HIV Flashcards by Jane Keery

SUMMARY

HIV infection causes what?

Which leads to what?

What is the single highest predictor of mortality in HIV?

AIDS

Opportunistic infections and AIDS related cancers

AIDS related conditions

How well did you know this?

Not at all

Perfectly

EPIDEMIOLOGY

What is the risk group with the highest proportion of HIV in the UK?

What follows it?

17% of individuals in the UK with HIV are undiagnosed. Who is this, and also late presentation, most likely to occur in?

Is HIV common in people who inject drugs?

MSM

Heterosexual populations from Sub-Saharan Africa

Heterosexual men

Not particularly

How well did you know this?

Not at all

Perfectly

TRANSMISSION

Though HIV can be isolated from a wide range of bodily fluids, what are by far the most common?

What is the most significant marker for transmission risk? When is this highest?

Semen, cervical secretions and blood

High HIV viral load - highest in acute infection

How well did you know this?

Not at all

Perfectly

SEXUAL TRANSMISSION

What % of infections does this account for?

What % occurs in homosexual men? And heterosexual couples?

What are some factors which increase transmission risk?

It is more commonly passed from who to who?

94%

51% / 45%

Trauma, concurrent STIs, genital ulceration

Men to women, and to the receptive partner in anal sex

How well did you know this?

Not at all

Perfectly

PARENTERAL TRANSMISSION

Give some examples of this?

Injection drug use

Infected blood products

Iatrogenic

How well did you know this?

Not at all

Perfectly

VERTICAL TRANSMISSION

At what points in pregnancy can this occur? When is the risk highest?

If the viral load is undetectable at delivery, what is the risk of vertical transmission?

What are some interventions to reduce the risk of vertical transmission?

HIV testing should be offered to which children?

In utero, during delivery or at breastfeeding - highest risk at breastfeeding

< 0.1%

Screening for infection in pregnancy, use of ARVs and avoidance of breastfeeding

Children born to HIV+ mothers, or untested mothes from endemic areas

How well did you know this?

Not at all

Perfectly

THE HIV VIRUS

The HIV virus is what type of virus?

As a result of this, it is characterised by the possession of which enzyme?

What is the target site for this virus?

Retrovirus

Reverse transcriptase

CD4+ receptors

How well did you know this?

Not at all

Perfectly

THE HIV VIRUS

What is the most frequently occurring strain of HIV globally?

HIV-1 is divided into 4 transfers, what are these? Which is the most common?

Which is the most virulent type of HIV?

HIV-2 is found where?

Are the drugs for HIV-1 effective for HIV-2?

HIV-1

M (most common), N, O, P

HIV-1

Almost entirely confined to Western Africa, with a little spread to Europe

Mostly not

How well did you know this?

Not at all

Perfectly

CD4

This is a glycoprotein which is found on the surface of a variety of cells. Give some examples?

CD4 is essential for what? Give some examples?

What are the normal parameters?

There is a risk of opportunistic infection when levels fall below what?

T helper lymphocytes (CD4+ cells), dendritic cells, macrophages and microglial cells

Induction of the adaptive immune response: recognition of MHC2 antigen presenting cell, activation of B cells, CD8+ T cells and cytokines

500-1600cells/mm3

< 200cells/mm3

How well did you know this?

Not at all

Perfectly

THE HIV VIRUS

Where does this initially infect?

It is then transported to where?

Infection is established when?

Then what happens?

Mucosal CD4+ cells, i.e. Langerhans cells and dendritic cells

Regional lymph nodes

Within 3 days of entry

Disseminated infection

How well did you know this?

Not at all

Perfectly

HIV INFECTION AND THE IMMUNE RESPONSE

A key driver of disease progression in HIV is immune activation - what is this?

HIV causes sequestration of cells in lymphoid tissue, what does this lead to?

Reduction in CD8+ T cell activation leads to what?

All of this leads to increased susceptibility to what?

A long term inflammatory state

Reduced circulating CD4+ cells

Dysregulated expression of cytokines, and increased susceptibility to viral infections

Viral, fungal and mycobacterial infections as well as infection induced cancers

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

What are the criteria for groups of people for whom HIV testing is universally offered?

High prevalence areas

Certain clinical settings

High risk groups

In the presence of ‘clinical indicators’

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

What is classed as a high prevalence area for HIV?

Testing should be performed on who?

