HIV Flashcards
How does HIV infect a cell?
HIV binds to CD4 receptors on T helper cells, monocytes and macrophages
These CD4 cells migrate to lymphoid tissue to replicate and infect new cells
This depletes and impairs CD4 cells until immune dysfunction occur
What is HIV?
Human immunodeficiency virus
A retrovirus
At what CD4 count does AIDS occur?
CD4 count of <200
Who should be tested for HIV!
All patients with an STI
Anyone registered at a GP where the prevalence in local population exceeds 1/500
Anyone who has had sexual contact with people from Africa, Far East, Caribbean
All sexual partners of known HIV+ people
Men who have sex with men
Injecting drug users
Patients where HIV is a differential
What are some clinical indicator conditions for HIV testing?
Bacterial pneumonia TB Early onset dementia Peripheral pneumonia Severe psoriasis Severe seborrhoiec dermatitis Recurrent HSV Oral candidiasis Chronic diarrhoea of unknown cause Hep B/C Lung cancer Lymphoma High grade CIN Thrombocytopenia Neutropenia Lymphopenia Unexplained retinopathy Mononucleosis type syndrome
Do you need to consent for an HIV test?
Yes
Patients have the right to refuse
The reasons for testing should be explained, and written info on HIV should be provided
Verbal consent should be documented
How long does the HIV antibody take to develop?
4-8 weeks
How long after infection can the antigen be detected?
2-4 weeks
How long is the window period for HIV?
12 weeks
How long does it take to get a result from HIV testing!
48-72 hours
All positive tests must be confirmed by additional testing?
How long does the point of care testing for HIV take?
15-40 mins
What should be mentioned when counselling patients about HIV testing?
May be offered as screening - not necessarily expecting to find anything, and offered to everybody
Treatment is effective, normal life expectancy
Full medical confidentiality is assured
Think carefully before telling people about it
Negative tests do not affect insurance
Positive tests do, but only as much as other health problems eg. Back pain
How should transmission of HIV from mother to child be prevented?
If CD4 low - HAART
If CD4 high - HAART timing depends on maternal viral load
If VL undetectable at term, consider vaginal delivery
Neonatal PEP for 4 weeks
Avoid breastfeeding
Risk can be dropped from 45% to <1%
What is PEP?
Post Exposure Prophylaxis
What should be done to prevent HIV transmission due to occupational exposure to HIV?
Assess injury as to risk of transmission
HAART - 3 drugs for 28 days - aim for within one hour, definitely within 72 hours
Give antidiarrrhoeals and Antiemetics
Go to A+E or occupational health
What is PEPSE?
Post Exposure Prophylaxis following Sexual Exposure
Who should be offered PEPSE?
Anyone who has had unprotected sexual contact or condom failure with a high risk source within last 72 hours
Who is a high risk source for HIV?
Known HIV+ Unconfirmed HIV status MSM IVDU From country of high HIV prevalence
What is involved on PEPSE?
HAART - three pills for 28 days, within 72 hours
STI screen
Emergency contraception?
When does primary HIV/seroconversion present after infection?
2-6 weeks after infection
Symptoms in >60%
What are the symptoms of primary HIV /seroconversion?
Sore throat Fever Lymphadenopathy Malaise/lethargy Arthralgia/myalgia Rash - maculopapular on trunk Orogenital/perianal ulceration Headache/meningism Diarrhoea
Can get oral infection if CD4 drops significantly for example candida, shingles
What oral conditions have HIV as a differential diagnosis?
Candida Oral hairy leukoplakia KS Gingivitis Aphthous ulceration
What general symptoms may be suggestive of HIV?
Lymphadenopathy
Weight loss
Night sweats
Confusion/dementia
What are some dermatological clinical indicator conditions for HIV?
Psoriasis Acne Impetigo Itchy folliculitis Seborrhoiec dermatitis Fungal infections HSV HZV Crusted scabies Molluscum contagiosum Viral warts
What are respiratory clinical indicator conditions for HIV?
Atypical pneumonia
Recurrent bacterial pneumonia
TB
What are the gastrointestinal clinical indicator conditions for HIV ?
Oesophageal candida
Chronic diarrhoea
What are the haematological clinical indicator conditions for HIV?
Thrombocytopenia
Lymphopenia
Lymphoma
What are some aids related malignancies?
Kaposi’s sarcoma
Non Hodgkin’s lymphoma
Invasive cervical adenoma
At what CD4 count should HAART be started?
CD4 500 - monitor
CD4 350-500 - HAART if hep b/c
CD4 < 350 - commence HAART
How is response to HAART monitored?
CD4 cell count
Plasma HIV viral load
What are the side effects of antiretrovirals?
Hypersensitivity - rashes - Stevens johnsons syndrome
Anaemia
Liver function abnormalities
Pancreatitis
Lactic acidosis
Peripheral neurosis
Lipodystrophy syndrome - hyperlipidaemia, insulin resistance, fat accumulation
What level of adherence is necessary in HAART?
95%
What are some drug interactions of HAART?
Methadone Sedatives Anti epileptics Antidepressants Ecstasy Other HIV drugs Hormonal contraceptives St. John's wort
Why is adherence necessary in HAART? And what happens with poor adherence?
Lowers drug levels, allows drug to replicate with low drug levels, and resistance develops
Interactions with other drugs may also lower drug concentrations
What are the components of HAART?
Usually two nucleoside reverse transcriptase inhibitors:
Zidovudine
Lamivudine
Tenofavir
And one Non-nucleoside reverse transcriptase inhibitor:
Efavirenz
Or one boosted protease inhibitor:
Darunavir
