Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-26T11:53:53.006Z Has data issue: false hasContentIssue false
  • English
  • Français

Egg-borne infections of humans with salmonella: not only an S. enteritidis problem

Published online by Cambridge University Press:  27 February 2014

E.J. THRELFALL ,
J. WAIN ,
T. PETERS ,
C. LANE ,
E. DE PINNA ,
C.L. LITTLE ,
A.D. WALES  and
R.H. DAVIES
E.J. THRELFALL*
Affiliation:
Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom
J. WAIN
Affiliation:
Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom
T. PETERS
Affiliation:
Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom
C. LANE
Affiliation:
Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom
E. DE PINNA
Affiliation:
Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom
C.L. LITTLE
Affiliation:
Gastrointestinal, Emerging and Zoonotic Infections, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, United Kingdom
A.D. WALES
Affiliation:
Animal Health and Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom
R.H. DAVIES
Affiliation:
Animal Health and Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom
*
Corresponding author: e.j.threlfall@btinternet.com
Get access

Abstract

The principal salmonella serovar associated with infections linked to eggs and egg products in the UK, most European countries and North America is Salmonella enteritidis. However, other serovars have also been implicated in a number of egg-associated outbreaks, most notably S. typhimurium exhibiting a range of phage types. The present article reviews human egg-associated salmonellosis associated with non-S. enteritidis serovars, predominantly in the European Union (EU) but also world-wide, using information from published literature and epidemiological databases. There are also brief reviews of S. enteritidis and of mechanisms leading to egg contamination by salmonella. The numbers of egg-associated infections caused by non-S. enteritidis serovars are fairly substantial (for example 22% of outbreaks and 11.5% of more than 20,000 cases in the EU in 2008), and such infections have resulted in hospitalisations and deaths. Furthermore, in parts of the world where S. enteritidis historically has not penetrated laying hen breeding flocks, egg-related salmonellosis is a problem associated specifically with non-S. enteritidis serovars. Control measures to limit the incidence of S. enteritidis and S. typhimurium in poultry flocks are vital. It is therefore important that close surveillance of salmonellosis incidence and serovars in laying flocks is used to establish suitable biosecurity and vaccination programmes throughout EU Member States and elsewhere.

Keywords

Salmonellaegg-related infectionsS. enteritidisS. typhimuriumcontrol
Type
Review Article
Information
World's Poultry Science Journal , Volume 70 , Issue 1 , March 2014 , pp. 15 - 26
Copyright
Copyright © World's Poultry Science Association 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

ANON. (2002) Public health investigation of salmonella enteritidis in raw shell eggs. CDR Weekly 12: 3-5. http://www.hpa.org.uk/cdr/archives/back_issues_list.htm (accessed 23rd Aug 2010).Google Scholar
ANON. (2003) Commission Regulation (EC) No 2295 ⁄ 2003 of 23 December 2003 introducing detailed rules for implementing Council Regulation (EEC) No 1907 ⁄ 90 on certain marketing standards for eggs. Official Journal of the European Union L340: 16-34.Google Scholar
