**4.2 Salmonellosis transmission, prevention, and next steps**

The most common mode of *Salmonella* transmission is through the ingestion of the bacterium in food derived from an infected animal or contaminated by feces of an infected animal or person (Mead et al., 1999). This includes raw and undercooked eggs or egg products, raw milk or milk products, poultry, meat, contaminated water, and any other food item that uses potentially contaminated ingredients. Farm animals used to produce these ingredients can become infected by eating feed and fertilizers prepared from contaminated meat scraps and bones. The infection can then spread by bacterial multiplication during rearing and slaughter. This chain of transmission can eventually lead to person-to-person fecal-oral transmission when a person comes in contact with contaminated feces and transmits it to others through a vehicle (e.g., food) or by direct transmission.

Other sources of transmission may occur from handling *Salmonella-*contaminated pet turtles, iguanas, chicks, and unsterilized pharmaceuticals of animal origin. Contact with pet turtles and other reptiles can be a very serious health risk to infants, small children, and adults with weakened immune systems (LACDPH, 2008). Hand-to-mouth and object-to-mouth behaviors are common among young children and can increase their risk for contracting salmonellosis. This resulted in a nationwide ban on the sale of turtles less than four inches in diameter in 1975 (US-CFR, 2010).

More recently, there have been several outbreaks of salmonellosis traced to consumption of raw fruits and vegetables, generally contaminated from manure on the outer surface of the fruit or vegetable. Manure contamination can be from the farm or during packing (Harris et al., 2003). In 1999, a multi-state outbreak of *Salmonella enterica* serotype Baildon (a rare serotype) was associated with raw, domestic tomatoes in the United States (Cummings K et al., 2001). This large outbreak resulted in 86 confirmed cases of salmonellosis.

Since there are several species of domestic and wild animals that can harbor *Salmonella* (e.g., poultry, swine, cattle, rodents and pets such as iguanas, tortoises, turtles, terrapins, chicks, dogs and cats), control policies and measures for preventing *Salmonella* infection are often more complex than for other foodborne pathogens. The fact that humans can also carry this bacterium either as mild, unrecognized cases or as convalescent carriers (i.e., those who have recovered from symptomatic illness, but are still capable of transmitting the pathogen to others) also contributes to this complexity. As carriers, humans can be particularly effective in spreading the disease in the population. Fortunately, chronic carrier states are rare in humans; they are, however, prevalent in animals.

Given that the most common mode of transmission is from handling and consuming infected food, the risk of exposure to salmonellosis can occur at multiple points in the food distribution chain, including retail food establishments and homes. Since the food distribution chain directly and indirectly affects all individuals, vigilant monitoring and regulation at multiple points in the chain are vital.

#### **4.2.1 Food distribution chain**

10 Salmonella – A Dangerous Foodborne Pathogen

bacterial foodborne pathogens. PulseNet routinely subtypes *E. coli* O157:H7, nontyphoid *Salmonella* serotypes, *Listeria* monocytogenes, and *Shigella*. The database encompasses 46 states, two local public health laboratories, and the food safety laboratories of the Food and Drug Administration and the U.S. Department of Agriculture. The national database of pulsed-field gel electrophoresis (PFGE) for foodborne bacterial pathogens helps track potentially unrelated cases in isolated geographic areas and identifies outbreak strains.

The most common mode of *Salmonella* transmission is through the ingestion of the bacterium in food derived from an infected animal or contaminated by feces of an infected animal or person (Mead et al., 1999). This includes raw and undercooked eggs or egg products, raw milk or milk products, poultry, meat, contaminated water, and any other food item that uses potentially contaminated ingredients. Farm animals used to produce these ingredients can become infected by eating feed and fertilizers prepared from contaminated meat scraps and bones. The infection can then spread by bacterial multiplication during rearing and slaughter. This chain of transmission can eventually lead to person-to-person fecal-oral transmission when a person comes in contact with contaminated feces and transmits it to others through a vehicle (e.g., food) or by direct

