Notes on the Occurrence of Taenia saginata in North China.

Abstract

In a recent communication from this department Faust (1923) says "Twenty-five years ago infestment with Taenia saginata was common in North China. The infection was brought down in cattle from beyond the Great Wall, which were slaughtered immediately and offered for sale in the markets. Today such infection occurs rarely in Peking and vicinity. The cattle come from the same locality and are presumably infected, but for economic reasons they are fattened for a period of from several months to a year in local yards and, when slaughtered, are relatively free from infection." The impression is quite general that the beef obtainable in Peking is not infected with tape-worm and is therefore safe for consumption without special inspection. The fact that this is an erroneous assumption is the primary reason for recording the following observations. Through the cooperation of an intelligent German butcher I have secured numerous samples of beef containing Cysticercus bovis. One piece weighing 3 lbs. from the leg muscles of an ox contained 4 cysts, and another weighing 5 lbs. contained 10. Four of the animals were bulls and one a cow in whose tenderloin several cysts were found. By casual examination then he discovered 5 infected animals in less than 300 examined, or roughly 2 per cent. Careful routine examinations made for municipal and scientific purposes by Hertwig (cited by Fantham, Stephens and Theobald, 1916) showed "that the cysticercus of the ox is found chiefly in the musculi pterygoides externi and interni, and since that time a far greater number of infected oxen have been found in Berlin." If, then, the infection in the leg muscles reaches the extent observed it is highly probable that a systematic search of the tongue and throat muscles would yield a much higher per cent. of infection, as it did in Germany. The inve!tigations of Hertwig lead to certain municipal regulations which are summarized by Fantham, Stephens and Theobald thus, "The flesh of oxen only slightly infected (containing not more than 10 living cysticerci) is sold in pieces of not more than 5 lbs. to customers after having been rendered innocuous by cooking, or by pickling for 21 days in 25 per cent. salt brine, or hanging for 21 days in suitable refrigerators; oxen in which only one cysticercus is found are allowed free commerce, and those strongly infected (i. e., containing more