Quantitative risk assessment of WSSV transmission through partial harvesting and transport practices for shrimp aquaculture in Mexico

Publication date: Available online 26 July 2017 Source:Preventive Veterinary Medicine Author(s): Edgar Sanchez-Zazueta, Francisco Javier Martínez-Cordero, María Cristina Chávez-Sánchez, Leobardo Montoya-Rodríguez This quantitative risk assessment provided an analytical framework to estimate white spot syndrome virus (WSSV) transmission risks in the following different scenarios: (1) partial harvest from rearing ponds and (2) post-harvest transportation, assuming that the introduction of contaminated water with viral particles into shrimp culture ponds is the main source of viral transmission risk. Probabilities of infecting shrimp with waterborne WSSV were obtained by approaching the functional form that best fits (likelihood ratio test) published data on the dose-response relationship for WSSV orally inoculated through water into shrimp. Expert opinion defined the ranges for the following uncertain factors: (1) the concentrations of WSSV in the water spilled from the vehicles transporting the infected shrimp, (2) the total volume of these spills, and (3) the dilution into culture ponds. Multiple scenarios were analysed, starting with a viral load (VL) of 1×102 mL−1 in the contaminated water spilled that reached the culture pond, whose probability of infection of an individual shrimp (Pi) was negligible (1.7×10−7). Increasing the VL to 1×104.5 mL−1 and 1×107 mL−1 yielded results into very low (Pi =5.3×10−5) and high risk (Pi =1.6×10−2) categories,...
Source: Preventive Veterinary Medicine - Category: Veterinary Research Source Type: research