From the above it is evident that in a small force of 20 men
under ordinary conditions 9 of them were sent to the hospital in five weeks, whereas a camp twenty times as large with attention from this Division only sent 14 to the hospital during the same
period of time.
The employees (both white and colored) at La Boca and Corozal
are remarkably free from malaria, and although two years ago the malarial sick rate at these two settlements was relatively high month after month it is now as low as at any similar location near the eacoast in warm countries. During the period of five weeks ending March 30, La Boca, with a population of 815 employees, sent only 12 cases of malaria to the hospital; and Corozal, with a population of 750 employees (mostly Italian laborers), sent only 3 cases of malaria to the hospital, and went for three weeks without
a case.
During the past several weeks the malarial sick rate (i. e., hos->
pital cases) among all employees living in the Canal Zone has been about 1 percent per week. It should be remembered that in 1904, when blood examinations for the malarial parasite were made at the Zone settlements, more than 80 per cent of persons examined showe d malarial infection. At the present time there is very little malaria among the American employees, and still less among their families. 'The Gorgona district has given the highest malarial record during the year. Most of the hospital cases there came from the camps at Juan Grande and Caballo Viejo. A large amount of clearing. near these two camps has been accomplished, and the camps are now being kept effectively screened. During the past two weeks a decided improvement in malarial conditions at Juan Grande has occurred. In several instances a marked advance in / the malarial sick rate has followed the arrival of new laborers at
certain camps. This matter was investigated and in some cases the malarial 'atients sent to the hospital had only been on the Isthmus from one to four days.' As malarial incubation takes a longer period than the time mentioned, there is n'o doubt.that many similar cases were not contracted on the Isthmus. In fact, a rise in malaria occurred at Corozal when the Italian laborers now stationed there first came. Investigation showed that some of these Italisns had had malaria before arrival, and a recurrence was to be
expected.,,
The Italian and Spanish laborers do not remain in their screened
quarters at night until they are ready to retire. They even go to sleep outside on the ground after dark, remain in localities where no sanitary work has yet been accomplished, and consequently are subject more to malarial infectionA than other people living at the camps where the- Efiropean laborers' barracks, ae located. Consequently, at certain camps most of the malaria is due to the lack of
ordinary precautions on the part of the laborer.
936A-07-3