1967 Volume 20 Issue 6 Pages 447-460
In order to elucidate the typhoid and paratyphoid B phage type distributions in Japan, during the period of 1956-1965, a total of 1, 808 typhoid cases from 1, 002 foci and 114 paratyphoid B cases from 87 foci were submitted for phage typing of their infected organisms, and the following results were obtained.
1. The typhoid strains tested fell into at least 30 Vi-phage types. The sequence of frequency as counted by foci was as follows : types D2 (20%), M1 (13%), E1 (12%), A (7.8%), N+D1 (7.4%), D1 (2.9%), D6 (2.8%), B2 (2.7%), 39 (1.5%), H (1.1%), J1 and 46 (0.80%) ; C5, L1 and 41 (0.50%) ; B1, B3, C4, D4, D10, E2, E4, E9, L2, T, 28, 29, 36, 38 and 47 (less than 0.50%) . Distri-bution of typhoid Vi-phage types in Japan was characteristic of preponderance of types D2 and M1.
2. Of the foci studied, 5.3% could not be assigned that their causative organisms belonged to any hitherto recognized Vi-phage type.
3. The prevalent typhoid Vi-phage types, D2, M1, E1, A and N+D1 were evenly encountered throughout the last ten years and distributed among almost throughout the country.
4. Some of the rearly recognized typhoid Vi-phage types were indigenous to the relatively limited areas.
5. Three new Vi-phage types, 39, 41 and 47 were identified.
6. Paratyphoid B phage types encountered were as follows: Types 3a (49%), 1 (33%), 3b (5.7%), Dundee (2.3%), 3aI (1.1%) and Beccles (1.1%) . The remainders could not he assigned to any known type.
