Oral fluid-based lateral flow point-of-care assays for pertussis serology

Introduction. Current serological diagnosis of pertussis is usually performed by ELISA, which is typically performed in larger diagnostic or reference laboratories, requires trained staff, and due to sample batching may have longer turnaround times. Hypothesis and Aim. A rapid point-of-care (POC) assay for pertussis serology would aid in both the diagnosis and surveillance of the disease. Methodology. A quantitative lateral flow (LF)-based immunoassay with fluorescent Eu-nanoparticle reporters was developed for the detection of anti-pertussis toxin (PT) and adenylate cyclase toxin (ACT) antibodies from oral fluid samples (N=100), from suspected pertussis cases with respiratory symptoms. Results. LF assay results were compared to those obtained with anti-PT IgG oral fluid ELISA. For an ELISA cut-off value of 50 arbitrary units, the overall agreement between the assays was 91/100 (91%), the sensitivity was 63/70 (90%) and the specificity was 28/30 (93%). No ACT-specific antibodies were detected from oral fluid samples; however, the signal readout positively correlated to those patients with high anti-PT IgG antibodies. Conclusion. The developed LF assay was a specific, sensitive and rapid test for serological diagnosis of pertussis with anti-PT antibodies and is a suitable POC test using oral fluid samples.