ARNEDO, A., BELLIDO, J.B., PAC, M.R., CRIADO, J., USERA, M.A., MESANZA, I., GONZALEZ, F., PEREZ, R. and CORTES, J.M. (1998) Brotes epidemicos de salmonelosis por consumo de huevos [Epidemic outbreaks of salmonellosis caused by eating eggs]. Enfermedades Infecciosas y Microbiologia Clinica 16: 408-412.Google Scholar
ASEFFA, A., MENGISTU, G. and TIRUNEH, M. (1994) salmonella newport: outbreak of food poisoning among college students due to contaminated undercooked eggs. Ethiopian Medical Journal 32: 1-6.Google Scholar
BARNHART, H.M., DREESEN, D.W., BASTIEN, R. and PANCORBO, O.C. (1991) Prevalence of salmonella enteritidis and other serovars in ovaries of layer hens at time of slaughter. Journal of Food Protection 54: 488-491.Google Scholar
BAUMLER, A.J., HARGIS, B.M. and TSOLIS, R.M. (2000) Tracing the origins of salmonella outbreaks. Science 287: 50-52.Google Scholar
BRAUN, P., MAYER, K. and FEHLHABER, K. (2002) Breaking procedure as an important way of contamination of the liquid egg product with salmonella enteritidis. Archiv Für Lebensmittelhygiene 53: 124-126.Google Scholar
BROUGHTON, E.I., HEFFERNAN, H.M. and COLES, C.L. (2010) salmonella enterica serotypes and antibiotic susceptibility in New Zealand, 2002-2007. Epidemiology and Infection 138: 322-329.Google Scholar
CARRAMIÑANA, J.J., HUMBERT, F., ERMEL, G. and COLIN, P. (1997) Molecular epidemiological investigation of salmonella typhimurium strains related to an egg-borne outbreak. Research in Microbiology 148: 633-636.Google Scholar
CARRIQUE-MAS, J.J., BRESLIN, M., SNOW, L., ARNOLD, M.E., WALES, A., MCLAREN, I. and DAVIES, R.H. (2008) Observations related to the salmonella EU layer baseline survey in the United Kingdom: follow-up of positive flocks and sensitivity issues. Epidemiology and Infection 136: 1537-1546.Google Scholar
CARRIQUE-MAS, J.J., BRESLIN, M., SNOW, L., MCLAREN, I., SAYERS, A.R. and DAVIES, R.H. (2009) Persistence and clearance of different salmonella serovars in buildings housing laying hens. Epidemiology and Infection 137: 837-846.Google Scholar
CDC (2008) salmonella surveillance: annual summary, 2006. US Department of Health and Human Services Centers for Disease Control. (Atlanta, Georgia, USA). http://www.cdc.gov/ncidod/dbmd/phlisdata/Salmonella.htm.Google Scholar
CHAPMAN, P.A., RHODES, P. and RYLANDS, W. (1988) salmonella typhimurium phage type 141 infections in Sheffield during 1984 and 1985: association with hens' eggs. Epidemiology and Infection 101: 75-82.Google Scholar
CHEMALY, M., HUNEAU-SALAUN, A., LABBE, A., HOUDAYER, C., PETETIN, I. and FRAVALO, P. (2009) Isolation of salmonella enterica in laying-hen flocks and assessment of eggshell contamination in France. Journal of Food Protection 72: 2071-2077.CrossRefGoogle ScholarPubMed
CHITTICK, P., SULKA, A., TAUXE, R.V. and FRY, A.M. (2006) A summary of national reports of foodborne outbreaks of salmonella Heidelberg infections in the United States: clues for disease prevention. Journal of Food Protection 69: 1150-1153.Google Scholar
CORKISH, J.D., DAVIES, R.H., WRAY, C. and NICHOLAS, R.A.J. (1994) Observations on a broiler breeder flock naturally infected with salmonella enteritidis phage type 4. Veterinary Record 134: 591-594.CrossRefGoogle ScholarPubMed
COX, N.A., DAVIS, B.H., WATTS, A.B. and COLMER, A.R. (1973) salmonella in the laying hen. 1. salmonella recovery from viscera, feces and eggs following oral inoculation. Poultry Science 52: 661-666.Google Scholar
