HIV Flashcards
(158 cards)
1
Q
What does HIV cause?
A
The Acquired Immunodeficiency Syndrome (AIDS)
+ Opportunistic infections
+ AIDS-related cancers
2
Q
What is the single highest predictor of mortality in AIDS?
A
AIDS-related conditions
3
Q
What proportion of deaths in AIDS are caused by a late diagnosis?
A
1/4
4
Q
People with HIV have a ‘near-normal’ life expectancy
A
TRUE
5
Q
HIV infection is not preventable
A
FALSE - it is preventable
6
Q
What type of virus is HIV?
A
A retrovirus
7
Q
Where did HIV 2 originate?
A
West Africa – Sootey mangabey (simian immunodeficiency virus)
8
Q
Is HIV 1 or 2 less virulent?
A
2
9
Q
Where did HIV 1 originate?
A
Central/West African chimpanzees
10
Q
What was responsible for the global pandemic starting in 1981?
A
HIV 1 group M
11
Q
What are the target site for HIV?
A
CD4+.
12
Q
CD4 (Cluster of Differentiation) is a glycoprotein found on the surface of a range of cells. Give examples of such cells.
A
- T helper lymphocytes (“CD4+ cells”)
- Dentritic cells
- Macrophages
- Microglial cells
13
Q
What are CD4+ Th Lymphocytes essential for?
A
The induction of the adaptive immune response.
14
Q
What roles in particular do CD4+ Th Lymphocytes carry out to achieve their aim of adaptive immune response induction?
A
- Recognition of MHC2 antigen-presenting cell
- Activation of B-cells
- Activation of cytotoxic T-cells (CD8+)
- Cytokine release
15
Q
List conditions that people with HIV have susceptibility to.
A
- Viral infections
- Fungal infections
- Mycobacteria infections
- Infection induced cancers
16
Q
What effect does HIV infection have on immune response?
A
- Cessation of cells in lymphoid tissue
- Reduced proliferation of CD4+ cells
- Reduction of CD8+ T cell activation
- Reduction in antibody class switching
- Chronic immune activation
17
Q
What happens to CD4+ cells in AIDS?
A
They essentially just stop replicating and die.
18
Q
Describe microbial translocation.
A
Because the gut is full of lymphoid tissue, it is attacked first.
It can then no longer protect itself, and bits of bacterial cells leak across the gut.
this leads to chronic immune activation.
19
Q
What are the normal parameters for CD4+ Th cells?
A
500-1600 cells/mm3.
20
Q
What level of CD4+ Th cells confers risk for opportunistic infections?
A
<200 cells/mm3.
21
Q
When does rapid replication of the HIV virus occur?
A
In very early and very late infection
22
Q
How often is there a new generation?
A
Every 6-12 hours
23
Q
What is the average time to death without treatment?
A
9-11 years
24
Q
Outline how infection goes from initial infection to dissemination.
A
- Infection of mucosal CD4 cell.
- Transport to regional lymph nodes.
- Infection established within 3 days of entry.
- Dissemination of virus.
25
Name 2 examples of mucosal CD4+ cells.
Langerhans and dendritic cells.
26
Up to what % present with symptoms?
80%
27
When is the average onset of sx of primary HIV infection?
2-4 weeks after infection
28
What are the primary symptoms of a HIV infection?
* Fever.
* Rash (maculopapular).
* Myalgia.
* Pharyngitis.
* Headache/aseptic meningitis.
29
What can a primary HIV infection often be mistaken for?
Glandular fever
30
What is the danger with primary HIV infection?
There is a very high risk of transmission
31
What happens during the asymptomatic phase of HIV infection?
* Ongoing viral replication.
* Ongoing CD4 count depletion.
* Ongoing immune activation.
32
What is there a risk of during the asymptomatic stage of HIV?
Onward transmission if remains undiagnosed.
33
What is the definition of ‘opportunistic infection’?
An infection caused by a pathogen that does not normally produce disease in a healthy individual.
It uses the “opportunity” afforded by a weakened immune system to cause disease.
34
What is the causative organism in Pneumocystis Pneumonia?
Pneumocystis jiroveci
35
What is the causative organism in Pneumocystis Pneumonia?
Pneumocystis jiroveci
36
What symptoms are associated with Pneumocystis Pneumonia?
* Insidious onset.
* SOB.
* Dry cough.
37
What symptoms are associated with Pneumocystis Pneumonia?
* Insidious onset.
* SOB.
* Dry cough.
38
What is the MAIN sign associated with Pneumocystis Pneumonia?
Exercise desaturation.
39
How may Pneumocystis Pneumonia appear on CXR?
