Sanitation in Panama

by William Crawford Gorgas

Sanitary work, generally speaking, was done only within a mile or so of the Canal itself. All brush and undergrowth were cleared within two hundred yards of houses and villages, and the ground carefully drained within the same area. There was no object in carrying sanitary work beyond the populated area. Even if mosquitoes bred where no human beings were living, no harm would be done, as there would be no one to infect.

All told, the country under the jurisdiction of the Isthmian Canal Commission amounted in area to about five hundred square miles, and only a hundred of this was affected by the work of the Sanitary Department. The great work of the sanitary inspector was his anti-mosquito work. In the early days he paid most attention to the stegomyia mosquito, but after the fall of 1905 when yellow fever had been conquered, attention was concentrated on the anopheles, the malarial mosquito.

For the elimination of the stegomyia, the inspector in these country districts took the same measures as described in Colon and Panama against these mosquitoes, though of course on a very much smaller scale. Against malaria, he had a sufficient number of laborers under one or more foremen, according to the size of the district, who cut the brush and undergrowth within two hundred yards of all villages, houses and dwellings, and who also cut the grass within this area whenever it reached a foot in height. This was done for several reasons. The adult mosquito is destroyed by wind or sunlight, and he seeks all sorts of shrubbery, grass and foliage for protection against both of these enemies. Therefore, if the brush, shrubbery and high grass is cleared off within two hundred yards around a dwelling, there is no shelter for the mosquito from either the wind or sunlight, and there are therefore no mosquitoes within this area.

The anopheles, the malarial mosquito, is not a mosquito of strong flight; two hundred yards is, in general, a good long flight for her. If there were trees and shrubs and bushes every few yards, the anopheles mosquito might travel very long distances and not be much exposed to either the sun or the wind. But if an area of two hundred yards around each building is kept clear, she will not often be able to cross such a zone without destruction, either by sun or wind. Clearing this zone exposes the ground to both sun and wind, and by these forces alone many of the smaller pools will be dried up and made unfit for mosquito breeding. I have often seen this measure alone, that is, clearing the zone, cause a swampy place which I had expected to have to drain, to become dry and cease to breed mosquitoes.

Oilers at Work In Marsh.

Burning Out Ditch With Oil Spray.

It was also the inspector’s duty to see to the drainage. For this purpose he had a properly trained body of men under his control. The drainage was, of course, very much more extensive in area than the grass and bush cutting, for not only had the cleared zone itself to be drained, but all the area within that zone, and also the water-courses leading off from the drained areas had to receive attention. Many times we found that anopheles were breeding very much beyond the two-hundred-yard limit and still coming into the village. In one case we had a very large flight of anopheles which lasted for two or three weeks, and they were found to be breeding more than a mile from the village of Gatun. So, as a matter of fact, our work was very many times carried beyond the two-hundred-yard zone.

The inspector used several methods of draining, being governed in his choice by local conditions.