In Canada, during 19931996 there were 29,670 lnboratory reported cases o/ Salmonella infections. The frequency of the five most common Salmonella seroîypes from human sources were as follows: S. Typhimurium I8.9Vo, S. Enteritidis I5.5Vo, S. Hadar B.3Vo, S. Heidelberg 7.9Vo and S. Thompson 3.2Vo. Although the rank and frequency of these serotypes varied from year to yea,; these five coûunon serotypes comprised 5 j.8Vo of the total Salmorlella serotypes isolated in Canada during 1993-1996. S. Heidelb erg ranked fi.rst at 20.17o (2'343/11,657) among nonhuman sources, followed by S. Hadar ar I2.5Eo (1,458/11,657). In addition to these, during this period tvvo new Salmonella serotyPes identified by LCDC were designated by the Institut Pasteur: S. Surrey isolatedfrom a patient involving travel to India and S' Taiping isolated lrom dried fish maw from Hong Kong. Recently, there has been an increase of salmonellosis in humans, which has been associated with exotic pets. From 1993 to 1995, an estimated 3Vo to SVo of all human cases were associated with exposure to exotic pets, including iguanas, pet turtles, sugar gliders and hedgehogs. During this period, 188 outbrealc belonging to various SaImonella serotypes were invesîigated. The major outbreaks belonged to the following serotypes: S. Enteritidis, S. Newport, S. Stanley, and S. Typhimurium. A stu.dy of outbrealcs and animal-host associations of the various serotypes by phngetyping indicated that contaminated poultry, eggs, alfalfa sprouts and bovine products appeared to be the common sources of human infections in Canada. During this period, there has been an increased number of cases o/S. Typhimurium phagetype (PT) 104, commonly known as definite type (DT) 104 (3 in 1993 to 144 in 1996) and they were found to be singularly or multiresistant to the fonowing anrtbiotics: ampicillin, chloramphenicol, streptomycin, sulphonamide and tetracycline (R-type ACSSuT). One episode of 10 cases o/ S. Tlphimuùtm DTI04, R-type ACSSuT occurred in 1995 was acquiredfrom contaminated meat. Monitoring o/S. Typhimvfum DT104 during 1995 antl 1996 revealed that R-type ACSSuT increasedfrom 38.3Vo in 1995 to 65Vo in 1996. Surveillance and hazard identification using phenotypic markers provide valuable epidemiological information on the incidence, trends and riskfactors related to outbreaks and clinical cases associated with Salmonella infections. *National Laboratory for Enteric Pathogens, Bureau of Microbiology, Inboratory Centre for Disease Control, Tunney's Pasture, Ottawa, Ontario, Canada INTRODUCTION Salmonellosis is one of 'the most impoftant public health disease problems, affecting more people and animals than any other single diseasel. In Canada, 234 Typhoid Fever and other Salmonellosis there was a total of 8057 laboratory-confirmed cases of salmonellosis in 1993,1324 cases in 1994,7138 cases in 19952, and 7319 cases in 1996. The incidence of human cases of salmonellosis is thought to be many times greater than the number of reported and confirmed cases, even in countries with well-organized surveillance activitiesl. In fact, it is estimated that each year in Canada alone, salmonellosis affects 2.4Vo of the total population, an equivalent of 627 ,200 cases of illness3. There can be little disagreement that with the impact of cost on medical care and the loss of productivity, salmonellosis is a very real and underestimated probleml. Surveillance activities of the National Laboratory for Enteric Pathogens involve the collection of national data on salmonellosis from federal, provincial, territorial and public health agencies. Monthly data representing cases of human disease and nonhuman isolates are analysed and disseminated in a timely fashion to health care professionals both nationally and internationally. National data can be used to investigate, identify and control outbreaks, monitor the trends of disease over time, determine risk factors, and detect emerging or re-emerging trends such as multiple drug resistance. In this study, the prevalence of Salmonella serotypes and phage types is examined. METHODS AND MATERIALS The Salmonellct cultures were submitted for identification, serotyping and for phage-typing by various Med J Indones provincial public health laboratories, federal laboratories and veterinary laboratories across Canada. Serotyping: All serotypes were identified using the typing schemes published by rhe World Health Organizationa. Phage typing: The standard Phage-typing technique described by Anderson and V/illiams5 was employed throughout this investigation. Phages and typing schemes were developed at LCDC (Table 4), or were obtained from the International Collaborating Centre for Enteric Phage typing, Central Public Health Laboratory, Colindale (UK). RESULTS AND DISCUSSION During the four-year period (1993 1996), a total of 41,327 Salmonellae isolated from human and nonhuman sources were reported in Canada through a nationwide surveillance system of the National Enteric Reference Centre, LCDC. Of the total,29,670 Salmonellae were isolated from human sources and the remaining 11,651 were isolated from nonhuman sources. In each of these years, increasing isolations of a few serotypes (Salmonella Typhimurium, ,S. Hadar, S. Enteritidis, S. Heidelberg) resulted in an increased number of cases in the annual total of reported cases of salmonellosis2. During the four-year period, the l0 most common serotypes accounted for 6l.6Vo (18.252) of the human isolates and 60.OVo (6993) of the nonhuman isolates (Table 1). Though the yearly rank offrequency ofthe Thble l. Ten Most Common SalmoneLla Serotypes Isolated in Canada From Human & Non-human Sources (1993-1996) Rank Human No. of Isolates* (%) Non-human No. of Isolates* (7o)

ABSTRACTA competitive enzyme immunoassay using a murine monoclonal antibody M105 directed against a genus‐specific epitope in the Salmonella lipopolysaccharide was used to identify over 200 strains of Salmonella submitted to the National Laboratory for Enteric Pathogens. The immunoassay rapidly identified 208 strains of Salmonella representative of subspecies I, II, IIIa, IIIb, IV, and V, including 89 different serotypes from 26 O serogroups. The competitive enzyme immunoassay did not give positive results with 3 strains of Citrobacter freundii and 4 strains of Escherichia coli which were submitted to our laboratory as suspect Salmonella.