**6. Prevention and control**

Prevention and control programs for infections caused by paratyphoid *Salmonellae* aim at protecting the health of the birds, ensure the safety of the consumers, and strengthen the reliability of the poultry production chain. In the case of *Salmonella*, measures recommended for prevention and control are not specific due to the large number of species and their complex epidemiological behavior. Similarly, variability in the implementation of these measures depends on the requisites determined by the international market, or the adaptation of the industry to the chronogram of production.

In the past 10 years, there have been important outbreaks of emerging foodborne diseases all over the world. These outbreaks showed sanitary authorities of the countries affected that there is an increasing need for measures to prevent the risk of transmission. This led the Food and Agriculture Organization (FAO) to create the WTO, which motivated countries to review their innocuousness policies, rules and strategies to ensure that the food consumed

Important Aspects of Salmonella in the Poultry Industry and in Public Health 197

observed that a mixture of formic and propionic acids was efficient in controlling *Salmonella*

Another important tool in *Salmonella* prevention and control is the use of quantitative thresholds. These values vary from country to country and correspond to the measures and control systems that are adequate for local production. These limits should be established based on scientific research and special attention should be paid to the use of antibiotics,

Indiscriminate use of antibiotics and addition of growth promoters in animal feed contributed to the emergence of resistance among strains of *Salmonella* and other bacteria (Berchieri Jr. & Barrow, 1998). Besides, according to Barrow (1999), after the therapeutic agent is removed, there may be a period in which birds may become susceptible to *Salmonella* infection, because their normal microbiota – which would inhibit *Salmonella*

Competitive exclusion is based on oral inoculation of the cecum contents of adult birds in newborn chicks, speeding the establishment of desirable intestinal microbiota (Nurmi & Rantala, 1973). The process attempts to prevent the establishment of pathogenic microorganisms in the intestinal mucous membrane. This is an important method in the control of *Salmonella* infection in birds with immature or debilitated intestinal microbiota

Another measure for *Salmonella* control and prevention is vaccination of susceptible birds (Gast, 1997). Nowadays, several studies have been carried out in order to evaluate the efficacy of live (Barrow et al., 1991; Hassan & Curtiss III, 1997) and inactivated vaccines (Timms et al., 1990; Gast et al., 1993; Nakamura et al., 1994; Miyamoto et al., 1999; Woodward et al., 2002). These studies support the use of vaccination, in a safe and efficient manner, as part of the prevention of infection in birds and contamination of eggs by

Notification and epidemiological records are important sources of information for inspection and control agencies, which may estimate which pathogens and foods may possibly be involved in foodborne disease outbreaks. For example, the presence of several *Salmonella* serotypes that did not show high prevalence some years ago, are found now in

Control of salmonellosis cases will be achieved by the adoption of some measures, such as frequent and systematic surveillance of food production and distribution. An efficient

It is concluded that salmonellosis outbreaks still occur daily, even when recommended biosafety measures to ensure the health of poultry herds are in place. This may be due to the lack of awareness on animal health issues and due to the difficult control of this

Birds may carry *Salmonella* spp. to inside of the industry by means of utensils, men, rodents, and mainly feces. Therefore, the microorganism may be introduced in all facilities and equipments of a slaughterhouse, negatively affecting the quality of final products and by-

Due to the wide distribution and variety of forms of *Salmonella* transmission, and the large number of foodstuffs involved in salmonellosis outbreaks, programs for guiding and

program both provides warranties in the production of safe foods and reduces costs.

poultry herds and represent an important public health problem worldwide.

products destined for human consumption and animal feed.

Typhimurium in artificially contaminated feed.

detergents, disinfectants and process temperature.

naturally – is also affected by the use of the antibiotic.

(submitted to antibiotic therapy).

*Salmonella* Enteritidis (Gast et al., 1992).

**7. Conclusions** 

microorganism.

by the population had appropriate sanitary conditions for international trade (Pan American Health Organization - PAHO, 2001).

General regulations issued all over the world for S*almonella* control and prevention are: Proposed Guidelines for the Control *Campylobacter* and *Salmonella* in chicken meat, from the Codex Alimentarius; Prevention, Detection and Control of *Salmonella* in poultry, Chapter 6.5 of the Terrestrial Animal Health Code of 2010, from the World Organization for Animal Health (OIE); Compliance Guideline for Controlling *Salmonella* and *Campylobacter* in Poultry, of May 2010, from the Food Safety Inspection Service and United States Department of Agriculture (FSIS/USDA); and the national programs for eradication control and surveillance of some *Salmonella* serotypes in breeding chickens and broilers, from the Ministry of Environment of Spain.

