HIV

Question 1

Describe HIV (3)

Answer 1

Human immunodeficiency virus.

Describes an RNA retrovirus that enters and destroys CD4 T-Helper cells.

Can progress to AIDS (Acquired immunodeficiency syndrome) which can result in immunocompromise and opportunistic infections

Question 2

What type of cells does HIV attack?

Answer 2

CD4 T-helper cells

Question 3

What is HIV seroconversion? (2)

Answer 3

Describes the time between exposure to a virus and when HIV antibodies become detectable in the blood.

Patients tend to develop flu-like symptoms in the first few weeks of infection (3-12 weeks).

Question 4

Give 5 features of HIV seroconversion

Answer 4

Sore throat

Lymphadenopathy

Malaise, myalgia, arthralgia

Diarrhoea

Mouth ulcers

Question 5

How is HIV transmitted? (3)

Answer 5

Unprotected anal, vaginal or oral sex

Mother to child during pregnancy, birth or breast feeding (vertical transmission)

Mucous membrane, blood or open wound exposure (i.e sharing needles, needle stick or blood splashed in eye)

Question 6

Name 4 AIDS defining illnesses (opportunistic infections/illnesses associated with a low CD4 count)

Answer 6

Oral Thrush - Candida albicans

Shingles - Herpes zoster

Pneumonia - Pneumocystis jirovecii

Kaposi’s sarcoma - HHV-8

Question 7

What test is used for HIV screening?

Answer 7

Fourth-Generation tests - HIV antibody and p24 antigen test

Can be detected as early as 2-3 weeks after exposure but results are more reliable after 45 days.

Question 8

When should HIV testing be performed in asymptomatic patients? What is done if this test is negative? What is done if the test is positive?

Answer 8

4 weeks after possible exposure.

If negative, repeat test at 12 weeks.

If positive, repeat to confirm diagnosis

Question 9

How does CD4 count relate to infection risk?

Answer 9

The lower the CD4 count, the higher the risk of opportunistic infections.

Question 10

What is the normal CD4 range? What CD4 range puts patients at high risk of opportunistic infections?

Answer 10

Normal = 500-1200 cells/mm3

High risk of infections = <200 cells/mm3

Question 11

What can be tested for to give an indication of viral load?

Answer 11

HIV RNA

Question 12

Give 3 focal neurological lesions that HIV increases the risk of developing

Answer 12

Toxoplasmosis (most common)

Primary CNS Lymphoma - Epstein Barr virus

Tuberculosis

Question 13

How would toxoplasmosis appear on a CT? What other test can be performed to distinguish from lymphoma?

Answer 13

Single or multiple ring enhancing lesion

Thallium SPECT negative

Question 14

What is the treatment for a focal toxoplasmosis lesion in a patient with hiv?

Answer 14

Sulfadiazine and pyrimethamine

Question 15

How may a toxoplasmosis lesion present? (3)

Answer 15

Headache, Confusion, Drowsiness

Question 16

How may lymphoma present on CT? What other test can be used to distinguish from toxoplasmosis?

Answer 16

Single lesion with solid enhancement.

Thallium SPECT positive

Question 17

How is CNS lymphoma associated with HIV managed?

Answer 17

Steroids + Methotrexate +/- radiotherapy

Question 18

Give 2 generalised neurological conditions associated with HIV

Answer 18

Encephalitis (due to CMV or HIV)

Cryptococcus (most common fungal infection of CNS)

Question 19

What treatment is offered to HIV patients?

Answer 19

Antiretroviral therapy (ART)

Question 20

What type of test can establish the resistance of each HIV strain to different medications, to help guide treatment?

Answer 20

Genotypic resistance testing

Question 21

When should ART be initiated in a patient with confirmed HIV?

Answer 21

As soon as they are diagnosed

Question 22

What 5 classes of antiretroviral therapy are available?

Answer 22

Protease inhibitors (PI)

Integrase inhibitors (II)

Nucleoside reverse transcriptase inhibitors (NRTI)

Non-nucleoside reverse transcriptase inhibitors (NNRTI)

Entry inhibitors (EI)

Question 23

What is the usual starting antiretroviral therapy regime?

Answer 23

Two NRTIs + either a PI or NNRTI

Question 24

Name 2 Nucleoside reverse transcriptase inhibitors (NRTIs)

Answer 24

Tenofovir

Emtricitabine

Question 25

Name 2 NNRTIs (non-nucleoside reverse transcriptase inhibitors)

Answer 25

Nevirapine

Efavirenz

Question 26

Name 2 Protease inhibitors (PIs)

Answer 26

Indinavir

Nelfinavir

Question 27

Name 3 side effects of protease inhibitors (indinavir/nelfinavir)

Answer 27

Diabetes

Hyperlipidaemia

Buffalo hump/central obesity

Question 28

What prophylaxis is given to HIV patients? When is it given?

Answer 28

Prophylactic co-trimoxazole

To protect against pneymocystis jirovecii pneumonia

Given if CD4 count is <200

Question 29

Give 3 additional management plans for HIV

Answer 29

Monitor lipids/give statin (HIV can increase risk CVD)

Annual cervical smears (HIV increases risk of HPV infection)

Vaccinations - Annual influenza, pneumococcal, HPV, Hep A/B

Question 30

Name 2 vaccines that should be avoided in HIV patients, and why

Answer 30

BCG and Typhoid

As are live vaccines

Question 31

How is HIV transmission prevented during pregnancy? (Use viral load load)

Answer 31

Under 50 - Normal vaginal delivery

Over 50 - Consider C-section

Over 400 - C-section

Question 32

What is given as infusion during labour and delivery in a pregnant mother positive for HIV?

Answer 32

IV Zidovudine

Question 33

What prophylaxis is given to babies born from HIV positive mothers? (2)

Answer 33

Low risk (mothers viral load <50) - Zidovudine for 2-4 weeks

High risk - Zidovudine, lamivudine and nevirapine for 4 weeks

Question 34

Is it safe to breastfeed when HIV positive?

Answer 34

No. Breastfeeding should be avoided.

Breastfeeding can sometimes be attempted if viral load is undetectable but this needs to be closely monitored

Question 35

What treatment can be offered after exposure, to reduce risk of transmission? When should it be offered?

Answer 35

Post-Exposure Prophylaxis (Emtricitabine/tenofovir + Raltegravir for 28 days)

Offered within 72 hours.

Question 36

What renal condition can occur in HIV? What are 5 key features?

Answer 36

HIV associated nephropathy (HIVAN)

Features;

Massive proteinuria (nephrotic syndrome)
Normal/large kidneys
Focal segmental glomerulosclerosis
Elevated urea/creatinine
Normotension