Foodborne diseases: A Public Health Challenge (New food Vehicles of…
Foodborne diseases: A Public Health Challenge
Emerging Foodborne Pathogens
Substantial progress has been made in preventing diseases such as typhoid fever
Conquered by pre-antiobiotic era by disinfection of drinking water, sewage treatment, etc
As well as cholera, bovine, tuberculosis and trichinosis have seemingly been controlled
New foodborne diseases have emerged
nontyphoid strains of Salmonella
V. vulnificus, E.coli and Cyclospora cayetanensis are examples of newly described pathogens that often are foodborne.
New food Vehicles of Transmission
Traditionally, the food implicated in a foodborne outbreak was undercooked meat, poultry or seafood, or unpasteurized milk.
Now, additional foods previously thought safe are considered hazardous. i.e. the internal contents of an egg were presumed safe to eat raw.
E. coli has caused illness through an ever-broadening spectrum of foods, beyond the beef and raw milk that are directly related to the bovine reservoir.
Contamination typically occurs early in the production process, rather than just before consumption.
Because of consumer demand and the global food market, ingredients from many countries may be combined in a single dish, which makes the specific source of contamination difficult to trace.
These foods have fewer barriers to microbial growth, such as salt, sugar, or preservatives; therefore, simple transgressions can make the food unsafe.
New Outbreak scenario
This scenario involves an acute and highly local outbreak, with a high inoculum dose and a high attack rate.
Diffuse and widespread outbreaks, involving many counties, states, and even nations, are identified more frequently and follow an entirely different scenario.
The new scenario is the result of low-level contamination of a widely distributed commercial food product. The outbreak is detected only because of a fortuitous concentration of cases in one location, because the pathogen causing the outbreak is unusual, or because laboratory-based subtyping of strains collected over a wide area identifies a diffuse surge in one subtype.
Contamination is the result of an event in the industrial chain of food production. Investigating, controlling, and preventing such outbreaks can have industrywide implications.
Changing surveillance strategies
Existing surveillance systems provide a limited and relatively inexpensive net for tracing large-scale trends in foodborne diseases under surveillance and for detecting outbreaks of established pathogens. .
They are less sensitive to diffuse outbreaks of common pathogens, provide little detail on sporadic cases, and are not easy to extend to emerging pathogens.
Changes in health delivery may impinge on the way that diagnoses are made and reported, leading to artifactual changes in reported disease incidence
Implications of outbreaks for Public Health Activities
When diffuse outbreaks are detected, a local health department may need to investigate a few cases that are part of a larger outbreak despite their apparently small local impact.
When a diffuse outbreak of a potentially foodborne pathogen is detected, rapid investigation is needed to determine whether the outbreak is foodborne, and if possible, identify a specific food vehicle.
These investigations, which typically include case-control studies, may need to be conducted in several locations at once
New approaches to the prevention of Foodborne Diesease
Meeting the complex challenge of foodborne disease prevention will require the collaboration of regulatory agencies and industry to make food safely and keep it safe throughout the industrial chain of production.
Prevention can be "built in" to the industry by identifying and controlling the key points—from field, farm, or fishing ground to the dinner table—at which contamination can either occur or be eliminated.
Some simple control strategies are self-evident, once the reality of microbial contamination is recognized.