Other sources of transmission may occur from handling *Salmonella-*contaminated pet turtles, iguanas, chicks, and unsterilized pharmaceuticals of animal origin. Contact with pet turtles and other reptiles can be a very serious health risk to infants, small children, and adults with weakened immune systems (LACDPH, 2008). Hand-to-mouth and object-to-mouth behaviors are common among young children and can increase their risk for contracting salmonellosis. This resulted in a nationwide ban on the sale of turtles less than four inches in

More recently, there have been several outbreaks of salmonellosis traced to consumption of raw fruits and vegetables, generally contaminated from manure on the outer surface of the fruit or vegetable. Manure contamination can be from the farm or during packing (Harris et al., 2003). In 1999, a multi-state outbreak of *Salmonella enterica* serotype Baildon (a rare serotype) was associated with raw, domestic tomatoes in the United States (Cummings K et

Since there are several species of domestic and wild animals that can harbor *Salmonella* (e.g., poultry, swine, cattle, rodents and pets such as iguanas, tortoises, turtles, terrapins, chicks, dogs and cats), control policies and measures for preventing *Salmonella* infection are often more complex than for other foodborne pathogens. The fact that humans can also carry this bacterium either as mild, unrecognized cases or as convalescent carriers (i.e., those who have recovered from symptomatic illness, but are still capable of transmitting the pathogen to others) also contributes to this complexity. As carriers, humans can be particularly effective in spreading the disease in the population. Fortunately, chronic carrier states are

Given that the most common mode of transmission is from handling and consuming infected food, the risk of exposure to salmonellosis can occur at multiple points in the food distribution chain, including retail food establishments and homes. Since the food distribution chain directly and indirectly affects all individuals, vigilant monitoring and

al., 2001). This large outbreak resulted in 86 confirmed cases of salmonellosis.

rare in humans; they are, however, prevalent in animals.

regulation at multiple points in the chain are vital.

**4.2 Salmonellosis transmission, prevention, and next steps** 

transmission.

diameter in 1975 (US-CFR, 2010).

*Salmonella* prevention can be implemented in a number of ways, one of which is through environmental or system policies that improve regulation of potential sources of contamination. For example, the U.S. Department of Agriculture's Food Safety and Inspection Service currently recommends establishing facilities for irradiation of meats and eggs (USDA-FSIS, 2005). In addition, the need for improved sanitation inspection and supervision of abattoirs, food-processing plants, feed-blending mills, and egg grading stations is growing, as these are top sources of contamination for common foodborne pathogens in the United States (Batz *et al.*, 2011). Multiple regulatory outlets are currently responsible for monitoring different aspects of the U.S. food distribution chain. The Food and Drug Administration is responsible for the safety of approximately 80% of the nation's food supply, while other government entities, including the U.S. Department of Agriculture oversee the remainder. In covering such a broad enforcement responsibility, these agencies are continuously striving to reduce gaps in coordination and frequently collaborate on multiple efforts to ensure food safety. The World Health Organization (WHO) recommends strong communication, infrastructure, and coordination efforts among private, local, and federal regulatory sectors. The WHO also recommends the establishment of enhanced food safety standards in feed control regulation; cleaning and disinfection; vector control; and adequate cooking or heat-treating (including pasteurization or irradiation) of animalderived foods prepared for animal consumption (e.g., meat or bone or fishmeal and pet foods). U.S. agencies follow these standards.

The regulatory policies currently in place have been developed over many years in the United States. Starting in the early 1990s, farm-to-table egg safety efforts were developed by the Food and Drug Administration and the USDA Food Safety and Inspection Service (FSIS). Over the years, FSIS gained more regulatory authority in enforcing laws, including the Federal Meat Inspection Act (FMIA), the Poultry Products Inspection Act (PPIA), and the Egg Products Inspection Act. These particular laws or regulations required federal inspection and regulation of meat, poultry, and processed egg products prepared for distribution. In conjunction with these laws, the Food and Drug Administration and the FSIS conducted a joint *Salmonella Enteritidis* risk assessment in 1998. This assessment found that a broad-based policy encompassing multiple interventions from farm-to-table is more likely to be effective in eliminating egg-associated salmonellosis cases than a single policy directed solely at one stage of the production-to-consumption continuum.