* May be normal.
* Interstitial infiltrates, reticulonodular markings.
(looks a bit like cardiac failure, but without cardiac enlargement)
40
What methods are used to diagnose Pneumocystis Pneumonia?
BAL and immunofluorescence +/- PCR.
41
How is Pneumocystis Pneumonia treated?
With high dose co-trimoxazole (+/- steroid).
42
What is the prophylactic treatment of Pneumocystis Pneumonia?
Low dose co-trimoxazole.
43
Describe the relationship between HIV and TB.
EPIDEMIOLOGICAL SYNERGY!
People who are HIV + are more likely to get TB
44
What organism is associated with cerebral toxoplasmosis?
Toxoplasma gondii (associated with cat litter)
45
What is the CD4 threshold for cerebral toxoplasmosis?
<150
46
Outline 2 important features of cerebral toxoplasmosis in HIV.
- REACTIVATION OF LATENT INFECTION
| - MULTIPLE CEREBRAL ABSCESSES (chorioretinitis)
47
Outline the signs and symptoms of cerebral toxoplasmosis.
* Headache.
* Fever.
* Focal neurology.
* Seizures.
* Reduced consciousness.
* Raised intracranial pressure.
48
What organism is responsible for cyclomegalovirus?
CMV
49
What is the CD4 threshold for Cyclomegalovirus?
<50
50
What can CMV virus also cause?
* Retinitis
* Colitis
* Oesophagitis
51
How may CMV infection present?
* Reduced visual acuity
* Floaters
* Abdo pain, diarrhoea, PR bleeding
52
What is therefore mandatory for all individuals with CD4<50?
Ophthalamic screening
53
Herpes zoster is _____ dermatomal and _________
Multi
| Recurrent
54
Herpes simplex is hypertrophic
TRUE
55
Herpes simplex is resistant to acyclovir
TRUE
56
What organism is responsible for HIV associated neurocognitive impairment?
HIV - 1
57
What is the CD4 threshold for HIV associated neurocognitive impairment?
Any
Increased incidence with increased immunosuppression though
58
What does HIV associated neurocognitive impairment present with?
Reduced short term memory +/- motor dysfunction
59
What is the causative organism in Progressive Multifocal Leukoencephalopathy?
JC virus
60
What is the CD4 threshold for the development of Progressive Multifocal Leukoencephalopathy?
<100
61
How does Progressive Multifocal Leukoencephalopathy present?
* Rapidly progressing focal neurology.
* Confusion.
* Personality change. (causes demyelination)
62
What is cachexia in HIV known as?
'Slims' disease
63
Slims disease has multiple causes, list some of these.
* Metabolic – chronic immune activation.
* Anorexia – multifactorial.
* Malabsorption/diarrhoea.
* Hypogonadism.
64
What organism is responsible for AIDS related Kaposi's sarcoma?
Human herpes virus 8 (HHV 8).
65
In the pre-ART era, what % of people with AIDS developed Kaposi’s sarcoma?
Up to 40%
66
What is Kaposi's sarcoma?
A vascular tumour
67
What is the CD4 threshold for Kaposi's sarcoma?
Any – but increased incidence with increased immunosuppression.
68
How does Kaposi's sarcoma present?
As spongy raised nodules or papules (vascular tumours) on CUTANEOUS, MUCOSAL and VISCERAL (ie. pulmonary, GI) surfaces.
69
How is Kaposi's sarcoma treated?
* If just on skin – treating HIV with HAART should help.
* Local therapies.
* Systemic chemotherapy.
70
What organism is responsible for AIDS related non-hodgkins lymphoma?
EBV (Burkitt’s lymphoma, primary CNS lymphoma).
71
What is the CD4 threshold for AIDS related non-hodgkins lymphoma?
Any - but incidence increases with immunosuppression
72
How does non-hodgkins lymphoma present?
* More advanced B symptoms
* Bone marrow involvement
* Extranodal disease
* ↑ CNS involvement
73
How is non-hodgkins lymphoma treated?
As for HIV, with the addition of HAART
74
What organism is responsible for AIDS related cervical cancer?
HPV
75
What is the difference between HPV infection in people with HIV compared to non-affected individuals?
* Persistence of HPV infection.
| * Rapid progression to severe dysplasias and invasive disease.
76
How often should women with HIV be screened for HPV
Every year, rather than every 3 years
77
Now, all MSM <45 are vaccinated against HPV due to risk of anal cancers
TRUE
78
HIV testing should be offered to all complicated HPV disease, give examples?
* Recalcitrant warts
| * High grade CIN, VIN, AIN, PIN
79
List some non-opportunistic symptoms/sources of symptoms in HIV.
