New Device Could Streamline HIV Testing

An experimental point-of-care test that replicates all the steps of enzyme-linked immunosorbent assay (ELISA) successfully detected both HIV and syphilis in a trial in Rwanda, according to a new study. The “lab on a chip,” termed “mChip” by the study authors, integrates new manufacturing procedures, fluid handling and signal detection in microfluidics into a single POC test, reported Samuel Sia, biomedical engineer at Columbia University, and colleagues.

Using the credit card-shaped mChip, researchers tested hundreds of locally collected human blood samples, injecting miniscule amounts of blood, - 1 microliter per sample - into the machine. For HIV, the device detected 100 percent of all HIV-positive cases, and returned one false positive for the 70 samples, the study authors reported. The dual HIV/syphilis test had similar accuracy for HIV, and for syphilis it detected 94 percent of cases, but had four false positives out of 67 samples.

Results were available within about 20 minutes, and Sia estimated the test cost could be about $2-$3. The results do not require user interpretation, the study authors reported. The technology also has the potential to simultaneously detect hepatitis B and C, gonorrhea, herpes, and chlamydia, Sia said.

Such a POC test would be a boon for the developing world, said experts not involved in the study.

The mChip is “rugged, easy to use, and doesn’t require a lot of infrastructure or training,” said Doris Rouse, vice president of RTI International and a global health technologies expert. The assay “can be done outside the lab with all the same advantages and sensitivity [for detection],” said Rosanna Peeling, a diagnostics researcher at the London School of Hygiene and Tropical Medicine.

The full study, “Microfluidics-Based Diagnostics of Infectious Diseases in the Developing World,” was published in Nature Medicine (2011;doi:10.1038/nm.2408).

The Friends of AIDS Foundation is dedicated to enhancing the quality of life for HIV positive individuals and empowering people to make healthy choices to prevent the spread of the HIV virus. To learn more about The Friends of AIDS Foundation, please visit: http://www.friendsofaids.org.


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