In this class are smallpox, diphtheria, scarlet fever, measles, mumps, chicken-pox and whooping-cough.
These latter are the so-called "childish diseases" which it was formerly considered impossible to escape, and little attempt was made to guard against them. Now they are recognized as serious, whooping-cough for its close relation to brain and spinal trouble; measles for their effect on the eyes and lungs; chicken-pox for its similarity to smallpox, and mumps for its general lowering of the tone of the system, allowing other diseases to gain a foothold.
Special serum treatment for diphtheria and vaccination for smallpox have greatly reduced the danger from these once greatly dreaded diseases.
Of preventable diseases none should receive more attention than typhoid fever, because it is a great scourge and yet it can be prevented by simple means. If we understand that typhoid is a dirt disease, that it comes only from dirt, we shall feel it a disgrace to have an epidemic of typhoid, though one of the saddest features about it is that we must suffer for the sins of others. The one who is attacked by typhoid fever may not be the one who has left dirt for the disease to breed in.
Typhoid fever germs are bred chiefly in manure piles, sewers, or cess-pools, and would not be transmitted to man directly, but there are several indirect ways in which they may be carried. Flies also breed in the same places. Their legs become covered with typhoid germs, and then they fly into houses directly on the food and cooking utensils. This is one of the most common ways in which the disease is carried, and doctors tell us that the common house-fly should be known as the "typhoid fly" so that people may know the serious danger that lurks in what was formerly considered as nothing worse than an annoying foe to clean housekeeping.
If houses are thoroughly screened, if cess-pools, manure piles and garbage are kept tightly covered, screened, or, still better, disinfected with chloride of lime, there will be no breeding-places left for flies and this will remove one of the greatest dangers.
The other danger lies in a polluted water or milk supply. Every sewer that is carried into a stream, every manure pile that drains into a water course is a menace to health.
Very frequently the farm well for watering stock is near the barn,—near the manure pile, which, as it drains, carries down millions of typhoid germs to the water-level below. The well becomes infected, the family drink from it, and soon there may be several cases of typhoid fever in the home.
Worst of all, the milk pails are rinsed at the well, and all the milk that is poured into them spreads the germs wherever the milk may be sold. In this way an epidemic may be carried to an entire town, and to persons who themselves have taken every precaution against the disease.
Drinking water should be boiled unless one is sure of the water-supply, and surface wells are never safe unless we know that they drain only from clean sources, and then the water should be analyzed frequently. Boiling absolutely destroys typhoid and other germs, and well repays the extra work it makes. One case of typhoid fever causes more work than boiling the water for years, if we consider the work only.