Any area where local prevalence is > 0.2%

All new patients registering with a GP, and all new hospital admissions

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

What are some clinical areas in which individuals should be tested for HIV as there is a higher prevalence of HIV in individuals accessing these services compared with the background population?

What are some clinical areas in which individuals should be tested for HIV since the risks associated with HIV in these settings are unacceptably high?

People with which conditions should always be tested?

GU medicine, sexual health clinics, TOP services, drug dependency services

Antenatal clinics, assisted conception services

TB, Hep B/C, lymphoma

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

HIV tests are now offered to high risk groups - what are some examples of these?

All patients diagnosed with an STI

MSM

PWID

People from endemic areas

And more…

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

You should always explain to people that they are being offered an HIV test and why. What are some benefits you should tell them about doing this if they were to be positive?

Antibody tests can give results in how long?

How are results given from home sampling approaches with specimens sent to a central lab?

That earlier testing and detection will improve long term health and protect partners

In minutes

Over the phone

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

When testing for HIV serology, what type of blood sample should be taken?

Which markers of HIV are used to detect infection?

Venous

Viral RNA, antigen (p24), antibody (to gp120)

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

What is the recommended UK first line assay?

What is the window period of this test where it may give a false negative?

If one of these tests is negative after what amount of time following exposure, it is highly likely to exclude HIV infection?

4th generation HIV test: tests for HIV antibody and antegen simultaneously

14-28 days

4 weeks

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

What is tested for in a 3rd generation assay?

How sensitive/specific is this test?

What is the window period?

Antibody only (IgG and IgM)

Very

20-25 days

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

Rapid HIV tests (POCT) are also known as what?

These are taken using what samples?

How is the result interpreted?

Home testing

Fingerprick or saliva

By the user

How well did you know this?

Not at all

Perfectly

TESTING FOR HIV

Recent infection testing algorithm (RITA) can also be known as what?

This can be used to identify if an infection has occured when?

What sample is used?

How is the sample analysed?

Home sampling

In the preceding 4-6 months

Fingerprick or saliva

It is sent back to the provider and the result is then communicated to the user

How well did you know this?

Not at all

Perfectly

HIV INFECTION

Without treatment, the average time to death after HIV infection is what?

In Europe, the diagnosis of AIDS remains based on what?

9-11 years

The diagnosis of specific clinical conditions (no inclusion of CD4 count)

How well did you know this?

Not at all

Perfectly

PRIMARY HIV

This refers to what time period?

What happens in this time period?

What proportion of people present with symptoms?

What is significant about the first 2-4 weeks?

The first 6 months following HIV acquisition

Uncontrolled viral replication, high levels in the plasma, and high infectiousness

80%

Can be silent, both clinically and serologically

How well did you know this?

Not at all

Perfectly

PRIMARY HIV

In a number of people, what clinical picture can present in the first 3-6 weeks following infection?

What are some features?

A self-limiting viral illness (may be confused for glandular fever)

Fever, rash, myalgia, pharyngitis, headache/aseptic meningitis

**_ASYMPTOMATIC HIV_** While the patient is asymptomatic, what is still happening? Is the person infectious? What happens to most people over 10 years or so before progression to symptomatic disease or AIDS? (though sometimes this can happen much quicker)

The virus is still replicating Yes A gradual decline in CD4 count

**_MANIFESTATIONS OF HIV_** What are some haematological manifestations of HIV?

Can cause a persistent thrombocytopenia/neutropenia/leucopenia Can cause unexplained anaemia of chronic disease

**_OPPORTUNISTIC INFECTION_** What is this?

This is an infection caused by a pathogen that does not normally produce disease in a healthy individual. It uses the 'opportunity' provided by a weakened immune system to cause disease.

**_OPPORTUNISTIC INFECTION_** What organism is a common cause of pneumonia in people with HIV? What type of organism is this? This will usually occur when the CD4 count is what? What is the onset of this condition? What are some symptoms? What is a sign?

Pneumocystis Jirovecii Fungus \< 200 Insidious onset Dry cough, SOB Exercise desaturation

**_OPPORTUNISTIC INFECTION_** What can be seen on a CXR of someone with PJ penumonia? What is the classic CT appearance? How is a diagnosis made? How is it treated? What can be used as prophylaxis?

May be normal, but may show interstitial infiltrates and reticulonodular markings Ground glass appearance Broncho-alveolar lavage (BAL) and immunofluorescence +/- PCR High dose IV co-trimoxazole (+/- steroid) Low dose co-trimoxazole

**_OPPORTUNISTIC INFECTION_** Rarer presentations of which common disease are more common in HIV patients? Give a few examples.

