A lateral flow assay for the immunodiagnosis of human cat‐transmitted sporotrichosis

BACKGROUND: Cat‐transmitted sporotrichosis (CTS) caused by Sporothrix brasiliensis has emerged as an important zoonosis in Brazil and neighbouring countries. OBJECTIVES: Evaluate the performance of a lateral flow assay (LFA) for the detection of anti‐Sporothrix antibodies in human sera. METHODS: A LFA for the detection of anti‐Sporothrix antibodies (Anti‐Sporo LFA) in human sera, developed by IMMY, was evaluated using 300 human sera collected prospectively at the Hospital de Clínicas, Federal University of Paraná (HC‐UFPR), in Curitiba, Brazil. These specimens included 100 sera from patients with CTS. CTS cases were classified as follows: 59 lymphocutaneous, 27 fixed cutaneous,13 ocular, and one mixed form. One‐hundred specimens from patients with other mycoses, including cryptococcosis (n = 32), candidemia (n = 27), paracoccidioidomycosis (n = 14), aspergillosis (n = 10), histoplasmosis (n = 9), fusariosis (n = 4), lobomycosis (n = 1), chromoblastomycosis (n = 1), mucormycosis (n = 1) and trichosporonosis (n = 1). And 100 specimens from apparently healthy volunteers (AHV). RESULTS: The Anti‐Sporo LFA showed a global sensitivity of 83% (95% confidence interval [CI] = 74%–90%), a global specificity of 82% (95% CI = 76%–87%), and accuracy of 82% (95% CI = 77%–86%). By clinical form sensitivity was as follows: Mixed form 100%, ocular 92%, lymphocutaneous 83% and fixed cutaneous 78%. False‐positive results were observed in 11 specimens from people with other mycoses and 26 specimens from AHV. CONCLUSION AND DISCUSSION: This study presents the results of the evaluation of the first lateral flow assay for the detection of anti‐Sporothrix antibodies in human sera. The findings here show evidence that IMMY's Anti‐Sporo LFA is a promising tool for the rapid diagnosis of CTS.