Food-borne infections endanger long-term health, especially for kids

Fair warning: Put down that salad or medium-rare cheeseburger you're eating, pitch the brie cheese you enjoy with a glass of wine, and clear the chicken and leafy greens from the plate in front of Junior. Because you're not going to want eat or serve any of them after you read what a pair of reports released Thursday by the Center for Foodborne Illness Research & Prevention, have to say:

Long after the painful stomach cramps and bloody diarrhea of a brush with tainted food is over, many of us suffer long-term health effects, mostly unrecognized, that are the result of food-borne pathogens. These lingering effects can be very bad -- as bad as premature death, paralysis, kidney failure and a lifetime of seizures or mental disability. Many researchers believe these persistent health consequences cause more disability, lost productivity, doctor-office visits and hospitalizations than the acute illnesses that follow exposure to a food-borne toxin.

And while high-profile cases of food-borne illness have been caught, publicized and probably brought to an early end in recent years (think spinach, alfalfa sprouts, ground beef, peanut butter and tomatoes), the incidence of poisoning by tainted food is probably vastly understated.

As if all that isn't bad enough, food-borne pathogens cut their widest swath of destruction among the youngest of us. Children under 4 are disproportionately the victims of poisoning by the food-borne pathogens Campylobacter, E coli O157:H7, Listeria monocytogenes and Salmonella. And roughly half of all reported cases of food-borne illness affect kids younger than 15. Because younger kids are smaller, it takes a smaller dose of harmful bacteria to sicken them, and their less-experienced immune systems don't combat food-borne pathogens as effectively as do those of adults. They're more vulnerable, too, because their stomachs don't produce the volume of acids that adult digestive systems do.

In addition to urging public health officials, physicians and researchers to do a better job of understanding and stopping outbreaks of food poisoning, the American Academy of Pediatrics, in a campaign called Make our Food Safe for the Holidays, urges the following steps for consumers:

• Cook meat thoroughly.
• Clean work surfaces, cutting boards and bowls thoroughly after using them on uncooked meats or eggs to prevent contamination of other foods.
• Wash produce before consuming it.
• When buying milk and juice, make sure they're pasteurized, and make sure that products made from milk are made with pasteurized milk.
• Report any food-borne illness to a local health department.

The Food & Drug Administration and the U.S. Department of Agriculture, which have shared responsibility for preventing, detecting, tracking and responding to food-borne illness, are exploring ways to improve their performance in tracking the sources of outbreaks. Meanwhile, here's a list of the chief culprits, the foods in which they're most commonly found and some of the possible long-term consequences of infection, all from the Center for Foodborne Illness Research & Prevention report:

Salmonella. The leading cause of food-borne illness in the United States, salmonella is harbored by foods with animal origins, including beef, poultry, milk and eggs. It causes 16,000 illnesses and 556 deaths per year. It can cause reactive arthritis -- painful and swollen joints mainly in the lower limbs -- from which patients generally recover in two to six months. Eye irritation and painful urination can also be long-term effects.

Campylobacter: Food-borne sources are raw and undercooked poultry, unpasteurized milk and contaminated water. It causes an estimated 2 million acute human illnesses (the vast majority in children under 4) and 124 deaths yearly. Long-term effects can include Guillain-Barre Syndrome, an acquired and sometimes permanent paralysis, reactive arthritis (like Guillain-Barre, an autoimmune reaction) and chronic arthritis.

E. Coli O157:H7: Disproportionately affecting children under 19, E. Coli can taint ground beef and other meats, green leafy vegetables, unpasteurized (or raw) milk and cheeses made from such milk. About 15% of children infected with E. coli O157:H7 develop hemolytic uremic syndrome, which can lead to kidney failure, chronic kidney problems, diabetes, high blood pressure, gallstones, irritable bowel syndrome, narrowed gastro-intestinal passages and neurological problems -- including seizures -- that can take as long four years to resolve.

