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When 3 and 4 gen hiv tests are conclusive?

Question: 

Hi!
Sorry for a long post. But I just want to make clear for me some very important things. I suppose, these things also important for MANY MANY other people.
So, many thanks in advance to you for this reply.
 
All volunteers write on this site, that 
"International testing guidelines for HIV testing state results can be considered conclusive at/after 3 months."
 
Can you please give a link to these guidelines?
 
Canadian:at http://www.bccdc.ca/NR/rdonlyres/2982E293-BD82-436D-B193-F929B5CEEBEC/0/...
written, that  "While maximum window periods for specific HIV tests are difficult to estimate, under the standard  testing algorithm at the Provincial Public Health Reference Laboratory it is estimated that greater than 95% of individuals will show detectable antibodies to HIV by 4 to 6 weeks, with greater than  99% having sero-converted by 3 months (as detected by Western Blot)."
 
Also Canadian:
http://www.bccdc.ca/NR/rdonlyres/C0486576-7398-4630-B71C-31A0D5EAEBDC/0/...
"With the HIV point of care test, if the test is negative and it has been longer than 3 months 
since the last time when you may have been exposed to  HIV then it means that the test is 
not seeing antibodies to HIV and you do not have HIV infection.  No further testing is 
needed."(page 24) However, in the same document written at the page 19: "Repeat testing 3 months  following exposure will rule out HIV infection in 99% of cases)"
 
But "greater 99%" is not the case :(
Where can I gen actual precise value(e.g. 99.9(8-9)%)
 
 
USA CDC writes at 
http://hivtest.cdc.gov/faq.aspx#exposure  - that up to 3 month, only 97% have antibodies. other - in 6 months.
 
While the same CDC writes at it's :"Module 6  HIV Testing and Counselling for PMTCT" - page 11 http://www.cdc.gov/globalaids/Resources/pmtct-care/docs/TM/Module_6TM.pdf
 
That "A negative result usually means that the person is not infected with HIV. In rare instances, a person with a negative or inconclusive result may be in the “window period.” This is the period of time between the onset of infection with HIV and the appearance of detectable antibodies to the virus. The window period lasts for 4 to 6 weeks but occasionally up to 3 months after HIV exposure. Persons at high risk who initially test negative should be retested 3 months after exposure to confirm results."
 
For EU recomendations - it's 3 months.(6 months for PEP therapy, "unability to produce antibodies", organs transplantations).
For UK http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf
"If individuals report high-risk activity within the ‘window period’ of POCTs (currently 12 weeks), either
repeat testing in 12 weeks or attendance at a local healthcare HIV testing site should be encouraged."
(page 15)
 
So. How it may be, that according to UK guidelines 12 months is totally conclusive 100%(without explanation)
According to US CDC - 12 months - conclusive only on 97%
According to EU - 12 months - conclusive with exceptions.
According to Canada bccdc - 12 months conclusive on 99% WITHOUT further reteesting needed...
 
So. Where is the truth? As for me 99% - is not the case. It should be 99.89-99.99%(then other 0.11-0.01% is just a statistical error)
 
Can you please share an official web-link, where
"International testing guidelines for HIV testing state results can be considered conclusive at/after 3 months."
 
Many, many thanks in advance.
 

Answer: 

Hi there,
Thank-you for your questions. There is no "international HIV testing authority" that we refer to (it would be great if that existed!) but as you demonstrated, in Canada, US and UK, all testing is recommened at 3 months or 12 weeks. By looking at testing standards in various countries, much like you have done, it is evident that internationally, it is accpeted that testing at/after 3 months is conclusive, except in rare cases (such as someone who took PEP or has an immunodeficiency disorder). Abosolutely nothing you have quoted says anything about 12 months- everything refers to 12 weeks.
No test (for anything) will be 100% ever- it is simply not possible. In addition, no government website will conclusively rule out an infection because they have no idea who is reading the information & what that particular person's health situation is. This is why the medical professionals at the clinic or testing site you visit should be trusted- they are experts at what they do and are able to make accurate and reliable recommendations around further testing or not. 
I hope this helps address your concerns & that you can find peace and acceptence with your HIV test results and status.
In health,
MonicaAIDS Vancouverhelpline@aidsvancouver.org604.696.4666, Monday-Friday 9am-4pm