OTHER PATHOLOGICAL CONDITIONS 307 
both on the coast and in the interior of Liberia. In the school children of Mon- 
rovia and of Cape Mount the rate of hookworm infection was not below 45 per 
cent, while in the interior at Gbanga it was 84.6 per cent. The actual rate of 
infection was higher in all these instances because it was usually not practi- 
cable in these patients to make more than a single examination. The Ascaris 
infection in the different localities averaged about sixty-one per cent. Maass 
found in the northwestern border of Liberia about ninety-six per cent of the 
patients examined were infected with ancylostomes, and that the rate of Ascaris 
infection was only a trifle lower. We found that in spite of its prevalence 
severe cases of hookworm infection were not common in Liberia. The patients 
seemed to be not at all or very little affected by the infestation with the 
common intestinal parasites except in a few instances. Gordon! in his studies 
of the West African races made in Freetown, has previously called attention to 
this fact. He studied the effects of ancylostomiasis on the health of 137 natives, 
and those of Ascaris and Trichuris on 89 of the same cases, and showed that 
these infections, or a combination of them, produced no noticeable changes in 
the haemoglobin percentage, or in the physique and general fitness, or the men- 
tality of the individuals examined; nor did he find that the presence of the 
parasite was associated in any way with albumin or casts in the urine. He also 
pointed out that the Ascaris and Trichuris infections did not appear to be as- 
sociated with a low standard of energy, nor was the percentage of cases of 
ancylostomiasis, or the average degree of infection, necessarily noticeably greater 
in a group of individuals with a lower standard of energy than in one with a 
higher standard. However, in a few individuals severely infected, the possi- 
bility of some association between the ancylostomiasis infection and the low 
standard of energy was suggested. 
The occurrence of schistosomiasis has already been referred to in Chap- 
ter XVI. It is very common in the interior of Liberia, but very rare on the 
coast, and Dr. Bouet believes that all cases seen in Monrovia have become 
infected inland. Maass found Schistosoma haematobium in northwestern Libe- 
ria, but did not observe Schistosoma mansoni. We have already noted the pres- 
ence of both. 
Dysentery is rarer in Liberia than in many tropical countries. While both 
amoebic and bacillary forms occur, the absence of large numbers of cases of 
dysentery in Liberia is striking. Enteritis was also seldom complained of by 
the natives and Dr. Shattuck found that when intestinal symptoms were com- 
plained of they could generally be attributed to gluttony. 
COSMOPOLITAN DISEASES 
Smallpox occurs in Liberia and a case of the disease was seen by us near 
our camp on the Du River shortly after our arrival. This man was employed 
on the Firestone rubber plantations. In order to prevent the spread of in- 
fection among the other native laborers, all those employed in the vicinity 
1 Gordon: Ann. Trop. Med. and Parasit. (1925), XIX, 429. 
