THE EFFECT OF HEAT ON THE SPORES OF BACILLUS BOTULINUS

GEORGINA SPOONER BURKE
1919 Journal of the American Medical Association  
Following the period of infancy there is a quiescent phase in the mortality from tuberculosis, throughout which the deaths decrease year by year, although the number of infections, as shown by the tuberculin reaction, steadily increases. These infections are due probably to latent carriers, to individuals who from time to time shed tubercle bacilli. A daily examina¬ tion of the sputum of a series of individuals, carried out carefully and for a period of months, might well be undertaken in order
more » ... undertaken in order to test the validity of this hypothesis. There is a second active phase in connection with the mortality from tuberculosis. This is commonly associated with the third quinquennium of life. If we study the deaths year by year, rather than by quinquenniums, we find that this period begins at 13 years of age, and that it is not coincident in females and in males. Among the former it sets in rather sharply at the age of 12, whereas among the boys the flare up does not manifest itself until the age of 16. This distinction was found to hold good for several large cities, and is governed probably by the onset of puberty. This uniform periodicity in the increase of deaths from tuberculosis, taking place in both girls and boys at a definite year of life, leads us to believe that the disease is due to an "autogenous reinfection" from some latent focus, rather than a fresh infection from a tuberculous individual. Much good could be accomplished in combating tuberculosis both in infants and at puberty-by provid¬ ing country préventoriums in connection with the large cities. In view of the mortality incidence out¬ lined above, it would seem advisable to change the present usage in regard to the older children and to restrict these institutions to girls from the ages of 10 to 16 and to boys from 14 to 18. In this way provision would be made for hygienic measures two years before the onset of the second period of high mortality. 16 West Eighty-Sixth Street. Health of Food Handlers in New York City.-New York City under its Sanitary Code has a regulation regarding the examination of food handlers, requiring them to obtain certificates of health from the health department. An analysis of the results of the examination of 1,980 of these persons, as set forth in an abstract in the American Journal of Public Health, shows that 1,590 of these were males and 390 females ; 80.2 per cent, were in the age period between 20 and 44 years ; 81 per cent, were restaurant and hotel workers and 16 per cent, were confectioners and bakers. Of the 81 per cent., 44.2 per cent, were waiters and waitresses, 19.6 cooks and 9.1 per cent, dishwashers and kitchen employees. The exami¬ nation of these cases was very thorough. It was found that 32.1 per cent, of the males and 13.3 per cent, of the females were free from disease or any other condition worthy of mention. But among the diseases and defects found were 10 cases of active tuberculosis, 3 arrested cases and 12 sus¬ pected cases; 19 cases of active syphilis and 32 of suspected syphilis, and 6 cases of gonorrhea. The prevalence of this latter disease among women was not determined. There were 370 cases of anemia, 112 cases showing eye diseases, 124 cases of heart disease, 64 of diseases of the arteries, 237 cases of varicose veins, 110 cases of colds and rhinitis, 25 cases of chronic bronchitis, 104 cases of pulmonary emphy¬ sema, 208 cases of pyorrhea alveolaris, 288 cases of dental caries, 202 cases of pharyngitis, 62 cases of hernia and 133 cases of flatfoot. Bakers and cooks seem to suffer par¬ ticularly from cardiovascular disease, anemia, flatfoot and respiratory disorders. There are four methods commonly used in the home for canning fruit and vegetables. They are: 1. The hot pack method, in which, the fruit and vegetables are cooked in the open kettle till done and then sealed in clean jars while hot. 2. The cold pack method, in which the fruit or vegetables are first blanched, then packed in jars and the jars put into water and boiled for one continuous period of from one and a half to five hours. 3. Intermittent or fractional sterilization, the fruit or vegetables being packed cold in the jars and the jars placed in water and boiled from fifteen to sixty minutes on each of three successive days. 4. Pressure canning, in which the filled jars are sterilized with steam under pressure. Of these methods the first two are probably more generally used because they require no special apparatus as for pressure canning, and the work is completed in one day, whereas the fractional method requires three days. The latest books on bacteriology state that the spores of B. botulinus are easily killed, a temperature of 80 C. (176 F.) for sixty minutes being sufficient. If this statement were true of all strains of B. botulinus-, any one of the four methods of canning mentioned would be amply sufficient to sterilize fruit or vegetables contaminated with B. botulinus, and development of toxin in jars would indicate gross carelessness on the part of the cook. Seven cases of botulism were investigated by Dr. E. C. Dickson of Leland Stanford Junior University School of Medicine during the winter of 1917 and 1918, and in four of these cases I succeeded in iso¬ lating Bacillus botulinus, either from dead chickens, sick hogs or directly from the cans of fruit or vege¬ tables. In two of these cases, vegetables were canned by the cold pack (one period) method. One of the cooks stated positively that she had kept the filled jars in a covered boiler with the water actively boiling for three hours. She did not, however, blanch the peas before placing them in the jars. In the third case of poisoning the beans were canned by the frac¬ tional method, and in the fourth case, in which the poisoning of eight persons followed the eating of canned apricots, the fruit was cooked in the open kettle and sealed, while hot, in the jars. As the cook was one of the first victims, there are no data as to just how long the fruit was cooked. In view of these conflicting data, a series of experi¬ ments were begun to determine the effect of heat on the spores of B. botulinus.
doi:10.1001/jama.1919.02610020006002 fatcat:iopjbcj2rbdtrabkwddqkkdzja