1)Complement-fixation tests with a soluble typhus antigen on sera collected from the indigenous population at various localities in Lower (Nile Delta) and Upper Egypt and the Southern Sudan revealed positive reactors in all three regions sampled. The highest percentage of positives was found in Lower Egypt (19.3), the next highest in Upper Egypt (13.2) and the lowest in the Southern Sudan (3.7).
2)The rate of positives increases with the age of the donor.
3)By utilizing specific epidemic and murine complement-fixing antigens, 35 of 50 current typhus infections were found to be of the epidemic type and 15 of the murine type.
4)A high percentage (34%) of 116 rodents captured at Alexandria gave a positive complement fixation reaction, but none of 146 rodents captured in a village in the Nile Delta was positive.
5)Though, since 1947, typhus has been at a low ebb—less than one case reported per 100,000 population—both louse-borne and murine typhus continue to occur, and in view of a growing-up, non-immune population and a developing resistance of the Egyptian lice to DDT, the danger, under favoring conditions, of epidemics in the future should not be ignored.
Present address: Yale University Medical School, 333 Cedar St., New Haven, Connecticut.