Vaccination responsible for dramatic fall in salmonella infections

Vaccination responsible for dramatic fall in salmonella infections
Mass poultry vaccination programmes introduced to combat Salmonella infections have led to a dramatic fall in the number of cases.

Mass poultry vaccination programmes introduced to combat Salmonella infections have led to a dramatic fall in the number of cases since the late 1990s, according to a researcher at the University of Liverpool.

are important food-borne pathogens worldwide, causing diarrhoea, vomiting, nausea, fever and abdominal pain. There are currently around 6 million cases of illness from Salmonella across the EU each year, the majority of which are linked to food items such as eggs, chicken, beef, pork, salad vegetables and dairy products.

Between 1981 and 1991, the number of rose by 170% in the UK, driven primarily by an epidemic of Salmonella Enteritidis which peaked in 1993. A raft of were introduced into the including movement restrictions, compulsory slaughter and disinfection procedures, as well as a voluntary industry-led vaccination scheme that began in breeding in 1994 and in laying flocks in 1998.

Code of practice

Legislation requiring compulsory slaughter of poultry infected with Salmonella has now been revoked but the of poultry has continued by those breeders subscribing to the Lion Quality Code of Practice and using the Lion Mark on eggs. The code of practice requires of all young hens destined to lay Lion eggs against Salmonella, as well as traceability of hens, eggs and feed, a best-before date stamped on shells and hygiene controls at packing stations. Lion eggs now account for around 85% of the total market.

Sarah O'Brien, Professor of Epidemiology and Zoonoses, from the University's Institute of Infection and , attributes a dramatic fall in the number of Salmonella cases in humans to this mass vaccination programme in poultry.

Professor O'Brien said: "We have seen a marked decline in the number of incidences of Salmonella infection, shown by two significant studies conducted 10 years apart. These studies found that the number of cases fell from 1.6 cases per 1,000 person years for a study conducted from 1993 to 1996 to 0.2 cases per 1,000 person years for the same study conducted from 2008 to 2009.

"In addition, the number of laboratory-confirmed cases of illness dropped from more than 18,000 in 1993 to just 459 in 2010.

"The nature of public health interventions often means that evaluating their impact is complex as they are often implemented simultaneously. The decrease in laboratory confirmed human cases coincides quite closely with the introduction of vaccination programmes in breeder and laying flocks. It is probable that no single measure contributed to the decline in Salmonella cases but the relationship between vaccination programmes and the reduction in human disease is compelling and suggests these programmes have made a major contribution to improving public health."

The research is published in Clinical Infectious Diseases.

add to favorites email to friend print save as pdf

Related Stories

Phagevet-P: Applying viruses to treat bacterial diseases

Sep 20, 2012

The quest for enhanced food safety has driven research into novel treatments for bacterial diseases in livestock. A European consortium proposed the use of bacteriophages (bacteria-targeting viruses) to treat ...

Salmonella in garden birds responsive to antibiotics

Jun 02, 2008

Scientists at the University of Liverpool have found that Salmonella bacteria found in garden birds are sensitive to antibiotics, suggesting that the infection is unlike the bacteria found in livestock and humans.

Recommended for you

Can robots help stop the Ebola outbreak?

4 hours ago

The US military has enlisted a new germ-killing weapon in the fight against Ebola—a four-wheeled robot that can disinfect a room in minutes with pulses of ultraviolet light.

New bird flu case in Germany

4 hours ago

A worrying new strain of bird flu has been observed for the first time in a wild bird in northern Germany, the agriculture ministry said Saturday.

Mali announces new Ebola case

Nov 22, 2014

Mali announced Saturday a new case of Ebola in a man who is fighting for his life in an intensive care unit in the capital Bamako.

Plague outbreak kills 40 in Madagascar: WHO

Nov 22, 2014

An outbreak of plague has killed 40 people in Madagascar, the World Health Organization said, warning that the disease could spread rapidly in the country's densely populated capital Antananarivo.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.