CRAIGIASIS 137 



many districts where amebic dysentery is endemic the first 

 rudiments of sanitation are unknown and every possible method 

 of transmission of amebic dysentery is given full opportunity. 

 Polluted drinking water, uncleanUness, transmission by flies, 

 and the almost universal use of " night-soil " (human faeces) 

 for fertilizer, all help the cause of dysentery and account for its 

 prevalence. 



The segregation and cure of dysentery patients, and the care- 

 ful disposal of their fseces, is not enough to eradicate the disease 

 entirely since there are many immune carriers of the disease who, 

 though apparently well, harbor the encysted amebse in their 

 faeces and thereby constitute a source of danger to the community. 

 It is estimated that in the tropics about ten per cent of infected 

 persons show no marked symptoms. Thorough sanitation 

 throughout the community is the only preventive measure which 

 is adequate. 



Still another factor in the distribution of dysentery amebae 

 is the rat. Dr. Lynch of Charleston, S. C, discovered that in 

 that city rats suffered from amebic dysentery as well as man. 

 The fact that rats became infected by eating infected human 

 faeces, the frequent occurrence of the disease in rats in houses 

 where human amebic dysentery has occurred, and the ready 

 transmission of the disease from rat to rat indicate that the rat 

 infection is identical with that in man, and is not due to the ameba 

 peculiar to rats, E. muris, and that rats may play an important 

 r61e in the spread of the human infection. It may be that rat 

 destruction will prove to be an important preventive measure 

 against amebic dysentery. 



Craigiasis 



Closely related to amebic dysentery in cause, symptoms, 

 treatment and prevention is a form of dysentery caused by 

 amebae of the genus Craigia (or Paramoeba), and hence called 

 " craigiasis." The parasite of this disease was discovered by 

 Captain C. F. Craig, of the United States Army, in the Philip- 

 pines a few years ago, and named by him Paramoeba hominis, 

 a name which was later changed to Craigia hominis. A nearly 

 allied species, C. migrans, was discovered by Barlow in natives 

 of Honduras. Cases of infection with one or the other of these 

 parasites have also been reported from southern United States, 