Tuberculosis Symptomatic primary infection Reactivation of latent infection Miliary TB Extra-pulmonary TB

**_OPPORTUNISTIC INFECTION_** What is the organism that causes cerebral toxoplasmosis? What type of organism is this? What is the usual CD4 threshold for this? What are some conditions it can cause? Contrast enhanced CT of the brain will show what?

Toxoplasma gondii A single celled parasite \< 150 Multiple cerebral abscesses, chorioretinitis Multiple ring enhancing lesions

**_OPPORTUNISTIC INFECTION_** What are some conditions which can be caused by CMV infection? What is the CD4 threshold for this? What are some potential presentations? What type of screening should take place related to this virus and for who?

Retinitis, colitis, oesophagitis \< 50 Reduced visual acuity/floaters or abdominal pain/diarrhoea/bleeding Ophthalmic screening should take place for all individuals with a CD4 count \< 50

**_OPPORTUNISTIC INFECTION_** What is a multidermatomal and potentially recurrent skin infection that occurs in patients with HIV? What is significant about herpes simplex infection in people with HIV?

Herpes Zoster Extensive, hypertrophic and aciclovir resistant

**_OPPORTUNISTIC INFECTION_** Which type of HIV causes HIV associated neurocogntive impairment? What is the CD4 limit for this? What can it present with?

HIV-1 There isn't one, the risk is increased with any immunosuppression Short term memory loss +/- motor dysfunction

**_OPPORTUNISTIC INFECTION_** What is the organism involved in progressive multifocal leaukoencephalopathy? What is the CD4 count for this? What is its onset? How can it present?

JC virus \< 100 Can be quite rapidly progressive Focal neurology, confusion, personality change

**_OPPORTUNISTIC INFECTION_** What is Slim's disease? What are some potential aetiologies for this?

HIV associated wasting Metabolic, anorexia, malabsorption, hypogonadism

**_AIDS RELATED CANCERS_** What are the 3 main AIDS related cancers?

Kaposki's sarcoma Non-Hodgkin's lymphoma Cervical cancer

**_AIDS RELATED CANCERS_** What virus is responsible for Kaposki's sarcoma? What type of tumour is this? What is its characteristic appearance? Where are some sites that this can present? How is it treated?

Human Herpes Virus 8 (HHV8) A vascular tumour, usually well circumscribed with a characteristic purple hue Cutaneous, mucosal, visceral, lymphatics HAART, local therapies, systemic chemo

**_AIDS RELATED CANCERS_** What organism is involved in causing Non-Hodgkin's lymphoma? How does this behave? How is it treated?

EBV Frequently very aggressive and rapidly progressive As for HIV, and HAART

**_AIDS RELATED CANCERS_** What organism is responsible for causing cervical cancers? What happens when people with HIV are infected with HPV? If anyone presents with complicated HPV disease, what should be done?

HPV Rapid progression to severe dysplasias and invasive disease HIV testing

**_MONITORING HIV_** What are the two main ways of monitoring HIV? How often are these tests performed? Which of them is used as the standard marker of treatment efficacy? What can cause the above investigation to rise? What patients should be treated for HIV?

CD4 count and viral load (HIV RNA) Every 4-6 months Viral load Immunisations or acute infections (do not carry out measurements within a month of these) All patients, regardless of the CD4 count

**_MONITORING HIV_** Following initiation of treatment with ART, when should a reduction in viral load be seen? When will it reach its peak? If a rising viral load is seen in a patient whose adherence is assured, what does this indicate?

4 weeks 10-12 weeks Drug failure

**_HIV TREATMENT_** What are the main groups of ARVS?

Reverse transcriptase inhibitors Protease inhibitors Integrase inhibitors CCR5 blockers Fusion inhibitors

**_HIV TREATMENT_** What are the two main types of reverse transcriptase inhibitors? Usually, what drugs are used to form the 'backbone' of ART? What is the first line regimen in most places? Which reverse transcriptase inhibitor is used in almost everyone with HIV? Which type is it?

Nucleoside/nucleotide analogues (NRTIs) and non-nucleoside analogues (NNRTIs) 2 NRTIs Tenofovir and emtricitabine Tenofovir - NRTI

**_HIV TREATMENT_** Tenofovir (NRTI) is associated with what side effect? Abacavir (NRTI) is associated with what side effect? What should be done before the above drug is started? What are some side effects of NNRTIs?

