Tuesday, August 12, 2008

Early Test for Cancer Isn’t Always Best Course

August 12, 2008

Sometimes what you don’t know might end up being better for you.

For years patients have been told that early cancer detection saves lives. Find the cancer before the symptoms appear, the thinking goes, and you’ve got a better chance of beating the disease.

So it might have seemed surprising last week when a panel of leading medical experts offered exactly the opposite advice. They urged doctors to stop screening older men for prostate cancer, which will kill an estimated 28,600 men in the United States this year.

Their advice offered a look at the potential downside of cancer screening and our seemingly endless quest to detect cancer early in otherwise healthy people. In this case, for men 75 and older, the United States Preventive Services Task Force concluded that screening for prostate cancer does more harm than good.

“We’ve done a great job in public health convincing people that cancer screening tests work,” said Peter B. Bach, a pulmonologist and epidemiologist at Memorial Sloan-Kettering Cancer Center in New York City. “We’re uncomfortable with the notion that some screening tests work and others don’t. That seems mystifying to people.”

But the reality is that while some cancer screening tests — like the Pap smear for cervical cancer or mammography for breast cancer — clearly save lives, the benefits of other screening tests are less clear.

Studies of lung cancer screening, for instance, have failed to prove that it prolongs life. A mass screening for neuroblastoma in Japanese infants was halted after it became clear that the effort wasn’t saving children and worse, led to risky treatments of tumors that weren’t life threatening.

The case seemed stronger for screening for prostate cancer. By some measures, death rates from the disease in the United States have plummeted since the introduction of the screening test for prostate specific antigen, which detects levels of a protein that can signal prostate cancer.

The data, in fact, are highly misleading. The introduction of screening can trigger big statistical fluctuations that can be difficult to interpret. But if you look at prostate cancer statistics in the 1970s, long before screening was introduced, death rates have dropped only slightly since then. The small decline seems largely because of improvements in treatment, many experts say, though others point to early detection as the reason.

Whether there really is a measurable benefit from PSA screening for younger men won’t be known for a few more years, after data from two major clinical trials studying the test are reported.

How can it be that finding prostate cancer early doesn’t help save lives? For starters, a large percentage of prostate cancers aren’t deadly. They are slow growing and unlikely to result in any symptoms before the end of a man’s natural life expectancy. By some estimates, as many as 44 percent of the men who are treated for prostate cancer as a result of PSA testing didn’t need to be. Had they been left alone, they would have died of something else and never known they had cancer.

“Screening tests don’t only pick up life-threatening cancers, they pick up tumors that look identical to traditional tumors, but they don’t have the same biologic behavior,” said Dr. Barry Kramer, associate director for disease prevention at the National Institutes of Health. “Some are so slow growing they never would have caused medical problems in the person’s natural life span.”

In the case of PSA testing, the Preventive Services Task Force, an expert panel that makes recommendations about preventive care for healthy people, said there was not enough evidence to recommend for or against screening of younger men, although they urged doctors to advise men of all the risks and benefits of screening. But they did conclude that 75 is the age at which the risks clearly begin to outweigh the benefits, and the disease, if detected, would most likely not have a meaningful effect on life expectancy.

Another problem with determining the value of screening is that it results in “lead time bias.” For instance, someone diagnosed with lung cancer at the age of 65 may die at 67 and be remembered as a two-year survivor. If the same man had been diagnosed at 57 through screening and died at the age of 67, he would be known as a 10-year survivor. That sounds a lot better, but the reality is that diagnosis and treatment didn’t prolong his life. He died at 67 either way.

“Even a harmful screening test could appear on the surface as a helpful test,” Dr. Kramer said. “Because you measure survival from the date of diagnosis, even if the person dies of the same cause on the same day they would have without screening, it looks like survival was longer.”

Any screening test can lead to false positives, followed by invasive and risky tests. Large numbers of people often end up being poked, prodded and tested only to discover they’re fine.

Biopsies to detect prostate cancer get mixed reviews. Some men find them to be a minor discomfort; others say they were left in debilitating pain. Once cancer is found, surgery, radiation or hormone therapy, or “watchful waiting,” may be advised.

Treatments for prostate cancer can cause significant harm, rendering men incontinent or impotent, or with other urethral, bowel or bladder problems. Hormone treatments can cause weight gain, hot flashes, loss of muscle tone and osteoporosis.

“It’s just a needle stick, but the cascade of events that follows are fairly serious,” Dr. Bach said. “I think the burden is on medicine to try and generate some evidence that the net benefits are there before drawing that tube of blood.”

The problem with prostate screening is that some men are very likely to have been saved by early detection. But how many have been hurt?

“I’m a little worried we may look back on the prostate cancer screening era, after we learn results of clinical trials, and see that we’ve harmed a lot of people without doing them good,” said Dr. David Ransohoff, a professor of medicine and cancer screening researcher at the University of North Carolina at Chapel Hill. “By being so aggressive with so many people, did we do the right thing? I don’t know that it’s going to turn out that way.”

Thursday, July 17, 2008

U.S. Obesity Epidemic Continues to Grow

By Steven Reinberg

HealthDay Reporter
Thursday, July 17, 2008; 12:00 AM

THURSDAY, July 17 (HealthDay News) -- Despite wide-ranging efforts to encourage Americans to lose weight, the number of U.S. adults who are obese increased almost 2 percent between 2005 and 2007, a new report found.

In 2007, 25.6 percent of adults reported being obese, compared to 23.9 percent in 2005, according to the finding in the July 18 issue of the U.S. Centers for Disease Control and Prevention'sMorbidity and Mortality Weekly Report.

"The epidemic of adult obesity continues to rise in the United States, indicating that we need to step up our efforts at the national, state and local levels," Dr. William Dietz, director of CDC's Division of Nutrition, Physical Activity, and Obesity, said in a news release. "We need to encourage people to eat more fruits and vegetables, engage in more physical activity and reduce the consumption of high-calorie foods and sugar-sweetened beverages in order to maintain a healthy weight."

The percentage of adults who are obese varies by state and region, according to the report. For example, in Alabama, Mississippi and Tennessee, 30 percent of the residents reported being obese, compared with 18.7 percent in Colorado, which had the lowest prevalence of obesity.

Obesity was most prevalent in the South, with 27 percent of residents classified as obese. In the Midwest, the number was 25.3 percent; in the Northeast, 23.3 percent; and in the West, 22.1 percent, according to the report.

In terms of age, among those 50 to 59 years old, 31.7 percent of men and 30.2 percent of women were obese. For those 19 to 29, 19.1 percent of men and women were obese.

