RNase HII-assisted amplification (RHAM) for rapid point-of-care monkeypox detection

Mpox poses an ongoing global public health threat, with case numbers rising beyond traditionally endemic regions in Central and Western Africa. Rapid detection of the causative agent, the Monkeypox virus (MPXV), is critical for outbreak control, yet laboratory infrastructure and trained personnel remain scarce in many affected areas. Point-of-care molecular diagnostics offer a practical solution by enabling timely testing without specialized equipment or elaborate nucleic acid extraction. We evaluated the performance of an extraction-free RNase HII-assisted amplification (RHAM) assay for MPXV detection by Pluslife Biotech, a novel isothermal amplification technology providing results in under 30 minutes. The Pluslife RHAM test demonstrated pan-MPXV clade reactivity, detecting all four MPXV clades (Ia, Ib, IIa, IIb) with high analytical sensitivity and no cross-reactivity to other poxviruses or other clinically relevant pathogens. The assay proved compatible with diverse clinical specimen types, including lesion swabs, oropharyngeal swabs, rectal swabs, urine, semen, and wound exudate. As part of routine diagnostics at the German Consultant Laboratory for Poxviruses, in a comprehensive evaluation of 206 clinical specimens against diagnostic real-time PCR, the Pluslife RHAM test achieved a diagnostic sensitivity of 94.2% (95% CI: 85.8-98.4%) and a specificity of 100% (95% CI: 97.3-100%). Notably, samples with higher viral loads (Ct <30) showed 100% sensitivity. Time-to-result correlated significantly with viral load, enabling faster diagnosis in high-viral-load cases. The Pluslife RHAM test represents a practical, sensitive, and rapid point-of-care solution for MPXV detection in resource-limited settings, combining strong analytical performance with operational simplicity to support timely outbreak response and clinical decision-making.