HIV testing Flashcards
In 2018, what proportion of the 103,800 people living with HIV in the UK were diagnosed?
93%
Of those diagnosed with HIV how many are on ART?
97%
What proportion of people with a HIV viral load result are undetectable?
97%
What prevalence of undiagnosed HIV is considered cost-effective for HIV screening?
1 in 1000 (0.1%)
What is the estimated prevalence of undiagnosed HIV in England? Is universal population screening indicated?
0.016%; therefore universal testing not supported
People belonging to which groups at increased risk of exposure to HIV (10)?
MSM Female sexual contacts of MSM Black Africans IVDU (past or present) Sex workers Prisoners Trans women People from a country with high (>1%) DIAGNOSED seroprevalence Sexual contact from high seroprevalence country Person whose mother living with HIV
In which healthcare settings should HIV opt-out testing be offered (5)?
Sexual health services Addiction and substance misuse services Antenatal services Termination of pregnancy services Hepatitis B and C, TB and lymphoma services
What is the UK prevalence of UNDIAGNOSED HIV in MSM, Black African men and women AND PWID?
MSM 0.68% (6 in 1000)
Black African 0.71 (7 in 1000)
PWID 0.089%
Is the undiagnosed prevalence threshold for testing in pregnancy the same as general population?
No, lower
0.0075%
cost-effective
How are indicator conditions of HIV categorised?
AIDS defining
or
Non-AIDS defining associated with an undiagnosed IV seroprevalence >1 in 1000
Who should have an annual HIV test at minimum?
PWID
sex workers
Sexually active MSM
What factors suggest 3 monthly HIV testing for MSM?
Condomless anal sex
Multiple or anonymous sexual partners
> 10 sexual partners in 12 months
Drug use during sex (Grade 1B evidence for meth and poppers)
What is the sensitivity and specificity of blood-based self-tests approved in Europe?
> 99%`
What generation assay is used for the self-test for HIV?
Second or Third gen
Which groups of people may benefit from HIV self-testing?
High prevalence of HIV
Vulnerable populations less likely to access testing
People who test frequently due to ongoing risk
What is the benefit of dried blood spot samples over mini tube samples for self-sampling HIV tests?
Better processing rates; 98.8% vs 55.7%; mini-tubs limited by inadequate blood volume
What is the window period (99th percentile estimate) for 4th generation HIV serology?
45 days
What is the window period (99th percentile estimate) for 3rd generation HIV serology?
60 days
What is the window period (99th percentile estimate) for all POCTs for HIV?
90 days
Which type of test for HIV should be first line/gold standard?
4th generation venous sampling
How might PEP, PrEP or early ART affect the HIV test serology?
Blunt the HIV antibody response
Non-reactive, atypical or non-progressive
What are the structural, policy, legal and organisational Barriers to testing HIV?
Access to services
Testing environment
Service capacity
Cost
What are Barriers to testing HIV at the healthcare provider level?
Clinicians may lack relevant knowledge/skills
Non-HIV specialist
Lack of relevant communication skills/ability to undertake risk assessment
Lack of skill to use rapid POCT
What are Barriers to testing HIV at the individual level?
Lack of awareness or perception of being low risk of IV
Fear of a positive result
