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Cheap, easy, and sensitive HIV test? Yes please! [erv]
HIV diagnosis is The Root of most of the problems we have in HIV World.
“How can we get more people antiretrovirals?”… How can you give someone antiretrovirals before they have been diagnosed with HIV?
“How can we stop HIV transmission to sexual partners?”… Condoms work, but why would you insist people in committed monogamous relationships wear condoms if neither one was HIV positive?
“How can we stop HIV transmission to babies?”… Pre-birth antiretrovirals work, but why would you give an expectant mom anti-HIV drugs if she was not HIV positive?
We need to know if someone is HIV+ before any of these other problems become problems.
Roughly 20% of the people infected with HIV do not know it. Sure, some of that it because people wont/are afraid to get tested. But some people cant get tested. They cant afford it, their physicians cant afford it, their governments cant afford it. Not just the gross cost of reagents and man-power for people trained to do/interperet HIV tests– The equipment to read the tests (ELISA plate readers, Western Blot imagers, Real-Time PCR machines) is beyond cost prohibitive (and quite useless if you do not have electricity).
Literally and philosophically– How do you solve a problem you cannot see?
Well, the smart-ass answer would be “Make an HIV test you can read/see with the naked eye”.
Apparently, the smart-ass answer is the right answer:
Plasmonic ELISA for the ultrasensitive detection of disease biomarkers with the naked eye
It looks like a totally easy idea to implement:
- Take something that already works for HIV-1 detection, an ELISA, and make it a liquid (‘plasmonic’, lol).
- Take the readout from an ELISA (requires a machine) and make it easy to read with the naked eye (“coloured nanoparticle solutions of characteristic tonality” aka blue=positive, red=negative).
- Make sure its super sensitive. Like, just as sensitive as an extremely expensive Real-Time PCR protocol.
See? Totally simple!
LOL!
Conceptually it is simple, but what they had to do to make this actually work… I dont want to know the trail of trouble-shooting and epic failures behind this innovation, but it is absolutely fantastic. Basically, if no HIV proteins are there, the nanoparticles in this solution remain dispersed, and the solution looks red. If HIV particles are there, the nanoparticles start sticking together, a chemical reaction occurs, and the solution looks blue.
No super special (read: expensive) plates or equipment needed, just mix everything together.
Of course, it would suck if the test only worked if you were REALLY HIV positive, and had LOTS of HIV proteins around for this reaction to work. Certainly it would still have some utility, but we want an HIV test to be very sensitive, so you dont send someone home with an HIV- diagnosis when they are actually HIV+.
The ‘gold standard’ of HIV tests, RT PCR, can detect <50 copies>
What can this test do?
p24 was also detected with the naked eye in the sera of HIV-infected patients showing viral loads undetectable by a gold standard nucleic acid-based test.
I could hardly believe that, but they put pics of the assays in the paper. The tests from HIV- people are pink, the tests from HIV+ people with high or undetectable-by-gold-standard viral loads is a bluish purple.
Detection of HIV is the FIRST problem we have in HIV World. This looks like a pretty damn exciting solution!
2012-11-02 15:24:45
Source: http://scienceblogs.com/erv/2012/11/02/cheap-easy-and-sensitive-hiv-test-yes-please/
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