Breaking the numbers down by race/ethnicity and sex, obesity prevalence was highest for non-Hispanic black women (39.0 percent), followed by non-Hispanic black men (32.1 percent).

Education levels play a role, too. For men, obesity prevalence was lowest among college graduates (22.1 percent) and highest among those with some college (29.5 percent) and a high school diploma (29.1 percent). For women, obesity prevalence was lowest among college graduates (17.9 percent) and highest among those with less than a high school diploma (32.6 percent).

None of the states or the District of Columbia has met the "Healthy People 2010" goal of reducing the prevalence of obesity to 15 percent or less, the CDC said.

"Obesity is a major risk factor for a number of chronic diseases such as type 2 diabetes, heart disease and stroke. These diseases can be very costly for states and the country as a whole," Deb Galuska, associate director for science at the CDC's Division of Nutrition, Physical Activity and Obesity, said in a news release.

The CDC defines obesity as a body mass index (BMI, a ratio of weight to height) of 30 or above. An adult who is 5-feet, 9-inches tall is considered obese if he or she weighs 203 pounds.

In compiling the data, the CDC used its Behavioral Risk Factor Surveillance System, which collected information on more than 350,000 adults through telephone interviews. The researchers calculated BMIs using information reported by survey participants.

"These data from the CDC confirm that the epidemic of obesity continues to spread, whether looking at population trends in the short- or long-term," said Howard D. Sesso, an assistant professor of medicine in the Division of Preventive Medicine at Brigham and Women's Hospital in Boston.

The likelihood of America meeting the Healthy People 2010 objectives for obesity prevalence appears dim, Sesso said. "This report highlights the need not only to outright prevent the development of obesity over the life-course, but also to improve efforts to reduce body weight in those already classified as obese," he said.

Thursday, June 5, 2008

Pregnant Women, Children Cautioned on Dental Mercury

By Avram Goldstein

June 5 (Bloomberg) -- The mercury in dental fillings may have toxic effects on fetuses and young children, U.S. regulators said for the first time as part of a legal settlement.

After decades of debate about the safety of mercury amalgam dental fillings, the Food and Drug Administration added the statement on ``safety concerns'' to its Web site this week, said agency spokeswoman Peper Long in a telephone interview today. The FDA agreed to post the warning about the dangers for developing human brains to settle a lawsuit by a collection of environmental groups, consumers and state officials.

In the settlement, the FDA agreed to bring to a conclusion by July 2009 a regulatory review of mercury in fillings that began in 2002. The process could result in a requirement that prescribing information warn dentists and pregnant women of nervous system dangers to fetuses and young children with developing brains, Long said.

``Gone are all of FDA's claims that no science exists that amalgam is unsafe,'' said Michael Bender of Vermont, a plaintiff in the lawsuit, in a statement today on PR Newswire. ``The FDA has moved to a more neutral course, while still recognizing the serious health risks posed by amalgam in particular for children and unborn children, for pregnant women, and for those with mercury immuno-sensitivity.''

Mercury is a neurotoxin that can interfere with brain growth and has been shown to affect cognitive and motor-skill development, according to the Environmental Protection Agency.

Dental Association Denials Begin

The American Dental Association, the largest group of U.S. dentists, said the settlement amounts to little because it doesn't change the current use of mercury. Cavities are filled with the amalgam, made of mercury and a powder containing silver, tin, copper, zinc and other metals. Dentists have used it for more than 100 years.

``Dental amalgam remains a safe, affordable and durable cavity-filling choice for dental patients,'' the dental group said in a statement today on PR Newswire. That belief, the group said, is based on ``extensive studies and scientific reviews of dental amalgam by government and independent organizations worldwide.''

An FDA panel of independent advisers voted 13 to 7 in 2006 to reject the agency's conclusion that the available literature supports continued use of mercury in fillings. The agency had said it reviewed 34 studies and found no evidence the metal releases harmful mercury vapors in the mouth from chewing or during dental procedures.

Data Sought

Many members of the panel, which included doctors and dentists, said the risks associated with mercury fillings can't be quantified without better data on short-term exposure and certain patient groups. About 30 percent of the more than 150 million fillings placed in the U.S. each year are made of amalgam.

Patient advocates urged the panel to recommend that the FDA ban amalgam in favor of tooth-colored composite resins, which they said are safer and just as effective.

Dentists argued that fillings containing mercury are stronger, cheaper and more durable, and said the amount of mercury exposure from fillings is minuscule when compared with fish and other dietary sources.

The lawsuit was filed in December in U.S. District Court in Washington and then assigned by a federal trial judge to a magistrate who served as a mediator, Long said. FDA officials added the cautionary language to the agency Web site on June 3 with ``uncharacteristic speed,'' Bender said.

The case is: Moms Against Mercury v. Eschenbach, 07cv2332, U.S. District Court for the District of Columbia.

Les' comments:

If we were to apply the Dental Association mind-set to the rest of technology we'd still be communicating by telegraph, riding in horse drawn buggies and using candles for light. Safe compounds are out there, insist on them. My dentist urged me to use the modern compounds, plus who wants a big-ass black spot on their teeth?!

Saturday, April 5, 2008

Bacteria resistant to antibiotics

By Julie SteenhuysenThu Apr 3, 5:48 PM ET

Several strains of bacteria in the soil can make a meal of the world's most potent antibiotics, researchers said on Thursday, in a startling finding that illustrates the extent to which these germ-fighting drugs are losing the war against superbugs.

A study of soil microbes taken from 11 sites uncovered bacteria that could withstand antibiotics 50 times stronger than the standard for bacterial resistance.

"It certainly was very surprising to us," said George Church, a geneticist at Harvard Medical School in Boston, whose research appears in the journal Science.

"Many bacteria in many different soil isolates can not only tolerate antibiotics, they can actually live on them as their sole source of nutrition," Church said in an audio interview on the journal's Web site.

Other researchers have found antibiotic-eating strains of bacteria, but Church's study is among the most systematic. It offers more clues about why bacteria quickly develop resistance to antibiotics, and why drug companies must constantly develop new antibiotics to defeat them.

Church's team initially set out to find organisms in the soil that remove toxins from cellulose, the material that gives plants structure. They took samples from a variety of sites, including a cornfield fertilized by manure from cows that were fed antibiotics.

Microbes taken from these soil samples could easily defeat toxins from cellulose, which they expected. Then the researchers tested the microbes against antibiotics, something they thought would be toxic.

"We were expecting them to grow on cellulose and we weren't expecting them to grow on antibiotics," Church said.

