FOOD THAT KILLS

Hokitika Guardian, 5 August 1926, Page 4

FOOD THAT KILLS

POISONING—ITS- CAUSE AND PREVENTION.

(By J. B. S. Haldane, Header in BioChemistry, Cambridge University, in the London “ Daily Mail.”)

With the reappearance of the sun has come this year’s first serious outbreak of so-called food poisoning. The large majority ot cases occur during warm weather, and this summer wo may expect an unusually largo number owing to the coal stoppage. For the most potent safeguards that wo have against this danger are the kitchen range and the gas-cooker. England 7 is fourtnate in producing verv fete naturally poisonous loods. Occasionally a poisonous fungus is found among a batch of mushrooms, and in 1921 three women in Liverpool nearly died from eating mutton stuffed with, sage which contained belladonna leaves. But in Japan nearly a hundred people die every year from eating a poisonous fish, the fugu; and Cuba boasts of no fewer than seventy-two different species of fish which may cause death or illness. This country lias seen a few outbreaks of arsenic, zinc, and copper poisoning, mostly in beer or cider, including the terrible catastrophe in 190(1 which killed at least seventy people and affected nearly ten thousand. But in more than nine cases out of ten the poison is made by bacteria, much tho commonest source being an organism called “ Bacillus ajrtrycke.” DESTROYED BY COOKING. .

Many bacteria manufacture toxins, hut fortunately these are generally destroyed by boiling or by tho digestive juices. Diphtheria and tentanus toxins are deadly if injected, but, like snake venoms, they are harmless when taken by the mouth or injected after heating. The bacteria which cause ordinary putrefaction are almost 'harmless to adults when taken by the mouth, and though if allowed to act on food for a sufficiently long time they produce moderately poisonous substances called ptomaines, it would require a very heroic bacteriologist to eat meat rotten enough to contain a fatal or even a dangerous dose of them. In spite of the verdict at several inquests it is extremely unlikely that anyone lias ever died of ptomaine poisoning. Tlbe Bacillus rertrycke and its allies, however, make a poison which resists both cooking and digestion. If the contaminated food lias been cooked after its infection the bacteria are dead but the poison remains. When the food is eaten it causes intense vomiting and other symptoms of digestive upset, but very rarely death. If tho living germs are swallowed, they gfov for some time In the patient, and may continue to, manufacture their poisons for a week or more.

Death is a good deal commoner m these cases, hut even here the vast majority recover completely. The source of tho poison is tinned food in about half the cases, and it is particularly interesting that fifteen out of the last sixteen tins of meat causing poisoning in England came from "South America, although only about half of our tinned meat comes from that country. Potted meats, meat pies and other products made from scraps of meat come next on the list, but milk, ice cream and cheese are also occasionally poisonous.

Vegetables’ and fresh meat are much more rarely dangerous. Tn almost all cases the food lias appeared to he perfectly sound, and gave no warning either hv taste or’ smell. DEADLIEST KNOWN POISON.

How do the, bacteria reach the food? It is almost always infected alter cooking. and the bacteria are then given time to grow before ic- is enten. Pigs, mice and rats seem to he the most usual sources of infection, though occasionally human beings and cattle have been incriminated. In many cases the poisonous meat had been kept in filthy conditions.

Much food poisoning could undoubtedly he prevented if the manufacture of ire cream and “made-up” meat foods were only/ permitted in licensed, and properly inspected places. The most serious kind of food poisoning is botulism, of which only one outbreak as been recorded in Britain. Eight people ate “ wild duck ” paste sandwiches at Loch Maree in 1922 and all died from a paralysis which began in the muscles of their eyes and spread until they were unable to breathe. Th« poison is made by a bacillus which call' only live iti the absence of oxygen. It is therefore mainly found in tinned or bottled foods, but occasionally in the interior of sausages and bains. Botulimis toxin is the most poisonous of all known substances when taken by the mouth. About sixty pounds of it would probably he sufficient to kill the entire human race. | Fortunately, it is destroyed by cooking. - I fn America, most of the hundreds of . cases on record have been caused by , preserved vegetables, such as string; beans, spinach, olives and asparagus, ■ and in view of the large amounts of American canned vegetables imported into England tbo occurrence of an ont : break from this source is only a question of time. To sum up. a great deal can 'and should he done to check food contamination at its sources, but nothing except some minutes’ insertion in boiling water can render food in tin, stoneware or glass containers absolutely safe for human consumption.