The lessons learned from the Food and Drug Administration (FDA) and the FSIS joint evaluation efforts contributed to the development and implementation of the FDA's new food safety strategy – coined as the "new egg rule" (Figure 4). This rule is considered very comprehensive and is aimed at preventing *Salmonella Enteritidis* in shelled eggs during production, storage, and transportation. Ironically, (as mentioned in section 2.1) one of the largest Salmonella outbreaks in U.S. history that led to a massive recall of about half a billion eggs and more than 2,000 reported illnesses occurred just prior to implementation of these new regulations during the summer of 2010 (Hutchison, 2010). The new egg rule requires production plants to implement intense rodent control, limits on contamination from people and equipment, regular egg tests, egg storage temperatures that retard *Salmonella* growth, and a requirement that egg producers maintain records documenting their compliance with these regulations. Modeled after several existing state programs (e.g., Pennsylvania Egg Quality Assurance Program), the new egg rule will, according to some farms, increase costs of production to about a penny per dozen (Hutchison, 2010). However, the Food and Drug

The Burden of Salmonellosis in the United States 13

On July 1, 2011, in the state of California (U.S.A.), a food handler card law was implemented. This law requires that all employees of retail food establishments who prepare, store or serve food, must have a California Food Handler Card. This regulation applies to servers, chefs/head chefs/cooks/head cooks, bartenders, bussers (i.e., those who help assist the server by cleaning tables and other duties), and hosts and hostesses who handle food. Supervisors, including the general manager, may also need to carry the card if they do not already have a Food Protection Manager Certification. To receive a card or become certified, a person must take a basic food safety training course and pass a test with a score of 70% or better; the card is only valid for up to three years. Thus, food service employees must take the course every three years. Currently, the U.S. National Restaurant Association (ServSafe® California Food Handler Program), ProMetric, and the U.S. National Registry for Food Safety Professionals are the only

Implementation of this program demonstrates the importance of preventive measures at the restaurant and/or retail level. For instance, not all food handlers at the different stages of food preparation in a given establishment may be entirely aware of raw products that are contained in certain foods, dishes, or recipes handed down to them by restaurant management or by other food handlers. A few examples include raw or partially cooked eggs (e.g., 'over easy' or 'sunny side up,' eggnogs, and homemade ice cream), the use of dirty or cracked eggs, pooled eggs (i.e., combining multiple eggs together), and dishes containing eggs that are not immediately cooked. Generally, all of these practices should be avoided or at least substituted with the use of pasteurized egg products (or irradiated egg

Other preventive measures should include prohibiting individuals with diarrhea from food preparation. Known *Salmonella* carriers may require isolation or long-term monitoring and should definitely be discouraged from preparing food for others as long

In December 1997, in response to increased media attention of foodborne illness stemming from unsafe and unhygienic food handling practices in restaurants, the County of Los Angeles government passed an ordinance that focused on increasing transparency and consumer awareness of hygiene and sanitation practices at restaurants and other retail food establishments through restaurant inspections (Fielding, 2008; Zhe Jin and Leslie, 2003). Prior to its passage, the Department of Health Services routinely conducted hygiene inspections among restaurants in Los Angeles County. However, the results of these inspections were not made public. Thus, under the new mandate, inspection results were required to be posted as a letter grade corresponding to an aggregated inspection score (i.e., 90-100 = A, 80-89 = B, 70-79 = C, etc.) (Figure 5). Specifically, it required that restaurants and other retail food facilities publicly post their assigned letter grade (using a standardizedformat grade card, see Figure 5), typically near the entrance, within five feet of the point of entry so the score would be visible to patrons (Simon, et al. 2005; Zhe Jin and Leslie, 2003). A month prior to the adoption of the ordinance, as a direct response to the need for transparency and consumer awareness, the County of Los Angeles Board of Supervisors requested that the Department of Health Services, which at the time included the Department

**4.2.2 Restaurant and retail food environments** 

three providers that can issue cards within California.

products) if use of raw eggs is necessary for a recipe.

as they shed the organism.