Surprised by how easily the microbes devoured the antibiotics, Church and colleagues did a broader test, exposing hundreds of microbes to 18 antibiotics representing most of the major classes of naturally occurring and synthetic antibiotics, including penicillin and the widely prescribed antibiotic ciprofloxacin.

"We could find ... bacteria that could grow on almost all of them," depending on the bacteria and the source of the soil, Church said.

The bacteria were not known to attack humans, but some were close relatives, such as members of the Burkholderia cepacia complex, a group of bacteria that infect people with cystic fibrosis, and Serratia marcescens, which can cause blood infections in people with compromised immune systems.

Church said the finding underscores the extent to which bacteria have developed resistance to antibiotics, a process that started almost as soon as penicillin was introduced in the 1940s. Overuse and misuse of antibiotics have since fueled the rise of drug-resistant superbugs.

"This is yet another way of looking at resistance," Church said of the study. He said the microbes he found may be using a new way to disarm the antibiotics, but it may take some time to figure that out.

One antibiotic resistant infection, caused by a strain known as methicillin-resistant Staphylococcus aureus, or MRSA, is blamed for killing 19,000 people in the United States in 2005.

Monday, March 10, 2008

Area Tap Water Has Traces of Medicines

Tests Find 6 Drugs, Caffeine in D.C., Va.

By Carol D. Leonnig
Washington Post Staff Writer
Monday, March 10, 2008; B01

The Washington area's drinking water contains trace amounts of six commonly used drugs that typically turn up in wastewater and cannot be filtered out by most treatment systems.

The pharmaceuticals -- an anti-seizure medication, two anti-inflammatory drugs, two kinds of antibiotics and a common disinfectant -- were found in very small concentrations in the water supply that serves more than 1 million people in the District, Arlington County, Falls Church and parts of Fairfax County. But scientists say the health effects of long-term exposure to such drugs are not known.

Pharmaceuticals, along with trace amounts of caffeine, were found in the drinking water supplies of 24 of 28 U.S. metropolitan areas tested. The findings were revealed as part of the first federal research on pharmaceuticals in water supplies, and those results are detailed in an investigative report by the Associated Press set to be published today.

In addition to caffeine, the drugs found in water treated by the Washington Aqueduct include the well-known pain medications ibuprofen and naproxen, commonly found in Aleve. But there were also some lesser-known drugs: carbamazepine, an anti-convulsive to reduce epileptic seizures and a mood stabilizer for treating bipolar disorders; sulfamethoxazole, an antibiotic that can be used for humans and animals in treating urinary tract and other infections; and monensin, an antibiotic typically given to cattle. In addition, the study uncovered traces of triclocarban, a disinfectant used in antibacterial soaps.

That the drugs were found so commonly nationwide highlights an emerging water dilemma that the public rarely considers. The drugs we use for ourselves and animals are being flushed directly into wastewater, which then becomes a drinking water source downstream. However, most wastewater and drinking water treatment systems, including Washington's, are incapable of removing those drugs.

And although the chemicals pose no immediate health threat in the water, the health effects of drinking these drug compounds over a long period is largely unstudied. Some scientists said there is probably little human health risk; others fear chronic exposure could alter immune responses or interfere with adolescents' developing hormone systems.

Washington's water regulators and utility officials say they are not alarmed by the findings because the drugs are found at such low levels -- parts per trillion, a tiny fraction of the amount in a medical dose. But they do view these "emerging contaminants" with concern.

"What concerns me is we're finding pharmaceuticals in the river that we rely upon for drinking water," said Thomas P. Jacobus, general manager of the Washington Aqueduct. "If we can't get them out, we have to find a way to neutralize them if we find there's a health effect from them."

Jacobus said the aqueduct leadership will recommend in the next few months likely upgrades for water treatment to deal with an array of newly identified and increasing contaminants in the water. The aqueduct uses chlorine, which kills a wide group of bacteria and breaks down some chemicals but cannot disrupt pharmaceuticals. Studies show ozone water treatment is the most effective in zapping such drugs.

The U.S. Geological Survey and the U.S. Department of Agriculture have been screening Washington's and other cities' water supplies for pharmaceuticals in the first research project on pharmaceuticals in the water. The Washington Aqueduct, an arm of the U.S. Army Corps of Engineers, does not regularly screen for caffeine or pharmaceuticals, nor do most water utilities.

The drugs discovered in testing over the past two years typically get into the water supply because they pass through a user's body and are flushed downstream. The U.S. Environmental Protection Agency is studying some pharmaceuticals for their impact on public health but has not set safety standards for any of the drugs.

"We recognize it is a growing concern, and we're taking it very seriously," Benjamin H. Grumbles, the EPA's assistant administrator for water, said of the drugs' presence.

There is no clear evidence of a human health threat from such low levels of pharmaceuticals. But scientists warn that, because there has been very little study of the long-term or synergistic effects of this kind of drug exposure, water providers and regulators need to exercise caution. Although experts agree that aquatic life are most at risk from exposure to the drugs in rivers and streams, researchers are concerned about what they don't know about human health effects.

In other findings from its reporting, the AP said officials in Montgomery County and Fairfax have found numerous pharmaceuticals in their environmental watersheds but do not test their drinking water supplies for the same chemical compounds.

Nationwide, the AP reported that researchers found anti-depressants, antacids, synthetic hormones from birth control pills, and many other human and animal medicines in the water. In San Francisco, tests found a sex hormone. In New York, the water tested positive for heart medicines and a prescription tranquilizer.

The Associated Press contributed to this report.

Saturday, March 8, 2008

FDA/EPA advisory on the dangers of methylmercury

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March 2004EPA-823-R-04-005
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What You Need to Know About Mercury in Fish and Shellfish

2004 EPA and FDA Advice For:
Women Who Might Become Pregnant
Women Who are Pregnant
Nursing Mothers
Young Children

Fish and shellfish are an important part of a healthy diet. Fish and shellfish contain high-quality protein and other essential nutrients, are low in saturated fat, and contain omega-3 fatty acids. A well-balanced diet that includes a variety of fish and shellfish can contribute to heart health and children's proper growth and development. So, women and young children in particular should include fish or shellfish in their diets due to the many nutritional benefits.

However, nearly all fish and shellfish contain traces of mercury. For most people, the risk from mercury by eating fish and shellfish is not a health concern. Yet, some fish and shellfish contain higher levels of mercury that may harm an unborn baby or young child's developing nervous system. The risks from mercury in fish and shellfish depend on the amount of fish and shellfish eaten and the levels of mercury in the fish and shellfish. Therefore, the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) are advising women who may become pregnant, pregnant women, nursing mothers, and young children to avoid some types of fish and eat fish and shellfish that are lower in mercury.

