Campylobacter Blog - Surveillance & analysis on Campylobacter news & outbreaks

People from Walkerton Canada who had gastroenteritis after drinking water contaminated with Escherichia coli O157:H7 have a higher long-term risk than other people of developing hypertension, renal impairment and cardiovascular disease, research has shown. "Long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with Escherichia coli O157:H7: a prospective cohort study."

A prospective cohort study was set up in Walkerton, Ontario, Canada to investigate any long-term health problems following contamination of the town’s water supply in May 2000 with E. coli O157:H7 and Campylobacter.

Researchers recruited 1977 adult participants of whom almost all (99%) said they had drunk the contaminated water. Of these, 1067 (54%) had had acute gastroenteritis, and 378 sought medical attention.

Participants were followed up annually, with physical examination and laboratory assessment. This included height, weight, blood pressure, serum creatinine concentration, random (spot) urine analysis for albumin: creatinine ratio; in some years fasting serum glucose measurement, oral glucose tolerance testing and 24-hour urine collection were also done.

People who had had acute gastroenteritis during the E. coli outbreak were 1.3 times more likely to develop hypertension, 3.4 times more likely to develop renal impairment and 2.1 times more likely to have a cardiovascular event such as a heart attack or stroke, compared with people who had not been ill or only mildly ill. We have certainlly seen these risks for people who develop Hemolytic Uremic Syndrome (HUS), but not for more mild illnesses.

“Our findings underline the need for following up individual cases of food or water poisoning by E. coli O157:H7 to prevent or reduce silent progressive vascular injury.” They suggest that annual monitoring of blood pressure and periodic monitoring of renal function may be warranted. They add: “These long term consequences emphasize the importance of ensuring safe food and water supply as a cornerstone of public health.”

Guillain-Barre syndrome is a condition in which the body's immune systems attack its nerves, often after infection with a respiratory bug or stomach flu.

Although acute cases are an emergency, most people recover completely, according to the Mayo Clinic.

Q: What are its symptoms?

A: While its first symptoms are usually weakness and numbness in the extremities, it can eventually paralyze the entire body, according to the Merck Manual of Medical Information. Symptoms are often worst in the first two or three weeks.

In 5% to 10% of cases, the muscles that control breathing become so weak that patients need to be put on a ventilator. In another 10% of cases, muscles that control swallowing are so weakened that patients need to be fed through a tube into the stomach.

Q: How is it treated?

A: Doctors may cleanse the blood, removing harmful antibodies, or give patients a treatment called immune globulin, with protective antibodies with donors, according to the Mayo Clinic.

Q: Do people recover?

A: Most patients improve slowly over several months, even without treatment, according to the Merck Manual. Early treatment can speed up recovery, allowing patients to improve within days or weeks. Although there's no known cure, treatment can ease recovery, according to the Mayo Clinic.

About 30% of adults still suffer from some muscle weakness three years later, however. Fewer than 5% of patients die in the early stages of the disease.

Q: How common is it?

A: Guillain-Barre affects one or two out of every 100,000 people.

Q: What causes it?

A: Doctors don't know the exact cause of Guillain-Barre, and some cases appear without any clear trigger, according to the Mayo Clinic. One of the most common triggers is campylobacter, a type of bacteria often found in undercooked chicken or other food. Guillain-Barre has also been triggered by surgery; the Epstein-Barr virus; Hodgkin's disease; mononucleosis; HIV, the virus that causes AIDS; and rabies.

In an infamous outbreak in 1976, hundreds of people who received a swine flu vaccine developed Guillain-Barre, although scientists question whether the shots were really the cause. The Centers for Disease Control and Prevention has not seen any increase in Guillain-Barre related to vaccination against the H1N1 virus.

Q: How is the immune system involved?

A: The disease occurs when the immune system — which typically protects the body from illness by attacking viruses and other foreign invaders — instead attacks the myelin sheath, a coating that protects the nerves. Damage to this critical coating, which acts like insulation, interferes with the way that nerves send signals between the body and brain, according to the Mayo Clinic.

What would a Thanksgiving turkey be without its stuffing, and what better place for that stuffing than inside the turkey?

Despite the tradition involved, a food-safety specialist in Penn State's College of Agricultural Sciences says some practices are worth reconsidering, especially since Mom may not have fully appreciated the risk of foodborne illness.

"Cooking a stuffed turkey is riskier than cooking an unstuffed one, because it takes longer for the stuffing to reach the proper internal temperature of 165 degrees F when it is placed into the cavity of the bird," said Martin Bucknavage, food safety specialist in the department of food science. "While people concern themselves about cooking the bird to 165 degrees F, they must ensure that stuffing also achieves that temperature."

Bucknavage noted that often the turkey ends up overcooked in getting the stuffing to the proper temperature, or the stuffing ends up undercooked because the turkey is removed from the oven when the bird is at the right temperature, but the stuffing is not.

