COCKLES 263 



if possible, be restricted or supervised. (4) Further, as a protective 

 measure of the first importance, oysters should be cleansed, after 

 fattening on a contaminated bed, by being deposited for several 

 weeks at some point along the coast which is washed by pure sea- 

 water. (5) Eetention in dirty-water tanks, in uncleanly shops and 

 warehouses, should also be prohibited. 



Other shell-fish than oysters do, from time to time, cause 

 epidemics or individual cases of gastro-intestinal irritation, and prob- 

 ably contain various germs. These they acquire in all probability 

 from their food, which by their own choice is frequently of a doubt- 

 ful character. 



In a preliminary inquiry into " Cockles as agents of Infectious 

 Diseases," Dr Klein detected the B. coli in 3 out of 8 cockles 

 which had been taken from a foreshore polluted with the discharge 

 from a sewer outfall, and also B. enteritidis sporogenes in 4 of them. 

 No typhoid bacilli were detected. In 8 raw cockles in their 

 shells bought from a street hawker, Dr Klein found no typhoid 

 organisms, but B. coli was found in 5 out of the 8 cockles and 

 B. enteritidis sporogenes in 4 out of the 8.* In subsequent experi- 

 ments Dr Klein came to the conclusion that a mussel immersed for 

 twenty-two hours in cholera-infected water retained the bacilli of 

 cholera for forty-eigh.t hours after immersion in clean sea-water, and 

 the same may be said in respect of typhoid infection. Indeed, evi- 

 dence was obtained showing that the typhoid bacillus could multiply 

 in cockles. He also showed that merely pouring boiling water over 

 a heap of shell-fish did not necessarily destroy either cholera or 

 typhoid infection contained in them.f Since the time of these 

 investigations, a number of outbreaks of disease, including enteric 

 fever, have been traced to the consumption of mussels and cockles, 

 and it has been shown that the cooking which these shell-fish 

 undergo is not sufficient to rid them of poisonous pollution. 



In 1902 several cases of typhoid occurred in "Wandsworth due 

 to infected cockles, and a number of similar cockles being examined 

 by Dr Klein showed the presence of B. coli and other allied forms, 

 and by other workers (Lister Institute) during the same year the 

 typhoid bacillus itself is stated to have been isolated from cockles 

 derived from a sewage-polluted laying.^ 



In 1903 an outbreak of typhoid fever occurred in Glasgow, 

 which was traced to the consumption of sewage-polluted shell-fish 

 at a neighbouring seaside town. An examination of a number of 

 shell-fish from this particular locality was made by Dr E. M. 

 Buchanan, the Corporation bacteriologist, who reported that — (1) All 



* Report of Medical Officer to Local Oovernment Board, 1899-1900, p. 574. 



t IMd., 1900-01, pp. 564-71. 



t Report of Medical Officer of Eealth of City of London, 1902, pp. 134-49, 



