In general, it can be stated that the changes in production systems have produced a positive effect in the health status of the population of pigs. However, this swine production management knowledge including health management has been developed in a multistage-production separated approach, providing a very strong knowledge area, but in a separated fashion, resulting in unlinked prevention/control measurements, throughout the production cycle or production chain (different production phases).
The Infection/Prevention Chain concept is a tool for disease management understanding, under a whole herd (systematic) approach, where we are putting together new and existing knowledge in swine diseases management, connecting epidemiological events (infection chain
) alongside the herd/production system (production chain
), using a logical chain thinking to create this new concept focused in disease prevention in a comprehensive way (prevention chain).
Persistence of infection, shedding patterns, vertical transmission, horizontal transmission and lateral infection should be considered as critical epidemiological pieces participating in the “infection chain” of swine pathogens throughout the complete production process (whole herd) resulting in the clear manifestation of clinical symptoms with the correspondent production and financial losses due to the increase of mortality, cull rate, treatments and lack of performance, also subclinical forms of the diseases. This “chain” starts with gilt development and introduction into the sow herd and ends in growth-finish populations or keeps going with gilt production.
This “chain thinking”
allows us having a more linked and comprehensive approach
to understand the epidemiology and prevention of major infectious agents by matching “production chain” with “infection chain”, resulting in a “prevention chain” extremely focused in the entire production system and stages instead of just the sow or only the piglet.
Therefore, this approach can help to modify or re-adjust the intervention strategies
(animal flow, management and prevention protocols), utilized for controlling or preventing the disease, considering the whole “infection chain” of the agent, allowing an appropriate “prevention chain” approach. The goal is to create a way of thinking where the understanding of the root of the problem is considered as the first step of this whole herd approach.
PRRSv Infection/Prevention Chain
This concept fits perfectly to the whole herd approach or systematic approach proposed for PRRSv. A summary of the Infection/Prevention Chain of PRRSv is described below.