The last two posts, here and here, have discussed point-of-care testing with respect to chlamydia...and we saw that the test may be ahead of its time. The company which manufactured the tests, Diagnosis for the Real World (DRW), should, however, be applauded for thinking outside the box.
And even more than the test for chlamydia, the company should be heralded for its work with HIV in the field settings. A little primer about diagnosing HIV in pediatrics in resource poor settings, first.
In the rich world, clinicians make a presumptive diagnosis of HIV in a patient with a rapid antibody test. They then confirm the diagnosis with a secondary test, usually a western blot. And finally, the clinician can evaluate the extent of immunocompromised state by counting the CD4 cells.
In poor settings, however, the prohibitive expense of western blot and CD4 machines precludes their use. Instead, the WHO and most international organizations use two positive rapid antibody tests to confirm the HIV diagnosis. Sometimes, if someone has access to a CD4 machine, a 'dried blood spot' can be sent, but it still may take weeks to get the results.
The problem increases logarithmically with infants who may have HIV in these poor settings. As they usually breastfeed until the age of two, there's no way to ensure that any positive antibody test doesn't reflect the transmitted maternal HIV antibodies. And so it's almost impossible to diagnose infants with HIV in resource-poor settings...until...now, through a joint project by DRW and MSF (Medicines Sans Frontieres) called:
...SAMBA:
"Because there is no simple test available today, infants with HIV in developing countries are rarely diagnosed before they reach 18 months. This is why almost all children currently under treatment in Médecins Sans Frontières' programmes are over two years. Without treatment, half of all children infected with HIV die before their second birthday.
The SAMBA (Simple AMplification BAsed nucleic acid test) technology aims to significantly simplify current viral load tests. If successfully developed, it can be used to test viral load at district hospital level in developing countries, and therefore more widely available to resource-poor settings. SAMBA will require little equipment compared to the highly expensive machinery that today's viral load demands. Unlike currently available tests, the SAMBA test and its ingredients do not need to be refrigerated. The technology will also allow the test to be used as a point-of-care test, and provide results while the patient is waiting."
How sweet it could be if it succeeds.
(oh and the koala bear pics have nothing to do with SAMBA...but well, you got to look at really cute koala bears while reading this super serious post! Pic one from cewoldt and pic two from wesley macdonald, both at flickr.com)
UPDATE: Welcome, Grand Rounds visitors - feel free to roam around on this blog - usually with at least a post a day about New Orleans, international health, evidence based medicine, et al. And thank you to SHP for the haiku laden referral (and yes, the koalas really have nothing to do with nothing). Finally, for my three loyal readers, head over to Trick-Cycling for Beginners for this week's Medical Grand Rounds - some of the best the medical blogosphere has to offer.
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