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Coccidia parasitic in man 
no clinically recognizable “coccidiosis " due to this parasite has yet been 
described. It is true that the oocysts have generally been found in the faeces 
of patients suffering, or who had recently suffered, from dysentery or diarrhoea; 
but this is probably merely because the faeces of persons with no intestinal 
ailments are not usually examined. When symptoms of intestinal disorder 
have accompanied the infection, they have generally been attributable to 
other causes. Cragg (1917), for example, records two fatal cases in which 
“there was a very heavy infection" with Isospora. One died from “the 
rupture of an old dysenteric ulcer," and Entamoeba histolytica was found in 
the stools: the other succumbed to bacillary dysenterv—Shiga’s bacillus 
having been isolated before death. He concludes that in both these cases 
“there was other adequate cause for the patient’s condition, and no indication 
of the pathogenicity of the Coccidium." Post mortem examinations were made 
of both these cases, but unfortunately nothing is recorded concerning the state 
of the patients’ small intestines 1 . 
In this connexion the case which I found (1916) at Walton Hospital may 
be mentioned. The patient was not suffering from any intestinal ailment, 
though he had had diarrhoea on the Gallipoli Peninsula in the previous year. 
He was in hospital for varicocele, and was one of the series of seventy non- 
dvsenteric patients whose stools I examined for protozoal infections. No in¬ 
fections with Isospora were discovered among the 130 patients with intestinal 
ailments examined at the same hospital. 
Treatment. No method of treatment has yet been discovered which will 
get rid of an Isospora infection—or, for that matter, of any coccidia! infection 
in any animal. Emetine appears to be the only drug which has hitherto been 
tried. Wenyon and O’Connor (1917) treated an infected patient with emetine 
hydrochloride—administered hypodermically and by the mouth simulta¬ 
neously—and record that the oocysts disappeared from the stools during 
treatment and were not found again for a month following. But O'Connor 
has since treated two more cases wdth emetine, and found that the drug was 
without effect. Similar observations are recorded by Savage and Young 
(1917). Moreover, it is to be noted that the oocysts of this parasite have 
several times been first found in the stools after the patients had been treated 
with emetine: and it is not uncommon for them to disappear completely with¬ 
out any specific treatment. 
Attempts to infect animals experimentally . Several attempts have been made 
to infect animals other than man with I. hominis, but without success 2 . 
1 Cragg (1917), for some reason which is not apparent, seems to have supposed that Isospora 
hominis inhabits the liver. He mentions that “nothing unusual was found in the liver" in one 
case; and says of the other, “unfortunately the liver was not examined.” So far as I am aware, 
an Isospora which inhabits the liver has not yet been discovered. 
2 Fantham (1917) has recently claimed to have infected kittens with I. hominis, and says he 
produced in their intestines a “condition resembling that seen in the human intestine examined 
post mortem.” This, however, has never been described, so far as I am aware; and the statement 
can hardly be accepted without some concrete evidence to support it. 