**Los Angeles County, California (U.S.A.)** 

**United States, California** 

Administration projected an average annual cost of about \$24,100 per farm site, which translates into about \$0.30 cents per *layer* (i.e., a layer is a chicken that produces eggs) (USDA-APHIS, 1999). One of the benefits of this new egg rule, if properly regulated, is that it can potentially outweigh the healthcare-associated costs of treating salmonellosis. The Food and Drug Administration expects that the rule will decrease *Salmonella* in plants by 60%, save more than 30 lives each year, and avert more than 79,000 cases of salmonellosis annually (USDHHS, 2009). The preventive measures that were included in this new rule have been demonstrated to be relatively effective for preventing the spread of *Salmonella Enteritidis* (USDHHS, 2009). Moreover, shelled eggs were targeted by these measures because they are the predominant source of foodborne *Salmonella Enteritidis*-related outbreaks in the United States (USDHHS, 2009).

Fig. 4. Consumer health information guide released by the Food and Drug Administration and the U.S. Department of Agriculture on September 2010 outlining the new egg rule.

One of the anticipated hurdles of the new egg rule may be implementation barriers, such as the limited capacity of smaller facilities to comply with the required preventive measures. Smaller farms may not be as prepared as larger farms to meet the rule's requirements during the initial stages of implementation. More specifically, they may be less likely to have adequate refrigeration capacity, effective rodent control, an efficient biosecurity program, and the necessary measures in place to limit laying hens' exposure to manure on building floors. The Food and Drug Administration (FDA) has anticipated this need to assist smaller farms. Currently, there is an FDA exemption in place for producers with small flocks (i.e., less than 3,000 laying hens). The agency's strategic decision to target the largest producers is based on its goal of having the greatest impact in terms of farm-to-table distribution of eggs. This is a reasonable approach, at least in the initial years of implementation. Eventually, consideration for expanding this rule to apply to smaller farms may be beneficial.

### **4.2.2 Restaurant and retail food environments**

#### **United States, California**

12 Salmonella – A Dangerous Foodborne Pathogen

Administration projected an average annual cost of about \$24,100 per farm site, which translates into about \$0.30 cents per *layer* (i.e., a layer is a chicken that produces eggs) (USDA-APHIS, 1999). One of the benefits of this new egg rule, if properly regulated, is that it can potentially outweigh the healthcare-associated costs of treating salmonellosis. The Food and Drug Administration expects that the rule will decrease *Salmonella* in plants by 60%, save more than 30 lives each year, and avert more than 79,000 cases of salmonellosis annually (USDHHS, 2009). The preventive measures that were included in this new rule have been demonstrated to be relatively effective for preventing the spread of *Salmonella Enteritidis* (USDHHS, 2009). Moreover, shelled eggs were targeted by these measures because they are the predominant source of foodborne *Salmonella Enteritidis*-related

Fig. 4. Consumer health information guide released by the Food and Drug Administration and the U.S. Department of Agriculture on September 2010 outlining the new egg rule.

One of the anticipated hurdles of the new egg rule may be implementation barriers, such as the limited capacity of smaller facilities to comply with the required preventive measures. Smaller farms may not be as prepared as larger farms to meet the rule's requirements during the initial stages of implementation. More specifically, they may be less likely to have adequate refrigeration capacity, effective rodent control, an efficient biosecurity program, and the necessary measures in place to limit laying hens' exposure to manure on building floors. The Food and Drug Administration (FDA) has anticipated this need to assist smaller farms. Currently, there is an FDA exemption in place for producers with small flocks (i.e., less than 3,000 laying hens). The agency's strategic decision to target the largest producers is based on its goal of having the greatest impact in terms of farm-to-table distribution of eggs. This is a reasonable approach, at least in the initial years of implementation. Eventually, consideration for expanding this rule to apply to smaller farms

outbreaks in the United States (USDHHS, 2009).

may be beneficial.

