The Andean Mountain Range is the fundamental reason for the success of Chile's prevention of Foot and Mouth Disease. 1987, was the most recent year that Chile experienced a FMD outbreak, which was attributed to the import of contraband, such as animal products and livestock from Argentina.
Historical Timeline of FMD in Chile
The important dates that show the progression of FMD in Chile and how the Chilean government reacted to stop the occurrence of FMD and has lead to their current FMD-free status.
Overview of FMD Surveillance, Control, and Biosecurity in Chile
Chile’s FMD control program consists of three important facets: surveillance, control, and biosecurity, which are implemented by Chile’s Agrarian and Livestock Service, SAG (Servicio Agricola y Ganadero), a unit of the Agriculture Ministry. This organization is comparable to the United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS).
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.
There are various strategies utilized to control FMD outbreaks. Chile implements a “stamping out” policy. This entails the slaughter of any infected animal(s) or any animal(s) associated with infected animals. The animals are then burned or buried after slaughter is completed. It is important to point out that slaughtering the animals within 24 hours of diagnosis with FMD is critical to prevent further spread.
Chile is a unique country because of its natural barriers: the Atacama Desert in the north, the Andes to the east, the Pacific Ocean to the west, and Antarctica to the south. Nevertheless, Chile does employ certain measures to control the import and movement of foreign products.
Overview of FMD Surveillance and Control in the United States
The U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) is responsible for protecting U.S. livestock resources from the introduction of foreign pests and diseases that would harm U.S. livestock and devastate the U.S. livestock industry.
United States vs. Chile - Risks of each system
Due
to Chile’s natural barriers, the threat of an introduction of FMD is primarily
limited to importation, tourism, bioterrorism, and illegal migration of animals
across the Andes. By comparison,
the U.S. lacks such physical barriers and shares borders with two countries, and
therefore, an extensive amount of resources are poured into surveillance of the
American-Mexican border, including control programs within Mexico itself.
There are two important implications that are important when discussing FMD outbreak: political and economical.
Important Landmarks in the history of Foot and Mouth Disease
Important dates in time of FMD recognition and experimentation.
Foot and Mouth Disease (FMD), Fiebre Aftosa in Spanish, belongs to the Picornaviridae virus of the genus Aphthovirus.FMD is pH sensitive as it becomes inactivated at a pH below a 6.5 or above 11. FMD thrives at a pH range of 6.7 – 9.0 with decreasing temperature. In cell culture, the virus can stay viable for up to a year at 4° C.
The serotypes of FMD differ in their geographical distribution with only types O, A, and C located in South America currently.
Geographic Serotype Prevalence of FMD
The serotypes are restricted to specific geographic areas of the world. Therefore, the presence of a different serotype to a respected region indicates the occurrence of illegal activities, such as contraband or terrorist attack.
The virus infects cloven-hoofed animals including: cattle, domestic and wild (feral) swine, sheep, goats, llamas, wild deer and elk, and camelids. In camelids, the disease presents asymptomatically, but pigs are the principle amplifiers of the virus. The disease is not zoonotic, however humans may act as carriers of the virus.
The virus invades epithelial cells, with clinical signs resulting from vesicular lesions that progress to ulcerations on the oral cavity, esophagus, upper GI tract, coronary band, udder, and between the digits.
Transmission occurs through contact with infected animals, infected animal products, fomites, people, vehicles, ingestion or inhalation of virus, and through semen or embryos.
FMD has almost 100% morbidity. Mortality is less than 1%; however, in young animals the mortality rate is usually higher.
Currently, there are FMD killed virus vaccines available. However, this vaccine is only affective if the vaccine matches up with the correct FMD virus type and subtype – there are no universal FMD vaccines at this time. Strategically, vaccination may be used in an emergency situation to help localize an outbreak, especially if the preferred policy of stamping out is not quickly containing the disease.
