Microbiology

1- Introduction

Human and animal populations share many infections, either directly or through food. A number of factors, including poverty, increased food trade, and changes in food production and food preservation methods have over recent decades resulted in an increased foodborne disease burden and significant potential of global spread of pathogens through food. However, a thorough and scientific estimation of this disease burden has until lately been missing, at national as well as international level. On the other hand, it could be argued that even in the case where a specific disease burden cannot be attributed to food, preventive or proactive action could still lead to improved safety of the food we eat. However, one of the great disappointments in the food safety and food control area in most countries has been the lack of efficient collaboration and data sharing between relevant sectors (primarily agriculture and health).

Although the (sometimes deliberate) non-collaboration between sectors has been going on everywhere for many decades, it was primarily the global outbreaks of avian influenza in 2003– 2004 that alerted the world, including political leadership, to the need for a cross-sectoral approach, linking animal and human health. From 2004, this was referred to as the “ One World, One Health” concept, and later as the “ One Health” concept, based on the recognition that human and animal health are inextricably linked (World Bank, 2008).

2- Size of the Foodborne Disease Problem

Foodborne

Although the estimated disease burden related to food is very significant in all countries, the major focus on food safety has over recent decades mostly been related to well-publicized outbreaks of foodborne disease or foodborne contamination events. Most consumers all over the world have heard of bovine spongiform encephalopathy (BSE) spreading out from the United Kingdom in 1996, about the spread of highly pathogenic avian influenza (HPAI) from Asia in 2003 and 2004, and about the major outbreak of Verotoxin-producing Escherichia coli (VTEC ) in a number of European countries in 2011. Food safety authorities, however, in many countries often like to point out, and are actually correct in pointing out, that these events— highly publicized as they might be— do not really reflect the food safety reality and have in effect caused a limited disease burden even at the global level. The same authorities, however, often use similar statements when more localized outbreaks caused by Salmonella , enterohemorrhagice. coli , or Listeria occur because of contaminated eggs, contaminated produce, or contaminated ready-to-eat foods. But here the real, total disease burden is actually very significant. The best estimate we have of the comprehensive (sporadic and outbreak) foodborne disease burden comes from the United States where it is estimated that one-third of the U.S. population has a case of microbiological foodborne disease every year (Mead et al., 1999).

People confronted with such figures often comment that such disease is just simple diarrhea and will only result in a few days of discomfort. Although this is true in many cases, the same study estimates that every year approximately 5000 U.S. citizens (later down regulated to 3– 4000) die from such disease, and a significantly higher figure is hospitalized, often with longterm effects lasting years. A Dutch study (Havelaar et al., 2012) estimated the burden of disease from 14 food-related pathogens in the Netherlands to be 13,500 Disability Adjusted Life Years (DALY) in 2009, lower than the burden of pneumonia (72,000) but similar to urinary tract infections (15,600).

Extrapolating Dutch and American figures to the rest of the world gives us  an astounding disease figure related to the preventable contamination of something we all need on a daily basis: our food.

What about the situation in other parts of the world? Based on national reporting, the World Health Organization (WHO) estimates that around 1.8 million children under 5 years of age die every year from diarrhea caused by contaminated food or water. As usual, the poorest part of the population is at the highest risk: in general, malnutrition can result in a 30-fold increase in the risk for diarrhea-associated death. When considering these estimates it is important to realize that they do not include the very significant burden of microbiological diseases not confined to diarrheal expression, including dangerous blood, renal, and brain infections; Reiters syndrome (reactive arthritis); Guillain-Barré syndrome (autoimmune nerve disease); abortions; and so on.

Foodborne diseases not only significantly affect people’ s health and wellbeing but also have economic consequences for individuals, families, communities, businesses, and countries. These diseases impose a substantial burden on healthcare systems and markedly reduce economic productivity. The loss of income due to foodborne disease perpetuates the cycle of poverty.

In a study from the United States, Scharff (2012) estimated the aggregated annual cost of foodborne (microbiological) illness to be $78 billion ($29– $145 billion). Estimates of the economic consequences of food contamination events or foodborne disease outbreaks through altered conditions affecting national food export are not forthcoming. However, in several major single incidents, the total health and socioeconomic costs have been measured in hundreds of millions of U.S. dollars. The major E. coli outbreak in Europe in 2011 is claimed to have cost almost $3 billion in human damage (health costs, sick leave, and so on), while European farmers estimated their losses to more than $400 million per week (outbreak lasted at least 4 weeks).

Efficient prevention of food safety problems requires full integration of the food production chain: “ from farm to fork” or “from boat to throat,” recognizing that the critical point for efficient prevention might be at the farm for some problems or at the retail level for others. Most present-day food safety systems are not built according to this important principle. Incoherence of the systems has led to inconsistency and in some cases inefficiency of food safety systems. Although prevention of foodborne disease, of course, has to be based on good general hygienic practices, it is important to focus our efforts toward the real risks in the population. Any system to efficiently prevent foodborne disease problems should be based upon a solid evidence base. Therefore, the data-gathering efforts related to food contamination and foodborne disease need to be coordinated. Likewise, monitoring, surveillance, and control efforts should be geared toward common goals. This coordination is missing in many food safety systems currently, thus leading to a very weak evidence base and, potentially, to uninformed decisions and poor political support.