HIV Flashcards
(73 cards)
1
Q
How is HIV spread?
A
- Sexual transmission
- Injection drug misuse
- Blood products
- Vertical transmission
- Organ transplant
2
Q
When can a patient be tested for HIV without giving consent?
A
Unconscious patients can be tested if you think it is in the patient’s best interest
3
Q
What does the HIV do?
A
Infects and destroys cells of the immune system especially Th cells that have CD4 receptors on their surface
4
Q
Where are CD4 receptors found?
A
- Lymphocytes
- Macrophages
- Monocytes
- Cells in the brain and skin
- Other
5
Q
What happens in HIV?
A
- CD4 count declines & HIV viral load increases
- Increasing risk of developing infections and tumours
- The severity of these illnesses is greater the lower the CD4 count (normal CD4 > 500)
6
Q
When are most AIDS diagnoses made?
A
When the CD4 count <200
7
Q
What is the pragmatic approach to HIV?
A
Consider symptomatic and asymptomatic disease
8
Q
What is clinical stage 1 of HIV?
A
- Asymptomatic
- Persistent generalised lymphadenopathy
9
Q
What is clinical stage 2 of HIV?
A
- Weight loss
- Minor mucocutaneous manifestations
- HZV infection
- Recurrent URTI
10
Q
What is clinical stage 3 of HIV?
A
- Significant weight loss
- Unexplained chronic diarrhoea
- Unexplained prolonged fever
- Thrush
- Oral hairy leukoplakia
- Pulmonary TB
- Severe bacterial infections
11
Q
What is clinical stage 4 of HIV?
A
- Wasting syndrome
- Encephalopathy
- Progressive multifocal leukoencephalpathy
- Cryptococci’s, extrapulmonary
- Many others…
12
Q
What types of infection are you more prone to with a CD4 count <350?
A
- Thrush
- Skin changes
13
Q
What types of infection are you more prone to with a CD4 count<200?
A
- PCP
- TB
- Cryptosporidiosis
- Kaposis lymphoma
- Toxoplasmosis
- Cryptococcal meningitides
- CMV MAC
14
Q
Is it AIDS or HIV?
A
- Certain infections and tumours that develop due to a weakness in the immune system are classified as AIDS illnesses. If you have no symptoms then you have HIV infection only.
- Virtually everyone with an AIDS illness should recover from it and then be put on antivirals to keep them free from any future illness.
15
Q
Respiratory: AIDS defining conditions
A
- TB
- Pneumocystis
16
Q
Neurology: AIDS defining conditions
A
- Cerebral t toxoplasmosis
- Primary cerebral lymphoma
- Cryptococcal meningitis
- Progressive multifocal leucoencephalopathy
17
Q
Dermatology: AIDS defining conditions
A
Kaposi sarcoma
18
Q
Gastroenterology: AIDS defining conditions
A
Persistent cryptosporidiosis
19
Q
Oncology: AIDS defining conditions
A
NH lymphoma
20
Q
Gynaecology: AIDS defining conditions
A
Cervical cancer
21
Q
Ophthalmology: AIDS defining conditions
A
Cytomegalovirus retinitis
22
Q
What is the natural history of HIV?
A
- Acute infection: seroconversion
- Asymptomatic
- HIV related illnesses
- AIDS defining illness
- Death
23
Q
What happens when HIV antibodies first start to develop?
A
Primary HIV/Seroconversion
- Approximately 30 - 60% of patients have a seroconversion illness
- Abrupt onset 2-4 weeks post exposure, self limiting 1-2 weeks
- Symptoms generally non-specific and differential diagnosis includes a range of common conditions (can present like glandular fever)
24
Q
What do symptoms of seroconversion include?
A
- Flu-like illness
- Fever
- Malaise and lethargy
- Pharyngitis
- Lymphadenopathy
- Toxic exanthema
25
What is the treatment for HIV?
- Not currently curable
| - Combined ART taken as a combined pill once a day
26
What are the principles of antiretroviral therapy?
- Different classes of drugs acting on different stages in HIV lifecycle
- Combination antiretroviral therapy (cART) means at least 3 drugs from at least 2 groups
- Adherence needs to be over 90% - support patient
- cART can lead to a normal life but side effects can be significant eg metabolic, lipodystrophy,
27
Where do the treatments act?
