{"id":16315,"date":"2020-12-13T13:30:34","date_gmt":"2020-12-13T13:30:34","guid":{"rendered":"https:\/\/i-base.info\/qa\/?p=16315"},"modified":"2024-10-14T09:14:55","modified_gmt":"2024-10-14T09:14:55","slug":"how-long-after-any-risk-does-it-take-hiv-tests-to-be-accurate","status":"publish","type":"post","link":"https:\/\/i-base.info\/qa\/16315","title":{"rendered":"How long after any risk does it take HIV tests to be accurate?"},"content":{"rendered":"

Hi<\/p>\n

Thanks for your question as a few people have asked this recently.<\/p>\n

i-Base don’t usually answer questions about testing because the service is for mainly about HIV treatment. Also because\u00a0we have put all the testing info online. (See: https:\/\/i-base.info\/qa\/11844<\/a>).<\/p>\n

However, as this is a technical question and because\u00a0guidelines recently changed it is good to briefly answer here. The answer also depends on the test you are using.<\/p>\n

    \n
  1. If you are testing at home and getting the results without<\/strong> posting samples back to a laboratory, these are likely to be ‘3rd generation’ tests. The window period for accuracy is 90 days<\/strong> after the exposure.<\/li>\n
  2. If you are sampling at home and posting the sample back to a lab<\/strong>, these ‘3rd generation’ tests have a window of 60 days<\/strong>.<\/li>\n
  3. If you want a faster test result you need to go to a sexual health clinic for a ‘4th generation’ test. 4th generation tests will pick up 95% of infections by<\/strong> about 30 days<\/strong> and more than\u00a099% of infections by 45 days<\/strong>.<\/li>\n<\/ol>\n

    New UK guidelines (BHIVA) recommend people now wait 45 days instead of the previously recommended 30 days (see page 19 of the PDF referenced below). [1]<\/p>\n

    This change is to cover public health benefits relating to whether or not a second confirmatory test is needed. The 30-day window meant that a negative result needed to be confirmed a few months later with a second test. The higher accuracy from waiting until six weeks (45 days) means that a second confirmatory test is no longer needed,<\/p>\n

    However, some people are either extremely anxious about waiting, especially after a higher risk. In this case someone might benefit from an earlier test, even if slightly less conclusive, and then have the confirmatory test later.<\/p>\n

    It is unclear whether HIV clinics in the UK will still offer this flexibility to test twice when anxiety is high.<\/p>\n

    Reference<\/p>\n

      \n
    1. BHIVA\/BASHH HIV testing guidelines (2020). See page 19 for test windows)
      \n      https:\/\/www.bhiva.org\/HIV-testing-guidelines<\/a> (webpage)
      \n      https:\/\/www.bhiva.org\/file\/5f68c0dd7aefb\/HIV-testing-guidelines-2020.pdf<\/a> (PDF file)<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

      Hi, I am worried about a recent risk and I want to know how long I have to wait before taking a test. Thanks.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,22],"tags":[],"class_list":["post-16315","post","type-post","status-publish","format-standard","hentry","category-all-topics","category-hiv-testing"],"_links":{"self":[{"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/posts\/16315","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/comments?post=16315"}],"version-history":[{"count":1,"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/posts\/16315\/revisions"}],"predecessor-version":[{"id":24207,"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/posts\/16315\/revisions\/24207"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/media?parent=16315"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/categories?post=16315"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/qa\/wp-json\/wp\/v2\/tags?post=16315"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}