# What diseases is donated blood tested for? **URL:** \ **Category:** Factual Questions\ **Created:** [October 12, 2006, 2:41pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197 "2006-10-12T14:41:20Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Capt.Ridley\_s\_Shooting\_Party](https://avatars.discourse-cdn.com/v4/letter/c/cc9497/32.png) [@Capt.Ridley\_s\_Shooting\_Party](https://boards.straightdope.com/u/Capt.Ridley_s_Shooting_Party)\ **Post date:** [October 12, 2006, 2:41pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/1 "2006-10-12T14:41:20Z")
All the fuss over whether homosexuals can donate blood begs the question as to how thoroughly blood is tested after donation. What tests are donations put through in a typical Western country (UK, USA, Canada etc)? How safe if this blood if having a gay experience ten years ago can tar you for life? ---
**Author:** ![One\_And\_Only\_Wanderers](https://avatars.discourse-cdn.com/v4/letter/o/838e76/32.png) [@One\_And\_Only\_Wanderers](https://boards.straightdope.com/u/One_And_Only_Wanderers)\ **Post date:** [October 12, 2006, 2:42pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/2 "2006-10-12T14:42:25Z")
I think it’s more along the lines of the tests being expensive, so if you are high risk, they’d rather not have your blood, as the probability of it being thrown out after the test is too high. ---
**Author:** ![Antigen](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Antigen](https://boards.straightdope.com/u/Antigen)\ **Post date:** [October 12, 2006, 3:03pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/3 "2006-10-12T15:03:50Z")
Tests performed routinely on all donor blood units by Hema-Quebec: - HIV type 1 and 2 - Hepatitis B and C - Human T-cell lymphotropic virus (HTLV; linked to some leukemias and lymphomas) - Syphilis In all these, the test looks for the antibody, so once you’ve been infected, even if you feel fine, you’re ineligible to donate. Exception: Hepatitis B. If you’ve recovered from HepB and no longer have the active virus circulating in your blood, or you’ve been vaccinated, you’re still allowed to donate. - Cytomegalovirus (CMV) - done on _some_ blood units, because most people have already been exposed to CMV and it’s not a problem. The testing is only to identify a number of CMV negative units which are put aside for use in infants and immunocompromised people who have no prior CMV exposure. - West Nile Virus - done on blood collected between June 1st and November 30th, when West Nile virus is more likely to be around. Still only experimental. The blood is also tested for blood type including weak variants of the Rh factor that may otherwise be missed, and they are screened for the presence of antibodies against blood group antigens. Reference: _Circular of Information for the use of Labile Blood Products_, June 2005 edition, published by Hema-Quebec. ---
**Author:** ![Spiff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiff/32/9852_2.png) [@Spiff](https://boards.straightdope.com/u/Spiff)\ **Post date:** [October 12, 2006, 3:06pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/4 "2006-10-12T15:06:22Z")
It varies, but here’s a minimum: HIV Hepatitis B Hepatitis C Syphilis Human T-lymphotropic virus (HTLV), type 1 and type 2 Blood organizations also save money by testing small samples from 10-12 donors mixed together. If these comingled samples pass all tests, all of the donations are cleared for use. If any positive reactions pop up, the same tests are done again on two comingled sets of 5-6 donors. The process is repeated until the infected unit or units are found. ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [October 12, 2006, 9:35pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/5 "2006-10-12T21:35:39Z")
Why isn’t the blood tested for HIV? Is that a really expensive test? ---
**Author:** ![Captain\_Amazing](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Captain\_Amazing](https://boards.straightdope.com/u/Captain_Amazing)\ **Post date:** [October 12, 2006, 9:37pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/6 "2006-10-12T21:37:57Z")
[QUOTE=ZipperJJ] Why isn’t the blood tested for HIV? Is that a really expensive test? [/QUOTE] Blood is tested for HIV. ---
**Author:** ![Antigen](https://avatars.discourse-cdn.com/v4/letter/a/848f3c/32.png) [@Antigen](https://boards.straightdope.com/u/Antigen)\ **Post date:** [October 12, 2006, 9:38pm UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/7 "2006-10-12T21:38:23Z")
[QUOTE=ZipperJJ] Why isn’t the blood tested for HIV? Is that a really expensive test? [/QUOTE] HIV is in both the lists of tests provided in this thread. _First_ in both lists, in fact. Trust me, it’s tested for. Both the antibody and the DNA of the virus itself are tested for. ---
**Author:** ![Hirundo82](https://avatars.discourse-cdn.com/v4/letter/h/919ad9/32.png) [@Hirundo82](https://boards.straightdope.com/u/Hirundo82)\ **Post date:** [October 13, 2006, 3:04am UTC](https://boards.straightdope.com/t/what-diseases-is-donated-blood-tested-for/376197/8 "2006-10-13T03:04:46Z")
Most labs in the US now test for West Nile Virus as well.