Food-borne illness caused by micro-organisms is a large and growing public health problem…
Food contamination creates an enormous social and economic burden on communities and their health systems…
- most countries with systems for reporting cases of food-borne illness have documented significant increases over the past few decades in the incidence of diseases caused by micro-organisms in food, including pathogens such as Salmonella, Campylobacter jejuni and enterohaemorrhagic Escherichia coli, and parasites such as cryptosporidium, cryptospora, trematodes;
- approximately 1.8 million children in developing countries (excluding China) died from diarrhoeal disease in 1998, caused by microbiological agents, mostly originating from food and water;
- 1 person in 3 in industrialised countries may be affected by food-borne illness each year;
- in the United States, some 76 million cases of food-borne illness, resulting in 325 000 hospitalisations and 5000 deaths, are estimated to occur each year. It has been estimated that 10% of all US chickens have salmonella and 60-80% campylobacter* (20% of the latter is resistant to antibiotics);
- in 1996, an outbreak of Escherichia coli O157:H7 in Japan affected over 6,300 school children and resulted in 2 deaths. This is the largest outbreak ever recorded for this pathogen;
- while most food-borne diseases are sporadic and often not reported, food-borne disease outbreaks may take on massive proportions. For example, in 1994, an outbreak of salmonellosis due to contaminated ice cream occurred in the USA, affecting an estimated 224,000 persons. In 1988, an outbreak of hepatitis A, resulting from the consumption of contaminated clams, affected some 300,000 individuals in China.
The increased incidence of food-borne disease due to microbiological hazards is the result of a multiplicity of factors, all associated with our fast-changing world…
- there are only limited data on the economic consequences of food contamination and food-borne disease. In the USA, diseases caused by the major pathogens alone are estimated to cost up to US$35 billion annually (1997) in medical costs and lost productivity;
- the re-emergence of cholera in Peru in 1991 resulted in the loss of US$500 million in fish and fishery product exports that year;
- the medical costs and the value of the lives lost during just five food-borne outbreaks in England and Wales in 1996 were estimated at UKŁ 300-700 million (US$542-1,245 million);
- the cost of the estimated 11,500 daily cases of food poisoning in Australia was calculated at AU$ 2.6 billion (US$4,69 billion) annually.
- demographic profiles are being altered, with increasing proportions of people who are more susceptible to microorganisms in food;
- extensive food distribution systems raise the potential for rapid, widespread distribution of contaminated food products. Changes in food production result in new types of food that may harbour less common pathogens.
- intensive animal husbandry technologies, introduced to minimise production costs, have led to the emergence of new zoonotic diseases, which affect humans. Safe disposal of manure from large-scale animal and poultry production facilities is a growing food safety problem in much of the world, as manure frequently contains pathogens.
- changes in eating patterns, such as a preference for fresh and minimally processed foods, the increasingly longer interval between processing and consumption of foods and the increasing prevalence of eating food prepared outside the home all contribute to the increased incidences of food-borne illness ascribed to microbiological organisms;
- the emergence of new pathogens and pathogens not previously associated with food is a major public health concern. E. coli O157:H7 was identified for the first time in 1979 and has subsequently caused illness and deaths (especially among children) owing to its presence in ground beef, un-pasteurised apple cider, milk, lettuce, alfalfa and other sprouts, and drinking-water in several countries. Salmonella typhimurium DT104 has developed resistance to five commonly prescribed antibiotics and is a major concern in many countries because of its rapid spread during the 1990s.
* Campylobacter: a weak bacteria that can be killed by exposure to oxygen. It is commonly contracted by eating undercooked poultry or drinking raw milk.