COX, N.A., BERRANG, M.E. and CASON, J.A. (2000) salmonella penetration of egg shells and proliferation in broiler hatching eggs - a review. Poultry Science 79: 1571-1574.Google Scholar
COYLE, E.F., PALMER, S.R., RIBEIRO, C.D., JONES, H.I., HOWARD, A.J., WARD, L. and ROWE, B. (1988) salmonella enteritidis phage type 4 infection: association with hen's eggs. Lancet 332: 1295-1297.Google Scholar
DAVIES, R. and BRESLIN, M. (2003) Observations on salmonella contamination of commercial laying farms before and after cleaning and disinfection. Veterinary Record 152: 283-287.Google Scholar
DAVIES, R. and BRESLIN, M. (2004) Observations on salmonella contamination of eggs from infected commercial laying flocks where vaccination for salmonella enterica serovar enteritidis had been used. Avian Pathology 33: 135-146.CrossRefGoogle ScholarPubMed
DE BUCK, J., VAN IMMERSEEL, F., HAESEBROUCK, F. and DUCATELLE, R. (2004) Colonization of the chicken reproductive tract and egg contamination by Salmonella. Journal of Applied Microbiology 97: 233-245.Google Scholar
DEFRA (2010) Zoonoses report United Kingdom 2008. Department for Environment Food and Rural Affairs. (London, Defra). http://www.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/zoonoses/reports.htm (accessed 23rd Aug 2010).Google Scholar
DOORDUYN, Y., VAN DEN BRANDHOF, W.E., VAN DUYNHOVEN, Y., WANNET, W.J.B. and VAN PELT, W. (2006) Risk factors for salmonella enteritidis and typhimurium (DT104 and non-DT104) infections in The Netherlands: predominant roles for raw eggs in enteritidis and sandboxes in typhimurium infections. Epidemiology and Infection 134: 617-626.Google Scholar
DYDA, A., HUNDY, R., MOFFATT, C.R.M. and CAMERON, S. (2009) Outbreak of salmonella typhimurium 44 related to egg consumption. Communicable Diseases Intelligence 33: 414-418.Google Scholar
EFSA (2007a) The Community summary report on trends and sources of zoonoses, zoonotic agents, antimicrobial resistance and foodborne outbreaks in the European Union in 2006. EFSA Journal 130.Google Scholar
EFSA (2007b) Report of the task force on zoonoses data collection on the analysis of the baseline study on the prevalence of salmonella in holdings of laying hen flocks of Gallus gallus. EFSA Journal 97.CrossRefGoogle Scholar
EFSA (2009a) The Community Summary report on food-borne outbreaks in the European Union in 2007. EFSA Journal 271.Google Scholar
EFSA (2009b) Quantitative estimation of the impact of setting a new target for the reduction of salmonella in breeding hens of Gallus gallus. EFSA Journal 1036: 1-68.Google Scholar
EFSA (2010a) The Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and food-borne outbreaks in the European Union in 2008. EFSA Journal 8: 1496.Google Scholar
EFSA (2010b) Scientific Opinion on a quantitative estimate of the public health impact of setting a new target for the reduction of salmonella in laying hens. EFSA Journal 8: 1546.Google Scholar
FOLEY, S.L., NAYAK, R., HANNING, I.B., JOHNSON, T.J., HAN, J. and RICKE, S.C. (2011) Population dynamics of salmonella enterica serotypes in commercial egg and poultry production. Applied and Environmental Microbiology 77: 4273-4279.CrossRefGoogle ScholarPubMed
FSA (2004) Report of the survey of salmonella contamination of UK produced shell eggs on retail sale. U. Food Standards Agency. http://www.food.gov.uk/science/surveillance/fsis2004branch/fsis5004eggs (accessed 11th April 2011).Google Scholar
