Surveillance Methodology

 

Chile is divided into 13 regions, with the capital city of Santiago located in the Metropolitan Region.  In each of the 13 regions in Chile, a central SAG office is located in the main city of that region.  These regions are further divided into quadrants or subdivisions to help aid in localization of an outbreak.  There are 5 subdivisions to each region, with each sub-division having a governmentally employed veterinarian who maintains records of the population and distribution of livestock species in that area.  There are 165 governmentally employed veterinarians.  SAG veterinarians maintain the legal power to slaughter any animals suspected to be FMD positive.  This reliance on a network of veterinarians to find a foreign animal disease is very effective, which was exemplified during the 1987 FMD outbreak that was contained within 15 days of the first case.




Due to the presence of the Andes Mountains, there are highlands (veranadas) and lowlands that the farmers use in seasonal rotation for grazing land for their livestock. Prior to movement of herds up to the veranadas, a veterinarian assigned to the herd must issue a health certificate and a route of ascent must be determined and recorded.  Furthermore, this veterinarian is responsible for monitoring herd health and number of animals every two weeks while the herd is in the veranadas.  Prior to descending, all animals are randomly tested using an ELISA antibody assay as a detection system for FMD.  If positive, the animal is retested with the ELISA antibody assay and VIA antigen AGID to confirm the presence of FMD virus.  In addition, animal numbers within the herd are reassessed, and any discrepancies are explained and documented.  These surveillance measures, in conjunction with legal repercussions (i.e. the incarceration of the smuggler and the slaughter of all smuggled animals), have led to a significant decrease in the incidence of smuggling of livestock from Argentina into Chile.  Quarantine requirements imposed by other countries prior to exportation of livestock to Chile have inadvertently assisted Chile with surveillance of FMD.  These surveillance measures are heightened during times of alert and emergency, and are explained in control measures.

 

In the background, the lab where the livestock blood samples are tested for the presence of the FMD virus.




Here is an example of the Health Certificate that is used by the veterinarians to access the herd health.  Click to enlarge.