A Great Challenge
Lyme disease is the most common vector-borne infectious disease in North America and Europe. Caused by the spirochete bacterium Borrelia burgdorferi, it is characterized by a rash in infected skin and leads to major symptoms if left untreated. Though many tests have been developed to diagnose this disease, the currently available tests are expensive and lack sensitivity (true positive rate) when it comes to the early stages of the infection.
Fortunately, a team of scientists from The University of California, Los Angeles, has recently developed a new inexpensive and trustful way of detecting this infection. They claim that this new procedure does not need previous training to be implemented, and that its sensitivity can be greater than 90%.
Figure 1: Lyme disease testing procedure. Adapted from ACSNANO
How does it work?
Figure 2: Illustration of the complexed reactions that lead to identification of the lyme disease. Adapted from ACSNANO
This novel test consists of a paper based multicomplex vertical flow assay, where small paper layers are covered in various disease-specific target proteins that interact with different antigens present in human samples. The protein-antigen interaction results in an observable change in colour. Upon the completion of the test, they generate a colour pattern that can be analyzed by a computer or even a smartphone. This allows possible diagnosis of the disease within minutes and increases specificity (true negative rate) and sensitivity in its early stages. The test has also been optimized with positive and negative controls to avoid false diagnoses, and it is enclosed in a 3D printed case for easy handling.
Major Improvements to Technology
Figure 3: Reported data on test sensitivity, specificity and Area Under the Curve. Adapted from ACSNANO
Previously used examinations could cost up to 400 USD per test, and their average time for diagnosis is currently over 24 hours. They also have very low sensitivity to the early stages of the disease, with values of less than 50% being reported. As mentioned by the authors, this assessment has a material cost of 0.42 USD per test which greatly reduces costs for diagnoses. They also report values of sensitivity of over 90% in early stages of Lyme disease and a specificity value of 87%. Nonetheless, this team of researchers have demonstrated the correct diagnosis of the disease in a matter of minutes making this process efficient, easy and available to the public at a reduced cost.
-Aron Engelhard