Renal dysfunction Hypersensitivity reactions Test for the HLA gene responsible for the hypersensitivity reaction Rashes and elevated liver enzymes

**_HIV TREATMENT_** To which class of drugs do tenofovir, abacavir, zidovudine, stavudine, lamivudine and emtricitabine belong? To which class of drugs do efavirenz, nevirapine, etravirine and rilpivirine belong?

NRTIs NNRTIs

**_HIV TREATMENT_** To which class of drugs do fosamprenavir, atazanavir, darunavir, lopinavir and saquinavir belong? When should these drugs be used? What are some side effects?

Protease inhibitors If you suspect a patient is going to have poor compliance, or for resistant cases Abnormalities of blood sugar control and fat metabolism leading to increased CV risk

**_HIV TREATMENT_** Raltegravir, dolutegravir and elvitegravir are examples of which class of drug? What is so good about these drugs?

Integrase inhibitors Safety and tolerability profiles are better than other drugs

**_HIV TREATMENT_** Maraviroc is an example of which class of drug? What is significant about the action of these drugs?

CCR5 blocker Binds to a host cell rather than a viral target

**_HIV TREATMENT_** Enfuviratide is an example of which class of drug? How is this given? Who is it given to and why? Does it tend to have more or less side effects than other drugs?

Fusion inhibitor SC twice daily Very expensive, so only given to people who have no other option Generally less

**_HIV TREATMENT_** What is HAART? How is this given? What is a side effect that can be caused by all drugs?

A combination of 3 different drugs from at least 2 drug classes to which the virus is susceptible They should all be combined into one tablet which is taken once daily Diarrhoea

**_HIV TREATMENT_** In terms of drug interactions, what is important to know about a) NNRTIs? b) protease inhibitors? What are some conditions you should be aware of regarding drug interactions? What is another infection that can be treated with the same treatments as for HIV, providing two of the agents work against this condition?

a) Potent liver enzyme inducers b) Liver enzyme inhibitors TB and Hep C Hep B

**_HIV TREATMENT_** Why are multiple drugs from different classes given to patients? Why is it important to pick a drug which fits in with the patient's lifestyle? Is it acceptable to start and stop HIV drugs? HIV patients should always talk to their doctor if they want to stop a drug. Why?

Because the virus is unlikely to become resistant to all 3 Because good adherance is the most important way of reducing the risk of resistance No, you are actually better to not be on any drugs at all than to do this Different drugs have different half lives and so should be phased out at different times to try and prevent resistance

**_PARTNER NOTIFICATION_** Is this process compulsary? What are some different strategies? What duty does the doctor have to partners?

No Partner referral, provider referral or conditional referral None, unless they are a known 3rd party in which case they have a duty of care

**_PREVENTION OF TRANSMISSION_** If a person has an undetectable viral load, what is the risk of them passing on HIV to a regular partner? How should a baby be delivered if the mother has a) an undetectable viral load? b) a detectable viral load? What is given after delivery to the neonate of an HIV + mother if she has a) an undetectable viral load? b) a detectable viral load? How should a neonate of an HIV+ mother be fed?

0% a) Vaginal deliver b) C-section a) 4 week PEPSE with 1 drug b) 4 week PEPSE with 3 drugs Always formula feed

**_REPRODUCTION AND HIV_** Before having unprotected sex, patients should wait until when? If they are still worried about having unprotected sex but they want a baby, they should only do it when? What should be done with regards to ARV treatment and pregnancy?

The viral load is undetectable Around the time of ovulation Initiating ARV treatment during pregnancy increases the risk of miscarriage, so patients should ideally be on this beforehand

**_REPRODUCTION AND HIV_** What are some options for couples wanting to conceive where only one is HIV positive?

Treatment is prevention - get the affected partner to an undetectable viral load Consider PrEP for the unaffected partner

**_PrEP_** What is this? What makes a patient qualify for this? What is the drug combination used?

The use of ARVs by people who are HIV negative prior to potential exposure High risk for HIV, aged 16+, currently HIV-, committed to 3 monthly follow up, Scottish resident Tenofovir and emtricitabine

**_PEPSE_** When can this be used? How long is the treatment given for? The recipient should be monitored for what? What should the patient be tested for before this is given?

Up to 72 hours following exposure 4 weeks Toxicity Established HIV