A field-expedient method for detection of leptospirosis causative agents in rodents.

Abstract : We have developed a thermal-stable, pathogenic Leptospira TaqMan PCR assay intended to support pathogen surveillance in reservoir populations. The assay is packaged specifically for use with a portable, ruggedized real-time PCR thermocycler. Limit of detection was established at ≤100 fg (20 organisms). Sensitivity and specificity were 100% concordant with conventional PCR results using a broad test panel of human pathogenic and nonpathogenic Leptospira, genetic near neighbors, and clinically significant organisms. In blind testing using a panel (n=50) of pathogenic Leptospira infected and noninfected Rattus species samples, assay sensitivity results were 100% concordant with conventional PCR. Tests performed under field conditions using wild-collected rodent kidney extracts demonstrated the mobility of the system. During field evaluation, samples were processed and analyzed in 3 hours. Thermal stabilized reagents allowed transportation, storage, and analyses under ambient temperatures. The system provides a promising aid in leptospirosis control programs.