HIV Flashcards
Which groups are most at risk from HIV infection in the UK?
MSM STILL HIGHEST (followed by Black women then Black men)
What aspects of HIV infection are measurable?
- The p24 antigen is measurable and can be detected before the HIV Ab is produced
- We can also measure viral load and CD4 count
What types of sexual intercourse are highest risk for contracting HIV? (list the order)
Type of sex: Receptive anal intercourse > receptive vaginal intercourse > Insertive anal intercouse > Insertive vaginal intercourse
Trauma: traumatic sexual behaviour such as fisting
Concurrent infection: e.g. HSV, Gonorrhoea, BV, Syphilis
What way other than sexual is HIV transmitted?
MOTHER TO CHILD
- antenatal (opt out testing)
- intra-partum (C section reduces risk, if HIV is well controlled woman can have vaginal delivery)
- BREASTFEEDING (encourage to not breast feed if detectable virus levels)
IVDU transmission - RARE,
HepC risk much higher
BLOOD TRANSFUSION (pre 1985 in UK)
OCCUPATIONAL(health care)
- risk assess donor and recipiant
- obtain consent to test patient
- assess recipients eligibility for PEP
- *should be done by uninvolved clinician**
4 ways stages of HIV can present?
1) Primary HIV
2) Asymptomatic (screening)
3) Symptomatic (pre AIDS related complex)
4) Advanced HIV (AIDS)
Describe the first phase of the HIV infection. What is it? When does it happen? Symptoms? What supports diagnosis?
The PRIMARY PHASE - AKA SEROCONVERSION
- this is very contagious stage (very high viral load and low CD4 count)
- happens 2-6 weeks post infection
- vague symptoms (flu like, lymphadenopathy, rash, fever, pharyngitis) often mistaken for glandular fever/meningitis
Tests
- Negetive recent HIV test
- HIV test may reveal +ve p24 antigen but -ve p24 antibody
What stage of HIV comes after the seroconversion?
what is it?
how long does it last?
test results?
THE ASYMPTOMATIC STAGE
- This is where CD4 count and viral count returns slightly to normal
- Although asymptomatic it does damage immune system
- Can last 5-10 years but possibly longer
- Only way to detect is HIV test (will have +ve antibodies)
What stage of HIV comes after the asymptomatic stage?
How may it present?
What do you find on blood results?
SYMPTOMATIC STAGE …
(signs of weakened immune system)
NON-SPECIFIC
- diarrhoea (suspect if cryptosporidium)
- fever
- lymphadenopathy
- myalgia
ORAL
- oral hairy leukoplakia (related to EBV)
- oral candida
SKIN
- Seborrhoeic dermatitis
- Muli site herpes zoster (shingles)
- Folliculitis
- HIV associated neuropathy
RECURRENT BACTERIAL INFECTIONS
- pnuemonia
- impetigo
BLOODS
- lymphopenia (low WCC)
- thrombocytopenia (low platelets)
What stage of HIV comes after the symptomatic stage?
what is it?
what are symptoms?
ADVANCED HIV (AIDS)
- get opportunistic infections and certain cancers (aids defining conditions)
- low CD4 count <200 showing damage to immune system
- poorer prognosis
What is the basis of treatment for HIV?
What is the aim of treatment
- Treatable not curable
- Lifelong treatment with Highly active anti retroviral therapy (Usually this is a combination of 3 different types of retroviral)
- The aim is an undetectable viral load
- START HAART AS SOON AS HIV DIAGNOSIS (regardless of CD4)
Broader aims are 90/90/90
- 90% of people with HIV know they have it
- 90% of these on HAART
- 90% of these with undetectable viral load
What drug interactions might there be with anti retrovirals?