GANTOIS, I., EECKHAUT, V., PASMANS, F., HAESEBROUCK, F., DUCATELLE, R. and VAN IMMERSEEL, F. (2008) A comparative study on the pathogenesis of egg contamination by different serotypes of Salmonella. Avian Pathology 37: 399-406.Google Scholar
GARBER, L., SMELTZER, M., FEDORKA-CRAY, P., LADELY, S. and FERRIS, K. (2003) salmonella enterica serotype enteritidis in table egg layer house environments and in mice in US layer houses and associated risk factors. Avian Diseases 47: 134-142.CrossRefGoogle ScholarPubMed
GAST, R.K., GUARD-PETTER, J. and HOLT, P.S. (2002) Characteristics of salmonella enteritidis contamination in eggs after oral, aerosol, and intravenous inoculation of laying hens. Avian Diseases 46: 629-635.CrossRefGoogle ScholarPubMed
GREIG, J.D. and RAVEL, A. (2009) Analysis of foodborne outbreak data reported internationally for source attribution. International Journal of Food Microbiology 130: 77-87.Google Scholar
GUAN, J., GRENIER, C. and BROOKS, B.W. (2006) In vitro study of salmonella enteritidis and salmonella typhimurium definitive type 104: survival in egg albumen and penetration through the vitelline membrane. Poultry Science 85: 1678-1681.Google Scholar
HALL, R. (2002) Outbreak of gastroenteritis due to salmonella typhimurium phage type I 35a following consumption of raw egg. Communicable Diseases Intelligence 26: 285-287.Google ScholarPubMed
HATAKKA, M. (1992) salmonella outbreak among railway and airline passengers. Acta Veterinaria Scandinavica 33: 253-260.Google Scholar
HENNESSY, T.W., CHENG, L.H., KASSENBORG, H., AHUJA, S.D., MOHLE-BOETANI, J., MARCUS, R., SHIFERAW, B. and ANGULO, F.J. (2004) Egg consumption is the principal risk factor for sporadic salmonella serotype Heidelberg infections: a case-control study in FoodNet sites. Clinical Infectious Diseases 38 Suppl 3: S237-243.Google Scholar
HERIKSTAD, H., MOTARJEMI, Y. and TAUXE, R.V. (2002) salmonella surveillance: a global survey of public health serotyping. Epidemiology and Infection 129: 1-8.Google Scholar
HOGUE, A., WHITE, P., GUARD-PETTER, J., SCHLOSSER, W., GAST, R., EBEL, E., FARRAR, J., GOMEZ, T., MADDEN, J., MADISON, M., MCNAMARA, A.M., MORALES, R., PARHAM, D., SPARLING, P., SUTHERLIN, W. and SWERDLOW, D. (1997) Epidemiology and control of egg-associated salmonella enteritidis in the United States of America. Revue Scientifique et Technique de l'Office International Des Epizooties 16: 542-553.Google Scholar
HOOP, R.K. and POSPISCHIL, A. (1993) Bacteriological, serological, histological and immunohistochemical findings in laying hens with naturally acquired salmonella enteritidis phage type 4 infection. Veterinary Record 133: 391-393.Google Scholar
HPA (2011) All human isolates reported to the Health Protection Agency Centre for Infections. England and Wales, 2000-2010. UK Health Protection Agency. http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Salmonella/EpidemiologicalData/salmDataHuman/ (accessed February 25th 2013).Google Scholar
HUMPHREY, T.J., WHITEHEAD, A., GAWLER, A.H., HENLEY, A. and ROWE, B. (1991) Numbers of salmonella enteritidis in the contents of naturally contaminated hens' eggs. Epidemiology and Infection 106: 489-496.Google Scholar
ISSACK, M.I., HENDRIKSEN, R.S., LUN, P.L., LUTCHUN, R.K. and AARESTRUP, F.M. (2009) salmonella enterica serovar typhimurium in Mauritius linked to consumption of marlin mousse. Foodborne Pathogens and Disease 6: 739-741.CrossRefGoogle ScholarPubMed
