HIV: diagnosis and assessment, HIV pre-test discussion, Risk assessment, positive HIV testEarly diagnosis allows monitoring with pre-symptomatic HAART, Implications of testing, antibody test is serum Assess patient knowledge,

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I work in the epicentre of HIV - the middle of sub-Saharan Africa. This is our approach. 

HIV: diagnosis and assessment


HIV pre-test discussion: HIV infection is usually diagnosed by detecting antibodies in a serum sample. However, in suspected infections or 2 to 4 weeks after a specific high-risk incident (e.g. needle-stick injury) plasma should be tested for HIV p24 antigen and RNA by a nucleic acid amplification technique (e.g. PCR). Testing should always be done with informed consent and assurance about the confidential nature of the process. Points to cover include:
  • Risk assessment: e.g. sex practices, travel, drug use, occupation, blood/blood products exposure
  • Very high risk:
    • unprotected sexual contact with an HIV infected partner
    • receipt of infected blood products
    • sharing injecting equipment with HIV infected person.
  • If risk within 72 hours consider post-exposure prophylaxis
    • High risk:
      • unprotected anal sex (especially receptive)
      • sex or sharing injecting equipment with people from countries with a high HIV prevalence.
  • Assess patient knowledge: ensure that the individual understands the nature and transmission of HIV. Advise on risk reduction.


  • The standard antibody test is serum (saliva and finger prick tests available if venepuncture impossible): (the serum test is a blood test)


    • detects antibodies to HIV 1 and 2, does not diagnose AIDS.


    • seroconversion often within 4 to 6 weeks but may take up to 12 weeks, a window period, repeat testing may be required. Repeat saliva testing advised 14 weeks after risk. It is therefore important to determine the date of the last risk.


    • positive standard screening tests need to be validated by different method(s) which may incur delays. Rarely indeterminate results are obtained requiring repeat sampling.
Implications of testing


  • Early diagnosis allows monitoring with pre-symptomatic HAART if appropriate and development of strategies to avoid transmission including post exposure prophylaxis


  • In pregnancy: allows informed choices about the management of pregnancy, especially the use of antiretroviral treatment (both mother and infant), and avoidance of breastfeeding to decrease vertical transmission. Arrangements for early monitoring of the infant's health


  • If negative, elimination of needless anxiety
But if positive HIV Blood test:


  • psychological impact of result


  • social and work implications (e.g. surgeon). May affect travel to, or work in certain countries


  • life insurance restrictions/weightings. A positive result (or awaiting a test result) must be declared on application forms

  • Arrangements for giving results
    • How/when the result will be provided (especially in high-risk situations)
    • If positive who will he/she tell, how will the individual cope, what support is available.
  • Document that information has been provided on
    • positive, negative, and indeterminate results
    • how, when, and where results will be given and whether written confirmation is required
    • follow up and the possible need for repeat testing to confirm positive results or cover the window period.
  • Obtain and document informed consent.


This is a check-list that we have adopted 
Risk assessment Yes No Further inform.
Prior HIV test When:
Blood transfusion/products When:
Where:
Injecting drug user (shared equipment) Last time:
Sex with people from countries with a high HIV prevalence Last time:
Homosexual/bisexual man or sex with homosexual/bisexual man Last time:
Contact with HIV Last time:
No risk
Low/medium risk
High risk
Information provided
Benefits of early identification and treatment explained
Implication of positive result (especially if high risk)
3-month window explained
Insurance explained
Result giving explained
Consent to test obtained
HIV test taken
Repeat test required When:


Post-test counselling
The content and timing of the discussion will depend upon the patient's reaction to a positive or negative result.

The aims of post-test counselling are to


  • address the immediate concerns and provide support for those who are positive and also negative (especially the very anxious)


  • provide information on the prevention of HIV transmission


  • ensure patient is aware of need for confirmatory/repeat testing if appropriate.
If HIV positive


  • address immediate reactions and assess need for psychological intervention.


  • provide further basic information about the natural history of HIV, reinforcing the difference between HIV and AIDS and efficacy of treatment.


  • construct a management plan which meets the needs of the patient.


  • give details of support services.


  • offer follow-up appointments and ongoing support which may include addressing issues concerned with employment, travel, legal matters, and support for carers and partners.


  • provide information on what further investigations will be required.
Seronegative HIV infection
Negative HIV antibody test with HIV infection (after excluding specimen handling errors) is well-recognized during the window period. It is otherwise very rare and identified only when clinical presentation suggests HIV/AIDS with a negative HIV antibody test but positive PCR for HIV RNA/DNA (or viral culture). Possible causes:


  • profound hypogammaglobulinaemia


  • seroreversion extremely rare


  • HIV group O infection


  • unknown.


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