Handheld device promises reliable, fast, cheap point-of-care Medical laboratory testing in world’s remote areas
New clinical laboratory testing technology is about to revolutionize how HIV and syphilis testing is conducted in developing nations and remote areas. For the first time, researchers have successfully field-tested a rapid, sensitive, and low-cost test for HIV and syphilis that could replace the more expensive and less efficient tests currently available for use.
The new multiplex assay is called “mChip” and consists of a clear plastic device approximately the size of a credit card. It uses blood samples of 1 microlitre and produces results within 20 minutes. During the field study, this pathology testing device was 100% accurate in detecting HIV-positive cases and there was only one false positive out of 70 total samples, according to the report published online by Nature Medicine. This pathology testing device showed equally impressive results when used as a dual test of HIV and syphilis, with similar accuracy for HIV and 94% detection of syphilis cases. False positives for syphilis ran at four out of 67 total samples.
Some experts see this as a huge step. According to an article in the Washington Post, Doris Rouse, a Vice President at RTI International in North Carolina, specializing in global health technologies, observed: “What’s especially exciting about this device is that it’s rugged, easy to use and doesn’t require a lot of infrastructure or training.”
According to Columbia University’s website, the low-cost handheld “mChip” assay is being developed in a three-way collaboration among Columbia Professor Samuel Sia, Ph.D., Claros Diagnostics Inc. (a venture capital-backed startup company co-founded by Sia in 2004), and the Mailman School of Public Health at Columbia.
mChip Reduces Need for Skilled Test Interpretation
Sia, a biomedical engineer at Columbia University in New York, and his colleagues tested the “lab on a chip” device in Rwanda, where the adult population has an HIV-infection rate reported to be 3%. When testing for HIV, Rwandan patients typically provide blood samples at the local hospital, which forwards the samples to a national medical laboratory for analysis. This is an expensive and time-consuming process with turnaround times of days or weeks. The mChip requires less blood, can be used at point of care, and can produce results on HIV and syphilis within 20 minutes with the same advantages and sensitivity as testing performed in medical laboratories.
“We’ve taken what’s long been a great theoretical concept and shown that it can be done in the field,” study author Sia stated. He noted that the trials were conducted in a difficult environment with minimal infrastructure. Sia added that the chip also shows promise for use in simultaneous, single-device detection of other HIV-related diseases, such as hepatitis B and C, herpes, gonorrhea, and chlamydia. At present, there are few cheap tests for these diseases that offer high reliability.
Shiva Goudar, a researcher with Jawaharlal Nehru Medical College in Belgaum, India, sees huge advantages to the new HIV test technology. Explaining that many patients live two or three hours away from the hospital laboratory centers where blood samples are drawn, Dr. Goudar observed in the Washington Post article that the lab on a chip could be used by primary-care providers within the patient’s village. “[D]oing this test at the point of care cuts down on the time, effort and logistics of transport for the blood sample,” Goudar noted.
The new rapid HIV test offers a number of advantages over the existing lateral flow technology HIV test. The legacy test, available for decades, is also cheap and returns results in 30 minutes. Unlike the new lab on a chip device, however, the lateral flow test has not shown itself reliable across multiple test environments and different types of infection.
Sia’s research team estimates the new “mChip” will cost between $2 and $3. Lateral flow tests can exceed $4 per test and do not carry the benefit and cost-efficiency of multiple infection detection. Another advantage of the new device is the reduced need for test-result interpretation. This is a step that is still required by most lateral flow tests. In fact, Sia is working on a separate device that will read the results of the chip test with the goal of eliminating the need for a skilled laboratory worker to interpret the clinical laboratory test results.
Last December Dark Daily reported the potential for the new microfluidic nanotechnology to create reliable “mini-labs” for use by physicians in their in-office labs. The mChip is an example of how such technology can dramatically enhance delivery of testing and diagnostic services to remote and poor regions of the world.
Further, these new tests show pathologists and clinical laboratory managers how technology can allow health workers without years of specialized training to conduct diagnostic tests which are fast and accurate. Despite successful trials and excitement from the global health community, the mChip has yet to garner IVD manufacturer sponsorship to take the technology into the clinical laboratory testing market in developed countries.
Pamela Scherer McLeod
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