KEENE, W.E., HEDBERG, K., CIESLAK, P., SCHAFER, S. and DECHET, A. (2004) salmonella serotype typhimurium outbreak associated with commercially processed egg salad - Oregon, 2003. Morbidity and Mortality Weekly Report 53: 1132-1134.Google Scholar
KELLER, L.H., BENSON, C.E., KROTEC, K. and ECKROADE, R.J. (1995) salmonella enteritidis colonization of the reproductive tract and forming and freshly laid eggs of chickens. Infection and Immunity 63: 2443-2449.Google Scholar
KIST, M.J. and FREITAG, S. (2000) Serovar specific risk factors and clinical features of salmonella enterica ssp. enterica serovar enteritidis: a study in South-West Germany. Epidemiology and Infection 124: 383-392.Google Scholar
LACONCHA, I., BAGGESEN, D.L., REMENTERIA, A. and GARAIZAR, J. (2000) Genotypic characterisation by PFGE of salmonella enterica serotype enteritidis phage types 1, 4, 6, and 8 isolated from animal and human sources in three European countries. Veterinary Microbiology 75: 155-165.Google Scholar
LISTER, S.A. (1988) salmonella enteritidis infection in broilers and broiler breeders. Veterinary Record 123: 350.Google Scholar
LITTLE, C.L., SURMAN-LEE, S., GREENWOOD, M., BOLTON, F.J., ELSON, R., MITCHELL, R.T., NICHOLS, G.N., SAGOO, S.K., THRELFALL, E.J., WARD, L.R., GILLESPIE, I.A. and O'BRIEN, S. (2007a) Public health investigations of salmonella enteritidis in catering raw shell eggs, 2002-2004. Letters in Applied Microbiology 44: 595-601.Google Scholar
LITTLE, C.L., WALSH, S., HUCKLESBY, L., SURMAN-LEE, S., PATHAK, K., GATTY, Y., GREENWOOD, M., DE PINNA, E., THRELFALL, E.J., MAUND, A. and CHAN, C.H. (2007b) Survey of salmonella contamination of non-United Kingdom-produced raw shell eggs on retail sale in the northwest of England and London, 2005 to 2006. Journal of Food Protection 70: 2259-2265.Google Scholar
LITTLE, C.L., RHOADES, J.R., HUCKLESBY, L., GREENWOOD, M., SURMAN-LEE, S., BOLTON, F.J., MELDRUM, R., WILSON, I., MCDONALD, C., DE PINNA, E., THRELFALL, E.J. and CHAN, C.H. (2008) Survey of salmonella contamination of raw shell eggs used in food service premises in the United Kingdom, 2005 through 2006. Journal of Food Protection 71: 19-26.Google Scholar
MARCUS, R., RABATSKY-EHR, T., MOHLE-BOETANI, J.C., FARLEY, M., MEDUS, C., SHIFERAW, B., CARTER, M., ZANSKY, S., KENNEDY, M., VAN GILDER, T. and HADLER, J.L. (2004) Dramatic decrease in the incidence of salmonella serotype enteritidis infections in 5 FoodNet sites: 1996-1999. Clinical Infectious Diseases 38 Suppl 3: S135-S141.Google Scholar
MASON, B.W., WILLIAMS, N., SALMON, R.L., LEWIS, A., PRICE, J., JOHNSTON, K.M. and TROTT, R.M. (2001) Outbreak of salmonella indiana associated with egg mayonnaise sandwiches at an acute NHS hospital. Communicable Disease and Public Health 4: 300-304.Google ScholarPubMed
MESSENS, W., GRIJSPEERDT, K. and HERMAN, L. (2005) Eggshell penetration by Salmonella: a review. World's Poultry Science Journal 61: 71-85.Google Scholar
MITCHELL, E., OMAHONY, M., LYNCH, D., WARD, L.R., ROWE, B., UTTLEY, A., ROGERS, T., CUNNINGHAM, D.G. and WATSON, R. (1989) Large outbreak of food poisoning caused by salmonella typhimurium definitive type 49 in mayonnaise. British Medical Journal 298: 99-101.Google Scholar
MIYAMOTO, T., BABA, E., TANAKA, T., SASAI, K., FUKATA, T. and ARAKAWA, A. (1997) salmonella enteritidis contamination of eggs from hens inoculated by vaginal, cloacal, and intravenous routes. Avian Diseases 41: 296-303.Google Scholar
