Food poisoning- How well the world is managing the food-borne diseases?

Food-borne pathogens, innumerable in number, cause a catalogue of diseases, many of them with potential to cause death. Why is that we are not able to prevent such food poisoning episodes totally inspite of enormous scientific knowledge and large resources at our disposal? The question is a difficult one to answer satisfactorily though many reasons can be cited. Think of the gigantic size of this sector spanning across more than 150 countries in 5 major continents. According to some estimates food processing industry produces more than 50, 000 products at any given time and at least 10% of these are replaced by new products using new technologies. In such a scenario where millions of hands are involved in handling the food from farm to the fork and an extended distribution spanning over 15000 Km where do we look for the culprits whenever a food poisoning episode breaks out? It is like picking a pin from a haystack! Still world has done reasonably well so far .

Globally the out put of processed foods is variably placed at 1.6 to 4.8 trillion  dollars from a raw material base worth 48 trillion dollars. How far these figures are reliable we do not know but by any standard the dimension of this sector is gigantic. If this is so how well we have done in controlling this scourge with the facilities, expertise and experience at our disposal?  World wide 2 billion cases of food borne disease incidences are reported every year though some doubts remain regarding such a high figure. Except in developed countries like the US, Europe, Australia etc the documentation of food-borne diseases incidences in most other countries, is a sham lacking credibility. USA reports that there were 47.8 million cases of food related incidences, working to about 1600 cases per 1 lakh population which highlights the seriousness of food poisoning in that country. Out of this 9.4 million cases were pathogen related, caused by 31 known bugs. Even after hospitalization and best medical care Americans are known to get, there were more than 3000 deaths which could not be prevented. In the UK there were 5.5 million food poisoning cases, almost 1 in 16 of the population affected by infection carried by the foods they consumed. Compare this with what is happening in Asia where there were 7 lakh deaths caused by spoiled foods, it is said!.

What are these pathogens about which world is so scared of? They can be bacteria, viruses, fungi etc which cause symptoms to appear in 12-72 hours. These symptoms include vomiting, fever, aches, diarrhea and others. How can these vectors gain access to foods? Through negligence in handling, processing, storage and due to bad sanitary environment. Campylobacter jejuni, Salmonella spp, Escherichia coli 0157:H7 are the major causative organisms for a major part of the food poisoning cases reported in many countries. There are many other bugs like B.cereus, Listeria spp, Shigella spp, Streptococci spp, Staphylococcus spp and a few others pitching in to cause other food poisoning episodes. Bacteria like Clostridium botulinum, Clostridium perfringens and Bacillus cereus secrete enterotoxins which are poisonous while Aflatoxins and Ochratoxins are secretary products from fungi like Aspergillus parasiticus and Aspergillus flavus. If we know so much about these predators in our foods what holds us back to improve the process technologies to ensure their destruction totally? Unfortunately many food borne diseases are caused during post-processing phase of food handling which is outside the control of the manufacturers. 

One would assume that the food industry will be keen to deploy most reliable, fastest and lowest cost diagnostic tools to detect and eliminate pathogens from their raw materials, intermediate materials and final packed products.  Researchers from the US have claimed to have developed a new diagnostic tool for detecting the presence of bacteria, viruses and other pathogens precisely and quickly. The test is based on the accepted biological theory that each and every microorganism has a specific and unique biomarker in their cells that could be DNA or RNA and by targeting this marker through a specially designed biochip, presence of these vectors can be detected fast. Though the present stage of development is confined to single biochip for each individual pathogen, there appears to be technical feasibility of developing multiplex chips that has the ability to detect several pathogens at one go.

Probably the enthusiasm of the scientists was spurred by the sufferings of millions of people affected by food poisoning and naturally they assumed that the food industry would be the perfect market for their new innovation. The quick time test they developed is claimed to identify, several bugs including the dreaded E. coli 0157, which has caused a number of deadly outbreaks in the United States and other parts of the world. Their test also is supposed to identify other pathogens responsible for brucellosis also which results from eating undercooked meat or unpasteurized dairy products. Though their test was inexpensive and fairly fast, the food industry does not seem to be too impressed as the latter wanted even faster tests that could give results in a jiffy! 

