute infection
19
Q
Someone is positive only for HBsIg. Diagnosis?
A
Vaccinated therefore immune
20
Q
Someone is positive for HBsIg and HBcIgG. Diagnosis?
A
Immune due to previous infection
21
Q
Someone is positive for HBsAg, HBcIgG and HBeAb but negative for HBcIgM and HBsIg. Diagnosis?
A
Chronic infection
22
Q
What is the most likely outcome of HBV infection?
A
Complete recovery -
23
Q
What LFT picture does Hep A give?
A
Hepatic damage + raised bilirubin
24
Q
Apart from complete recovery and chronicity how else can HBV infection resolve?
A
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