Listeria monocytogenes: An estimated 2,500 in the U.S. are infected with Listeria each year, and roughly 500 of them die. Listeria monocytogenes taints vegetables grown in contaminated soil or fertilizer, contaminated meat or poultry products. Cold cuts, hot dogs, smoked seafood, raw milk and soft cheeses made from such milk are common sources. In pregnant women -- roughly one-third of those victims --  listeriosis can cause miscarriage, premature death or stillbirth. Surviving fetuses may have mental retardation, hearing loss or brain damage. Adults infected with listeriosis can suffer neurological effects, including seizures and impaired consciousness. About a third experience cardiorespiratory failure.

--Melissa Healy

Now about that salmonella outbreak ... no, no, the turtle-related one

The resulting consternation was small by food-borne-illness standards, but the 2007 salmonella outbreak was the country's largest to date involving turtles. And it has proven to be excellent fodder for researchers from the Centers for Disease Control and Prevention and elsewhere to assess just how those infections came about.

Of 107 people sickened in the outbreak, the median age was 7, the researchers reported online today in the journal Pediatrics. As for the turtles, 87% were the cute little kind that kids just have to have and that they'll take really, really good care of, they promise; 34% were bought in a pet store.

One of the more interesting facts in the abstract and in an Associated Press story is that many people were unaware of the salmonella risk posed by turtles. (The Associated Press also reports that two girls swam with the turtles.)  

Interesting, considering that references to salmonella and turtles are fairly ubiquitous and have been for, oh, more than three decades now.... In fact, here's a CDC fact page on the matter. It begins: Is a turtle the right pet for your family?

The answer: "Did you know that the sale of turtles less than 4 inches has been banned in the United States since 1975? This is because turtles pose a high risk of spreading disease, especially to children. The ban by the U.S. Food and Drug Administration (FDA) has prevented an estimated 100,000 cases of salmonellosis annually in children. This ban prohibiting the sale of small turtles likely remains the most effective public health action to prevent turtle-associated salmonellosis."

So the answer would be no?

Here's the earlier news story about the outbreak: Salmonella carried by pet turtles sickens 100.

And here's a recent in-depth look from staff writer Karen Kaplan at the organism behind the outbreak: There's no escaping salmonella. It begins, quite notably: "This is salmonella’s world. We’re just living in it."

-- Tami Dennis

Photo: What's on that turtle? Perhaps salmonella. Credit: Karen Tapia-Anderson

Old blood raises death risk in trauma patients receiving transfusions

A victim of severe trauma who gets as little as a single unit of blood that's been stored for more than a month is twice as likely to die as an equally injured patient who gets transfused with fresher blood, a new study finds.

Red blood cells stored longer than 28 days significantly increased trauma patients' risk of developing fatal deep vein thrombosis or multi-organ failure for six months after transfusion, a team of pediatric intensive-care specialists in Connecticut reported today in the journal Critical Care.

The new study is the latest to raise concerns about rules governing the use of about 29 million units of blood transfused every year in the United States. The American Red Cross says donated blood has a "shelf life" of 42 days, after which it must be discarded if not used.

Two earlier studies -- one looking at a general hospital population requiring transfusion and a second at heart surgery patients -- found that the use of longer-stored blood in transfusions resulted in poorer outcomes. Hospital patients administered blood stored longer than four weeks were three times as likely to acquire an infection in the hospital than those who got fresher blood. Heart patients infused with blood stored longer than two weeks were 64% more likely to die than those whose red blood cells were more briefly in storage.

Though hospitals typically use their longest-stored blood first to avoid wasting the precious resource, the authors of the Critical Care study suggest that physicians might consider the "preferential use" of younger blood on the most critically injured trauma patients. The result would likely mean more blood reaches its expiration date before it can be used. But lives could be saved.

-- Melissa Healy

Nasal sprays may help prevent spread of colds

People with colds who sneeze can spread germs into the air and infect others. But there may be a way to reduce the chances of spreading your colds to others. A study presented today shows that oxymetazoline, the compound found in many over-the-counter decongestant nasal sprays, appears to reduce the levels of rhinovirus in nasal secretions.

Researchers from the University of Virginia, Charlottesville, assigned 39 volunteers, who were infected with rhinovirus, to receive either a nasal decongestant or saline spray. They received three puffs a day for five days. By the second day, those receiving the oxymetazoline had much less virus in their nasal secretions. However, people in both groups still had colds that lasted an average of 6.1 days.