Statins Steroids Anti-anxiety/sedatives Anti-coagulants Chemotherapy drugs Anti-TB drugs Some recreational drugs Mutli-vitamins or antacids
*use liverpool drug interaction website**
Name some AIDS defining illnesses? (resp, term, neuro, oncology, GI, eyes)
Respiratory
- Pneumocystis pneumonia (PCP)
- TB (worsens when starting AVT)
Derm
-Kaposi’s sarcoma (purple lesions on skin-can get in lungs
Neuro
- Cerebral Toxoplasmosis (SOL-ring lesions of CT)
- PML (progressive multifocal leucoencephalopathy)-presents like a stroke
- Cryptococcal meningitis
Oncology
- Invasive cervical cancer
- Non-hodgkin’s lymphoma
GI
- Persistant cryptosporidiosis
- Osophageal candida
Eyes
-Cytomegalovirus retinitis (painless progressive LOV)
How long does it take for HIV infection to show up on screening? (p24 antigen and p24 antibody?)
- p24 antigen detected 2-4 weeks
- p24 antibody detected 4-8 weeks
- Therefore 4 weeks should detect the virus
- If they present <4 weeks still do test, antigen may be detected
- if +ve follow up with another confirmation test, but don’t delay treatment
What types of testing are there and which ones are most accurate?
Point of care testing - can be done by self at home
If test is positive it is known as REACTIVE - there is a high rate of false positives so they person should have a VENOUS SAMPLE sent off to the lab for analysis (much more accurate)
What information should be given to a patient with a diagnosis of HIV?
If they have a detectable viral load they must not have unprotected sex (against the law)
Should use condoms at all times
If their viral load is undetectable for 6 months they are very unlikely to pass it on - they can try for a baby etc.
What type of virus is HIV
How does it affect cells in the body?
HIV is an RNA retrovirus that binds to and copies its DNA into T lymphocytes (otherwise known as CD4 cells)
How long does it take for HIV to bind and integrate to human DNA
The virus takes around3-5 days after exposure to integrate into human DNA
Should a mother with HIV be advised to breast feed her baby?
In UK advised to bottle feed
What are investigations for HIV ?
Routine bloods
-FBC/UsEs/LFts/lipid and bone profile/glucose
Serology
-Hep A, B, C, Syphilis
- HIV viral load (disease progression)
- CD4 count (risk of oputunistic infections-AIDS)
- HIV drug resistance profile
What is the treatment for cryptosporidium diahhroa?
This is an acid fast stain +ve
SUPPORTIVE TREATMENT
Treatment of PCP/Pneumocystic pneumonia?
When would you treat prophylactically?
Treatment of PCP is co-trimoxasol (with steroids if hypoxic)
**if their CD4<200 then just treat prophylactically
Treatment of cerebral toxoplasmosis (SOL)?
How does this treatment work?
-Treatment of cerebral toxoplasmosis is sulfadiazine and pyrimethamine
- Pyrimethamine is a folic acid antagonist and sulphadiazine is a sulphonamide antibiotic. The synergistic action of these drugs sequentially blocks the folate metabolism>inhibits DNA synthesis in the parasite.
- Folic acid should be administered with the regimen to prevent haematologic toxicity.
Treatment of oesophageal candida?
Treatment of oesophageal candida is fluconazole
Whats cons of Rapid point of care test for HIV?
Cons
- some are 3rd generation (pick up antibodies after 12 weeks, don’t pick up antigen)
- need second confirmation with venous sample (4th generation-4 week window)
If +ve do you tell contacts?
- Anonymous provider referral good for casual contacts (not marriage)
- If future transmissions are preventable failure to disclose result in criminal proceedings
How long does it take to become undetectable on HART
- 1-6 months to BECOME
- 6 months to STAY
No risk of transmission!
What is PrEP?
What is PEPSE?
PrEP=Pre exposure prophylaxis (like the pill)
- daily tablet
- 7 day lead up or 24 hours before
- (tenofovir and emtricitabine)
PEPSE=Post exposure sexual prophylaxis
- take within 72 hours of sex-ideally 24 hours) (like morning after pills
- have to take tablets every day for 28 days and encourage HIV test after (in 12 weeks)
How do we prevent mother to child transmission?
- Routine antenatal screening (opt out)
- Offer elective C section (give ART 4 hours before C section)
- ART therapy for +ve women
- PEP for 4 weeks after birth
- Formula feeding provided with vouchers if low income
Example of HAART therapy?
Side effect?
Nucleoside reverse transcriptase inhibitors
Side effect: peripheral neuropathy