Together with many other biosafety measures, monitoring of these bacteria, which may be associated with foodborne disease in humans, is one of the great objectives of the poultry industry. Health education actions that emphasize personal hygiene habits, mainly correct hand washing, care in food preparation, handling, storage and distribution, are recommended for food handlers. Main prevention strategies should be: selection of raw materials; carefully cleaning of equipment and utensils; adequate supply of potable water; adequate garbage disposal and sewage treatment; adoption of good manufacturing practices and implementation of the HACCP; removal of asymptomatic carriers from the production area, and adequate methods for transportation and preservation. All these actions are in compliance with the recommendations of public health authorities from all over the world (ICMSF, 2002; Brazil, 2002; Reuben et al., 2003).

Literature information show that one year after the implementation of *Salmonella* control in Finland, prevalence was below 1% in egg and bovine, swine and poultry meat production, decreasing the occurrence of salmonellosis outbreaks (Maijala et al., 2005). Food hygiene, therefore, is based on the adoption of preventive and control measures. The HACCP system is an efficient tool to remove disease-causing agents. The system provides specific protection against foodborne disease, and leads to reduction in costs and warranties of microbiologically safe foods.

The risk of vertical transmission may be minimized by bacteriological and serological monitoring of breeding chicken lots, resulting in *Salmonella*-free birds; by purchasing birds more resistant to *Salmonella* infection (Bumstead, 2000); by culling birds that are carriers of the microorganism; by treatment of eggs that are still in the sheds, and careful incubation of dirty and cracked eggs (Berchieri Jr., 2000).

Biosafety and sanitary management are important to reduce the environmental presence of *Salmonella*. According to Gast (1997), one of the methods employed to achieve this aim is cleaning and disinfection of the sheds with chemical disinfectants. However, not all disinfectants are efficient and depend, for example, on their behavior in the presence of large amounts of organic material (Berchieri Jr. & Barrow, 1996). Together with this, it is important to control rodents found in bird sheds. These animals have an important role in *Salmonella* infection by contaminating the environment and transmitting the microorganism to birds and eggs (Henzler & Opitz, 1992).

Specific procedures that aim at controlling *Salmonella* in bird feed include pelleting and use of organic acids (Silva, 2005). According to Gama (2001), as pelleting is carried out at temperatures over 60ºC, the process may eliminate *Salmonella* from poultry feed, provided that the feed is not recontaminated by handling, rats or insects. Iba & Berchieri Jr. (1995), observed that a mixture of formic and propionic acids was efficient in controlling *Salmonella* Typhimurium in artificially contaminated feed.

Another important tool in *Salmonella* prevention and control is the use of quantitative thresholds. These values vary from country to country and correspond to the measures and control systems that are adequate for local production. These limits should be established based on scientific research and special attention should be paid to the use of antibiotics, detergents, disinfectants and process temperature.

Indiscriminate use of antibiotics and addition of growth promoters in animal feed contributed to the emergence of resistance among strains of *Salmonella* and other bacteria (Berchieri Jr. & Barrow, 1998). Besides, according to Barrow (1999), after the therapeutic agent is removed, there may be a period in which birds may become susceptible to *Salmonella* infection, because their normal microbiota – which would inhibit *Salmonella* naturally – is also affected by the use of the antibiotic.

Competitive exclusion is based on oral inoculation of the cecum contents of adult birds in newborn chicks, speeding the establishment of desirable intestinal microbiota (Nurmi & Rantala, 1973). The process attempts to prevent the establishment of pathogenic microorganisms in the intestinal mucous membrane. This is an important method in the control of *Salmonella* infection in birds with immature or debilitated intestinal microbiota (submitted to antibiotic therapy).

Another measure for *Salmonella* control and prevention is vaccination of susceptible birds (Gast, 1997). Nowadays, several studies have been carried out in order to evaluate the efficacy of live (Barrow et al., 1991; Hassan & Curtiss III, 1997) and inactivated vaccines (Timms et al., 1990; Gast et al., 1993; Nakamura et al., 1994; Miyamoto et al., 1999; Woodward et al., 2002). These studies support the use of vaccination, in a safe and efficient manner, as part of the prevention of infection in birds and contamination of eggs by *Salmonella* Enteritidis (Gast et al., 1992).

Notification and epidemiological records are important sources of information for inspection and control agencies, which may estimate which pathogens and foods may possibly be involved in foodborne disease outbreaks. For example, the presence of several *Salmonella* serotypes that did not show high prevalence some years ago, are found now in poultry herds and represent an important public health problem worldwide.

Control of salmonellosis cases will be achieved by the adoption of some measures, such as frequent and systematic surveillance of food production and distribution. An efficient program both provides warranties in the production of safe foods and reduces costs.
