690 apparently normal infants and children from Assiut-Upper Egypt--were submitted to Widal test. They were 0-15 years old, of both sexes (382 males and 308 females) and from both the urban and rural localities (433 and 257 respectively). --The frequency of single agglutinin titers is discussed. --The dual Widal titer combining "O" agglutinin in a titer of 1/40 or more with "H" agglutinin 1/80 or more, was fulfilled by 252 (36.5%) :-- A--106 (15.3%) showed a simultaneous rise of T."H", paratyphi A "H" and paratyphi B "H" agglutinins suggesting an effect of recent previous T.A.B. vaccination. B--146 persons (21.1%), showed a rise of only one or two "H" agglutinins, probably an effect of natural exposure to enteric fever agents reflecting the endemicity of infection. Further study of this group revealed: 1--There is a past experience with a single enteric fever agent in 63 persons (9.1%) with the following order of frequency : S.typhi (5.2%), S. paratyphi A (2.9%) and S. Paratyphi B. (1.01%). 2--The distribution of the group with rise of only one or two "H" agglutinins, by age, sex and locality is discussed. Apparently there is an initial high rate in the first year of life that declines in the age group 1--5 years to increase in the age group 6--9 years and the older age groups.