Shrimp MultiPath™ multiplexed PCR white spot syndrome virus detection in penaeid shrimp

Area of Science:

• Aquaculture
• Veterinary Diagnostics
• Molecular Biology

Background:

• White spot syndrome virus (WSSV) causes significant economic losses in the global shrimp industry.
• Effective surveillance and diagnosis are critical for managing WSSV outbreaks.
• Current diagnostic methods require improvement in terms of cost and accessibility.

Purpose of the Study:

• To validate the performance metrics of the Shrimp MultiPathTM (SMP) WSSV assay.
• To compare the SMP WSSV assay with existing quantitative PCR (qPCR) methods.
• To evaluate the use of synthetic DNA for assay validation.

Main Methods:

• Analytical sensitivity, specificity, and repeatability testing of the SMP WSSV assay.
• Bayesian latent class analysis to estimate diagnostic sensitivity and specificity using data from shrimp populations in Latin America.
• Comparison of SMP WSSV assay metrics against World Organisation for Animal Health and Commonwealth Scientific and Industrial Research Organisation recommended qPCR assays.
• Validation using synthetic double-stranded DNA analyte in pathogen-naïve shrimp tissue homogenate.

Main Results:

• The SMP WSSV assay demonstrated high analytical sensitivity (~2.9 copies) and perfect analytical specificity (~100%).
• Intra- and inter-run repeatability showed a coefficient of variation <5%.
• Diagnostic metrics revealed 95% sensitivity and 99% specificity, outperforming current qPCR assays.
• Synthetic DNA proved a viable substitute for clinical samples in validation.

Conclusions:

• The SMP WSSV assay is a highly sensitive, specific, and cost-effective tool for WSSV detection.
• Its performance is comparable or superior to existing qPCR methods.
• The assay is suitable for both diseased and apparently healthy shrimp surveillance, aiding in early detection and management of white spot disease.