Reducing the virus in nasal secretions, however, may help prevent it from spreading into the ears, chest or into the environment through sneezes and coughs.

The study was presented today at the Interscience Conference on Antimicrobial Agents and Chemotherapy.

-- Shari Roan

Is your beach contaminated with MRSA?

Staphylococcus aureus is a common bug that can cause serious infections. An antibiotic-resistant strain, called MRSA (methicillin-resistant Staphylococcus aureus), has increased dramatically in recent years. It typically spreads in hospitals. But it's also found in healthy people in the community. It spreads from skin-to-skin contact with someone who is infected, or by touching surfaces contaminated with the germ.
 
Little is known about places in the environment where MRSA can hide. A study presented today, however, is the first to show that public beaches may be reservoirs for the bug. Staph was isolated in marine water and in intertidal beach sand in nine of 10 public beaches in Washington state, and half of the strains were MRSA, according to the study from researchers at the University of Washington. When examined, those strains appeared to be the type that spreads in hospitals rather than community-acquired MRSA.

How beaches are becoming contaminated with hospital-acquired MRSA is unknown, said the lead author of the study, Dr. Marilyn C. Roberts. The study was presented this morning at the Interscience Conference on Antimicrobial Agents and Chemotherapy in San Francisco.

"Where all these organisms are coming from and how they are getting seeded, we don't know," Roberts said. The samples were "grab-and-go" samples, meaning that researchers didn't spend a lot of time thinking about where to collect the samples. And, Roberts said, "the fact that we found these organisms suggests [beach contamination] is much higher than we normally thought."

Another study on beach sand, published in June in the Journal of Epidemiology, found that people who dug in the sand or covered themselves with sand were more likely to have diarrheal illnesses in the following week or two compared with beachgoers who just walked on the beach or lay on the sand. The most likely scenario for MRSA infection, Roberts said, is getting sand in a cut or abrasion. But the risk of getting MRSA at the beach cannot be estimated at this time.

"We don't know what the risk is because nobody's done a good study," she said.

Roberts also tested two beaches in Southern California and did not find MRSA. But that should not reassure beachgoers in California -- or anywhere. Testing of the samples from California beaches was delayed, which may have affected the quality of the test, Roberts said.

The best advice for beachgoers is to cover open skin wounds and wash off sand thoroughly. People who have weakened immune systems because of other illnesses should take special care with open wounds.

"I'm not telling people not to go to the beach," Roberts said. "But if, all of a sudden, you have a skin rash and it doesn't get better, you need to go and be seen."

-- Shari Roan

Photo credit: Allen J. Schaben / Los Angeles Times

As for colloidal silver, you can't say you weren't warned

With cold and flu season arriving a bit earlier than usual this year, consumers may be tempted to try colloidal silver. They even may be tempted to try it in large doses. Here's some advice: Don't.

The substance is currently pitched as a flu fighter, among other things. Harumph. Not only is there no proof colloidal silver works in such a fashion, it's not the harmless tonic some would have you think.

We've said this before, of course, but Paul Karason drives the point home better than we ever could. The man turned blue (seriously) after taking large quantities of the substance, simply water laden with silver particles.

Here's the Today/MSNBC story (with photos -- worth seeing).

As for the "I told you so's":

In May: Scam 'cures' for swine flu face crackdown The FDA and FTC target peddlers of colloidal silver and other potentially harmful products. Tamiflu and Relenza are the only approved treatments.

In February: Does colloidal silver boost immunity or overall health? The metal is popular in alternative medicine circles, but claims are unproven and large doses can be harmful.

As that story notes: "Contrary to claims made by some websites, silver in large enough doses can cause side effects. In rare cases, it can collect under the skin and react with sunlight to create a permanent bluish tint, a condition known as argyria. Although unsightly, argyria is not dangerous."

And heck, in 2003: Be leery of the silver bullet

Here's more on colloidal silver products from the National Center for Complementary and Alternative Medicine. It notes that silver has been used medically for centuries, but that, you know, modern medicine has some advantages over it.

