Fondue with chicken causes campylobacter infections in Switzerland

Meat fondue with chicken is one of the primary risk factors for a campylobacter infection in Switzerland in winter, a new study shows. At the end of each year, the reported case numbers of this severe intestinal infection increase in Switzerland. This increase over the festive season can be attributed to the consumption of Fondue chinoise.

In Switzerland, between 7000 and 8000 persons fall ill with a campylobacter infection annually. This makes it the most frequent bacterial disease transmitted through food. Contamination of chicken meat with campylobacter bacteria during the slaughtering process is one of the known causes of the infection. An increase of campylobacteriosis case numbers is being observed throughout Europe. Human cases of campylobacteriosis must be reported to the relevant authorities in Switzerland.

In Switzerland, an unusual increase in campylobacteriosis case numbers can be observed in the period around Christmas and New Year. Therefore, the Swiss Federal Office of Public Health, in agreement with the Swiss Federal Food Safety and Veterinary Office has commissioned Swiss TPH to perform a case control study in order to investigate this increase over the festive season.

"We are relying on data subject to reporting and telephone interviews with affected persons for this," study leader Daniel Mäusezahl of Swiss TPH says.

The researchers interviewed affected persons who had fallen ill with a campylobacter infection between December 2012 and February 2013. An independent laboratory examination had confirmed a campylobacter infection in all interviewed persons. The focus of the interviews was on risk factors, the consultation of a doctor and the course of the illness experienced by the affected persons.

Fourfold increased risk when consuming a meat fondue

The study identified two factors for an increased risk of infection with campylobacter pathogens. On the one hand, the risk of infection increased by a factor of four when consuming Fondue chinoise. About half of the notified campylobacteriosis cases over the Christmas and New Year period can be attributed to this source of infection.

The study also shows that the risk of infection can be decreased by hygienic measures at the table. As soon as the meat fondue consumers used compartmented or separate plates for raw and cooked meat, the risk of an infection decreased by a factor of up to five. Likewise, the risk of an infection decreased when consuming meat that had been previously frozen. "Campylobacter infections among consumers could be avoided to a large extent by employing the appropriate hygiene behaviour measures," Daniel Mäusezahl says.

Another risk factor for a campylobacter infection identified by the study was travelling abroad over the Christmas season. However, persons returning from a trip with diarrhea are tested more frequently for infection which might also explain this increased finding.

No harmless illness

Campylobacter infections are experienced as a severe illness by affected persons. On a scale from 1 "harmless" to 10 "very severe," half of the patients had rated the subjectively experienced symptoms with 8 or more points. Persons who have fallen ill primarily complained of diarrhea (98%), abdominal pain (81%), fever (66%), nausea (44%) and vomiting (34%). The patients stated an average duration of illness of seven days; about 15% were hospitalised.

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The above story is based on materials provided by Swiss Tropical and Public Health Institute . Note: Materials may be edited for content and length.

Food allergies: A new, simple method to track down allergens

Although food allergies are common, sufferers often don't know exactly what in foods cause their allergic reactions. This knowledge could help develop customized therapies, like training the body's immune system to respond to certain proteins found in foods. However, determining which protein in a food causes an allergic response to a patient requires time-consuming tests that often ignore rare or unexpected allergens. Publishing in Analytical Chemistry, EPFL scientists have developed a highly-sensitive method that can quickly and accurately identify the culprit proteins even at very low concentrations. The method has been successfully tested in the context of cow milk allergy.

Food allergies are becoming widespread in the Western world today, affecting around 6-8% of children and about 3% of adults. These types of allergies occur when the body's immune system mistakes a harmless food protein for a threat and attacks it as it would normally do with a bacterium or a virus. This causes symptoms like swelling, rashes, pain, and even life-threatening anaphylactic shocks.

Cow milk allergy is common among children, preventing them from breast feeding and drinking milk, although some outgrow the allergy by six years of age. Allergies, including food allergies, are caused when our immune system produces antibodies to destroy "enemy" molecules, like those from bacteria and viruses. In the case of milk allergies, the antibodies are called "IgE." Medical doctors can diagnose milk allergies by simply detecting an overproduction of IgE, but that does not tell them which one of the numerous proteins in milk -- and other foods -- is causing the allergic response.

The team of Hubert Girault at EPFL has developed a highly-sensitive method that uses a patient's IgE to determine specifically which protein induces allergic responses in them. The method uses a well-established technique called immunoaffinity capillary electrophoresis (IACE). First, IgE antibodies from the patient's blood are isolated by interaction with magnetic beads that are coated with a different type of antibody. The "bead" antibodies recognize and bind the patient's IgE antibodies. This takes place inside a long and narrow glass tube, only 50 micrometers in diameter, called a "capillary." The bound antibodies are then flushed out of the capillary and powerfully attached to the magnetic beads through a process called 'crosslinking', which keeps them from detaching. The beads with the patient's IgE are then placed again inside the capillary.

The test begins when milk is injected through the capillary. As the milk's proteins pass over the patient's IgE antibodies, the ones that cause allergies are caught by them, while the others exit on the other side. The beads are then washed with a strong chemical that causes the allergy-inducing protein to dissociate from the patient's IgE antibodies. The isolated, "culprit" protein is then identified using mass spectrometry, which is a technique that analyzes compounds according to their mass and electrical charge.

The method offers a personalized way to identify the exact proteins that can cause food allergies to a patient, which can help develop an effective treatment. It is also quicker, as it does not require the detection and quantification of a patient's specific IgE antibodies or the laborious and resource-intensive diagnostic methods used currently. Finally, it provides higher accuracy than conventional allergy-testing methods, as it can detect tiny amounts of allergic proteins, even if they are unexpected and rare. This also means that the method can be extended beyond milk to other foods like nuts and wheat products.

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The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne . Note: Materials may be edited for content and length.

Bone-house wasps [Life Lines]

Bone-house wasps protect their young by building walls made of ant carcasses. Image from: Merten Ehmig

A new species of wasp that protect their young with walls made of ant carcasses has been discovered in the forests of China. Dr. Michael Staab from the University of Freiburg discovered the new species which he named Deuteragenia ossarium meaning “bone-house wasp” since the wasps reminded him of the ossuaries in Europe with structures decorated from human bones.

Sedlec Ossuary in the Czech Republic. Image from Wikipedia.

Similar to the ossuaries, the bone-house wasps use alive or dead ants to create plugs that help seal off their nests from predators. Dr. Staab believes the pungent smell of the ant carcasses may help to ward off predators or camouflage the nest. The jet black wasps look unlike any other species of wasp currently known.