—from Epidemiological Bulletin, Vol. 21 No. 3, September 2000—

Situation of Foot-and-Mouth disease in South America

Foot-and-mouth disease is an acute, highly contagious, viral disease that affects domestic and wild biungulate animals. Its clinical signs are characterized by fever and the formation of vesicles, mainly in the cavity of the mouth or nose, the interdigital spaces, and the coronary knots of the hoof. There are 7 immunologically different serotypes of foot-and-mouth disease viruses (A, O, C, SAT1, SAT2, SAT3 and Asia1), and several subtypes. The O, A and C types are widely distributed around the world and are the only ones found in the Americas. The SAT1, 2 and 3, and Asia1 types are found in Africa and Asia. Adequate control programs do not protect countries against the appearance of new subtypes or exotic types and given that the disease is highly contagious, a fast diagnosis is required, involving the joint intervention of epidemiologists, veterinarians, and laboratory staff. The resulting decrease in production and depreciation of animal products generate severe economic losses in the affected countries.

Within the Hemispheric Plan for Eradication of Foot-and-Mouth Disease initiated at the end of the 1980s, affected countries work to control the disease with national and regional livestock vaccination campaigns, with the ultimate goal of eradication. In the Region of the Southern Cone, Argentina, Chile and Uruguay were internationally recognized as free of disease without vaccination and Paraguay and the area of the States of Rio Grande do Sul and Santa Catarina, Brazil as free with vaccination. In the Andean Region, the Colombian area of Urabá Chocoano was declared free of disease without vaccination and the recognition of the Atlantic coast as free with vaccination is imminent.

On 2 August 2000, the situation in the Southern Cone was affected when 4 animals tested positive for foot-and-mouth disease in the Locality of Clorinda, Province of Formosa, Argentina, on the border with Paraguay. The A 24 subtype of the A virus was isolated from one of the animals. Emergency sanitary measures were initiated, including the slaughter of seropositive and exposed animals in the Provinces of Formosa, Corrientes and Entre Ríos, the introduction of animal quarantine measures, and active epidemiological surveillance at the national level, supported by serological studies in high-risk animal populations.

In the Municipality of Joia, located in the northwest part of the State of Rio Grande do Sul, Animal Health Services Officials from the Secretary of Agriculture confirmed at the end of July the suspicion of foot-and-mouth disease in four small properties of predominantly family production. On 23 August, after several tests resulted negative for foot-and-mouth disease, the O virus was diagnosed as the etiologic agent of the disease. Since vaccination had been suspended as of May 2000 due to the state’s strategy to reach the status of free without vaccination, emergency sanitary measures had to be put in place, including the sanitary isolation of eight municipalities, the slaughter of 3,635 sick and exposed animals in 24 confirmed loci in four municipalities, the quarantine (prohibition of movements) of animals and the interdiction of commercialization of milk and other animal by-products.

On 5 September, authorities from the Colombian Livestock Institute (Instituto Colombiano Agropecuario, ICA) reported to the International Office of Epizootics (IOE) the existence of a herd affected with the O virus in a livestock property located in the Municipality of Necocli, Department of Antioquía, Colombia, outside the protected zone internationally recognized as free of foot-and-mouth disease without vaccination. The emergency measures included vaccination in the peripheral area and in the municipality, the sanitary slaughter and burial of sick and exposed animals, including pigs raised in the peripheral area.

Epidemiological research is in progress both in Brazil and Colombia in order to determine the origin of the disease. These events have had negative effects on the commercialization and exports of meats and animal products from the affected zones and countries towards the Canadian, US and Mexican markets, as well as to disease-free European and Asian countries. They have had a heavy economic impact on the producers, both in foreign and local markets.

The Pan American Health Organization, Regional Office of the World Health Organization, through the Pan American Foot-and-Mouth Disease Center (PANAFTOSA), has mobilized resources to provide the technical cooperation requested by affected and threatened countries, and has promoted technical cooperation among the countries, through existing formal entities that address problems related with foot-and-mouth disease such as: the Meeting of Ministers of Health and Agriculture (RIMSA), the Hemispheric Commission for the Eradication of Foot-and-mouth Disease (COHEFA), the South American Commission on Foot-and-Mouth Disease (COSALFA) and the Agreement for the Eradication of Foot-and-Mouth Disease in the River Plate Basin, among others.

Additional information on the situation of foot-and-mouth Disease in the affected countries can be found on the Web sites of PANAFTOSA and the OIE, and through the Animal Health Services of the Ministries of Agriculture of the countries. Links to some of these services are provided on PAHO's Public Health Surveillance in the Americas page.

View a report on Foot-and-Mouth disease previously published in the Epidemiological Bulletin: Vol. 19, No. 2 (pdf - 90.9KB), June 1998 issue, page 14.

Source: PAHO. Pan American Foot-and-Mouth Disease Center (PANAFTOSA). Division of Disease Prevention and Control, Veterinary Public Health Program (HCP/HCV)

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Epidemiological Bulletin , Vol. 21 No. 3, September 2000