[Model for the organizational structure of the Regional Service for Animal Health]. / Modelo de estructura organizativa para Servicios subnacionales de Sanidad Animal.

The organisational structure of any unit must be a reflection of the way in which work is distributed and of specialisation in the constituent parts. Co-ordination between these parts requires the establishment of standards, strategies, procedures and official controls, as well as a chain of command, in order to attain the desired objectives. The authors present an alternative model for designing an organisational structure for district Veterinary Services of a given country. This model will assist the establishment of basic criteria for evaluating such Services, facilitating their integration into the procedure for planning animal health activities, and providing a better comprehension of their function within the livestock sector.

Venezuelan equine encephalomyelitis and African horse sickness. Current status and review.

The arthropod-borne virus (arbovirus) diseases of livestock have worldwide impact. The prevention of an introduction of an exotic disease and the control of one subsequent to an introduction will require the attention, cooperation, and support of the livestock industry, regulatory agencies, and researchers. The most effective protection of our livestock industries is to prevent the introduction of an exotic disease agent. This implies complete restriction of animal imports and exports. However, "zero risk" is an unacceptable option in today's world of internationally integrated and interdependent agriculture. Scientifically sound and factually based regulatory decisions must be combined with continued vigilance and preparedness, as well as appropriately directed surveillance and research, to protect the world agricultural marketplace. Two exotic arbovirus diseases that are of current concern to the livestock industries and regulatory officials of the North American and Caribbean Basin countries are VEE and AHS. Devastating epizootics of VEE in equines have occurred frequently in the Western Hemisphere, but no recent epizootic activity has been documented. Naturally occurring foci of sylvatic, equine nonpathogenic VEE virus subtypes, however, do exist in the tropical countries of the hemisphere. The relationship of these sylvatic virus foci to the origin of equine virulent epizootic VEE virus subtypes is unknown. AHS epizootics had been confined to Africa, the Middle East, and the Indian subcontinent until recent outbreaks in 1966 and 1987-1990 in Spain. With the recurrence of AHS in Spain for the past four years, concern about the possible introduction into potential vector species and equines in the Western Hemisphere has increased. This review addresses the current VEE and AHS virus activity and the potential for outbreaks in the Western Hemisphere.