Study of the pattern of Widal test in infants and children; II. Pattern of Widal test in children with enteric fevers. An attempt to define the diagnostic titer for upper Egypt

Abstract

The study embodied 45 children with enteric fevers proved by bacteriological culture of blood, stools and urine and 20 children with rheumatic fever. Widal test was done for the rheumatic fever cases and was done repeatedly at weekly intervals for the enteric fever cases. The clinical features of children with enteric fevers was discussed. By contrasting the results of Widal test in children with enteric fever with the results in apparently normal infants and children from the same locality, a minimal diagnostic dual Widal titer was suggested. This combines "O" agglutinin in a titer of 1/160 provided that the other "H" agglutinins are at a lower titer. This suggested diagnostic titer improved the specificity of Widal test. This titer is encountered only in 0.58% of normal individuals and in none of 20 children with rheumatic fever. This titer also yielded an excellent sensitivity to diagnose actual enteric fever cases reaching up to 93.3%. Bacterial isolates from enteric fever cases were S. typhi in 55.5%, S. paratyphi A in 33.3% and S. paratyphi B in 11.1%. Chloramphenicol therapy resulted in a higher cure rate and a more rapid defervescence than ampicillin therapy. Regarding the effect of these antibiotic therapies on the rise of Widal agglutinin titers in children with enteric fevers there are two observations : 1--A four fold rise, is uncommon. A two fold rise is the common finding. 2--There is no consistent difference between chloramphenicol and ampicillin as regards their effect on the rise of agglutinin titers.