Probably food industry does not want to save on the cost on the testing kit considering that the consequences of "not catching" the infection in time could be more disastrous in economic terms. A bench mark time of 2 hours was demanded to conclude the test which the above innovation was not able to achieve. That shifted the focus of the researchers to target medical industry where hospital sanitation is crucial to avoid infection of patients through ill maintained environment, furnishings, medical tools, foods served, human interface and many other sources. The test can also recognize the virus that causes Dengue fever, potentially valuable for surveillance activities both here and abroad, and human papillomavirus (HPV), which is linked to cervical and oral cancers. That is how a test targeted at food industry became a darling of the medical industry in no time. Thus food industry's loss became medical industry's gain! 

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

CAN FRESH PRODUCE "ABSORB" PATHOGENIC BACTERIA AND VIRUS? A DEBATING POINT

Contrary to the strong belief that plant foods are less vulnerable to contamination with bacteria and virus, an analysis of food poisoning episodes due to pathogens during the last one decade clearly shows that they can be equally at risks as the meat products are in contracting infection from the field. Too much attention to animal farms, abattoirs and poultry farms by the safety monitoring authorities probably ignored the potential for microbial contamination of plant foods from the growing areas through water, soil and manure. It was rather startling to note that almost half the food poisoning episodes in the world originated in plant foods like leafy greens, cantaloupes, mangoes, strawberries, peanuts, walnuts and others causing significant mortality among consumers. This situation probably calls for a more vigorous study to get a better insight into this reality. 

The cultivation practices and the farm land locations do contribute to the vulnerability of agricultural crops to microbiological contamination. Inputs like water, and manure can be critical in maintaining freedom from pathogens while proximity to animal and poultry farms and sewage processing facilities makes the plant crops doubly susceptible to cross contamination with high probability. If the cultivated area is near to forest areas visits by animals during nights cannot be entirely avoided and their fecal droppings are a strong source of microbes of different types with varying pathogenicity. There is also the possibility of pathogens getting on vegetables and fruits in processing facilities where they are cleaned up and packed for distribution to super markets. Storage and distribution facilities if not properly sanitized frequently can cause cross contamination. In the absence of reliable traceability regime it may e next to impossible to pin point the source of contamination.

A revealing fact is that in most contamination episodes with fruits and vegetables the pathogens are found mostly on the surface though no studies have ever been carried out to find out whether these bacteria are present inside also and if so how deep they are inside. It will be a terrible tragedy if contaminating organisms find their way inside the plant and the crops through the root system. After all the fields where plants are grown can have billions of microorganisms belonging to hundreds of different species, most of them benign but some highly pathogenic. It has  to be remembered that the deadly E.coli O157:H7 strain which caused many poisoning episodes during the last few years originated in the field where soil was contaminated with fecal droppings of animals like deer and pigs. In spite of so many studies taken up to find whether disease causing bugs like bacteria and viruses can really be absorbed by the roots to be ending up in edible parts of the plant, no evidence had surfaced which support the theory that they might enter the plant under right circumstances.

It is true many bacteria show an ability to migrate towards the roots of many plants but they stay just there without migrating into the internal parts of the plant. Yet they do posses the potential to spread to other external parts of the plant during harvesting and cleaning. This is the reason why new food safety laws being enacted in some countries stipulate that for ensuring safety of fresh produce it is imperative that pathogen free water is used for irrigation and washing, the equipment and machinery deployed do not harbor pathogens and the farm workers are provided with clean water for washing their hands clean during all farm operations. In fact growing of organic foods is an ideal model for main stream agriculture community to emulate for keeping their produce free from disease causing microorganisms. Probably world is moving slowly to a stage where fresh produce which are consumed without cooking are grown only under strictest environmental and field conditions that will not give any scope for contamination with bacteria like Listeria, Salmonella and E.coli O157:H7.

When food borne diseases are discussed there is a unique creature that causes more than 60% of food poisoning episodes which has not received much attention at the hands of food microbiologists and this is the ubiquitous Noroviruses which can contaminate foods during handling stage. It was recently discovered that these viruses have the uncanny ability to contaminate surface areas of fruits and vegetables and normal washing may not be that much effective in getting rid of them easily. This is all the more true with leafy greens like spinach and lettuce which have many openings on the leaf surface called stomata for regulating transmission of gases and water vapor. The guard cells which are located on the surface of the cells can be penetrated easily by viruses,  provide a safe place for the viruses especially when there is a film of water on the surface. Standard washing procedures are not effective in gorging them out and if the contamination density is high, such consignments can cause poisoning episodes when sold in the retail market. Probably in such cases prevention is better than cure and there is no alternative but to guard against contamination at every stage of handling them to exclude incidence of Norovirus contamination.                    

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com