HIV

Question 1

What is the difference between HIV / AIDS?

Answer 1

HIV:

• having contracted the human immunodeficiency virus

AIDS:

• HIV progresses and the person becomes immunodeficient
• they are susceptible to opportunistic infections
• now referred to as late-stage HIV

(acquired immunodeficiency syndrome)

Question 2

What is HIV and how does it cause illness?

Answer 2

• it is a RNA retrovirus
• the virus enters and destroys CD4 T-helper cells of the immune system
• reverse transcriptase integrates HIV DNA into host DNA, which takes 3-5 days after exposure
• HIV virions budding out will destroy the host T cell

Question 3

How does HIV typically present?

Answer 3

• there is an initial seroconversion flu-like illness within a few weeks of infection (primary HIV)
• the person is then asymptomatic until the condition progresses to immunodeficiency
• immunodeficient patients develop AIDS-defining illnesses** + **opportunistic infections
• this progression can take several years

Question 4

Why does it take several years for HIV to progress to immunodeficiency?

Answer 4

• the CD4 cells are destroyed faster than they are being made
• it takes time for the CD4 count to become so low that immunodeficiency results

Question 5

How can HIV be transmitted?

Answer 5

• unprotected anal, vaginal or oral sexual activity
• mother to child at any stage of pregnancy, birth or breastfeeding (vertical transmission)
• mucous membrane, blood or open wound exposure to infected blood or bodily fluids
  
  • e.g. sharing needles, blood splashed in an eye

Question 6

What type of sex is associated with an increased risk of HIV transmission?

Answer 6

• receptive anal intercourse is the highest risk, followed by:
• receptive vaginal intercourse
• insertive anal intercourse
• insertive vaginal intercourse (lowest risk)

Question 7

What other sexual factors can increase the risk of HIV transmission?

Answer 7

• trauma (e.g. sexual assault / fisting) that damages the skin
• presence of other STIs / genital infections
  • e.g. HSV, gonorrhoea, syphilis, BV

Question 8

What is the risk of contracting HIV from oral sex?

Answer 8

• the likelihood of transmission is rare, but it is possible
• the person who is receiving is at greater risk
• dental treatment / bleeding gums / ulcerative conditions increase the risk

!! HIV cannot be transmitted through saliva !!

(i.e. kissing / sharing cups)

Question 9

What is involved in the natural history of HIV?

Answer 9

• there is a sharp drop in CD4 count shortly after primary infection
  
  • opportunistic infections may arise at this point
• CD4 count then comes back up and stays steady for some time
• it then gradually declines as HIV viral load increases
  
  • this is when symptoms start to develop

Question 10

What are the typical symptoms of primary HIV infection (seroconversion)?

Answer 10

• symptoms begin 2-6 weeks** after infection and last for **5-10 days
• fever
• pharyngitis
• lymphadenopathy
• skin rash
• myalgia
• headache / malaise
• N&V

!! a recent negative HIV test supports the diagnosis !!

Question 11

Why would a HIV test be negative during primary infection?

Answer 11

• it can take up to 3 months for antibodies against HIV to be made
• p24 antigen may be positive at this stage, but antibodies will be negative

Question 12

How can someone tell they are in the asymptomatic stage of HIV infection?

Why is it important to detect this?

Answer 12

• the only way to tell is by doing a blood test for HIV
• there is ongoing viral replication causing immune system damage during this stage
• this chronic inflammatory state increases the risk of malignancy + cardiovascular disease

Question 13

What symptoms may develop when someone enters the symptomatic stage of HIV infection?

Answer 13

skin lesions:

• folliculitis
• multi-site herpes zoster
• seborrhoeic dermatitis

oral lesions:

• candidiasis
• oral hairy leukopenia

recurrent bacterial infections:

• pneumonia
• impetigo

abnormal blood results:

• lymphopenia
• thrombocytopenia

non-specific symptoms:

• diarrhoea
• fever
• myalgia
• persistent lymphadenopathy

Question 14

When do AIDS-defining illnesses occur?

Answer 14

• these are associated with end-stage HIV infection
• the CD4 count has become so low that opportunistic infections / malignancies can occur

Question 15

Why are there worse outcomes associated with diagnosis at a late stage?

Answer 15

• the lower the CD4 count, the greater the damage to the immune system
• there is less chance of immune system recovery

Question 16

What are examples of AIDS-defining illnesses?

Answer 16

1. Kaposi’s sarcoma
2. pneumocystis jirovecii pneumonia
3. cytomegalovirus infection
4. candidiasis (oesophageal / bronchial)
5. lymphomas
6. tuberculosis

Question 17

What is the drawback of HIV testing using HIV antibodies?

Answer 17

• it can take up to 3 months to develop antibodies to the virus
• HIV antibody tests can be negative for 3 months following exposure
• a repeat test is required within 3 months if the initial test is negative

Question 18

What test can detect HIV earlier than the antibody test?

Answer 18

testing for the p24 antigen:

• this is a antigen specific to HIV
• it can given a positive result earlier in infection than the antibody blood test

Question 19

What 2 tests are used in the monitoring of HIV?

Answer 19

• CD4 count
• viral load (VL)

Question 20

What is the CD4 count and why is it monitored?

