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Obstetrics and Gynaecology > HIV > Flashcards

Flashcards in HIV Deck (30)
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1
Q

What is HIV?

A

Single stranded RNA retrovirus

Infect and replicate with CD4 (T helper) cells

2
Q

Describe the life cycle of HIV

A

1 Penetrate into host CD4 and empty contents
2 Reverse transcriptase to convert viral RNA into double stranded DNA
3 Integrase - DNA combined with host DNA
4 Infected cell divide - viral DNA also read and viral proteins made
5 Immature virus push out of cell retaining some cell membrane
6 Virus mature when protease cut viral protein chains - assemble to create working virus
7 Host cell destroyed

3
Q

What happens to CD4 levels for a patient with HIV?

A

Upon seroconversion (making anti HIV antibodies) patient may experience flu like symptoms and CD4 levels fall - extremely infectious

Over next months-years, infection enter latent phase - CD4 drop and viral load increase but asymptomatic

HIV can then become symptomatic and eventually develop into AIDS

4
Q

How is HIV transmitted?

A

Unprotected sexual contact

Sharing injecting equipment

Medical procedures - blood products, skin grafts, organ donation, artificial insemination

Vertical transmissio

5
Q

What groups of people should HIV testing be encouraged in?

A

MSM
IV drug users
High prevalence areas
Unprotected sex with partner who has lived or been to Africa

6
Q

How does HIV present in the seroconversion illness phase?

A

1-6 weeks post infection

Sore throat
Fever
Lymphadenopathy
Malaise
Arthralgia
Diarrhoea
Maculopapular rash
Mouth ulcers
7
Q

How does symptomatic HIV after the latent phase present?

A

Weight loss
High fever
Frequent opportunistic infections

8
Q

What is important to explain in the counselling before a HIV test?

A

Check understanding
Explain significance of window period
Explain results need to be in medical record
Positive test must be disclosed in insurance application
Informed consent
Benefits of HIV testing
Arrange results appointment
Hep B and C test - if due to needle sharing
STI testing - if due to unprotected sex

9
Q

What is the window period for HIV?

A

Time between infection and antibodies appearing - usually 4-6 weeks but can take upto 12

10
Q

What are the benefits of HIV testing?

A

If negative - reassured

If +vs - effective treatment can prevent illness and ensure infection not transmitted

11
Q

What would you do with the results from a HIV test?

A
-ve = consider retest due to window period
\+ve = repeat test to confirm
12
Q

What investigations are done for HIV?

A

Clotted blood sample - combined HIV antibody and P24 antigen
FBC - anaemia, thrombocytopenia, lymphocytopaenia, CD4
ESR - raised
Screen for STI’s
Baseline CXR

13
Q

Describe the use of a HIV antibody test

A

Most common and accurate test
Usually consist of ELISA and western blot
Most people develop antibodies at 4-6 weeks, 99% by 12
No indication of disease progression

14
Q

Describe the use of the P24 antigen test

A

Positive between 1 and 4 weeks for HIV

Used as additional screening tool

15
Q

How is HIV managed?

A

HAART -
2 NRTI (nucleoside reverse transcriptase inhibitor) + either
Protease Inhibitor or NNRTI (non-nucleoside reverse transcriptase inhibitor)

16
Q

What is an example of an NRTI and its adverse effects?

A

Zidovudine

Peripheral neuropathy, myopathy, anaemia, black nails

17
Q

What is an example of an NNRTI and its adverse effects?

A

Nevirapine

P450 interaction, rash

18
Q

What is an example of a protease inhibitor and its adverse effects?

A

Indinavir

Diabetes, hyperlipidaemia, buffalo hump, central obesity, p450 inhibitor

19
Q

What other drugs can be used for HIV?

A

Integrase inhibitor - raltegravir

Entry inhibitor - Maraviroc

20
Q

What are the general side effects for HAART?

A
Hypersensitivity - fever or rash
Psychiatric - nightmares, sleep disturbance, mood changes
Hyperlipidaemia
Lipodystrophy
T2DM
Fanconi syndrome - proximal tubule dysfunction
Lactic acidosis and hepatic toxicity
Peripheral neuropathy
Bone marrow suppression
Pancreatitis
21
Q

What non pharmacological measures are used for patients with HIV?

A

Promote CVS health - at more risk
Annual cervical cancer screening
Immunisations upto date

22
Q

How is HIV monitored?

A

CD4 - reflect degree of immunocompromise

  • Variable so trend more important than single value
  • Determinant for opportunistic infection prophylaxis

Viral load - reflect rate of viral replication

  • Rising load may indicate non adherence
  • linked to CD4 decline and disease progression
23
Q

What are the risks associated with a CD4 count 400-500?

A

Hodgkins lymphoma

Cervical cancer

24
Q

What are the risks associated with a CD4 count 350-400?

A
Bacterial skin infections
Recurrent bacterial chest infections
TB
Oropharyngeal candida
Fungal infections
Seborrhoeic dermatitis

Lymphadenopathy and sweats

25
Q

What are the risks associated with a CD4 count 200-350?

A

Oral hairy leukoplakia (EBV)
Shingles
PCP
Persistent herpes infection

Non-hodgkins lymphoma

Weight loss

26
Q

What are the risks associated with a CD4 count 100-200?

A
Oesophageal candida
Histoplasmosis
Cryptococcal meningitis
Cerebral toxoplasmosis
Cryptosporidosis

Kaposis sarcoma

Diarrhoea, wasting

27
Q

What are the risks associated with a CD4 count <100?

A

CMV infections
Atypical mycobacterium infections

Primary cerebral lymphoma

Dementia

28
Q

How is HIV transmission risk reduced in pregnancy?

A

ART during pregnancy
Short course ART for newborn
C section - can do vaginal in women with ART and undetectable viral load
Avoid breastfeeding

29
Q

What prophylaxis is given if someone is suspected to have been exposed to HIV?

A

Post exposure prophylaxis if within 72 hours

1 month:
Truvada (OD) + Raltegravir (BD)

30
Q

How is HIV diagnosed?

A

HIV PCR and p24 antigen
4 wks after possible exposure in asymptomatic

If - and asymptomatic - repeat at 12 weeks