On July 1, 2011, in the state of California (U.S.A.), a food handler card law was implemented. This law requires that all employees of retail food establishments who prepare, store or serve food, must have a California Food Handler Card. This regulation applies to servers, chefs/head chefs/cooks/head cooks, bartenders, bussers (i.e., those who help assist the server by cleaning tables and other duties), and hosts and hostesses who handle food. Supervisors, including the general manager, may also need to carry the card if they do not already have a Food Protection Manager Certification. To receive a card or become certified, a person must take a basic food safety training course and pass a test with a score of 70% or better; the card is only valid for up to three years. Thus, food service employees must take the course every three years. Currently, the U.S. National Restaurant Association (ServSafe® California Food Handler Program), ProMetric, and the U.S. National Registry for Food Safety Professionals are the only three providers that can issue cards within California.

Implementation of this program demonstrates the importance of preventive measures at the restaurant and/or retail level. For instance, not all food handlers at the different stages of food preparation in a given establishment may be entirely aware of raw products that are contained in certain foods, dishes, or recipes handed down to them by restaurant management or by other food handlers. A few examples include raw or partially cooked eggs (e.g., 'over easy' or 'sunny side up,' eggnogs, and homemade ice cream), the use of dirty or cracked eggs, pooled eggs (i.e., combining multiple eggs together), and dishes containing eggs that are not immediately cooked. Generally, all of these practices should be avoided or at least substituted with the use of pasteurized egg products (or irradiated egg products) if use of raw eggs is necessary for a recipe.

Other preventive measures should include prohibiting individuals with diarrhea from food preparation. Known *Salmonella* carriers may require isolation or long-term monitoring and should definitely be discouraged from preparing food for others as long as they shed the organism.

#### **Los Angeles County, California (U.S.A.)**

In December 1997, in response to increased media attention of foodborne illness stemming from unsafe and unhygienic food handling practices in restaurants, the County of Los Angeles government passed an ordinance that focused on increasing transparency and consumer awareness of hygiene and sanitation practices at restaurants and other retail food establishments through restaurant inspections (Fielding, 2008; Zhe Jin and Leslie, 2003). Prior to its passage, the Department of Health Services routinely conducted hygiene inspections among restaurants in Los Angeles County. However, the results of these inspections were not made public. Thus, under the new mandate, inspection results were required to be posted as a letter grade corresponding to an aggregated inspection score (i.e., 90-100 = A, 80-89 = B, 70-79 = C, etc.) (Figure 5). Specifically, it required that restaurants and other retail food facilities publicly post their assigned letter grade (using a standardizedformat grade card, see Figure 5), typically near the entrance, within five feet of the point of entry so the score would be visible to patrons (Simon, et al. 2005; Zhe Jin and Leslie, 2003).

A month prior to the adoption of the ordinance, as a direct response to the need for transparency and consumer awareness, the County of Los Angeles Board of Supervisors requested that the Department of Health Services, which at the time included the Department

The Burden of Salmonellosis in the United States 15

Risk Category Applies to, but not limited to: Number of Inspections per year


2 inspections per year

1 inspection per year\*

*\* If inspection score falls below 90, facility may be subject to additional inspections throughout the year.* 

Establishments in this category will increase number of inspections by one (i.e., a restaurant in the low-risk category assigned to risk assessment

RHIP Implementation

IV will go from the typical 1 inspection per year to 2 inspections

per year).


chicken and beef


prepackaged)


existing suspensions, violations, or investigations.

food establishments in Los Angeles County, California, USA.

stores








Table 3. The four risk assessment categories used to evaluate restaurants and other retail

Fig. 6. Number of Foodborne-Disease Hospitalizations by Year, Los Angeles County and the

High-Risk Category (Risk Assessment I)

(Risk Assessment II)

Low-Risk Category (Risk Assessment III)

Temporary-Risk Category

(Risk Assessment IV)

Rest of California, 1993-2000, USA.