Answer 20

• the number of CD4 cells in the blood
• this is an indicator of the risk of opportunistic infections
• CD4 count usually improves with treatment

Question 21

What is a normal CD4 count?

When is someone at greater risk of opportunistic infections?

Answer 21

normal range:

• 500 - 1,200 cells / mm³
• there is no need to monitor regularly if > 350 cells / mm³

end-stage HIV:

• < 200 cells / mm³
• the patient is at a high risk of opportunistic infections

Question 22

What does viral load measure?

Answer 22

• it is the number of copies of HIV RNA per ml of blood
• it is monitored to assess disease progression +/- treatment response

Question 23

What is a normal viral load?

Answer 23

• “undetectable” refers to a viral load below the detectable range
• this is usually 50 - 100 copies / ml
• the aim of treatment is to get viral load < 50 copies / ml

Question 24

What is the typical treatment regime for HIV?

Answer 24

• highly active antiretroviral therapy (HAART / ART) is used
• this is usually 3 different drugs in combination
• treatment is lifelong
• compliance is essential as viral replication under partial pressure can result in drug resistance

Question 25

What is the aim of HIV treatment?

Answer 25

to achieve a **normal CD4 count** and **undetectable viral load**

Question 26

What additional prophylaxis is given to patients with a CD4 count \< 200?

Answer 26

prophylactic **_co-trimoxazole_** * this is to protect against **pneumocystis jirovecii pneumonia**

Question 27

What is significant about HIV and cardiovascular risk?

Answer 27

* HIV **increases the risk** of developing cardiovascular disease * close monitoring of **_blood lipids / risk factors_** is required * **_statins_** may be started to reduce CVD risk

Question 28

How is cervical screening different for patients with HIV?

Answer 28

* they are offered **_yearly_ smear tests** * HIV predisposes to **_HPV infection_** and **cervical cancer**

Question 29

What is important about vaccinations in a HIV positive patient?

Answer 29

**_ALL vaccinations_** should be up to date: 1. influenza 2. pneumococcal 3. hepatitis A + B 4. tetanus 5. diphtheria 6. polio ***!! patients should AVOID live vaccines !!***

Question 30

What advice is given around sexual intercourse and HIV?

Answer 30

* condoms are advised for all acts of sexual intercourse * **transmission is almost unheard of** when the **viral load is undetectable**, but still possible * partners should have **regular HIV tests** * **_unprotected sex / pregnancy**_ are considered when _**viral load is undetectable_**

Question 31

When is a normal vaginal delivery recommended?

Answer 31

for all women with a **viral load \< 50 copies / ml**

Question 32

When is Caesarean section recommended? What medication may be given during the procedure?

Answer 32

* considered when viral load **\> 50 copies / ml** * highly recommended when viral load **\> 400 copies / ml** * **_IV zidovudine_** is given if viral load is **unknown** or there are **\> 10,000 copies per ml**

Question 33

What prophylactic treatment is given to low-risk babies?

Answer 33

* when mother's viral load **\< 50 copies / ml** * **_zidovudine**_ is given for _**4 weeks_**

Question 34

What prophylactic treatment is given to high risk babies?

Answer 34

* when mother's viral load **\> 50 copies per ml** * **_zidovudine, lamivudine + nevirapine_** are given for 4 weeks

Question 35

What is the recommendation for breastfeeding?

Answer 35

* HIV **can be transmitted during breastfeeding**, even when the **viral load is undetectable** ***!! breast feeding is not recommended !!*** * it is sometimes attempted with close monitoring if mother is very keen and viral load is undetectable

Question 36

What is the rapid point of care test for HIV?

Answer 36

* self administered blood test with an immediate result * if the test is positive, a blood test is required for confirmation

Question 37

When sending a venous blood sample to the lab to test for HIV, what must always be done as follow-up?

Answer 37

* a **second confirmatory sample** should be sent to ensure no labelling / lab process error * **action is taken based on first result**

Question 38

What are the guidelines around telling other people following a new HIV diagnosis?

Answer 38

* **encourage the patient to tell their contacts** (but this cannot be enforced) * **anonymous provider referral** is available * failure to disclose can result in criminal proceedings if the transmission was preventable

Question 39

What is pre-exposure prophylaxis (PrEP) and who may used this?

Answer 39

* taken by **_HIV-negative_** people **before, during and after sex** * **2 tablets** are taken **2-24 hours before** sexual activity * it can be taken daily or around sexual activities * it **_prevents HIV contraction_** but does not protect against other STIs * regular testing is required

Question 40

What is post-exposure prophylaxis (PEP)? When is it taken?

Answer 40

* HIV medications that are taken **_after high risk sex / exposure_** * medication taken for **28 days** * should be started as soon as possible, but can be taken **_up to 72 hours_** after exposure

Question 41

What is the current PEP regime?

Answer 41

* Truvada (emtricitabine + tenofovir) AND * raltegavir taken for 28 days

Question 42

When must HIV tests be performed in someone taking PEP?

Answer 42

* perform a HIV test **immediately** and **after 3 months** to confirm a negative status * individuals should **abstain from sexual activity** for 3 months