-- Tami Dennis

Credit: Los Angeles Times

FDA panel backs Cervarix for women, Gardasil for men

A Food and Drug Administration advisory panel today recommended that the agency approve the Cervarix vaccine against human papilloma virus (HPV) for use in women and that it expand the approval of the Gardasil HPV vaccine to use in men. The FDA is not obligated to follow the recommendations from its committees of outside experts, but it generally does so.

About 20 million Americans are infected by HPV each year. Most infections are cleared by the body, but the virus is thought to be responsible for an estimated 11,000 cases of cervical cancer each year, with 4,000 deaths. In men, HPV is linked with anal cancer, which strikes perhaps 2,000 men yearly, and with penile cancer, which is even rarer.

Gardasil was introduced in 2006 by Merck & Co. and protects against two strains of HPV that are associated with 70% of cervical cancers. It is also protective against two other strains that are associated with 90% of genital warts, which are sometimes precursors of anal and penile cancer. It is now recommended for use in girls and women ages 10 to 25.

SmithKlineGlaxo applied for approval of Cervarix, which protects against the same two cervical cancer strains as Gardasil, in 2007, but the agency asked for more information because of reports suggesting that use in pregnant women might lead to miscarriages. The advisory panel concluded that the evidence linking the vaccine to the miscarriages is not very good, although it suggested that the vaccine carry a warning about the possibility. The vaccine should "be marketed with the usual caveat that it shouldn't be used during pregnancy," said panel member Dr. Kenneth Noller of the Tufts University School of Medicine.

The panel also said that marketing for Gardasil could be extended to men ages 9 to 26, but conceded that probably not many would be likely to be immunized -- both because of the rarity of penile and anal cancers and the high cost of the vaccine, $400 for a three-dose regimen. Critics also argue that it is not yet clear how long the protection provided by the vaccine persists. The companies have studied it for only five years in women and three in men, and there are some hints that the protection may fade.

Critics of the vaccine claim that Gardasil was associated with 6,723 adverse events in 2008, including more than 1,000 considered serious and 142 that were considered life-threatening. The panel concluded, however, that it was "unlikely" that most of the events were related to the vaccine.

-- Thomas H. Maugh II

Bacterial infection linked to aggressive prostate cancer

Men who are infected with the sexually transmitted bacterium Trichomonas vaginalis have a slightly increased risk of developing prostate cancer and double the normal risk of developing the aggressive form of the disease that spreads throughout the body, Harvard researchers reported today in the Journal of the National Cancer Institute.

It is the second report this week potentially linking infections to prostate cancer. On Monday, other researchers reported in the Proceedings of the National Academy of Sciences that they had found much higher levels of a mouse leukemia virus in prostate cancer tissue than in healthy tissues, and the presence of the virus was also associated with more aggressive tumors. Although neither the bacterium nor the virus has been definitively shown to be a causative agent in the tumors, the two reports suggest that inflammation caused by an infection could be a major factor in causing the tumors or in accelerating their growth.

T. vaginalisis the most common nonviral sexually transmitted infection, striking an estimated 174 million people worldwide each year. It is easily treated with antibiotics, but is symptomless in about three-quarters of men and goes untreated unless a female sexual partner is diagnosed with an infection.

Epidemiologist Jennifer Rider Stark of the Harvard School of Public Health and her colleagues studied 673 participants in the Physicians' Health Study who had been diagnosed with prostate cancer and compared them with an equal number of healthy men in the study. Looking at blood samples collected 15 years earlier, they found that men who had antibodies to T. vaginalis in their blood were 23% more likely to develop prostate cancer and 2.17 times more likely to develop aggressive prostate cancer that spread to bones and elsewhere in the body, generally proving fatal.

Prostate cancer strikes more than 190,000 American men each year, killing more than 27,000. It is generally screened for with the prostate-specific antigen (PSA) test, but that assay identifies many tumors that progress only very slowly and for which no treatment is needed. Some studies have shown, in fact, that screening does not extend survival and leads to many unnecessary invasive procedures. Researchers have thus been searching for other markers that distinguish between prostate tumors that are aggressive and should be treated vigorously and those that grow very slowly and pose no threat to the bearer.  The new findings provide a fresh lead in the search for such markers.

