Privy Vaults.—Human excrement also affords an excellent breeding place for flies. In army camps the latrines are the points from which much infection is transmitted to troops, and thousands of the men have lost their lives by contracting typhoid fever transmitted in this manner. During the summer time all open vaults and dry closets should be treated continuously with lime, crude creolin or crude carbolic acid, and they should be carefully cleaned out at frequent intervals.
Garbage.—As a medium for the development of flies, garbage may be considered next in importance to excreta. The eggs of the fly hatch in about twenty-four hours, and garbage which is retained in the kitchen for that length of time may contain flies in the grub stage. To prevent this development, all garbage should be covered and pails should be emptied as often as possible. In country districts garbage should be burned in the kitchen or buried in the garden at frequent intervals, twenty-four hours being the maximum time it should be retained.
Vacant Lots.—Vacant lots frequently contain appreciable quantities of organic matter in a state of decomposition, affording favorable breeding places for flies. These vacant areas should be maintained in a state of scrupulous cleanliness.
Foodstuffs.—In order to prevent contamination of foodstuffs, all foods that are eaten in the raw state and all foods that are exposed for sale after having been cooked should be carefully protected from contact with flies, by screens or covers.
A point where rapid development of flies takes place is along the city's water front. This is due to the fact that many of the sewers do not discharge below the level of the water. All open drains should be eliminated, whether they be sewers, private house drains or drains from cess-pools.
Precautions to be Observed.—Keep the house free from flies. Every fly should be considered a possible disease carrier and should be destroyed.
Keep the windows of the house, especially the kitchen windows, carefully screened during the spring, summer and autumn.
Protect children from exposure to flies, particularly children who are ill, and do not allow nursing bottles to be exposed to flies.
Protect milk and other foodstuffs from contact with flies.
Keep the garbage outside of the house, carefully covered.