By following these 3 recommendations for selecting and eating fish or shellfish, women and young children will receive the benefits of eating fish and shellfish and be confident that they have reduced their exposure to the harmful effects of mercury.

  1. Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.

  2. Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.

    • Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.

    • Another commonly eaten fish, albacore ("white") tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.

  3. Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don't consume any other fish during that week.

Follow these same recommendations when feeding fish and shellfish to your young child, but serve smaller portions.

Frequently Asked Questions about Mercury in Fish and Shellfish:

  1. "What is mercury and methylmercury?"
    Mercury occurs naturally in the environment and can also be released into the air through industrial pollution. Mercury falls from the air and can accumulate in streams and oceans and is turned into methylmercury in the water. It is this type of mercury that can be harmful to your unborn baby and young child. Fish absorb the methylmercury as they feed in these waters and so it builds up in them. It builds up more in some types of fish and shellfish than others, depending on what the fish eat, which is why the levels vary.

  2. "I'm a woman who could have children but I'm not pregnant - so why should I be concerned about methylmercury?"
    If you regularly eat types of fish that are high in methylmercury, it can accumulate in your blood stream over time. Methylmercury is removed from the body naturally, but it may take over a year for the levels to drop significantly. Thus, it may be present in a woman even before she becomes pregnant. This is the reason why women who are trying to become pregnant should also avoid eating certain types of fish.

  3. "Is there methylmercury in all fish and shellfish?"
    Nearly all fish and shellfish contain traces of methylmercury. However, larger fish that have lived longer have the highest levels of methylmercury because they've had more time to accumulate it. These large fish (swordfish, shark, king mackerel and tilefish) pose the greatest risk. Other types of fish and shellfish may be eaten in the amounts recommended by FDA and EPA.

  4. "I don't see the fish I eat in the advisory. What should I do?"
    If you want more information about the levels in the various types of fish you eat, see the FDA food safety website www.cfsan.fda.gov/~frf/sea-mehg.html or the EPA website at www.epa.gov/ost/fish.

  5. "What about fish sticks and fast food sandwiches?"
    Fish sticks and "fast-food" sandwiches are commonly made from fish that are low in mercury.

  6. "The advice about canned tuna is in the advisory, but what's the advice about tuna steaks?"
    Because tuna steak generally contains higher levels of mercury than canned light tuna, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of tuna steak per week.

  7. "What if I eat more than the recommended amount of fish and shellfish in a week?"
    One week's consumption of fish does not change the level of methylmercury in the body much at all. If you eat a lot of fish one week, you can cut back for the next week or two. Just make sure you average the recommended amount per week.

  8. "Where do I get information about the safety of fish caught recreationally by family or friends?"
    Before you go fishing, check your Fishing Regulations Booklet for information about recreationally caught fish. You can also contact your local health department for information about local advisories. You need to check local advisories because some kinds of fish and shellfish caught in your local waters may have higher or much lower than average levels of mercury. This depends on the levels of mercury in the water in which the fish are caught. Those fish with much lower levels may be eaten more frequently and in larger amounts.

For further information about the risks of mercury in fish and shellfish call the U.S. Food and Drug Administration's food information line toll-free at 1-888-SAFEFOOD or visit FDA's Food Safety website www.cfsan.fda.gov/seafood1.html

For further information about the safety of locally caught fish and shellfish, visit the Environmental Protection Agency's Fish Advisory website www.epa.gov/ost/fish or contact your State or Local Health Department. A list of state or local health department contacts is available at www.epa.gov/ost/fish. Click on Federal, State, and Tribal Contacts. For information on EPA's actions to control mercury, visit EPA's mercury website at www.epa.gov/mercury.

This document is available on the web at http://www.cfsan.fda.gov/~dms/admehg3.html.

This document is also available in brochure format in both English and Spanish.

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Deal in an Autism Case Fuels Debate on Vaccine

March 8, 2008

WASHINGTON — Study after study has failed to show any link between vaccines and autism, but many parents of autistic children remain unconvinced. For the skeptics, the case of 9-year-old Hannah Poling shows that they have been right along.

The government has conceded that vaccines may have hurt Hannah, and it has agreed to pay her family for her care. Advocates say the settlement — reached last fall in a federal compensation court for people injured by vaccines, but disclosed only in recent days — is a long-overdue government recognition that vaccinations can cause autism.

“This decision gives people significant reason to be cautious about vaccinating their children,” John Gilmore, executive director of the group Autism United, said Friday.

Mr. Gilmore has filed his own claim that his son became autistic as a result of vaccinations.

Government officials say they have made no such concession.

“Let me be very clear that the government has made absolutely no statement indicating that vaccines are a cause of autism,” Dr. Julie L. Gerberding, director of the Centers for Disease Control and Prevention, said Thursday. “That is a complete mischaracterization of the findings of the case and a complete mischaracterization of any of the science that we have at our disposal today.”

Hannah, of Athens, Ga., was 19 months old and developing normally in 2000 when she received five shots against nine infectious diseases. Two days later, she developed a fever, cried inconsolably and refused to walk. Over the next seven months she spiraled downward, and in 2001 she was given a diagnosis of autism.

Hannah’s father, Dr. Jon Poling, was a neurology resident at Johns Hopkins Hospital at the time, and she underwent an intensive series of tests that found a disorder in her mitochondria, the energy factories of the cells.

Such disorders are uncommon, their effects can be significant but varied, and the problems associated with them can show up immediately or lie dormant for years.

There are two theories about what happened to Hannah, said her mother, Terry Poling. The first is that she had an underlying mitochondrial disorder that vaccinations aggravated. The second is that vaccinations caused this disorder.

“The government chose to believe the first theory,” Ms. Poling said, but added, “We don’t know that she had an underlying disorder.”

In a news conference on Thursday, Dr. Edwin Trevathan, director of the National Center for Birth Defects and Development Disabilities at the disease control agency, said, “I don’t think we have any science that would lead us to believe that mitochondrial disorders are caused by vaccines.”

Dr. Trevathan explained that children with mitochondrial disorders often develop normally until they come down with an infection. Then their mitochondria are unable to manufacture the energy needed to nourish the brain. As a result, they regress.

The Poling case has become a flashpoint in the long-running controversy over thimerosal, a vaccine preservative containing mercury. Some people believe that thimerosal is behind the rising number of autism diagnoses. Among them is Lyn Redwood, director of the Coalition for SafeMinds.

Many of the vaccines Hannah received contained thimerosal, and to Ms. Redwood, she is more proof of thimerosal’s dangers.

