HIV and AIDS

Question 1

What is the risk of vertical transmission of HIV in an untreated pregnant woman?

Answer 1

At birth: 25 to 35%.
Breastfeeding: 10 to 15% (of infants who were not infected in the womb or during birth)

These rates can be reduced dramatically by treating HIV-positive mothers with antiretroviral drugs while they are pregnant, in labour, and breastfeeding.

Question 2

Which two antigens are present on the surface of HIV particles? Which host antigen do they interact with?

Answer 2

gp120 and gp41 are present on the surface

gp120 combines and interacts with CD4 glycoprotein on the surface of host cells, particularly T-helper lymphocytes.

Question 3

Describe what is means by “seroconversion” in the context of HIV infection.

Answer 3

The time period during which HIV antibodies develop and become detectable. Seroconversion generally takes place 2-4 weeks post-exposure and is self-limiting 1-2 weeks after onset.
It is often, but not always, accompanied by non-specific flu-like symptoms including fever, rash, muscle aches and swollen lymph nodes. This can be useful in determining how long the patient has been infected for.

Question 4

Describe the presentation of a primary HIV infection

Answer 4

similar to glandular fever with rash, fever, pharyngitis and lymphadenopathy predominant, but EBV serology will be negative. Some patients develop diarrhoea, meningitis or neuropathy. There is also a risk of toxic exanthema (rash). The illness is self limiting and blood should be taken early in its course (acute phase serum) and during the convalescent period to test for HIV antibody.

Question 5

Give seven examples of opportunistic infections that can affect patients with HIV

Answer 5

• Pneumocystis jiroveci (carinii) pneumonia
• Candidiasis
• Mycobacterium avium complex
• Cryptosporidiosis
• Cerebral toxoplasmosis
• Tuberculosis
• CMV disease

Question 6

Give six classes of HIV anti-retroviral drugs

Answer 6

Nucleoside reverse transcriptase inhibitors
Non-nucleoside reverse transcriptase inhibitors
Protease inhibitors
Integrase inhibitors
Chemokine receptor antagonists
Fusion inhibitors

Question 7

Suggest some adverse affects that may be experienced when taking anti-retrovirals

Answer 7

Lipodystrophy
Anaemia (AZT)
Pancreatitis (especially didanosine)
Neuropathy (especially stavudine)
Hepatitis (especially nevirapine)

Drug interactions are common with protease inhibitors and NNRTI’s. where serum drug levels may need to be monitored.

Question 8

Which drug can be taken as pre-exposure prophylaxis against HIV?

Answer 8

Truvada: a combination of two HIV medications (tenofovir and emtricitabine). It is taken once daily by people who are not HIV positive but are considered at a high risk of infection.

Question 9

Name two tumours that are associated with HIV/AIDS

Answer 9

Kaposi’s Sarcoma

B-cell Lymphoma

Question 10

Give three skin manifestations of HIV/AIDS

Answer 10

Seborrheic dermatitis
Molluscum contagiosum
Shingles

Question 11

When should HIV patients begin antiretroviral treatment?

Answer 11

When CD4 count is less than 350,

When one or more AIDS-defining condition develops

Question 12

At what CD4 count is a diagnosis of AIDS usually given?

Answer 12

CD4 < 200

Question 13

Give some examples of AIDS-defining conditions

Answer 13

Tuberculosis
Cerebral toxoplasmosis
Cryptococcal meningitis
Kaposi's sarcoma (skin)
Non-hodgkin's lymphoma
Cervical cancer