Evaluation of two commercial rapid tests for laboratory diagnosis of Leptospirosis in Malaysia

Introduction: Leptospirosis is one of the most widely spread zoonotic diseases worldwide. Leptospirosis cases in Malaysian Ministry of Health hospitals has increased from 263 cases in year 2004 to 3665 cases in year 2012, with 365 deaths. Despite its high fatality rate, leptospirosis is curable with early treatment. Thus, accurate and rapid diagnosis is important to facilitate timely clinical decision-making. Objective: To evaluate two commonly used commercial rapid tests to detect leptospirosis among Malaysian patients. Methods: A total of 113 serum samples from leptospirosis patients based on clinical and laboratory findings were used to evaluate VISITECT-LEPTO (Omega Diagnostics, UK) and Leptorapide (Linnodee, Ireland). The sera comprised two groups: sera from acute patients (MAT+, PCR+) and from those with uncertain disease stage (MAT+, PCR non-done). Sera from healthy individuals and patients with other infectious diseases were also tested. Results & Discussion: Leptorapide and VISITECT-LEPTO showed low sensitivity (<34%) with acute leptospirosis patients' sera (MAT+, PCR+). When results of both groups of sera were considered, the diagnostic sensitivity was higher by Leptorapide (63%) but specificity higher by VISITECT-LEPTO (94%). Both kits seemed to show low effectiveness (<50%) as contributed by the large number of false negative and inconclusive results. Conclusion: Both leptospirosis detection kits showed low diagnostic sensitivity with acute patients' sera. Thus to improve diagnosis and prevent disease complications, there is an urgent need to develop a leptospirosis rapid test that is highly sensitive and specific in detecting acute stage of the disease.