A LAMP-based assay for rapid detection of human scabies using clinical skin scraping specimens

Scabies, a common parasitic skin disease caused by Sarcoptes scabiei var. hominis , presents diagnostic challenges because of its diverse clinical manifestations and the limited sensitivity of traditional methods, such as skin scraping. Here, we developed a loop-mediated isothermal amplification (LAMP) assay targeting two S. scabiei -specific genes, Sarcoptes scabiei allergen Sar s 3 ( Sars3 ) and Internal Transcribed Spacer 2 (ITS2). To enhance operational simplicity, a direct lysis protocol was employed, enabling rapid template DNA acquisition from skin scraping specimens without conventional DNA extraction. Primer sets were optimized for amplification speed and specificity; reaction temperatures were determined to be 67 °C for Sars3 and 61 °C for ITS2. The assay achieved detection within 35 min, with limits of detection of 10 3 copies for Sars3 and 10 2 copies for ITS2. No false-positive signals were observed across the 144 negative control reactions for each target. The assay demonstrated high specificity for non-target DNA from humans and house dust mites. Clinical validation using skin scrapings from patients with classic and crusted scabies yielded consistently positive results, whereas samples from non-scabies controls yielded negative results. These findings indicate that the developed LAMP assay provides a diagnostic platform for scabies, requiring minimal and portable equipment, making it suitable for clinical or point-of-care settings.