MUMMA, G.A., GRIFFIN, P.M., MELTZER, M.I., BRADEN, C.R. and TAUXE, R.V. (2004) Egg quality assurance programs and egg-associated salmonella enteritidis infections, United States. Emerging Infectious Diseases 10: 1782-1789.CrossRefGoogle ScholarPubMed
MURRAY, C.J. (1994) salmonella serovars and phage types in humans and animals in Australia 1987-1992. Australian Veterinary Journal 71: 78-81.Google Scholar
NAKAMURA, M., NAGAMINE, N., NORIMATSU, M., SUZUKI, S., OHISHI, K., KIJIMA, M., TAMURA, Y. and SATO, S. (1993) The ability of salmonella enteritidis isolated from chicks imported from England to cause transovarian infection. Journal of Veterinary Medical Science 55: 135-136.Google Scholar
OKAMURA, M., KAMIJIMA, Y., MIYAMOTO, T., TANI, H., SASAI, K. and BABA, E. (2001a) Differences among six salmonella serovars in abilities to colonize reproductive organs and to contaminate eggs in laying hens. Avian Diseases 45: 61-69.Google Scholar
OKAMURA, M., MIYAMOTO, T., KAMIJIMA, Y., TANI, H., SASAI, K. and BABA, E. (2001b) Differences in abilities to colonize reproductive organs and to contaminate eggs in intravaginally inoculated hens and in vitro adherences to vaginal explants between salmonella enteritidis and other salmonella serovars. Avian Diseases 45: 962-971.Google Scholar
ORTEGA-BENITO, J.M. and LANGRIDGE, P. (1992) Outbreak of food poisoning due to salmonella typhimurium DT4 in mayonnaise. Public Health 106: 203-208.Google Scholar
OTOMO, Y., ABE, K., ODAGIRI, K., SHIROTO, A., TAKATORI, K. and HARA-KUDO, Y. (2007) Detection of salmonella in spent hens and eggs associated with foodborne infections. Avian Diseases 51: 578-583.Google Scholar
OZFOODNET WORKING GROUP (2002) Enhancing foodborne disease surveillance across Australia in 2001: the OzFoodNet Working Group. Communicable Diseases Intelligence 26: 375-406.Google Scholar
OZFOODNET WORKING GROUP (2003) Foodborne disease in Australia: incidence, notifications and outbreaks. Annual report of the OzFoodNet network, 2002. Communicable Diseases Intelligence 27: 209-243.Google Scholar
OZFOODNET WORKING GROUP (2006) Burden and causes of foodborne disease in Australia: Annual report of the OzFoodNet network, 2005. Communicable Diseases Intelligence 30: 278-300.Google Scholar
OZFOODNET WORKING GROUP (2007) Monitoring the incidence and causes of diseases potentially transmitted by food in Australia: Annual report of OzFoodNet Network, 2006. Communicable Diseases Intelligence 31: 345-365.Google Scholar
OZFOODNET WORKING GROUP (2008) Monitoring the incidence and causes of diseases potentially transmitted by food in Australia: Annual report of OzFoodNet Network, 2007. Communicable Diseases Intelligence 32: 400-424.Google Scholar
OZFOODNET WORKING GROUP (2009) Monitoring the incidence and causes of diseases potentially transmitted by food in Australia: Annual report of OzFoodNet Network, 2008. Communicable Diseases Intelligence 33: 389-413.Google Scholar
PADRON, M. (1990) salmonella typhimurium penetration through the eggshell of hatching eggs. Avian Diseases 34: 463-465.Google Scholar
POPPE, C., JOHNSON, R.P., FORSBERG, C.M. and IRWIN, R.J. (1992) salmonella enteritidis and other salmonella in laying hens and eggs from flocks with salmonella in their environment. Canadian Journal of Veterinary Research 56: 226-232.Google Scholar