Moderate-Risk Category

of Public Health, draft a 17-point action plan to enhance the existing restaurant inspection process (Fielding, 2008). The recommendations outlined by this plan laid the groundwork for the ordinance. The plan called for establishing inspection scoring criteria, adopting letter grading, and increasing transparency of inspection results (Fielding, 2008). It also specified several enhancements to the existing program, such as requiring Environmental Health (EH) staff to undergo rigorous training to learn the new inspection procedures; restaurant managers and workers receive food safety training; a 24-hour restaurant hotline be established so that the public could report complaints about food establishments; and development of a new inspection schedule (Fielding, 2008). The drafting of the action plan and the subsequent passage of the ordinance led to the 1998 establishment of an improved inspection program, now known as the Restaurant Hygiene Inspection Program (RHIP). The program is currently under the supervision of the Los Angeles County Department of Public Health.

Fig. 5. Standardized-format grade cards given to restaurants and other retail food establishments upon receiving an inspection score. Los Angeles County, California, USA, 2011.

On July 1, 2011, an addendum to the RHIP's policy and procedures manual was added to the program. This addendum provided guidance on inspection frequency requirements, outlining inspection frequencies for food facilities based on risk assessment results for the facility. Risk assessment designation or category is defined as "the categorization of a food facility based on the public health risk associated with the food products served, the methods of food preparation, and the operational history of the food facility" (Environmental Health Policy and Operations Manual, 2011). Currently, there are four risk assessment categories used to evaluate restaurants (Table 3).

Since implementation, the Restaurant Hygiene Inspection Program in Los Angeles County has been considered a relatively effective strategy for reducing the burden of foodborne disease in the region. Credited for improving hygiene standards among food facilities in the county, the program has been theorized by some to have helped reduce foodborne illness hospitalizations (Figure 6). In the year following implementation of the RHIP (1998), the grading program was associated with a 13.1 percent decrease (p<0.01) in the number of foodborne disease hospitalizations in Los Angeles County (Simon et al., 2005), albeit other factors may have also been attributed to this decrease, including random chance. Figure 6 shows the number of hospitalizations in the county, as compared to the rest of California (Simon et al., 2005).

of Public Health, draft a 17-point action plan to enhance the existing restaurant inspection process (Fielding, 2008). The recommendations outlined by this plan laid the groundwork for the ordinance. The plan called for establishing inspection scoring criteria, adopting letter grading, and increasing transparency of inspection results (Fielding, 2008). It also specified several enhancements to the existing program, such as requiring Environmental Health (EH) staff to undergo rigorous training to learn the new inspection procedures; restaurant managers and workers receive food safety training; a 24-hour restaurant hotline be established so that the public could report complaints about food establishments; and development of a new inspection schedule (Fielding, 2008). The drafting of the action plan and the subsequent passage of the ordinance led to the 1998 establishment of an improved inspection program, now known as the Restaurant Hygiene Inspection Program (RHIP). The program is currently

under the supervision of the Los Angeles County Department of Public Health.

Fig. 5. Standardized-format grade cards given to restaurants and other retail food

assessment categories used to evaluate restaurants (Table 3).

establishments upon receiving an inspection score. Los Angeles County, California, USA, 2011. On July 1, 2011, an addendum to the RHIP's policy and procedures manual was added to the program. This addendum provided guidance on inspection frequency requirements, outlining inspection frequencies for food facilities based on risk assessment results for the facility. Risk assessment designation or category is defined as "the categorization of a food facility based on the public health risk associated with the food products served, the methods of food preparation, and the operational history of the food facility" (Environmental Health Policy and Operations Manual, 2011). Currently, there are four risk