The disease control centers, the Food and Drug Administration, the Institute of Medicine, the World Health Organization and the American Academy of Pediatrics have all largely dismissed the notion that thimerosal causes or contributes to autism.

Five major studies have found no link, and since thimerosal’s removal from all routinely administered childhood vaccines in 2001, there has been no apparent effect on autism rates.

Many of those who believe in an autism-vaccine link dismiss all this evidence, and Hannah’s case fuels their cause.

“Her story is very important because it echoes so many others, and it’s clear that thimerosal played a role,” said Rita Shreffler, executive director of the National Autism Association.

Dr. and Mrs. Poling said Hannah did not prove the case against thimerosal, but Dr. Poling noted that there was no debate that vaccines had risks.

“They’re not safe for everybody,” he said, “and one person for whom they proved unsafe happened to be my daughter.”

Dan Burton: Statement of Support of the Combating Autism Act (S.843)

Mr. Speaker, I rise in support of the Combating Autism Act of 2006 (S.843) as amended. I want to thank Chairman Nathan Deal and Chairman Joe Barton, and the Energy & Commerce Committee staff, for bringing this bill to the floor today.

Over the last five years or more, many of you have heard me speak many times on this floor about the subject of autism and you will likely continue to hear me speak on this issue because I believe we truly have our work cut out for us. About 20 years ago, autism was considered a rare disease, affecting about 1 in 10,000 children. Now, that rate is about 1 in 166; making autism the third most common developmental disability that children face, even more prevalent than things such as Down's Syndrome and other childhood cancers. In my own home State of Indiana we experienced a 923% cumulative growth rate for autism from 1992-2003. The annual growth rate of autism in Indiana averaged 27 % compared to an average of 7% for the growth rate of all disabilities.

This literal epidemic of autism is a looming and immediate economic crisis to our education system, our health care systems, our long-term housing and care system for the disabled, and most especially, to an ever increasing number of families across the country. Autism is a condition that has no known cure which means that this is a crisis that is simply not going to ``go away.''

Today we take a huge step forward in terms of dealing with this problem. Although in my opinion, only a down payment on the resources that we must invest in order to defeat this terrible scourge, the Combating Autism Act, commits nearly $1 billion - in essence almost a doubling of funding for autism - to autism research, including essential research on environmental factors, treatments, early identification and support services. This bill amounts to a long over due and vitally needed declaration of war by the Congress of the United States on autism.

Even so, while a needed step forward, this is not a perfect bill, because I believe we are missing a crucial opportunity to use this bill to help unravel the mystery of autism. Specifically, while the bill before us does include language on the need to research the environmental factors which may contribute to autism, it does not include a specific mandate that environmental research topics must include vaccines, other biologics, and their preservatives. Now I am not against vaccinations, but I do believe, as do many of my colleagues that there is a strong link between the mercury contained in a product called thimerosal - commonly used as a vaccine preservative - and children developing neurological disorders such as autism. In fact, my own grandson became autistic after receiving 9 shots in one day, 7 of which contained thimerosal.

Because of what happened to my grandson I took it upon my self to learn about autism and what I discovered during my research was deeply disturbing. During my tenure as Chairman of Government Reform Committee (1997-2002), and as Chairman of the Subcommittee on Human Rights & Wellness (2003-2005), a number of very credible national and international scientists testified at a series of hearings that the mercury in vaccines is a contributing factor to developing neurological disorders, including, but not limited to, modest declines in intelligence quotient (IQ), autism, and Alzheimer's Disease. And the body of evidence to support that conclusion gets larger every day.

Yet we continue to hear repeatedly in Congressional hearings, in media communications, and through government and scientific reports that ``there is no evidence that proves a connection between vaccines and autism." This conclusion is not too surprising when you consider that our health agencies seem to routinely dismiss out of hand any scientific study that does conclude thimerosal is a danger.

Experience tells us that, as with any other epidemic, while there may be underlying genetic susceptibilities, there usually is some type of environmental trigger as well, such as a virus, fungus, heavy metals, pollutants, or whatever. There has never, to the best of my knowledge, been a purely genetic epidemic. So, genetics alone cannot explain how we went from 1 in 10,000 children with autism spectrum disorders twenty years ago to 1 in 166 today. Considering that mercury is a base element and the most toxic substance known to science outside of radioactive materials, it is biologically plausible that mercury is an environmental trigger of autism.

Recent studies indicate that more than half of pediatricians said that in the previous year they had encountered at least one family that refused all vaccines, while 85 percent said they'd had a parent turn down at least one shot. Whether it's because of fear that mercury used as a preservative in childhood vaccines causes autism, or that the dangers of immunizations far outweigh their benefits, or that there is a conspiracy by drug companies, doctors and vaccine makers to conceal the harm, the facts are clear, more and more American families are fighting immunization.

It is imperative that we do all we can to restore the public's trust in vaccinations. And the only way we are going to resolve the conflict of opinion over thimerosal is through more research. Unfortunately, if the Department of Health and Human Services never funds or conducts the right studies, and given their current track record on the subject that is very likely what will happen, this question will forever remain unanswered. That will be a national tragedy because often once an environmental cause is discovered, immediate steps can be taken to prevent new cases and abate the epidemic. In addition, knowledge of the environmental cause or triggers often leads directly to more effective treatments.

For example, this bill promotes the use of evidence-based interventions for those at higher risk for autism. However, so long as we ignore the potential danger of mercury many biomedical interventions, such as restricted diet, applied kinesiology and/or chelation therapy - which many families have found to be the best treatments for their children with autism - will be excluded from the list of evidence-based treatments.

I stand here today not just as a concerned grandfather of an autistic child but as the voice for the hundreds of parents and families who continue to contact my office looking for help for their children. They are our constituents, we represent them in the People's House, and I hope we are all listening to them. The debate about mercury in vaccines must be addressed, investigated and resolved. Parents have a right to know what happened to their children regardless of where the truth lies. And we have a responsibility to those children and families already suffering. In the meantime, we should err on the side of caution and remove thimerosal, even trace amounts, from all vaccinations.

By failing to provide a clear Congressional mandate to research ALL of the potential environmental causes of Autism Spectrum Disorders (ASD), including vaccines and their preservatives, I believe we are handicapping our efforts to give all ASD patients the best possible quality of life and the ability to make the greatest possible contributions to society. I hope that in the coming weeks, months and years this Congress will push for further research into the question of thimerosal and autism so that one day we will be able to say that we have done everything possible to stop and treat this epidemic. In the meantime, I urge my colleagues to support this very good bill.