- Mucosal candidiasis
- Seborrhoeic dermatitis
- Diarrhoea
- Fatigue
- Worsening psoriasis (as this is CD8-mediated)
- Lymphadenopathy
- Parotitis
- Epidemiologically linked conditions
- STIs
- Hepatitis B
- Hepatitis C
80
What can haematological manifestations be caused by?
* HIV.
* Opportunistic infections (MAI).
* AIDS-malignancies.
* (HIV drugs)
81
What is the CD4 threshold of haem manifestations?
Any
82
ANAEMIA AFFECTS UP TO 90% of people with AIDS
TRUE
83
What % of all HIV infections in the UK does sexual transmission account for?
94%
84
What % of new infections in the UK does this account for?
96%.
- Sex between men (51%).
- Sex between women (45%).
85
What factors increase the risk of sexual transmission of HIV?
* Anoreceptive sex. (the anus has lots of CD4 cells)
* Trauma.
* Genital ulceration.
* Concurrent STI.
86
What type of cells are plentiful in the anus?
CD4
87
Outline the ways in which there is parental transmission of HIV.
* Injection drug use (sharing ‘works’).
* Infected blood products.
* Iatrogenic.
88
When may mother-to-child transmission of HIV occur?
* In utero/trans-placental.
* During delivery.
* During breastfeeding.
89
What proportion of at-risk babies will become infected with HIV?
1 in 4
90
What proportion of HIV+ infants will die before their first birthday if untreated?
1 in 3
91
In the UK, what is the risk of MTCT in the uk i) overall ii) when viral load undetected at delivery?
i) 1.2%.
| ii) <0.1%.
92
How many MSM have AIDS?
1 in 20
93
How many MSM have AIDS in London?
1 in 8
94
Who is the risk group with the highest proportion of HIV in the UK?
MSM (1:26 outside London and 1:8 in London).
95
What % of individuals living with HIV in the UK are undiagnosed?
17%
96
Who is most likely to be undiagnosed with HIV?
Heterosexual men
97
Who are most likely to present late with HIV?
Heterosexual men
98
HIV in PWID' is UNCOMMMON
TRUE
99
Where is universal screening of HIV done?
In high prevalence areas
100
Testing in the UK is done in the presence of clinical indicators
YES
101
When is universal screening recommended?
In high prevalence areas in the UK, where local prevalence is >0.2% (2/1000).
102
In universal testing, who are HIV tests recommended to?
* All general medical admissions.
| * All new patients registering at a GP.
103
Tayside’s prevalence is <0.2% (~1.5/1000), so universal testing is not recommended.
TRUE
104
Outline 5 situations where an op-out service for HIV testing is offered.
* TOP service
* GUM clinics
* Drug dependancy services
* Antenatal service
* Assisted conception service
105
Name 3 areas of high HIV prevalence.
* Sub-Saharan Africa
* Caribbean
* Thailand
106
What groups of people are offered HIV screening tests?
* MSM
* Females with bisexual partners
* PWID
* People with HIV + partners
* Adults from endemic areas
* Children from endemic areas
* Sexual partners from endemic areas
* History of iatrogenic exposure in endemic areas
107
How do you obtain consent for a HIV test?
1. Explain to patient they are being offered an HIV test and why (normalise)
2. What the benefits of testing are
(Improve long term health + Protect partner(s))
3. How and when they can expect to receive results
4. Reassure re: confidentiality
5. Written information can be made available
108
How should you, as a clinician, go about taking a HIV test?
1. Document consent (or refusal).
2. Obtain VENOUS sample for serology.
3. Request via ICE (accelerate if clinically indicated).
4. Ensure pathway in place for retrieving and communicating result
109
What should you do if a patient is incapacitated but you want to do a HIV test?
* Only test if in patient’s best interest.
* Consent from relative not required.
* If safe, wait until patient regains capacity.
* Obtain support from HIV team if required.
110
Which markers of HIV are used by labs to detect infection?
* RNA
* Capsule protein p24
* Envelope proteins gp120
111
What do HIV antibody tests detect?
HIV-1 and HIV-2 antibody detect IgM and IgG
112
When are antibody tests very sensitive/specific?
In established infection
113
What is the average window period of antibody tests?
average of 20-25 days.
114
What is the average window period of antibody tests?
Average of 20-25 days.
115
What do 4th generation HIV tests test for?
Combined antibody and antigen (p24).
116
By how much do 4th generation tests shorten the window period?
By ~5 days.
117
Outline the variation quoted in the window period.
14-28 days.
Variability between assays.
