EPIDEMIOLOGY OF AN UNUSUALLY PROLONGED OUTBREAK OF TYPHOID-FEVER IN TERRASSA, SPAIN

An unusually prolonged outbreak of typhoid fever, from 1988 to 1994, i n Terrassa (Barcelona, Spain), was caused by a casual food handler who was a carrier. The pattern of this outbreak suggested intermittent lo w-level exposure to Salmonella typhi. We found 70 patients with S. typ hi infections, 52 of whom were available for study. Medical records we re reviewed and patients were interviewed with use of a standard quest ionnaire. Phage typing and pulsed-held gel electrophoresis (PFGE) far strain subtyping were used to confirm the epidemiological data. The 27 outbreak strains shared the same phage type and the same PFGE pattern . Four sporadic strains shared the same phage type as the outbreak str ain. PFGE was found to be useful for differentiating strains for epide miological purposes.