Laboratory Testing of Salmonella paratyphi A in Taiwan, 1987-1996
2000 Vol.16 NO.6
In Taiwan between 1987 and 1996, 45 sporadic cases of Salmonella paratyphi A were detected. The majority of cases, a total of 24, occurred in the year 1996, thus accounting for 53% of all cases. 33 cases (73%) were imported; 8 (18%) were local sporadic cases; and 4 (9%) were of unknown origin. Most imported cases were infected in Southeast Asia: 31% in Thailand, 27% in Indonesia, 7% on mainland China, and 2% each in Singapore, Malaysia, Cambodia, and Myanmar. The pathogenic agents of 37 cases (82.2%) were detected by blood culture, 6 (5 carriers) (13.3%) from feces, one each (2.2%) from bile and bone marrow. There were slightly more affected males than females; and more cases were in the 21-40 and 41-50 age groups. Of the five carriers, one was male, and the other four were female. Cases were detected in each month except February and November, with more cases in March through October. The 42 strains of Salmonella paratyphi A detected in the past ten years were tested with Bio-test No. 1 kit (Eiken, Japan). When electronic codes of the 21 biochemical characteristics obtained from the strains were converted into computer codes, the strains were found to belong to four biological types. The typical biological type of Salmonella paratyphi A had 35 strains; the other 7 strains belonged to the other three biological types. They differed from the typical biological type by only one or two characteristics.