A survey of malaria in Egypt, made during the period August to December, 1936, is here reported. Three general localities were surveyed: The Valley of the Nile including Fayum, the Oasis of Siwa in the Western Desert, and the Suez Canal Zone.
Malaria is widespread in the Nile Valley. Not one of 29 localities of Lower Egypt proved to be free from it. Both parasite and spleen indexes were low in many localities, but those of villages near rice plantations or large bodies of fresh water were usually high. In Upper Egypt we found only one village malaria-infected, but it is likely that a more extensive survey would reveal more of them. We found very high indexes in the Siwa Oasis and in the Suez Canal Zone.
Among species of Plasmodium, vivax predominated in the majority of localities, but cases of falciparum infection occurred in nearly all parts of the territory. Malariae (quartan) was not found in the Nile Valley, but 5 cases of infection with this parasite were seen in the Canal Zone and in the Siwa Oasis.
The spleen index was generally lower than the parasite index. It would be a useful although not very accurate measure of the amount and distribution of malaria in Egypt. This survey afforded no definite measure of the amount of splenomegaly due to causes other than malaria. The spleen index of children was very low or nil in villages where the parasite index was low. Apparently the strain or strains of vivax present in Egypt are less apt to cause enlarged spleen and severe illness than those of falciparum.
We found much to indicate that pharoensis is an efficient carrier of malaria. This species has a decided avidity for human hosts. We found many specimens infected in nature with oocysts and a few with sporozoites. Its distribution in the Delta agrees well with that of malaria prevalence. We infected it in the laboratory with carriers of both falciparum and vivax. Its density is fairly high in man-inhabited tents, but low in houses and stables. With regard to other species of Anopheles we can add little information. We infected multicolor with falciparum in the laboratory but did not find it infected in nature.
We recommend further research, especially in regard to the seasonal incidence of malaria.
The extirpation of malaria in Egypt is hardly possible without a radical change in the system of irrigation. As a palliative measure we recommend the distribution of Gambusia. The restriction of rice cultivation to areas distant from large centers of population is a measure contemplated by the health authorities of Egypt, and likely to prove beneficial.