Thursday, February 28, 2008

If this happens a super flu bug is sure to follow

The New York Times
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February 28, 2008

Panel Advises Flu Shots for Children Up to Age 18

All children ages 6 months to 18 years in this country should receive an influenza shot every year, a federal advisory panel said on Wednesday.

The recommendation expands by about 30 million the number of children who should get annual flu shots. Current pediatric recommendations call for influenza vaccinations for children ages 6 months to about 5 years.

In expanding the new upper age limit to 18 years, the aim is to reduce both the time children and parents lose from visits to pediatricians and missing school and the need for antibiotics for complications, said Dr. Anne Schuchat, who directs the disease agency’s program on immunization and respiratory diseases.

An added expected benefit would be indirect — to reduce the number of influenza cases among parents and other household members, and possibly spread to the general community.

The recommendation, which is voluntary, was made by the Advisory Committee on Immunization Practice, which advises the Centers for Disease Control and Prevention in Atlanta. The C.D.C. and its parent, the Department of Health and Human Services, generally follow the advice of the committee, which is composed of vaccine experts from academia and the private sector.

The committee voted unanimously that the expanded immunization should start as soon as possible, but no later than the 2009-10 flu season. The centers expect that the vaccine industry, which made 132 million doses available this year, will be able to produce a sufficient supply in future years.

Every state but one has reported widespread influenza this winter. In Florida, activity is regional. Last week, the centers reported that 22 children had died in this influenza season.

The C.D.C. has long urged older adults and those with chronic ailments to get influenza shots each season.

In 2004, following the advisory committee’s recommendation, the centers urged that all infants ages 6 months to 23 months receive flu shots to protect them from serious complications of the viral illness. Hospitalization rates among the infant group rivals those among elderly Americans.

In 2006, the centers expanded the recommendation to include children ages 24 months to 59 months to provide them direct protection against influenza infection.

For initial protection, children ages 6 months to 9 years require two doses of flu vaccine, at least one month apart, the committee said. Then they should receive annual shots.

In a new study reported at Wednesday’s meeting, Dr. David K. Shay, who led a team from the C.D.C. and eight state health departments, found that full immunization against flu provided about a 75 percent effectiveness rate in preventing hospitalizations from influenza complications in the 2005-6 and 2006-7 influenza seasons. (The 75 percent rate could range, according to a standard statistical measure known as confidence intervals, from 41 percent to 91 percent.)

The study, which involved children ages 6 months to 23 months who had laboratory confirmed cases of influenza, will continue through this flu season. Because this season seems to be more severe than the last two, the researchers expect to have more cases to analyze and improve the statistical odds.

Vaccines are typically designed to protect against the three strains of influenza. Experts determine the strains based on data from current seasonal transmission and their judgment about future activity. Usually one or two strains are changed in each year’s vaccine.

But committees from the World Health Organization and the United States Food and Drug Administration voted earlier this month to change all three strains in next season’s vaccine. It is the first time that all three strains were changed at once, Dr. Nancy Cox, an influenza expert at the C.D.C., said in a news conference on Feb. 22.

The centers recommendations for annual flu shots for adults include all Americans ages 50 and older; people with chronic lung, heart and other ailments; health care workers; and women who will be pregnant during the influenza season.

Monday, February 25, 2008

New generation anti-depressants have little clinical benefit for most patients, research suggests.

Anti-depressants 'of little use'

The University of Hull reviewed published clinical trial data, and unpublished data secured under Freedom of Information legislation.

They found the drugs helped only a small group of the most severely depressed, and in most cases had no more effect than taking a dummy pill.

The Royal College of Psychiatrists said the findings were "very important".

In total, the Hull team, who published their findings in the journal PLoS Medicine, reviewed data on 47 clinical trials.

They focused on drugs in the class known as Selective Serotonin Reuptake Inhibitors (SSRIs), which work by increasing levels of the mood controlling chemical serotonin in the brain.

These included fluoxetine (Prozac), venlafaxine (Efexor) and paroxetine (Seroxat) - all commonly prescribed in the UK.

There seems little reason to prescribe anti-depressant medication to any but the most severely depressed patients
Professor Irving Kirsch
University of Hull

The number of prescriptions for anti-depressants hit a record high in England in 2006 - even though official guidance stresses they should not be a first line treatment for mild depression.

The researchers found that even the positive effects seen on severely depressed patients were relatively small, and open to interpretation.

The seemingly good result came from the fact that these patients' response to the placebo decreased, rather than any notable increase in their response to anti-depressants.

Lead researcher Professor Irving Kirsch said: "The difference in improvement between patients taking placebos and patients taking anti-depressants is not very great.

"This means that depressed people can improve without chemical treatments.

"Given these results, there seems little reason to prescribe anti-depressant medication to any but the most severely depressed patients, unless alternative treatments have failed to provide a benefit."

Saturday, February 23, 2008

Flu shot formula off target this year

When are people going to wake up to the flu vaccine hoax?

Washington Post
Published on: 02/11/08

Washington —- Seasonal influenza is spreading widely throughout the United States, with nearly half the cases caused by strains of the virus that are not directly covered by this year's flu vaccine.

Whether the winter will end up being worse than usual remains to be seen. Flu mortality in adults has been higher than in the last two years, but deaths in children —- an important marker of severity —- have been rare.

Nevertheless, this winter is likely to be one of the few times that public health experts lose the bet they make each year when they devise the formula for the flu vaccine —- eight months before the virus starts circulating in the fall to allow time to produce mass quantities of the vaccine.

"Most years, the prediction is very good," said Joseph Bresee, an influenza epidemiologist at the Atlanta-based Centers for Disease Control and Prevention. "In 16 of the last 19 years, we have had a well-matched vaccine."

But probably not this time.

What happened

Each year, the vaccine contains representatives of the three huge families of flu virus that are currently circulating. They are two main types of influenza A, H1N1 and H3N2, and influenza B.

The viruses in each of these lineages are constantly changing through mutation. Inevitably, one appears that is different enough that a person protected against them is not protected against the new variant.

A version of this scenario apparently happened twice this year.

> A new strain of H3N2 virus was identified in Brisbane, Australia, last February, a few weeks after the components of this winter's vaccine were chosen.

But it was too late to substitute "Brisbane/10" for the H3N2 strain, called "Wisconsin," that had been in the vaccine since the 2006-07 season. From the start of flu season until the beginning of February, 34 percent of flu viruses taken from patients around the country were Brisbane strains.

> At the same time, a strain of influenza B called "Yamagata," which is significantly different from the "Victoria" B strain in the vaccine, was taking off.