-- Thomas H. Maugh II

Daycare doesn't protect against asthma later

The "hygiene hypothesis" is a theory that young children who are exposed to a variety of germs will have a lower risk of developing asthma and allergies later in life. Studies on the hypothesis have been inconsistent. The latest study, published today in the American Journal of Respiratory and Critical Care Medicine, concludes that daycare has no effect on later respiratory illnesses.

The researchers, in the Netherlands, followed nearly 4,000 Dutch children over eight years. Parents completed questionnaires at various intervals of the child's life, from pregnancy to age 8. At that age, more than 3,500 of the children were assessed for specific allergies and asthma. Daycare use was also assessed each year.

The study found that children who started daycare early were twice as likely to experience wheezing in the first year of life compared with those who didn't go to daycare. But as the children became older, the illness pattern shifted. There was a trend for less wheezing among early attendees. By age 8 there was no association between daycare attendance and wheezing. The only children who stood out in the study were those who had early daycare attendance and older siblings. Those children had more than a fourfold higher risk of frequent respiratory infections and more than twofold risk of wheezing in the first year compared with children without older siblings and daycare.

"Children exposed to both early daycare and older siblings experienced most infections and symptoms in early childhood, without a protective effect on wheeze, inhaled steroid prescription or asthma symptoms until the age of eight years," the lead author of the study, Dr. Johan C. de Jongste, said in a news release. "Early daycare merely seems to shift the burden of respiratory morbidity to an earlier age where it is more troublesome than at a later age. Early daycare should not be promoted for reasons of preventing asthma and allergy."

-- Shari Roan

Photo credit: Luis Sinco  /  Los Angeles Times

Could a virus cause prostate cancer?

Utah researchers have found a mouse cancer virus in many human patients with prostate cancer, suggesting that the virus may play a role in the onset of the disease and in the development of more aggressive forms. If their findings can be validated, it might provide a way to distinguish fast-growing tumors that require therapy from the slow-growing forms that can be safely ignored for many years.

Viruses are known to cause a variety of human cancers. Hepatitis viruses, for example, cause liver cancer, while human papilloma virus causes cervical cancer in women and anal and penile cancer in men. The mouse mammary tumor virus has been found in many human breast cancers, but researchers are not sure what role, if any, it plays in development of the disease.

Dr. Ila R. Singh of the University of Utah and her colleagues have been studying a mouse virus called xenotropic murine leukemia virus-related virus, or XMRV. They, as well as researchers from UC San Francisco, had previously reported finding the virus in some human prostate cancers, but had not looked for it in normal prostate tissues.

In the new study, they looked for the virus in 200 human prostate cancers and in 100 samples of healthy prostate tissue. They reported today in the Proceedings of the National Academy of Sciences that they found the virus in 27% of the cancerous tissues, but in only 6% of the healthy tissues. The virus was most likely to be present in tumors that are considered more aggressive on the Gleason scale of malignancy.

A sequence analysis of the virus showed that it is a gammaretrovirus, one of a family of viruses that are known to cause leukemias and other cancers in animals, but that have not yet been shown to do so in humans. The gammaretroviruses insert their genetic information into the DNA of cells they infect. When this insertion occurs in the wrong position, it can induce the host cell to begin replicating out of control, producing a tumor.

The researchers found that XMRV replicates easily in cultured human prostate tissue, but not in other types of human tissues. But they have not shown that the virus causes tumors to grow. There are also many other unanswered questions, such as whether the virus infects women, whether it is sexually transmitted, and how prevalent it is in the human population.

If the virus could be linked to prostate tumors, it might open the door to new treatments and to prevention. A vaccine against the virus might prevent many cases of prostate cancer, just as the human papilloma virus vaccines prevent cervical cancer. The need for new approaches to prostate cancer is clear: It is second only to skin cancer as the most common form of cancer in males, affecting more than 190,000 American men each year and killing 27,000. Any improvement would be gratefully accepted.

-- Thomas H. Maugh II