text_1: Researchers Develop Simple Paper Test That Quickly Diagnoses Illnesses by Changing Colour
text_2: Paper diagnostic test strip. Image: McMaster UniversityThis news release reports on the development of paper test strips that amplify DNA or RNA from blood, sweat or urine and determine if the person taking the test has a disease. The strips are made of a polymeric sugar film integrated with the paper device. Once a sample is applied the paper changes color to indicate the presence of a marker for a “specific bacterium, virus, or even cancer,” according to the release. The researchers quoted in the release claim that these test strips can be easily and inexpensively manufactured and, because they are portable, could be used to diagnose or self-diagnose illness (such as Ebola) in remote areas before the subject even knows they are ill. But the release does not make clear how such a test could be used to diagnose and differentiate between the multitudes of different diseases and conditions that afflict humans. Besides skirting other important details such as ballpark cost of the strips and data backing up claimed benefits, the release doesn’t put the paper test in context. While the idea of a “simple” paper test to check for illness may sound novel to the public, paper diagnostic tools have been under development since at least 2007. Some diseases are contagious long before the patient has any symptoms. If a person could be diagnosed as contagious in an asymptomatic stage, then the spread of infection could be slowed or halted. A rapid test allowing patients tested in a clinic to know before they left if they had influenza or a cold, strep or a viral sore throat, would be advantageous because it would allow faster targeted treatments. Because such a diagnostic tools are predicted to be relatively inexpensive, portable, and easy to use, they might also hold enormous potential for helping health professionals in the developing world to quickly and accurately diagnose and treat disease.