MICROBIAL FOOD POISONING. 415 



B. coli, and B. bolulinus. These organisms, or at least some varieties of 

 them, produce powerful poisons which are not destroyed by boiling, 

 and therefore may remain in the food after thorough cooking. Moreover, 

 meat rendered poisonous by these bacteria may show no evidence of putre- 

 faction. B. (Protens) vulgaris has also been found in some samples of 

 poisonous meat, and this rinding is usually associated with definite evi- 

 dence of putrefaction. 



The symptoms of meat poisoning are usually those of acute gastro- 

 enteritis, vomiting, cramps, and diarrhoea. The patients often recover 

 very quickly, but occasionally the illness is rapidly fatal, or it may merge 

 into a subacute form resembling or identical with paratyphoid fever. In 

 those instances of poisoning due to the presence of B. botulinus the symp- 

 toms are of a different kind, consisting almost solely of nervous disturb- 

 ances, secretory and motor paralyses, without fever, resembling in many 

 respects poisoning with atropin. In this form of meat poisoning the 

 death rate is relatively high, occurring in about 40 per cent of the cases. 



FISH POISONING is of two general kinds, that due to poisons natural 

 to the fish, and that due to poisons formed by bacterial activity in the 

 flesh of the fish. Blanchard has applied the Spanish name " Siguatera" to 

 the first kind and the term "Botulism" to the second. In the Japanese 

 fish of the genus Tetrodon the roe is poisonous, giving rise to severe 

 gastro-intestinal irritation and convulsions. The remainder of the fish 

 is not poisonous. In some other fishes the sexual glands are poisonous 

 during the spawning season; others are provided with special poison 

 glands connected with protective spines or barbs. These are examples 

 of poisons natural to fish. Bacterial poisons are likely to be formed in 

 any kind of fish, given the suitable conditions, and thus give rise to the 

 kind of fish poisoning designated as botulism. Cases of this kind have 

 resulted from eating (spoiled) canned salmon and sardines. Poisoning may 

 also result from eating diseased fish, the effects being due to poisons 

 elaborated by the infecting bacteria in the body of the fish before consump- 

 tion. This appears to be a rather common form of fish poisoning in 

 Russia. B. paratyphosus has been isolated from some poisonous fish, and 

 certain toxicogenic anaerobes have been found in others. 



POISONING WITH SHELL-FISH is so well recognized that this form of 

 food is not customarily used at all during the warmer part of the year, 

 May to August inclusive, the months without an r in their names. Shell- 

 fish may serve as carriers of human infectious diseases, such as typhoid 