"It is the undercooked stuffing that poses the real risk," he said. "Bacterial pathogens such as Salmonella may be present in the cavity of the bird and can contaminate the stuffing. If the stuffing is not cooked thoroughly, Salmonella can survive and may infect those who consume it."

If you want a properly cooked, stuffed bird with less chance of foodborne illness, Bucknavage said, just cook your stuffing separately. To preserve a family tradition, stuff your fully cooked bird with the cooked stuffing before serving. If you simply must stuff your bird before cooking, take extra care to ensure the internal temperature of both the bird and the stuffing exceeds 165 degrees F before serving.

Another common practice that Bucknavage discourages is washing the outside surface of your store-purchased bird.

"The problem with this practice is that pathogenic bacteria often are embedded in the surface of the skin," he said. "When faucet water hits bacterial pathogens, they become aerosolized and land all over your kitchen counter, the faucet and you.

"The U.S. Food and Drug Administration says Campylobacter is one of the most common causes of diarrheal illness in the country, and undoubtedly, many of these cases are a result of cross-contamination in the kitchen. So there is no need to wash the outside of your bird -- the cooking process easily will kill these bacteria. But you still need to clean and sanitize your counter and any kitchen equipment that touches the raw bird."

Lastly, although Mom may have thawed that frozen bird on the counter overnight, this method has been shown to help increase the amount of pathogenic bacteria that might be present on the raw turkey. Rather, you can use one of three methods:

--Thaw in the refrigerator. "You should allow about 24 hours for every five pounds of turkey in a refrigerator set at 40 degrees F or below," he said. "Be sure to place the frozen turkey, breast side down, in the original wrapper in a container to prevent raw fluids from dripping on other foods. A 16-pound turkey will require three and a half days of refrigerated thaw time."

--Thaw under cold water. Submerge the wrapped turkey in cold tap water in a leak-proof plastic bag to prevent cross-contamination and to prevent excess pick-up of moisture. Allow 30 minutes per pound, and change the water every 30 minutes until the turkey is thawed.

--Thaw in your microwave. "You can do this if your microwave is large enough," Bucknavage said. "Follow the manufacturer's instructions, and be sure to cook the bird immediately once you've thawed it this way.

"Mother won't mind if you change a thing or two if it means keeping this generation's food safe," Bucknavage said.

The Food Standards Agency has published the findings of a new survey testing for campylobacter and salmonella in chicken on sale in the UK.

The survey showed that campylobacter was present in 65% of the samples of chicken tested. Salmonella was in 6% of samples, 0.5% of these samples contained S. enteritidis and S. typhimurium.

Andrew Wadge, Director of Food Safety at the Food Standards Agency, said: "The continuing low levels of salmonella are encouraging, but it is disappointing that the levels of campylobacter remain high. It is obvious more needs to be done to get these levels down and we need to continue working with poultry producers and retailers to make this happen. Other countries like New Zealand and Denmark have managed to do so; we need to emulate that progress in the UK."

As part of the Agency’s work to reduce levels of campylobacter in UK-produced chicken an international conference on campylobacter is being organised for 2010, where a range of options for tackling the bug will be discussed.

Campylobacter is the most common bacterial cause of food poisoning. It is responsible for around 55,000 cases of illness in the UK every year, and is therefore one of the key organisms the Agency is tackling in order to reduce levels of foodborne illness. Campylobacter can be found on meat, unpasteurised milk, and untreated water; however there is strong evidence that chicken is the most common cause of illness.

The FSA emphasises that while campylobacter is still present in a significant proportion of fresh chicken sold in the UK, cooking chicken properly all the way through will kill the bug, so consumers can avoid the risk of illness.

The UK-wide survey of fresh chicken at retail was carried out between May 2007 and September 2008. During the course of the survey, 3,274 samples were tested for the presence of campylobacter and salmonella.

We don’t get to report on a lot of good news here. Today, we do, though. The Washington Post is reporting that Navy scientist Patricia Guerry has made “discoveries that could lead to the first vaccine” for campylobacter jejuni. According to the report, such a vaccine could “potentially save tens of thousands of young lives in developing countries where the pathogen has proved deadly.”

Campylobacter jejuni is also a common illness in the U.S. In rare cases, it can lead to the development of Guillain Barre Syndrome (GBS). GBS is a very serious illness that causes nerve paralysis.

According to the Post:

The vaccine candidate against the pathogen Campylobacter jejuni, developed by Guerry, her colleagues at the U.S. Naval Medical Research Center in Silver Spring and Canadian scientist Mario Monteiro, successfully protected against infection in monkeys during testing last year and is slated for human clinical trials.

If the vaccine becomes a reality, it would be significant step forward in reducing foodborne illness in the U.S. and internationally.