A nanoparticle pseudo pathogen for rapid detection and diagnosis of virus infection.

We herein report a new rapid blood test for virus infection detection and diagnosis. A citrate gold nanoparticle is first coated with a virus lysate to form a gold nanoparticle pseudo pathogen. The gold nanoparticle pseudo virus is then mixed with a blood plasma or serum samples. If the blood sample is from a positive patient, the activated immune molecules in the blood such as antibodies, complement proteins and others will react with the nanoparticle pseudo virus, leading to nanoparticle aggregate formation. The nanoparticle aggregate formation is detected and measured using a particle sizing technique called dynamic light scattering. In this study, we applied this test for Zika virus infection detection. We tested blood plasma samples from 85 Zika positive patients, 40 Dengue positive patients, 10 Chikungunya positive patients, and 78 non-patient control samples collected from both endemic and non-endemic locations. The study shows that the new test has a higher sensitivity compared to some existing commercial tests in the market, while maintaining a similar specificity. Within 7 days from the symptom onset, the new test can detect 43% of the infected patients while a commercial anti-Zika IgM test detects only 26% of the infected patients. Within 14 days from the symptom onset, our new test detects 73% of the infected patients while the same commercial anti-Zika IgM test detects 53% of the infected patients. The test is extremely simple, easy to develop, with test results obtained within minutes. This new test platform may be potentially adapted for the detection and diagnosis of a wide range of viral infectious diseases, for example, the currently ongoing COVID-19.