252 CHAMBERLAIN. 



infections which they brought from the homeland. In these, if rein- 

 fection is avoided, the worms gradually die out. My work with soldiers 

 indicates that after a lapse of three years at least four-fifths of the 

 hookworm carriers have freed themselves of their parasites. Somewhat 

 similar results were obtained among infected soldiers in Cuba (20). 



THE OCCURRENCE OF UNCINARIASIS AMONG AMERICANS IN THE PHILIP- 

 PINE ISLANDS. 



Few of the soldiers recruited in the United States present any clinical 

 evidence of uncinariasis and infections after arrival in the Philippine 

 Islands should be comparatively rare, especially of late years, in view 

 of the universal care exercised by the Army as to clothing, food, and 

 water. Therefore, one would not expect to find hookworm disease widely 

 prevalent among the Americans in the Islands. A study of the literature 

 and statistics confirms this expectation. 



While it is known that cases of agchylostomiasis were being detected during 

 the early days of the American occupation (1898-1900), I can find no record 

 of examinations, and the first available report is that of Strong in 1900 (22). 

 Craig (8), in 1902, chronicled 18 cases found at the General Hospital in San 

 Francisco among soldiers returning from the Philippine Islands. All of his 

 cases seem to have been severe ones, and he states that the parasite in each 

 instance was the Old World species. 



In 1907 Cole (10) reported that since the organization of the Division Hos- 

 pital at Manila, in 1898, the entire number of cases of uncinariasis among officers 

 and men of the Regular Army in that institution had been 76. The total 

 number of white admissions during this period is not stated and can not now 

 be determined with accuracy, but it must have been over 25,000. This shows 

 that uncinariasis was either very rare, or was rarely recognized. Of Cole's 

 76 cases, 38 were admitted for uncinariasis and 38 for other conditions, the 

 ova of hookworm being found during the examination of the stools. 



To determine what numbers of Americans of late years are showing 

 infections with uncinaria, I have examined the records of the Division 

 Hospital for the period from June 14, 1905, to January 29, 1910. A 

 trifle over 8,200 white patients have been admitted and the ova of hook- 

 worms have been demostrated in the fasces of 71, a rate of infection of 

 considerably less than 1 per cent. Deducting the number of duplicate 

 examinations made in the positive hookworm cases, there have been over 

 8,000 examinations of stools during the period in which the 71 cases of 

 uncinariasis have been found. This shows its great infrequency. The 

 details of the positive cases are shown in Table I. 



As the Division Hospital is used mainly for the more serious and 

 chronic cases of disease, it occurred to me that a larger proportion of 

 infections with uncinaria among the white soldiers might be shown in 

 the records of the Army posts, since there the simpler cases of disease 

 would receive treatment and be cured. Therefore, I examined the records 

 of Fort William McKinley, a brigade post 6 miles from Manila. For 



