Salmonella control--past, present and future.

The perception of Salmonella infection as a problem to the poultry industry has changed as the industry itself has changed. Other factors include increasing awareness of health and food quality. Acquisition of more information on the microbiology of Salmonella and the epidemiology of infection in poultry and man, have not, with a few exceptions, enabled us to eliminate Salmonella from poultry and from the food chain. Control of the poultry pathogens S. Pullorum and S. Gallinarum, the major pathogens of concern to the industry in the early days of intensification, was achieved in many countries by a coordinated policy of hygienic measures together with serological testing and slaughter. However, fowl typhoid and pullorum disease remain major economic problems in many countries and attempts should continue to improve the methods for their control. More recent problems involving establishment in national flocks of Salmonella serotypes of public health significance, such as Typhimurium and Enteritidis are more intractable because of their more complex epidemiology involving extensive faecal excretion with associated environmental contamination and the existence of many additional reservoirs of infection. At the very minimum most countries are increasing monitoring of these and other serotypes. Some countries with relatively small, isolated national flocks have been able to reduce the incidence of infection in poultry and man to very low levels by rigorous monitoring and slaughter. Changes in legislation in the United Kingdom and the European Community will attempt to reduce the incidence of infection in breeding flocks and to reduce the significance of animal feed as a source of infection. Whilst these measures and continued research programmes are essential more could be done in terms of management, farm hygiene and feed production. A co-ordinated approach would require the approval of the industry in the first instance which presupposes a degree of financial support for some of the measures that would be necessary. Because of the potentially enormous cost of such control measures and the disruption to the poultry industry that could occur discussions must initially be instigated with relevant parties as to the desire for Salmonella control and the extent to which it should be taken.