- Reverse transcription inhibitors
- Integrase inhibitors
- Protease inhibitors
28
When should ART be commenced?
-Consider starting all patients at diagnosis regardless of CD4
If CD4 < 350 cells/mm3 encourage patients to start treatment
-If CD4 < 200 need to start as soon as possible
-Any pregnant woman:start before third trimester
29
What should pregnant women know about their delivery?
They can have a vaginal delivery if their viral load is undetectable
30
What ART is first line?
Three drug combination with treatment adjustment if VL not adequately suppressed after 4-6 weeks of therapy
31
What is the current life expectancy?
Life expectancy according to CD4 Nadir (lowest CD4 before starting therapy) in patient diagnosed aged 20
- CD4< 100 age 52
- CD4 100-200 age 62
- CD4 >200 age 70+
32
How long must patients be on treatment?
- Once treatment is started it must be maintained for the rest of life.
- It may need to change from time to time
- Always a need fro antiviral therapy
33
Why do treatments fail?
Poor adherence leads to viral mutation and resistance
Incomplete suppression
- Inadequate potency
- Inadequate drug levels
- Inadequate adherence
- Pre-existing resistance
34
What types of antiviral drugs are there?
- Nucleoside reverse transcriptase inhibitors
- Non-nucleoside reverse transcriptase
- Protease inhibitors
- Integrase inhibitors
35
What are the possible side effects of nucleoside reverse transcriptase inhibitors?
- Lipodystrophy
- Marrow toxicity
- Neuropathy
36
What are the possible side effects of non-nucleoside reverse transcriptase inhibitors?
- Skin rashes
- Hypersensitivity
- Drug interactions
37
What are the possible side effects of protease inhibitors?
- Lipodystrophy
- Drug interactions
- Diarrhoea
- Lipodystrophy
- Hyperlipidaemia
38
What are the possible side effects of integrase inhibitors?
Rashes
39
How can lipodystrophy be treated
Change drugs (less likely with newer agents)
Cosmetic procedures
- Facelift
- Liposuction
- Fillers
40
What are the challenges of HIV care in 2018?
- Osteoporosis
- Cognitive impairment
- Malignancy
- Cerebrovascular disease
- Renal disease
- Ischaemic heart disease
- Diabetes mellitus
- The ageing patient
41
How can HIV be prevented?
- Behaviour change and condoms
- Circumcision
- Treatment as prevention (VL undetectable = untransmissable (pregnancy))
- Pre-exposure prophylaxis (PrEP)
- Post-exposure prophylaxis for sexual exposure (PEPSE)
42
What is the future of HIV care?
- Therapeutic vaccines
- Long-acting injectable drug treatments
- Cure – “kick-kill” strategies
43
What is the epidemiology of HIV in Europe?
- M > F
- Variation between countries as to predominant route of spread
- UK is a low prevalence area
44
What is the main route of transmission within the UK?
- Sexual
| - Transmission by IVDU is actually <1% in the UK
45
What is the predominant form of HIV?
HIV-1
46
Describe the basic virology of HIV?.
- HIV-1 attaches to cells with CD4 on surface (Th) lymphocyte cells with certain chemokine receptors
- Integrase facilitates integration into host cell DNA
- Contains protease enzyme, needed for mature virus progeny
47
How is virus diversity produced?
- Retroviruses use reverse transcriptase to convert RNA to DNA
- There is lack of accuracy during replication fiving rise to virus diversity
48
What family does HIV belong to?
A group of retroviruses called lentiviruses
49
What does the virus require for replication?
- Host cell
| - RNA must be transcribed into DNA
50
What is the genome of retroviruses made of?
2 single chains of RNA
51
What specific form of HIV is responsible for the global HIV epidemic?
HIV-1 Group M
52
Briefly describe how a virus replicates?
- Binding and entry to host cell
- Reverse transcription
- Integration
- Transcription
- Assembly
- Release and protease
53
What is type of testing is used to diagnose HIV?
Antibody/antigen testing
54
Why are lab tests carried out in the management of HIV infection?
- Viral load
- HIV resistance testing
- Avidity testing
- Subtype determination
- Tropism testing
- Drug levels
55
What is the diagnostic window?