About 16 percent of all flu samples this winter are influenza B, and of them 93 percent are Yamagata.

Together, the Brisbane and Yamagata strains are accounting for 48 percent of all flu samples this winter —- and neither is in the vaccine.

Any benefit?

That does not mean the vaccine is without benefit. The immunity conferred by the Wisconsin strain may protect somewhat against its Brisbane descendant. A vaccinated person may have milder symptoms. But the vaccine is unlikely to prevent infection altogether in lots of people.

A study done by the Department of Defense last year after Brisbane emerged found that it was 52 percent effective in preventing infection.

That is much lower than the 70 percent to 90 percent protection provided by a well-matched vaccine given to healthy, young adults. But it is not useless, either.

"It wouldn't be optimal, but there should be a measure of protection, based on our past experience," said Nancy Cox, the chief flu virologist at CDC.

Protection against the Yamagata strain by the vaccine is probably also poor. The best evidence that Yamagata is not well covered by the vaccine is that it is just about the only strain of influenza B around.

"That probably indicates that the effectiveness of the vaccine may be less than ideal," Bresee said.

Next year?

Influenza virologists from around the world will gather in Geneva, Switzerland, this week to decide the formula for next year's vaccine.

Saturday, February 16, 2008

China Didn’t Check Drug Supplier, Files Show

A Chinese factory that supplies much of the active ingredient for a brand of a blood thinner that has been linked to four deaths in the United States is not certified by China’s drug regulators to make pharmaceutical products, according to records and interviews.

Because the plant, Changzhou SPL, has no drug certification, China’s drug agency did not inspect it. The United States Food and Drug Administration said this week that it had not inspected the plant either — a violation of its own policy — before allowing the company to become a major supplier of the blood thinner, heparin, to Baxter International in the United States.

Baxter announced Monday that it was suspending sales of its multidose vials of heparin after 4 patients died and 350 suffered complications. Why the heparin caused these problems — and whether the active ingredient in the drug, derived from pig intestines, was responsible — has not been determined.

The plant in Changzhou, west of Shanghai, appears to fall into the type of regulatory void that American and Chinese health officials are trying to close — in which chemical companies export pharmaceutical ingredients without a Chinese drug license.

China provides a growing proportion of the active pharmaceutical ingredients used in drugs sold in the United States. And Chinese drug regulators have said that all producers of those ingredients are required to obtain certification by the State Food and Drug Administration. However, some of the active ingredients that China exports are made by chemical companies, which do not fall under the Chinese drug agency’s jurisdiction.

In December, American and Chinese regulators signed an agreement under which China promised to begin registering at least some of the thousands of chemical companies that sell drug ingredients. Some of these companies are the source of counterfeit or diluted drugs, including those used to treat malaria.

Discussions that led to the accord began after an unlicensed chemical plant in China made a tainted drug ingredient that poisoned more than 170 people in Panama, killing at least 115.

The heparin plant in China has not been accused of providing a harmful product. The American majority owner of that plant, Scientific Protein Laboratories, also owns a plant in Wisconsin that produces the active ingredient in heparin for Baxter.

In response to questions, Scientific Protein issued a statement confirming that its Chinese plant had no license from the Chinese agency, but said that its raw ingredients come from a licensed supplier.

The statement added that an “independent private U.S. validation company” had found the plant to be in compliance with good manufacturing practices. And a spokeswoman for Baxter, which buys heparin’s active ingredient from Scientific Protein, said it had inspected the China plant less than six months ago.

A spokesman for China’s State Food and Drug Administration, Shen Chen, said Friday that “as far as we know, it is not a drug manufacturer — it is a producer of chemical ingredients.”

Eric S. Langer, managing partner of BioPlan Associates, which prepares and publishes reports on the biopharmaceutical and biotechnology industry, said he found it hard to believe that a company exporting the heparin ingredient would not be licensed by Chinese drug regulators.

“Being able to produce a pharmaceutical or a biologic in the U.S. or anywhere without having regulatory oversight really doesn’t happen,” Mr. Langer said, adding, “I find it surprising from a regulatory perspective, and I find it surprising from a business perspective.”

Karen Riley, a spokeswoman for the United States Food and Drug Administration, said inspectors from that agency would be visiting the Changzhou plant soon. Ms. Riley said she could not be more specific. Earlier in the week she described her agency’s failure to inspect the plant as a “glitch.”

Congress has criticized the oversight by the Food and Drug Administration of bulk pharmaceutical ingredients made by foreign manufacturers and sold in the United States. A growing number of those ingredients now come from China. Of the 700 approved Chinese drug plants, the United States agency has inspected only 10 to 20 each year.

Baxter makes roughly half of the United States supply of heparin, which is used widely for surgical and dialysis patients. Problems with Baxter’s heparin were first noticed late last year when four children undergoing dialysis in Missouri had severe allergic reactions minutes after being injected with the drug.

The F.D.A. then allowed Baxter to deliver heparin that it was in the midst of shipping, for fear that a total recall would lead to a shortage of the drug, but cautioned doctors to use as little of it as possible and to administer it very slowly.

The agency also suggested that doctors give steroids or antihistamines with the Baxter heparin to help prevent allergic reactions.

Erin Gardiner, a spokeswoman for Baxter, defended Scientific Protein, saying it had been making the heparin ingredient for more than 30 years. “They have been a good supplier,” she said.

Although the cause of the adverse reactions has yet to be determined, she said tests performed by her company had detected unspecified differences between some lots of the ingredient. She did not say whether the lots had come from China or from the Wisconsin plant, which Scientific Protein also owns.

Those differences had not turned up in routine testing that the company does on active ingredients, Ms. Gardiner said, but she said Baxter had used “advanced testing techniques” to find the differences. She added that it was unclear whether the finding was significant.

Two Congressional committees have asked the Food and Drug Administration for more information about inspections of plants making the active ingredient of heparin.

Andrew W. Lehren contributed reporting.

Friday, February 1, 2008

Tamiflu-Resistant Flu Found in Nine European Nations

By Jason Gale

Feb. 1 (Bloomberg) -- Influenza strains resistant to Roche Holding AG's Tamiflu were found in a samples from five more countries, indicating the mutant bug is more widespread than health officials reported earlier this week.

Tests on 437 virus specimens from patients with the H1N1 flu strain in 18 countries found 59 that harbored resistance to the pill, the European Centre for Disease Prevention and Control said in a statement yesterday. Resistant viruses were found in nine European countries, with Norway accounting for almost half.

