Imported cases of chloramphenicol resistant Salmonella typhi.

The Institute of Medical Research has been the national centre for phage typing of Salmonella typhi since 1970. The antibiotic susceptibility pattern of all the isolates are also monitored simultaneously. The first case of chloramphenicol resistant S. typhi was isolated in 1978 and since then, these strains have occurred sporadically. For the years 1986 to 1990, all the strains sent for phage typing were sensitive to chloramphenicol. Then in 1991, between March to July, there was an outbreak of 18 cases of chloramphenicol resistant S. typhi in Selangor Darnl Ehsan. Although investigations carried out did not find a common source responsible for the outbreak, one of the cases was a visitor who came from southern India, whose isolate was of the same phage type and antibiogram pattern t.