- The period of time between exposure and seroconversion when markers of infection (antibodies) are not detectable
- Testing during this period can give false negatives
- Length of window varies
56
What antibody/antigen testing is carried out?
- 4th generation ELISA assays which allow simultaneous detection of antibody and antigen
- Window period is 1 month
57
What is HIV genome detection (viral load) used for?
- Used to monitor the effectiveness of HIV treatment
- Used for diagnosis in presence of maternal antibody
- Detection of HIV RNA (range of 40 to >10 million genome copies / ml blood)
58
How does resistance develop?
- Acute infection
- Chronic infection
- Successful antiretroviral therapy
- Therapy failure
- Treatment interruption
- Salvage therapy and failure
59
How is HIV resistance testing carried out?
- Sequencing of the polymerase and protease genes
| - Identification of specific mutations that confer resistance to antiretroviral drugs
60
What is HIV resistance testing used for?
- Baseline at diagnosis
- Suboptimal treatment response
- Treatment failing
- Want to change treatment for another reason
61
What does tropism testing tells us?
Which co-receptor does the virus use to enter CD4 cells, required before using a CCR5 antagonist
62
What does drug level testing tell us?
Compliance
63
Do you have to tell your work when diagnosed with HIV?
- If an HIV test is not required for your work then no
- You may need to have an HIV test for a visa to work abroad
- If involved in healthcare, you need to avoid exposure-prone procedures (EPPs) (may not apply if on effective treatment)
64
How is HIV infection monitored?
- CD4 lymphocyte count
- HIV viral load
- Clinical features
65
What is the risk of transmisson of BBV to healthcare workers?
Percutaneous exposure (sharp instrument accidentally penetrating the skin) to:
- HBV surface antigen positive blood up to 30% = (1:3)
- HCV RNA positive blood ~ 3% = (1:30)
- HIV positive blood ~ 0.3% = (1:300)
```
Mucocutaneous exposure (blood or other body fluid splashes into the eyes, nose or mouth or onto broken skin) to:
-HIV positive blood <0.1% = (1:1000)
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66
What bodily fluids should be handled with the same precautions as blood?
- Cerebrospinal fluid.
- Pleural, peritoneal, pericardial fluid.
- Breast milk.
- Amniotic fluid.
- Vaginal secretions, semen.
- Synovial fluid.
- Any other body fluid containing visible blood.
- Unfixed tissues and organs.
- Saliva – dental procedures
- Exudate/tissue fluid from burns or skin lesions
67
What is the risk with HIV and bodies?
-HIV may be recovered for many days after
death.
-Little risk unless leakage of blood or body fluids.
68
What actions should be taken after blood/body fluid exposure?
First Aid:
- Wash off splashes on skin with soap & running water.
- Encourage bleeding if the skin has been broken
- Wash out splashes in the eye, nose or mouth.
- REPORT to senior manager or doctor AND to OHS.
69
The risk of infection following blood/body fluid exposure is assed by considering...
- The source of contamination
- The extent of injury and the type of sharp (if any) causing it
- The likelihood of B/C/HIV in the source
- The vaccination history
Ideally the source should be tested with informed consent
70
How is occupation exposure to HIV managed?
- Should receive post-exposure prophylaxis
| - Truvada and Kaltre within 48-72 hours of exposure and continued for 28 days
71
How should HBV occupation exposure be managed?
- Known responders who have completed course of vaccination= no prophylaxis or a booster
- Non-responders= consider booster and reassure
- Incomplete prophylaxis= complete vaccine schedule, accelerated course if severe risk
72
How is HCV prevented following occupation exposure?
- No vaccine available
- No immunoglobulin available for PEP
- No anti-viral therapy licenced for PEP
-Early treatment decreases risk of chronic infection →
important to test after exposure
73
How can exposure to BBV in the health care setting be prevented?
- Good basic hygiene with regular hand washing
- Cover existing wounds or skin lesions
- Take simple protective measure to avoid contamination of person and clothing with blood
- Protect mucous membrane of eyes, mouth and nose from blood splashes
- Prevent puncture wounds, cuts and abrasions in the presence of blood
- Avoid sharps usage
- Safe sharps handling and disposal
- Clear up bodily spillages and disinfect surfaces
- Follow procedure for the safe disposal of contaminated waste