Emerging resistance to Tamiflu, also known as oseltamivir, has led doctors to consider GlaxoSmithKline Plc's Relenza and other treatments for a disease the World Health Organization estimates causes 250,000 to 500,000 deaths globally each year. Experts are assessing the significance of the data and will release an interim assessment in the coming days, ECDC said.

``At this stage, it is impossible to say what the level of resistance is in influenza across Europe,'' the Stockholm-based health agency said. ``However from the limited data, the proportion of influenza viruses exhibiting resistance to oseltamivir must be significant, but not as high as in Norway.''

The H1N1 viruses identified in Europe that aren't susceptible to Tamiflu carry a so-called H274Y gene mutation that confers ``high-level resistance,'' Frederick Hayden, a researcher with the WHO's Global Influenza Program in Geneva, said in a Jan. 28 interview.

U.S. Strains

Of 109 H1N1 viral samples tested in the U.S. during the 2007-2008 flu season, 5.5 showed the same resistance-inducing mutation, according to the Centers for Disease Control and Prevention in Atlanta.

Recent tests on samples from Europe found viruses with the H274Y mutation in Germany, Netherlands, Portugal, Sweden and Finland, scientists from the U.K.'s Health Protection Agency said in a report published yesterday in Eurosurveillance, a newsletter on communicable diseases.

Earlier sampling found the mutant strain in France, the U.K., Denmark, France and Norway, the ECDC said in a Jan. 27 risk assessment report. Of 37 samples from Norway tested, 26 harbor resistance, the agency said yesterday.

``The oseltamivir resistance investigation is still in its early stages,'' researchers from the ECDC's Influenza Project Team wrote in a separate report in yesterday's Eurosurveillance. ``A more accurate picture will only emerge when many more specimens have been tested and more epidemiological information is available.''

Tests so far show that the mutated viruses are susceptible to Relenza and an older class of antiviral drugs known as adamantanes, the researchers said. There's insufficient evidence for authorities to consider changes to clinical guidelines, the researchers said.

No More Virulent

People who become ill with the Tamiflu-resistant H1N1 strain don't appear to become any more sick than people infected with ``normal'' seasonal flu, ECDC said.

Tamiflu, which generated 2.09 billion francs ($1.9 billion) in sales for Basel, Switzerland-based Roche in 2007, is the company's fifth-best-selling drug. Relenza, an inhaled medicine, had sales of 91 million pounds ($181 million) in 2006 for London-based Glaxo.

The medicines are being stockpiled by the Geneva-based WHO and governments around the world for use in the event of a pandemic, and to treat the H5N1 avian flu strain that's spread to more than 60 countries, infecting people in 14 of them.

The H5N1 bird flu strain could trigger a global outbreak if it adopts some of the characteristics of seasonal flu that enable it to be spread easily through coughing and sneezing.

To contact the reporter on this story: Jason Gale in Singapore at j.gale@bloomberg.net

Last Updated: February 1, 2008 00:53 EST

Wednesday, January 9, 2008

Latest Affront to Common Sense

California study finds no link between vaccine ingredient, autism

Tuesday, January 8, 2008

Rates of autism have increased in California despite the removal of the preservative thimerosal from childhood vaccines seven years ago, a finding that researchers say disproves the theory that the mercury in thimerosal causes the mysterious neurological disorder.

The study, which analyzed autism rates in young children over a 12-year period, is the first to offer hard evidence that thimerosal plays no role in autism. Results of the study were released Monday in the Archives of General Psychiatry, a publication of the Journal of the American Medical Association.

"Whatever the explanation for this increase in children with autism, exposure to mercury in vaccines is not it," said Robert Schechter, a medical officer with the California Department of Health Services and lead author of the study. "Vaccines with thimerosal and without have been safe and appropriate to give to our children."

But even as researchers held up the study as absolute evidence that childhood vaccinations do not cause autism, some parents were quick to point out what they saw as flaws in the report. They stand by their claim that exposure to mercury - be it in a vaccine or from environmental sources - is a major cause of autism.

Cases of autism, a neurological disorder marked by profound communication problems and impaired social skills, have exploded in the past two decades, pushing the condition to the forefront of medical research. Autism was considered rare before the 1990s, afflicting as few as 5 children per 10,000 births, but the Centers for Disease Control and Prevention estimated last year that as many as 1 in 150 children is diagnosed with autism now.

At least 300,000 children ages 4 to 17 had autism in 2004, according to the CDC, and as many as 1.5 million people in the United States currently have autism.

Symptoms usually appear in the first three years after birth. There is no cure, although therapy can help alleviate symptoms. Boys are nearly four times more likely to be diagnosed with autism than girls.

Many researchers believe there is a genetic component to autism, but several large and vocal parent groups are convinced that exposure to heavy metals - especially mercury - is a major culprit.

Until 2001, most childhood vaccinations included thimerosal, exposing children to a small but significant amount of mercury. Based on recommendations from pediatricians, thimerosal was removed from all childhood vaccinations in 2001. But rates of autism continued to increase, according to the new study.

The study found that rates of autism for 3-year-old children climbed from 0.3 per 1,000 births in 1993 to 1.3 per 1,000 births in 2003. Similar increases were shown for children of all ages.

Many neurological experts and child psychiatrists say the rise in autism rates is most probably due to increased awareness among parents and doctors, possibly resulting in over-reporting of symptoms. There also are cases of doctors giving autism diagnoses to children who have mild developmental disorders just to give them access to disability services, said Bryna Siegel, director of the Autism Clinic at UCSF.

"It's being over-reported, and we're just starting to do studies to figure out why that is," Siegel said. "A lot of clinicians will tell you off the record that they're well aware that kids with a diagnosis of autism will get a variety of services. They're willing to err on the side of autism to get those services."

Siegel said she understands why parents have been eager to prove a relationship between thimerosal and autism, but she thinks it's time to move past that theory.

"It's very hard for parents to find out that they've somehow passed this horrible disorder to their child," Siegel said. "But people like me are exasperated that so much money and attention has gone into disproving the mercury hypothesis, when it could have been going toward treatment and research."

Lyn Redwood, a board member of the National Autism Association who has a child with autism, said it's too soon to rule out environmental factors or even the role of thimerosal.

Many of the children in the California study probably got childhood vaccinations outside the United States, she pointed out. And it's now common for pregnant women to get flu shots, which still contain thimerosal and can therefore expose a fetus to mercury, she said.

"We need to look at these children and the metals in their body and not close the door on any theory," Redwood said. "When we get to the point where there is no more mercury in the vaccines, if they could go back to the database and figure out exposures for each child, then that's something. Otherwise, we're just guessing about whether or not there's an association."