Publication Abstract

Control of the spread of pathogens - regulatory approach, its history and present status

Control of the Spread of Pathogens—the Regulatory Approach, Its History and Present Status

D.J. Alderman

It has long been recognised that, in the aquatic environment, once a pathogen has been introduced into an area where there are susceptible animals, eradication is difficult to impossible. The nature of the aquatic environment is such that unlike pathogens in the land environment where localised eradication may be possible, once infected, entire watersheds and or extensive stretches of coastline may well be permanently affected. The most practical means of preventing the transfer of pathogens is to prevent the movement of animals or animal products that might carry a pathogen into uninfected areas. One of the first such controls was the Diseases of Fish Act 1937 in Great Britain. Designed originally to prevent the spread of furunculosis, although ineffective for that purpose, it was subsequently extended to cover other "notifiable" fish diseases.

In an era when freedom of international trade is of great importance, the Sanitary and Phyto-Sanitary agreement (SPSS) recognises that prevention of spread of disease is one of the few legitimate non tariff trade barriers that can be accepted Controls, which in the case of the Diseases of Fish Act applied just to the U.K. now apply to much larger geographical regions such as the E.U. Inevitably these require agreements between members of the block. This means that controls which, at the more local or national, level could be relatively flexible must today be formal and rigidly interpreted. The Office International des Epizooties (OIE) is the international body in respect of veterinary matters and, in particular, animal disease. In the aquatic environment the OIE published the "International Aquatic Animal Health Code" and an accompanying Diagnostic Manual in 1995. This reached its 3^rd edition in 2000. This code with advice on different diseases, health certification etc., provides an excellent background to the necessary techniques to prevent the introduction and spread of disease in the aquatic environment. Inevitably however, such approaches are likely to be more effective in preventing the spread of known diseases in known hosts, than to be able to cater for the unknown and the unexpected. One approach to the controlling the hazard of the unknown is the ICES Code of Practice on Introductions.

The merits, effectiveness and limitations of these various approaches to controlling the spread of pathogens in the aquatic environment are discussed.

Reference:

D.J. Alderman (2003) Control of the Spread of Pathogens—the Regulatory Approach, Its History and Present Status. pp In: Biosecurity in aquaculture production systems: exclusion of pathogens and other undesirables. Baton Rouge: World Aquaculture Society.

D.J. Alderman*

pp 215-231 In: Biosecurity in aquaculture production systems: exclusion of pathogens and other undesirables. Baton Rouge: World Aquaculture Society.