Monkeypox on a disc: Portable centrifugal microfluidic platform for multi-assay colorimetric LAMP

Monkeypox is currently the most important orthopoxvirus infection in humans. The increase in the number of cases, combined with its potential social impact and international spread, led the World Health Organization (WHO) to classify it as the most recent Public Health Emergency of International Concern (PHEIC). Although mainly endemic in resource-limited countries, quantitative Polymerase Chain Reaction (qPCR) remains the gold standard for detection but is challenging due to the need for specialized instrumentation. To address this, we propose an instrument-friendly molecular assay based on colorimetric Loop-Mediated Isothermal Amplification (LAMP), performed on a multi-assay polystyrene-toner (PST) centrifugal device. The new analytical device was designed to include chambers for loading the LAMP mixture and samples, interconnected channels for mixing them, and separate chambers for simultaneous LAMP amplification and visual detection of each sample. When evaluated in a panel of real clinical samples, compared to qPCR, the assay based on visual detection demonstrated 100.00% specificity, 91.67% sensitivity, and 95.83% accuracy, which increased to 100% accuracy when digital image analysis was employed, with a total analysis time of approximately 60 min. The relative simplicity of the assay may facilitate its implementation in resource-limited settings and contribute to expanding access to molecular detection of monkeypox.