Food poisoning outbreaks in U.S.

Press, Volume CXV, Issue 33912, 4 August 1975, Page 6

Food poisoning outbreaks in U.S.

(By

JANE BRODY

in the 'Wee l York Times." throityh

N.Z.P.A.) NEW YORK. Millions of Americans who never before wielded a hoe are now harvesting homegrown foods and canning them for yearround consumption, and the nation is experiencing a sudden increase in outbreaks of botulism, a deadly form of food poisoning.

[ Recorded outbreaks of [botulism —about 90 per cent i of which are caused by improperly preserved homecanned foods —last year exceeded the number of outI breaks in any year since 11935. This year they are runining slightly ahead of last [year’s total at this time. This has prompted the [United States Department of [Agriculture to conduct an expensive education programme [to bring information about safe canning techniques to ; urban as well as rural consumers. Old cookbooks and instructions that came with old canning equipment may, it cautions, be out Of date and inadequate to cope with the challenge of botulism. Even ' the department’s bulletin does not contain the latest advice on canning tomatoes, one of the most popular foods among home canners. After two botulism outbreaks last year involving home-canned tomatoes (formerly thought to be too acidic to support the growth of [botulism organisms), the [agency now recommends [mixing• citric acid with the i tomatoes —a quarter of a teaspoon to the pint, and half a [teaspoon to the quart. The source of botulism poisoning, a rod-shaped bacterium called Clostridium botulilinum, is practically lubiquiitous in soil, and can

f|be assumed to contaminate most harvested foods. The • organism forms spores that • readily survive boiling for six [hours or longer, and can be [destroyed only by heating qunder pressure, as in a pres•isure cooker. The bacterium itself, and its spores, are considered [[harmless if ingested. Howlever, under favourable conditions —which include a near! “lack of air, found in all! : [canned foods, and low acid ’land salt content, common in [most vegetables and meats — [the spores can germinate.! “They produce a toxin that is] [one of the most poisonous (substances known. Scientists! [estimate that about 16 ounces “of it would be enough to kill, the entire population of the] ’ world. The toxin attacks the ner-; ’ vous system, impairing com-; ; munication between the, ' motor nerves and the muscles! ; they stimulate. Early symp-j 1 toms often include nausea and vomiting, later blurred 1 vision, dry throat and difficulty in swallowing develop, followed by progressive weakness that can paralyse! the respiratory tract as well! as the limbs. The neurological symptoms! .typically appear in 18 to 361 [hours, but in rare cases after] [as long as eight days after; [ingestion of the toxin. In! [years past, more than 60 peri [cent of botulism victims died] [from the toxins effects. But] [since 1950 gradual improve-! ments in therapy have [brought survival rates to ap-; [proximately 75 per cent. | Unlike the spores, the i [toxin can be destroyed by] [boiling at ordinary pressures.] [Government agencies recomimend that al] vegetables—! acid or not, pressure-canned: lor not — be boiled for ten minutes after the jar is; ’opened and before its con-! [tents are sampled. This would protect the [consumer from botulism in case an error was made in the canning process and some! | spores survived and germin-[ [ated Contaminated foods do; [not necessarily smell, taste or ’look spoiled. Dr Marcus Horwitz, an expert on food-borne diseases at the Centre for Disease Control in Atlanta, says the most common error that leads to botulism is the failure to can under pressure those foods that could support spore growth. This means everything except tomatoes, fruits and pickled vegetables. [ This year, the home[canned foods involved in half of the eight botulism [outbreaks were beans, cab-] Ibage, carrots and peppers.