Chicken vaccination programmes have helped dramatically slash instances of non-typhoidal Salmonella in the UK, according to a recent study.
The paper , titled ‘The “decline and fall” of non-typhoidal Salmonella in the United Kingdom’, has been published in the journal Clinical Infectious Diseases.
It plots how the fall in incidences of Salmonella cases has coincided with the introduction of measures including an industry-led vaccination programme in broiler-breeder and laying poultry flocks.
The report states: “The incidence of Salmonella has been falling since 1997 and levels of Salmonella have fallen to pre‐epidemic levels and have stayed low.
National surveillance statistics
“When Salmonella peaked in 1993 in the UK, over 18,000 laboratory‐confirmed cases of illness were recorded in national surveillance statistics, yet by 2010 this had fallen to just 459. Thus the decline in non‐typhoidal salmonellosis witnessed in the UK in recent years reflects this major contraction in reports of Salmonella.”
The report also found that, when analysing the source of outbreaks where raw shell eggs were involved, nearly 50% of foodborne Salmonella outbreaks occurred in the food service sector.
It notes there have been national outbreaks of Salmonella linked to imported raw shell eggs in recent years.
It concludes: “It is probable that no single measure contributed to the decline in S. Enteritidis PT4 and that the combination of measures was successful.
“But the temporal relationship between vaccination programmes and the reduction in human disease is compelling and suggests that these programmes have made a major contribution to improving public health.
“If success in public health is defined by illnesses averted then the story of Salmonella in the UK, which has come down and stayed down, is good news.”
Legislation and food safety advice introduced to combat a UK Salmonella enterica epidemic that peaked in 1993 had also helped to reduce the instances of Salmonella infection, said the researchers.
Food safety programmes
Andrew Joret, chairman of the British Egg Industry Council, welcomed the report, highlighting that the British Lion Scheme had led the food safety programmes introduced to crack down on Salmonella.
“This report further underlines the success of the British Lion Scheme in effectively eradicating Salmonella in UK eggs,” he said. “But it also highlights the importance of food manufacturers, retailers and caterers ensuring that they take extra care when purchasing eggs or egg products.
“This is even more important when you consider that illegally produced eggs, from non-compliant cages, are still being produced in the EU.”
- Source: ‘The “decline and fall” of non-typhoidal Salmonella in the United Kingdom’; Clin Infect Dis. (2012) doi: 10.1093/cid/cis967
Author: Sarah O’Brien, University of Liverpool, Institute of Infection & Global Health, National Consortium for Zoonosis Research, Leahurst Campus