Variability between labs.
118
A negative 4th generation test performed at 4 weeks following an exposure is highly likely to exclude HIV infection
TRUE
119
How is a rapid HIV test (POCT) done?
Fingerprick specimen or saliva.
120
How long do results take for a POCT?
20-30 mins
121
What are the 2 categories of POCT?
3rd generation – Ab only.
or
4th generation – Ab/Ag
122
Outline the advantages of POCT.
* Simple to use.
* No lab required.
* No venepuncture required.
* No anxious wait.
* Reduce follow-up.
* Good sensitivity.
123
What are the disadvantages of POCT?
* Expensive ~£10
* Quality control
* Poor positive predictive value in low prevalence settings
* Not suitable for high volume
* Can’t be relied on in ?early infection
124
What can RITA be used for?
To identify if an infection has occurred within the preceding 4-6months.
125
What do RITA do?
Measure different types of antibodies or strength of antibody binding.
126
What is the largest downfall of RITA?
Have a large margin of error
127
Essentialy, what does RITA do?
This tests the antibody binding strength, and can tell you if an infection might be recent.
128
What are the advantages of RITA?
* Surveillance.
* Local epidemiology.
* Assess HIV testing programmes.
* Inform partner notification.
* Safer sex advice.
* Interpretation of CD4.
129
What are the disadvantages of RITA?
* Accuracy.
* Patient distress.
* Criminalisation.
130
What is CD4 a marker of?
How well the immune system is working
131
What is there an increased risk of the more the CD4 count falls?
Opportunistic infection
132
Outline the potential targets for anitviral drugs.
* Reverse transcriptase.
* Integrase.
* Protease.
* Entry – fusion, CCR5 receptor.
* Maturation.
133
What drugs have in-vitro effects against HIV?
Nucleoside analogues reverse transcriptase inhibitors (NRTI), e.g. zidovudine
134
Dual NRTI therapy reduced mortality by 33%
TRUE
135
The HIV virus is goof at developing resistance
TRUE
136
What is HAART defined as?
A combination of three drugs from at least 2 drug classes to which the virus is susceptible.
(ie. drugs which work at two different points in the cycle)
137
What is the purpose of HAART?
* Reduce virus load to undetectable.
* Restore immunocompetence.
* Reduce morbidity and mortality.
* Minimise toxicity (maximise tolerability).
138
What is key to preventing drug resistance in HIV?
ADHERENCE
ADHERENCE
ADHERENCE
139
Outline some key factors in an anti-viral wish list.
- Tolerability.
- Low toxicity.
- Low pill burden.
- Low dosing frequency.
- Minimal drug-interactions.
- High barrier to resistance.
140
Generally, protease inhibitors are what?
Potent liver enzyme inhibitors
141
Generally, NNRTI’s are potent what?
Liver enzyme inducers
142
Some drugs require pharmacological boosting (with potent liver enzyme inhibitors)
TRUE
143
Look at notes for HAARTS toxicity
Many HAART drugs cause side effects in different body systems
144
Partner notification and disclosure of HIV is a _________ process
Voluntary
145
What strategies may be used to encourage partner notification?
* Partner referral.
* Provider referral.
* Conditional referral.
146
Outline some barriers to partner notification and disclosure.
- Fear (rejection, isolation, violence)
- Confidentiality
- Stigma
147
What is stigma?
The shame or disgrace attached to something regarded as socially unacceptable
148
How can sexual transmission of HIV be prevented?
* Condom use
* HIV treatment
* STI screening and treatment
* Sero-adaptive sexual behaviours
* Disclosure
* Post-exposure prophylaxis
* Pre-exposure prophylaxis
149
THERE IS NO RISK OF TRANSMISSION BY CASUAL/HOUSEHOLD CONTACT!!!!
True
150
What are the conception options in a HIV+ male and HIV- female?
* Treatment as prevention.
| * PreP in female partner.
151
What are the conception options in a HIV+ female and HIV- male?
* Self-insemination.
* Treatment as prevention.
* PreP in male partner.
152
What should be given during pregnancy to prevent mother to child transmission?
HAART
153
How should baby be delivered if there is i) an undetected ii) a detected viral load?
i) Vaginal delivery.
| ii) Caesarean section.
154
What should be given to a neonate is their mother is HIV+?
4/52 PEP.
155
What should be baby be fed with if its mother is HIV +?
Exclusive formula feeding
156
What is the risk of MTCT in UK/Ireland?
<1%
157
What is the risk of MTCT if viral load is undetected at delivery?
<0.1%
158
HIV testing must be UPSCALED to reduce the undiagnosed fraction.
True