Since implementation, the Restaurant Hygiene Inspection Program in Los Angeles County has been considered a relatively effective strategy for reducing the burden of foodborne disease in the region. Credited for improving hygiene standards among food facilities in the county, the program has been theorized by some to have helped reduce foodborne illness hospitalizations (Figure 6). In the year following implementation of the RHIP (1998), the grading program was associated with a 13.1 percent decrease (p<0.01) in the number of foodborne disease hospitalizations in Los Angeles County (Simon et al., 2005), albeit other factors may have also been attributed to this decrease, including random chance. Figure 6 shows the number of

hospitalizations in the county, as compared to the rest of California (Simon et al., 2005).


Table 3. The four risk assessment categories used to evaluate restaurants and other retail food establishments in Los Angeles County, California, USA.

Fig. 6. Number of Foodborne-Disease Hospitalizations by Year, Los Angeles County and the Rest of California, 1993-2000, USA.

The Burden of Salmonellosis in the United States 17

Salmonellosis caused by nontyphoid strains remains the most common foodborne illness reported in the United States. In spite of effective public health and regulatory efforts to control and prevent this infectious disease, the morbidity, mortality, and years of potential life lost due to this foodborne pathogen continue to be substantial. The overall incidence of laboratory confirmed *Salmonella* infection was 17.6 cases per 100,000 persons in 2010, which remains higher than the Healthy People 2020 objective of 11.4 cases per 100,000 persons (Figure 2). Active surveillance and continual efforts in developing and implementing control policies have helped federal and local health agencies in the United States make significant strides in combating this disease. Lessons learned from these efforts, including ways to work collaboratively across agencies at different levels of the food distribution chain have been invaluable for informing present and future *Salmonella* control policies and preventive measures in the United States. These lessons may have global implications for other

The authors would like to thank Brenda Robles, Mirna Ponce, Lana Sklyar, Gloria Kim, and

Altekruse SF, Cohen ML, Swerdlow DL. (1997). Emerging foodborne diseases. *Emerging* 

Batz MB, Hoffmann S, Morris JG, Jr. (2011). *Ranking the risks: The 10 Pathogen-Food* 

Bermúdez-Aguirre D and Corradini MG. Inactivation kinetics of *Salmonella* spp. Under

Boehmer TK, Bamberg WM, Ghosh TS, et al. (2009). Health care-associated outbreak of

(CDC) Centers for Disease Control and Prevention. (2008). *Salmonellosis*. Retrieved May 8,

(CDC) Centers for Disease Control and Prevention. (2011). Vital signs: incidence and trends

Cruickshank JG and Humphrey TJ. (1987). The carrier food-handler and non-typhoid salmonellosis. *Epidmeiology and Infection*, Vol. 98, No. 3, (June, 1987), pp. 223-230. Cummings K, Barrett E, Mohle-Boetani JC, et al. (2001). A multi-state outbreak of *Salmonella* 

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*and Mortality Weekly Report*, Vol. 60, No. 22, (June, 2011), pp. 749-55.

*Combinations with the Greatest Burden on Public Health.* Gainesville, FL: Emerging

thermal and emerging treatments: A review. *Food Research International,* article in

Salmonella Tennessee in a neonatal intensive care unit. *American Journal of Infection* 

of infection with pathogens transmitted commonly through food --- foodborne diseases active surveillance network, 10 U.S. Sites, 1996--2010. *MMWR Morbidity* 

*enterica* serotype Baildon associated with domestic raw tomatoes. *Emerging* 

*infectious diseases*, Vol. 3, No. 3, (July-September, 1997), pp. 285-293.

Phyllis Thai for their technical assistance and contributions to this chapter.

Pathogens Institute, University of Florida.

press – Epub, available online June 24, 2011.

*Control,* Vol. 37, No. 1, (February 2009), pp. 49-55.

2011, Available from: www.cdc.gov/salmonella

**5. Conclusion** 

jurisdictions abroad.

**7. References** 

**6. Acknowledgement** 