POPPE, C., DUNCAN, C.L. and MAZZOCCO, A. (1998) salmonella contamination of hatching and table eggs: a comparison. Canadian Journal of Veterinary Research 62: 191-198.Google Scholar
SARNA, M., DOWSE, G., EVANS, G. and GUEST, C. (2002) An outbreak of salmonella typhimurium PTI35 gastroenteritis associated with a minimally cooked dessert containing raw eggs. Communicable Diseases Intelligence 26: 32-37.Google Scholar
SLINKO, V.G., MCCALL, B.J., STAFFORD, R.J., BELL, R.J., HILEY, L.A., SANDBERG, S.M., WHITE, S.A. and BELL, K.M. (2009) Outbreaks of salmonella typhimurium phage type 197 of multiple genotypes linked to an egg producer. Communicable Diseases Intelligence 33: 419-425.Google Scholar
STEPHENS, N., SAULT, C., FIRESTONE, S.M., LIGHTFOOT, D. and BELL, C. (2007) Large outbreaks of salmonella typhimurium phage type 135 infections associated with the consumption of products containing raw egg in Tasmania. Communicable Diseases Intelligence 31: 118-124.Google Scholar
STEPHENS, N., COLEMAN, D. and SHAW, K. (2008) Recurring outbreaks of salmonella typhimurium phage type 135 associated with the consumption of products containing raw egg in Tasmania. Communicable Diseases Intelligence 32: 466-468.Google Scholar
TAYLOR, D.N., BOPP, C., BIRKNESS, K. and COHEN, M.L. (1984) An outbreak of salmonellosis associated with a fatality in a healthy child: a large dose and severe illness. American Journal of Epidemiology 119: 907-912.Google Scholar
THRELFALL, E.J., FROST, J.A., WARD, L.R. and ROWE, B. (1990) Plasmid profile typing can be used to subdivide phage-type 49 of salmonella typhimurium in outbreak investigations. Epidemiology and Infection 104: 243-251.Google Scholar
TRIBE, I.G., COWELL, D., CAMERON, P. and CAMERON, S. (2002) An outbreak of salmonella typhimurium phage type 135 infection linked to the consumption of raw shell eggs in an aged care facility. Communicable Diseases Intelligence 26: 38-39.Google Scholar
VAN DE GIESSEN, A.W., AMENT, A.J. and NOTERMANS, S.H. (1994) Intervention strategies for salmonella enteritidis in poultry flocks: a basic approach. International Journal of Food Microbiology 21: 145-154.Google Scholar
VELGE, P., CLOECKAERT, A. and BARROW, P. (2005) Emergence of salmonella epidemics: the problems related to salmonella enterica serotype enteritidis and multiple antibiotic resistance in other major serotypes. Veterinary Research 36: 267-288.CrossRefGoogle ScholarPubMed
VIEIRA, A.R. (2009) WHO Global Foodborne Infections Network Country Databank – A resource to link human and non-human sources of Salmonella. ISVEE Conference. Durban, South Africa, 10-14 August 2009. http://www.who.int/gfn/activities/CDB_poster_Sept09.pdf.Google Scholar
WALES, A.D. and DAVIES, R.H. (2011) A critical review of salmonella typhimurium infection in laying hens. Avian Pathology 40: 429-436.Google Scholar
WARD, B., ANDREWS, R., GREGORY, J. and LIGHTFOOT, D. (2002) The use of sequential studies in a salmonellosis outbreak linked to continental custard cakes. Epidemiology and Infection 129: 287-293.Google Scholar
WEGENER, H.C., HALD, T., LO FO WONG, D., MADSEN, M., KORSGAARD, H., BAGER, F., GERNER-SMIDT, P. and MOLBAK, K. (2003) salmonella control programs in Denmark. Emerging Infectious Diseases 9: 774-780.Google Scholar
WHO (2010) Global Foodborne Infections Network (GFN) Country Databank. World Health Organisation. http://thor.dfvf.dk/gss (accessed 29th June 2010).Google Scholar