Climate and Health in Hot Countries and the Outlines of Tropical Climatology / A Popular Treatise on Personal Hygiene in the Hotter Parts of the World, and on the Climates That Will Be Met Within Them.

by George Michael James Giles

The natural history of the living organisms that are concerned in the propagation of malaria has been described with some detail, as suitable measures for the prevention of the disease must needs be based on a fairly competent knowledge of the subject, and is the more necessary as it is hardly possible to give any “rule of thumb” directions; because the circumstances on which the prevalence of malaria depends vary so greatly in different localities that, to ensure success, our operations must necessarily be modified in each case to meet local conditions.

In the following remarks, however, it is not proposed to deal with the question of prevention on a large and public scale, but only with such as can be adopted as measures of individual and personal hygiene, as the larger question of provincial and municipal anti-malarial sanitation cannot be adequately dealt with in a short treatise like the present.

Keeping always in view the just described data of the life history of the malarial parasite and of its temporary host, the mosquito, it is obvious that our measures of protection must be based on one or more of the following plans of action, any one of which, could it be carried to complete success, would suffice to “stamp out” the disease. These measures are:—

(1) To destroy the mosquitoes.

(2) To prevent mosquitoes biting man.

(3) To prevent mosquitoes from becoming infected, by isolating all cases of malaria in man.

In practice, however, it is extremely rare that anything like complete success can be attained on either of the three above indicated lines of action, especially as concerns the second and third methods, and though here and there localities may be met with in which the breeding places for mosquitoes are so circumscribed and easily dealt with as to render the actual extermination of mosquitoes practicable, in by far the majority of cases we must be content with a partial success all along the line, by adopting such measures as may be locally most practicable, based on any or all three of the above principles of action.

In the case, for example, of habitations placed in the midst of canal irrigation where ample and efficient subsoil drainage is impossible or too expensive, the attempt to destroy mosquitoes can be little better than a waste of time and money; for under such conditions the breeding places are so numerous, and appear so constantly in new and unexpected situations, as to defeat the utmost vigilance; and the thorough protection of all habitations against the invasion of mosquitoes, and the careful treatment of all cases with quinine, is all that can be done. On the other hand, in an exceptional case, such as that of the town of Ismailia in Egypt, where the rainfall is practically nil, and the breeding places all of artificial origin, the practical extermination of mosquitoes may be so easy a matter as to be effected at a small expense in a single year, with the immediate result of reducing the cases of malaria to a tithe of their previous numbers.

Measures of the first class, i.e., the extermination or diminution of the numbers of mosquitoes, can often be undertaken with considerable success by private individuals, the possibilities of success varying, of course, with the extent of the area directly or indirectly under his control.

The resident of a closely inhabited town can, it is needless to say, do no more than contribute his personal mite to the general welfare in this matter, with little chance of reaping much benefit unless his neighbours follow his example; but with the exception of diplomatic officials and merchants residing in places under oriental rule, where the safety of life and property are too badly secured to admit of their living outside town limits, it is rare for any European to be so situated, as in most of our colonies and dependencies the European quarter of the town consists of widely separated villas each surrounded with a garden of some size, with generally a small hamlet of dwellings for native servants and dependents included within its boundaries. In addition to this, there are often open spaces, of considerable extent, between the various “compounds” which, though not directly under one’s control, are so far “no man’s land” that no one will interfere with any one employing on them any of the measures required for anti-malarial sanitation, while the most litigious municipal council is hardly likely to object to the sprinkling of a little paraffin on the roadside puddles. In this way it will generally be possible to effect a good deal within a radius of three or four hundred yards of one’s dwelling, and actual experience has shown me that if all breeding places within such limits can be rendered harmless the number of stragglers that will stray across from places beyond will be too small to be seriously troublesome.