6. Early detection

“An early detection system is an efficient system for ensuring the rapid recognition of signs that are suspicious of a listed disease, or an emerging disease situation, or unexplained mortality, in aquatic animals in an aquaculture establishment or in the wild, and the rapid communication of the event to the Competent Authority, with the aim of activating diagnostic investigation with minimal delay.” (modified from OIE, 2004)

Early detection is the detection of an emerging disease situation within a country’s national territory within the shortest time frame possible. The aim of an early detection system is to ensure detection of the introduction of, or sudden increase in the incidence of, any disease of aquatic animals that has the potential of developing to epizootic proportions and/or causing serious socio-economic consequences. It embraces all initiatives that lead to improved awareness and knowledge of the distribution and behavior of disease outbreaks (and of infection) and that allow forecasting of the source and evolution of the disease outbreaks and the monitoring of the effectiveness of disease control campaigns. The key components of a national early detection system are given in Box 2.

BOX 2

Key components of a national early detection system
(modified from OIE, 2004)

Broad awareness, e.g. among the personnel employed at aquaculture establishments or involved in processing, of the characteristic signs of listed diseases and characteristics of other diseases that could be cause for concern (“emerging diseases”).
Experienced veterinarians or other aquatic animal health professionals trained in recognizing and reporting suspicious disease occurrence.
Ability of the Competent Authority to undertake rapid and effective disease investigation.
Access by the Competent Authority to laboratories with the expertise and facilities required to diagnose and differentiate listed and emerging diseases from endemic or benign infections.