BALANTIDIUM COLI 127 



Balantidium swims about in the contents of the large intestine 

 devouring particles of fiEcal material. As long as the animal 

 confines its activities to this, no ill effects result, but it also has 

 the power, like Endamceba histolytica, of invading the tissues 

 and causing ulceration, perhaps after an injury from some other 

 cause has given an opening for invasion. Although many in- 

 fected persons do not show any dysenteric symptoms, these are 

 likely to appear at any time. When they do appear, they are 

 of a very serious nature, and cause a high mortality. On post 

 mortem examination the large intestine is often found in a hor- 

 rible condition, ulcerated from end to end, with shreds of muti- 

 lated or dead tissue hanging from the walls. 



Unfortunately there is no specific treatment for balantidial 

 dysentery as there is for the amebic disease. In some cases 

 emetin and alcresta ipecac (see p. 135) have caused a disap- 

 pearance of the parasites, but these are not reliable remedies. 

 Salvarsan and methylene blue have also been recorded as suc- 

 cessful in some cases. Organic compounds of silver seem to 

 have some value in destroying Balantidium, and there are other 

 drugs and herbs of much local fame which are undoubtedly 

 sometimes effective. Rest and care of the general health are 

 always required. 



Prevention of balantidial dysentery consists not only in the 

 sanitary disposal of human faeces, as in the case of other human 

 intestinal protozoans, but also in the proper care of hogs, since 

 Balantidium is a common parasite of these animals, and is 

 probably normally a hog parasite. A large proportion of hogs 

 are infected in almost all warm and temperate countries, and it is 

 nearly always in hog-raising countries, and in places where there 

 is too close association between hogs and man, that balantidial 

 dysentery occurs. Around Manila, where the disease is fairly 

 common, the majority of the hogs are infected and pass encysted 

 parasites in their fseces almost constantly. In Colombia the 

 disease is found only in those altitudes where hogs are raised 

 and among those who raise them. 



