HIV Flashcards
1
Q
Origin of HIV infection?
A
- Zoonotic infection with simian immunodeficiency virus (SIV)
- First infecting local hunters
- HIV-1 is the cause of global pandemic
- HIV-2 causes similar illness but with slower progression
2
Q
What are the modes of transmission of HIV?
A
- Sexual contact
- Exposure to blood
- IV drug use
- Health case workers
- Blood products
- HIV infected mothers
- In utero
- Breastfeeding
3
Q
What is the major route of transmssion?
A
Heterosexual
4
Q
What determines the risk of contracting HIV after exposure?
A
- Integrity of exposed site
- Type and volume of fluid
- Level of viraemia in source person
5
Q
Name some factors which increase the risk of transmission of HIV?
A
- High viral load
- Rectal/vaginal lacerations
- Uncircumcised male partner
- Receptive anal intercourse
6
Q
Describe the properties of HIV?
A
- Enveloped RNA retrovirus
- From lentivirus family
7
Q
Describe the pathophysiology of HIV?
A
- After exposure, HIV travels to lymph nodes via dendritic cells
- Viraemia occurs
- Dissemintation to lymphoid organs
- Main sites of viral replication
8
Q
What cells does HIV infect?
A
- Cells bearing the CD4 receptor
- T-helper lymphocytes
- Monocyte-macrophages
- Dendritic cells
- Microglial cells in CNS
9
Q
Describe the diagnosis of HIV testing?
A
- Detecting host antibodies with:
- Rapid point of care tests
- Labarotory ELISA tests
- Positive antibody test from two different immunoassays confirms infection
10
Q
What patients should be offered HIV testing in the UK?
A
- Patients accessing sexual health services
- Patients accessing primary and secondary care
- With relevant risks
- Prison inmates
11
Q
Name some important aspects counselling following a positive HIV result?
A
- Explain meaning of the result
- Assess coping strategy
- Stress important of partner disclosure
- Facilitate notification of sexual partners
12
Q
Name some important baseline investigations investigating someone with HIV?
A
- CD4 count
- Viral load
- Screening for other investigations
- HBV, HCV, syphilis, TB
- FBC, LFTs
13
Q
What is the most important indicator of immune suppression in HIV?
How often should it be monitored?
A
- CD4 count
- Measured every 3-6 months
14
Q
What is a normal CD4 count?
What CD4 count results in severe immune suppression?
A
> 500 cells/mm3
< 200 cells/mm3
15
Q
How is the CD4 lymphocyte count determined?
A
Flow cytometry
16
Q
Describe measurements of viral load in HIV?
A
- Quantitative PCR of HIV RNA
- High viral loads experience more rapid declines of CD4 count
17
Q
What a re the clinical features of a primary HIV infection?
A
- Fever
- Maculopapular rash
- Pharyngitis
- Lymphadenopathy
- Oral and genital ulceration
- Bell’s palsy
18
Q
What does the appearance of anti-HIV antibodies occur?
A
2-12 weeks after the development of symptoms
19
Q
Describe AIDS?
A
- Defined by development of:
- Specific oppurtunistic infections
- Cancers
- Severe manifestations of HIV
20
Q
Name some conditions which an HIV patient is at risk of when there CD4 count is . less than 500?
A
- Tuberculosis
- Herpes zoster
- Kaposi’s sarcoma
- Oropharyngeal candidiasis
21
Q
Name some conditions which an HIV patient is at risk of when there CD4 count is . less than 200?
A
- Pneumocystis jiroveci pneumonia
- Chronic herpes simplex ulcers
- HIV-associated dementia
22
Q
Name some conditions which an HIV patient is at risk of when there CD4 count is less than 100?
A
- Cerebral toxoplasmosis
- Cryptococcal meningitis
- Progressive multifocal leucoencephalopthy
23
Q
Globally, what is the most common cause of morbidity and mortality in HIV patients?
A
Tuberculosis
24
Q
What is HIV wasting syndrome?
A
- Sign of advanced HIV infection
- Weight loss of > 10% body weight plus 1 of:
- Diarrhoea for over 1 month
- Chronic weakness
- Prolonged fever
25
What is used to treat pneumocystis jiroveci pneumonia in AIDS?
* Co-trimoxazole
* Adjunctive prednisolone
26
What is used to treat cerebral toxoplasmosis in AIDS?
