Food-borne diseases: the danger that lies within

It’s 1862, and the beginnings of a food safety revolution are in the air. The Grocer is little more than four months old when Louis Pasteur and his colleague Claude Bernard complete the first experiment with the heat treatment process that will soon become known as pasteurisation, paving the way for modern food preservation.

Over the next three decades, the work of Pasteur and others will bring about a radical change in our understanding of disease and food safety. Long-held beliefs such as ‘miasma theory’ - which suggested diseases were transmitted through bad smells - will be replaced by germ theory and microbiology.

Our timeline of the key moments in food safety history shows just how far our understanding of food-borne disease has evolved since the 1860s. “It’s incredible to think that when The Grocer was first published, we didn’t understand that micro-organisms caused illness and didn’t recognise that food could cause infections,” says David Clarke, microbiologist, and CEO of Red Tractor Assurance.

It’s not just our understanding of food safety that has changed. Over the past 150 years, food safey issues have increased both in complexity and number as the industry has gone global. The way we approach food safety has evolved in kind - although paradoxically one major issue that appeared to have disappeared seems to be rearing its ugly head again.

On the face of it, the world of 2012 couldn’t be more different from that of 1862. Laws during The Grocer’s early years focused primarily on preventing food from being unsound or adulterated - a significant problem in Victorian Britain, when copper was routinely added to boost the colour of foods such as butter and gin. By the late 1880s, when the scientific revolution was in full swing, food poisoning and food hygiene had become public health concerns. Even so, it was not until 1939 that it became compulsory to notify authorities about outbreaks of food-borne illness or that the Food and Drugs Act brought in laws to ensure basic hygiene standards.

More than 70 years on, the focus is now very much on how the industry manages its increasingly global supply chain. High standards of food safety in the UK and other parts of the developed world offer little protection from contamination and disease if food produced to lower standards elsewhere ends up being imported, points out Tony Hines, head of food security and crisis management at Leatherhead Food Research.

“We may have very slick controls in the UK and in Europe, but that isn’t always the case elsewhere in the world,” he says, alluding to last year’s deadly E.coli outbreak in Germany - ultimately traced back to contaminated fenugreek seeds imported from Egypt.

It’s a concern shared by Dr Barbara Lund, a visiting scientist at the Institute of Food Research. Large, sophisticated suppliers and retailers have sufficiently robust procedures to maintain safety when sourcing from around the globe, she says. Smaller traders and consumers, however, can be vulnerable, especially as an increasing number buy foods and ingredients online. “The sale of food over the internet is just not well regulated,” says Lund.

This increasingly global focus is also reflected in the priorities of the Food Standards Agency, which says that - in addition to its key projects to combat campylobacter, listeria and norovirus (p164) - monitoring changes to how foods and ingredients are sourced, produced, processed and consumed around the world now forms a vital part of its work to ensure food sold in the UK is safe to eat.

“We need to be proactive in maintaining our intelligence on the ways in which the food system is developing, and our analysis of how this and other factors - such as the economic situation - may affect new or re-emerging risks, in the UK and across the world,” says a spokesman.

The potential risks of unsafe imports are exacerbated by a rapidly-growing population, believes Hines, citing predictions by the World Wildlife Fund that the world will need to produce as much food in the next 40 years as it has over the past 8,000 to feed it.

Food adulteration may seem a problem from a bygone era but, Hines warns, with more people now depending on ever scarcer water and food resources, there is a greater incentive for unscrupulous operators to commit food fraud and artificially bulk up ingredients.

“What we did 150 years ago is still happening in other, less developed parts of the world,” he says, highlighting a recent case involving milled paprika powder that was in part ground roof tiles - and recent reports of dairy processors in China boosting the protein content of their milk by adding extracts from leather, an incident that echoed the 2008 scandal in which six babies died after melamine - an industrial chemical - was added to milk also to mask its true protein content.

Closer to home, one of the biggest food scares involving adulteration in recent times occurred in February 2005 when 470 food products in the UK had to be recalled after Sudan 1 - a potentially carcinogenic red dye - was detected in chilli powder.

As for the adulteration issue that poses the most likely risk to UK consumers, animal feed is the area to keep a close eye on, suggests Hines. “Many of our recent food safety scares can be traced back to animal feed,” he says. “If, as expected, we all start eating more meat, where will all the animal feed come from?”

Climate change could also pose a threat. As global temperatures rise, new diseases could travel north to the UK, according to Dr Julian Little of Bayer Crop Science. “Fungal infections in particular are likely to become more prevalent, putting pressure on our supply chains and potentially affecting food prices,” he says.

Changes in UK demographics are also set to throw up new food safety challenges. The elderly, and those undergoing treatments for conditions such as cancer, typically have less robust immune systems. As their number increases, existing safety advice may have to be rethought, warns Lund. “Someone with a compromised immune system can be vulnerable to contracting food poisoning from far lower quantities of pathogens,” she says.

Listeria poses a particularly serious risk, she adds. “I understand it may be difficult for retailers to do this, but vulnerable people should routinely be advised by GPs to avoid foods such as unpasteurised cheeses and raw bean sprouts.”

Elsewhere, a growing gap between the safety and preparation techniques used by large processors and the technology available in the average home is causing concern. “There’s a tendency to extend shelf life for many convenience and chilled foods - but although temperature can be controlled effectively by major manufacturers and retailers, that is not necessarily the case in smaller shops and the home,” says Lund.

She is equally unimpressed by the rise of the celebrity chef and the subsequent adoption of complex professional cooking methods by consumers - with sous vide cooking a particular bugbear. “The major producers know how to produce sous vide food safely,” she says, “but, again, it’s often a different story in the home.”

Recent outbreaks of food-borne diseases associated with fresh produce mean fruit and veg can expect greater scrutiny in the future. “In the meat industry, we have very good controls as a result of BSE and foot and mouth,” says Hines. “With fruit and veg, that’s not necessarily the case. For example, we already know chemistry is used to enhance crops, but we don’t understand pesticide science particularly well.”

Fresh produce is also on Lund’s list of foods to watch. “I expect to see a general increase in concern regarding fresh produce,” she says. “With increasing global trade and more and more packaged products, it’s an area to keep an eye on.”

But although the industry faces a daunting list of global and domestic food safety challenges, it’s not all doom and gloom, insists Little. “The good thing is that we have robust tracking and tracing procedures,” he says. “Yes, there might be scary new diseases that come in, but taking things off shelves has never been easier or faster.”

If the past 150 years were the ‘golden age of microbiology’, a time when giant leaps forward in understanding what causes and prevents food-borne illness were made, a good chunk of the next 150 are likely to be spent implementing that knowledge and enforcing existing safety in an increasingly complex and global supply chain.

Not that all the issues will be new. Many recent outbreaks have been about “the same old problems and the same old mistakes,” points out Clarke. The key challenge will be to avoid repeating them.