(Press-News.org) 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.
Salmonella 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 salmonella infections rose by 170% in the UK, driven primarily by an epidemic of Salmonella Enteritidis which peaked in 1993. A raft of control measures were introduced into the poultry industry including movement restrictions, compulsory slaughter and disinfection procedures, as well as a voluntary industry-led vaccination scheme that began in breeding flocks in 1994 and in laying flocks in 1998.
Legislation requiring compulsory slaughter of poultry infected with Salmonella has now been revoked but the mass vaccination of poultry has continued by those breeders subscribing to the Lion Quality Code of Practice and using the Lion Mark on eggs.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 mandatory vaccination 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 Global Health, 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 (1) to 0.2 cases per 1,000 person years for the same study conducted from 2008 to 2009 (2).
"In addition, the number of laboratory-confirmed cases of illness dropped from more than 18,000 in 1993 to just 459 in 2010 (3).
"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.
Notes to editors:
1. Tam CC, Rodrigues LC, Viviani L et al. Longitudinal study of infectious intestinal disease in the UK (IID2 study): incidence in the community and presenting to general practice. Gut 2012; 61(1): 69-77.
2. Wheeler JG, Sethi D, Cowden JM et al. Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance. The Infectious Intestinal Disease Study Executive. BMJ 1999; 318(7190): 1046-5
3. Laboratory reports of human Salmonella cases in the UK, 1981 to 2010 – Health Protection Agency; Health Protection Scotland; Public Health Agency of Northern Ireland
4. The University of Liverpool is one of the UK's leading research institutions with an annual turnover of £410 million, including £150 million for research. Liverpool is ranked in the top 1% of higher education institutions worldwide and is a member of the Russell Group. Visit www.liv.ac.uk or follow us on twitter at: http://www.twitter.com/livuninews. END
Vaccination responsible for dramatic fall in Salmonella infections
2013-01-16
ELSE PRESS RELEASES FROM THIS DATE:
Genetics plays major role in victimization in elementary school
2013-01-16
This press release is available in French.
Quebec City, January 16, 2013—Genetics plays a major role in peer rejection and victimization in early elementary school, according to a study recently published on the website of the journal Child Development by a team directed by Dr. Michel Boivin, a research professor at Université Laval's School of Psychology.
To come to this conclusion, Boivin and his team tested over 800 twins at three time points: when they were in kindergarten, Grade 1, and Grade 4. This sample consisted of 41% monozygotic twins—"true" twins who share ...
Breast cancer mortality has not declined in women over 85
2013-01-16
Since 1992 the number of deaths linked to breast cancer in Spain has decreased among young and middle aged patients but not among the elderly. Spanish researchers also predict that it will continue to decline over the next decade, although more slowly as observed up until now.
A new study headed by a team of Spanish researchers has analysed breast cancer mortality in Spain among different age groups from 1981 to 2007, setting a valid prediction up until 2023.
Studying this age-related tendency is interesting because any improvement could have significant social and ...
Paging Dr. Charles Dickens!
2013-01-16
Charles Dickens' tales are filled with immortal characters — think of A Christmas Carol's Scrooge and Great Expectations' Miss Havisham. But more than whims of literary invention, his characters and plots often deal with the difficult social realities of Victorian England. His portrayal of the disabled — both in terms of medicine and the social discrimination they faced — is no exception.
"Social attitudes towards the disabled can often be traced through art, from ancient times through today," explains Prof. Avi Ohry of Tel Aviv University's Sackler Faculty of Medicine, ...
Computational methods reveal how hospital-acquired bacteria spread
2013-01-16
Scientists at the Academy of Finland's Centre of Excellence in Computational Inference Research have developed novel computational methods that have yielded essential knowledge of how hospital-acquired bacteria spread and develop. These new methods, based on randomised algorithms, make it possible to analyse extensive genomic data significantly faster and more efficiently than previously. By applying these results, it is possible to better follow hospital-acquired infections in the future, or even fight them in real time.
The new methods are used to develop models of ...
New UMass Amherst research shows fishways have not helped fish
2013-01-16
AMHERST, Mass. – Despite modern designs intended to allow migratory fish to pass, hydropower dams on major Northeast U.S. waterways, including the Merrimack and Connecticut rivers, have failed to let economically important species such as salmon, shad and river herring reach their spawning grounds, say a team of economists and fish ecologists including Adrian Jordaan of the University of Massachusetts Amherst.
This raises serious questions about the impact of new dams now being planned and constructed on major waterways worldwide, say the researchers in the current ...
Engineer making rechargeable batteries with layered nanomaterials
2013-01-16
MANHATTAN, Kan. -- A Kansas State University researcher is developing more efficient ways to save costs, time and energy when creating nanomaterials and lithium-ion batteries.
Gurpreet Singh, assistant professor of mechanical and nuclear engineering, and his research team have published two recent articles on newer, cheaper and faster methods for creating nanomaterials that can be used for lithium-ion batteries. In the past year, Singh has published eight articles -- five of which involve lithium-ion battery research.
"We are exploring new methods for quick and cost-effective ...
U of T and Harvard study finds growing 'weight extremes' in the developing world
2013-01-16
Obese and overweight people are gaining weight rapidly in low-and middle-income countries while those who are severely undernourished are not experiencing similar weight gains, according to a University of Toronto and Harvard School of Public Health study.
This growing divide may force governments in the developing world to care for people who fall dramatically short on their calorie intake while simultaneously treating health problems associated with obesity, including diabetes and heart disease.
"One might think that as a country grows economically, the majority of ...
Study finds a new culprit for epileptic seizures
2013-01-16
CAMBRIGDE, MA -- Epileptic seizures occur when neurons in the brain become excessively active. However, a new study from MIT neuroscientists suggests that some seizures may originate in non-neuronal cells known as glia, which were long believed to play a mere supporting role in brain function.
In a study of fruit flies, the researchers identified a glial-cell mutation that makes the flies much more prone to epileptic seizures. Mutations in the gene, which influences glial cells' communication with neurons, appear to make neurons much more excitable. That excitability ...
New Antarctic geological timeline aids future sea-level predictions
2013-01-16
Radiocarbon dates of tiny fossilised marine animals found in Antarctica's seabed sediments offer new clues about the recent rapid ice loss from the West Antarctic Ice Sheet and help scientists make better predictions about future sea-level rise. This region of the icy continent is thought to be vulnerable to regional climate warming and changes in ocean circulation.
Reporting this month in the journal Geology a team of researchers from British Antarctic Survey (BAS), the Alfred Wegener Institute for Polar and Marine Research (AWI) and the University of Tromsø presents ...
Yaks are back
2013-01-16
NEW YORK (January 16, 2013) — A team of American and Chinese conservationists from the Wildlife Conservation Society and University of Montana recently counted nearly 1,000 wild yaks from a remote area of the Tibetan-Qinghai Plateau. The finding may indicate a comeback for this species, which was decimated by overhunting in the mid 20th century.
The team counted 990 yaks in a rugged area called Hoh Xil – a national nature reserve nearly the size of West Virginia but devoid of people. The remote region lies in the mid-eastern Tibetan-Himalayan highlands, home to some ...