* Pyrimethamine
* Sulphadiazine
27
What is used to treat cryptococcosis in AIDS?
* Amphotericin B
* Flucytosine
28
What is used to treat oesophageal candidiasis in AIDS?
Fluconazole
29
Describe Kaposi's sarcoma?
* Spindle cell tumour
* Due to sexually transmitted HSV-8
* Mucocutaneous lesions and lymphoedema +/- B symptoms
30
Describe primary HIV infection?
* Incubation period 2-4 weeks after exposure
* Often presents similar to glandular fever
* Maculopapular rash can differentiate HIV
* Lymphopenia, thrombocytopenia and elevated liver enzymes
31
Differentials for primary HIV infection?
* Glandular fever
* Primary toxoplasmosis
* Secondary syphilis
32
What is the median time from infection to AIDS development in adults with asymptomatic HIV infection?
9 years
33
Describe progressive multifocal leucoencephalopathy (PML)?
* Stroke-like episodes and cognitive impairment
* Vision impairment due to involvement of occipital cortex
* Diagnosis:
* Characteristic MRI appearance
* JC virus in CSF by PCR
* No specific treatment exists
34
Co-trimoxazole prophylaxis in HIV patients?
* Reduces risk of oppurtunistic infections:
* Pneumocystis jiroveci pneumonia
* Cerebral toxoplasmosis
* Malaria
* SE: hypersensitivity causing maculopapular rash
35
What can be used as prophylaxis for TB in HIV patients?
* Isoniazid
* All of the following must be absent:
* Cough
* Fever
* Weight loss
* Night sweats
36
What are the goals of anti-retroviral therapy in HIV?
* Keep viral load low for as long as possible
* Increase CD4 count over 200 cells/mm3
* Improve quality of life
* Reduce HIV transmission
37
What are the different categories of anti-retroviral drugs for HIV?
* Nucleoside reverse transcriptase inhibitors (NRTIs)
* Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
* Protease inhibitors (PIs)
* Integrase inhibitors
* Chemokine receptor inhibitor
38
Examples of NRTIs?
* Abacavir
* Tenofovir
39
Examples of NNRTIs?
* Efavirenz
* Rilpivirine
40
Example of PIs?
Atazanavir
41
Example of integrase inhibitors?
Raltegravir
42
Example of chemokine receptor inhibitor?
Maraviroc
43
What is the standard anti-retroviral regimens?
* 2 NRTIs + 1 of:
* NNRTI
* Protease inhibitor
* Integrase inhibitor
44
Complications of anti-retroviral therapy?
* Immune reconstitution inflammatory syndrome (IRIS)
* Lipodystrophy
* Hypersensitivity rashes
45
Anti-retroviral in pregnancy?
* CD4 count falls by 25% in pregnancy due to haemodilution
* HIV disease progession is not altered
* Begin anti-retroviral treatment at beginning of second trimester
* Caesarean section is associated with lower risk of transmission
46
Describe PrEP?
* Pre-exposure prophylaxis
* Daily tenofovir plus emtricitabine
* Reduces risk of HIV acquisition
47
Describe PEP?
* Post-exposure prophylaxis
* First dose within 6 hours
* HIV antibody testing at 3 months post exposure
48
Describe hairy leukoplakia?
* EBV-associated lesion on the side of the tongue
* Indicative of HIV
* Cannot be scraped off
* Candida lesions can be scraped off the tongue
49
What is the test for EBV diagnosis?
Monospot test
50
What would you do if you come across hairy leukoplakia?
* Test for HIV
* Do not perform the monospot test
51
In terms of CD4+ count, which diseases fall within the 200-500 region?
* Oral thrush
* Shingles
* Hairy leukoplakia
* Kaposi sarcoma
52
In terms of CD4+ count, which diseases fall within the 100-200 region?
* PMLE
* HIV dementia
* Cryptosporidiosis
* Cerebral histoplasmosis
* Pneumocystic jiroveci pneumoniae
53
In terms of CD4+ count, which diseases fall within the 50-100 region?
* Aspergillosis
* Oesophageal candidiasis
* Cryptococcal meningitis
* Primary CNS lymphoma
54
In terms of CD4+ count, which diseases fall within the \<50 region?
Cytomegalovirus retinitis
