Campylobacter reviewed
been published by scientists from North Carolina University, US.
The report coincides with a number of food scares related to the
safety of poultry.
The review, published in the Institute of Food Technologists, includes a description of the pathogen, distribution of the infection, how it spreads, and interventions to reduce infection. Campylobacter is the leading bacterial cause of human gastroenteritis in the US, with 40,000 cases and approximately 680 deaths documented annually.
Doses as low as 500 organisms have been reported to cause illness - equivalent to one drop of raw chicken juice. Campylobacter is routinely found in cattle, sheep, swine, and avian species.
The report says that avian species are the most common host, probably because of their higher body temperature. Research has shown that Campylobacter reach their highest populations on poultry during the warmer months when up to 97 per cent of samples tested were positive for C. jejuni. However Campylobacter outbreaks have also been associated with raw milk, contaminated water and contact with pets and farm animals.
There are several species of Campylobacter (C. jejuni, C. coli, C.lari and C. uppsaliensis) capable of causing human illness. C. jejuni is implicated in approximately 85 per cent of the cases with the remaining 15 per cent being caused by C. coli. These are referred to as thermophilic Campylobacters, being able to grow at 37oC - 42 oC.
C. jejuni has been shown to survive for more than 4 hours at 27 oC and 60 per cent to 62 per cent relative humidity on some common clean or soiled food contact surfaces. However, Campylobacter can be killed by heating to above 60 oC, and populations reduced but not eliminated by freezing. Although Campylobacter will not survive below a pH of 4.9, it is capable of growing in the pH range of 4.9 - 9.0, and grows optimally at pH 6.5 - 7.5.
The publication of the guide coincides with a number of food scares related to the safety of poultry. Last month for example, the Dutch government ordered the culling of 600 ducks on a farm after routine blood tests showed signs of antibodies to a mild strain of bird flu. There are fears of a return of the virus that devastated much of northern Europe's poultry industry last year.
The agriculture ministry said in a statement that it had decided to order the culling of the ducks after antibodies showed up which could indicate the birds were in contact with the contagious virus. A follow-up test has not confirmed an outbreak of bird flu but a further test was not able to rule out a mild strain of the virus.
The safety of chicken eggs in the UK has also been challenged. The UK's Soil Association claimed that as many as one in eight eggs may contain residues of a veterinary drug that are potentially harmful to humans.
The drug in question, lasalocid, is permitted in poultry raised for meat. But the Soil Association claims that tests on eggs by the UK government's veterinary medicines directorate show residues were found in 12 per cent of egg samples last year, up from 1 per cent in 1999. This means that consumers may be eating up to three million eggs a day containing residues.
Similar drugs have been reported to cause severe illness and death in livestock such as cattle, turkeys and sheep. The Soil Association says that although there is no direct evidence of potential poisonous effects on humans from lasalocid, checks have never been made.
"Publication of this new CFA Guidance is very timely bearing in mind recently publicised incidents involving unauthorised or banned veterinary residues," said Kaarin Goodburn, CFA's secretary general.
"We anticipate that this Guidance will prove to be aninvaluable reference tool for all involved in the chilled food chain, particularly as the European Commission is currently reviewing legislation in this area."
Consumption of under-cooked poultry and/or the handling of raw poultry are risk factors for human Campylobacter infection. Contamination occurs both on the farm and in poultry slaughter plants.
The rest of the article goes into some detail of the critical hazard points and how use of the Hazard Analysis and Critical Control Point HACCP system may reduce occurrence of the pathogen. The authors conclude that further effort is needed to design more efficient and effective washing systems at the processing plants.
