Scientists from the University of Pennsylvania (PA, USA) have developed a new instrument-free, portable test for Zika virus. The point-of-care test delivers rapid diagnosis – within 40 mins – and costs only US$2 per test. The team hope that the diagnostic will aid disease monitoring and control, particularly in light of the upcoming Olympic Games in Rio de Janeiro, Brazil, where Zika virus has been widely reported.
The WHO has recently announced that there is no need to postpone the Olympic Games in Rio due to the presence of Zika virus, a decision that has been contested by some public health experts. Meanwhile, scientists continue to work on diagnostic tests that can rapidly and reliably detect the virus.
Previous low-cost diagnostic tests have been reported as unable to detect low levels of the disease, or incapable of distinguishing between Zika and similar viruses, such as dengue. The new diagnostic test, published in Analytical Chemistry, addresses this shortfall. The test is designed to offer rapid, low-cost and reliable detection.
The researchers identified a stretch of genetic code that is almost identical in 19 different strains of Zika present in the Americas, but not in other pathogens. By targeting this genetic region, the team developed the new diagnostic system, which requires only the addition of water to operate.
The diagnostic costs only US$2 per test, and returns a result within 40 mins. It tests saliva samples, and if the Zika-specific genetic region is detected, a dye in the system will turn blue. The team state that the test will function even with only low levels of the virus present.
The researchers hope that the test could provide the sought-after rapid point-of-care diagnoses required in the wake of the Zika epidemic. They highlight that it would be of particular use in resource-poor settings.
Sources: Song J, Mauk MG, Hackett BA, Cherry S, Bau HH, Liu C. Instrument-free point-of-care molecular detection of Zika virus. Anal. Chem. doi:10.1021/acs.analchem.6b01632 (2016) (Epub ahead of print); www.acs.org/content/acs/en/pressroom/presspacs/2016/acs-presspac-june-29-2016/portable-test-rapidly-detects-zika-in-saliva-for-2.html