Two percent of U.S. schoolkids – or about a million children – have been diagnosed with some sort of autism, according to the latest government report released on Wednesday -- or at least their parents say they have. It’s a large increase since the last report but experts stress it doesn’t necessarily mean more children are developing autism.

Instead, the numbers suggests that more children are being diagnosed as they get older – probably because of many factors, including increased awareness and more services both to diagnose children and help them, the researchers said.

“Our findings suggest that the increase in prevalence may be due to increased recognition of autism spectrum disorders in recent years, especially when the symptoms were mild,” Stephen Blumberg of the National Center for Health Statistics, which published the report, said in a telephone interview.

“Parents are more aware. Professionals are more aware. There may be more access to diagnostic services.”

Autism describes a range of conditions and disorders – some of which a few years ago were not even recognized as conditions. It can range from the very mild social awkwardness seen in some cases of Asperger’s syndrome, to severe and debilitating symptoms that prevent children from interacting in a normal way, prevent learning and often require medication. Some children with autism were classified as mentally retarded in years past, while others struggled quietly with no idea they could benefit from therapy.

Parents should not worry that something new has been happening to kids, says Dr. Marshalyn Yeargin-Allsopp of the Centers for Disease Control and Prevention, which is monitoring autism in several ways. “We don’t want them to be frightened by the numbers. We want them to recognize that there are things they can do that make a difference in their child’s life,” she said.

Tanya Paparella of the University of California Los Angeles Center for Autism Research and Treatment says she thinks it very possible that kids have been going undiagnosed.

“A child who is verbal, who has good language, who is highly intelligent – those are children where I think parents and even teachers and the layperson might not necessarily have thought that was a child with autism spectrum disorder,” says Paparella, who was not involved in the study.

“In the past, people really thought children on the autism spectrum had significant learning difficulties and we know now that is not necessarily the case. We know there are children who may be highly intelligent and do very well in areas of academics.” Such kids may have been seen merely as quirky, Paparella says.

Just last April, the CDC reported that one in 88 U.S. children has autism of some sort. That data comes from a different survey, one looking at kids of all ages.

This latest report comes from the 2011–2012 National Survey of Children’s Health, an independent national telephone survey of households with children. Parents were asked if any of their children had or had been diagnosed with autism.

“Based on parent reports, the prevalence of diagnosed autism spectrum disorder in 2011–2012 was estimated to be 2 percent for children aged 6–17,” the report reads. “This prevalence estimate (1 in 50) is significantly higher than the estimate (1.16 percent, or 1 in 86) for children in that age group in 2007.”

The biggest increase was seen in boys aged 14–17. “In 2011–2012, school-aged boys were more than four times as likely as school-aged girls to have an autism spectrum disorder (3.23 percent compared with 0.7 percent),” the report says. Most of the new cases were classified as mild.

Because autism is usually diagnosed in the toddler years, the findings suggest that most of the increase is due to new recognition of autism in children who had it, but whose parents or doctors hadn’t realized it, the report says.

Blumberg notes that most evidence suggests autism develops in the womb, perhaps from a combination of genetic predisposition and other, outside factors.

It does have implications for the health and education systems, Blumberg says.

“The data certainly suggest that a greater number of parents are dealing with autism spectrum disorder with their kids,” he said. “Those parents are likely to make demands on the system, the health care system or education system, and the number of parents making those demands is higher than we had previously  thought.”

Paparella says many of the newly diagnosed children don’t need help in school so much as broader help in coping with other people. ‘These are children who often need intervention in social skills,” she said.

“They benefit from learning how to interact with other children, how to be able to take another child’s perspective, how to problem solve and negotiate in a way that is not straightforward.”

Yeargin-Allsopp said the 2006 Individuals with Disabilities Education Act made many more programs and resources available. “We want parents to know that it is important that children have screening for developmental delays or disorders,” she said.

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They live underwater, eat bloodworms, and are promoted on pet websites. But African dwarf frogs can carry salmonella.

An outbreak tied to the frogs sickened nearly 400 people, mostly children, from 2008 to 2011.

Since these miniature amphibians can live up to 18 years, some linked to the outbreak may remain in U.S. home aquariums. That's according to government researchers in a Monday report from the journal Pediatrics.

Five outbreak-linked cases also occurred last year. No one died.

The Centers for Disease Control and Prevention advises washing hands after touching the frogs' aquarium water and says young children should not clean aquariums.

The California breeder linked to the outbreak briefly suspended distribution and cooperated with authorities.

Related:

• Pet hedgehogs sicken more with salmonella
• More recalls of pet jerky treats
• Pet turtles sicken kids in 34 states

By Julie Steenhuysen
Reuters

The U.S. Centers for Disease Control and Prevention (CDC) on Thursday warned state and local health officials about potential infections from a deadly virus previously unseen in humans that has now sickened 14 people and killed 8. 

Most of the infections have occurred in the Middle East, but a new analysis of three confirmed infections in Britain suggests the virus can pass from person to person rather than from animal to humans, the CDC said in its Weekly Morbidity and Mortality Report on Thursday.

The virus is a coronavirus, part of the same family of viruses as the common cold and the deadly outbreak of Severe Acute Respiratory Syndrome (SARS) that first emerged in Asia in 2003. The new virus is not the same as SARS, but like the SARS virus, it is similar to those found in bats.

So far, no cases have been reported in the United States.

According to the CDC's analysis, the infections in Britain started with a 60-year-old man who had recently traveled to Pakistan and Saudi Arabia and developed a respiratory illness on Jan. 24, 2013. Samples from the man showed he was infected with both the new virus and with H1N1, or swine flu.

This man subsequently passed the infection to two members of his household: a male with an underlying illness who became ill on Feb. 6 and subsequently died; and a healthy adult female in his household who developed a respiratory illness on Feb. 5, but who did not need to be hospitalized and has recovered.

The CDC said people who develop a severe acute lower respiratory illness within 10 days of returning from the Arabian Peninsula or neighboring countries should continue to be evaluated according to current guidelines.

The health agency said doctors should be watchful of patients who develop an unexplained respiratory infection within 10 days of traveling from the Arabian Peninsula or neighboring countries. The CDC has set up a special website with updates on the infections.

Symptoms of infection with this new virus include severe acute respiratory illness with fever, cough and shortness of breath. Neither the CDC nor the World Health Organization has issued travel restrictions related to the virus.

AP

Nearly six months after injectable steroids made by the New England Compounding Center were implicated in an outbreak of fungal meningitis and other infections, more people are turning up ill, including those who previously tested clear of infection.

Nearly six months after the start of a deadly fungal meningitis outbreak blamed on tainted pain shots, patients who originally tested clear are showing up sick, raising worries that the incubation period for illness may be longer than anyone thought.

Though the flood of patients has slowed dramatically, two or three people each week are still reporting infections caused by contaminated steroids in the outbreak that has killed 48 and sickened more than 700, officials with the Centers for Disease Control and Prevention said.

Among those new patients are people who received mold-tainted doses of the drug methylprednisolone, but who previously got MRIs or lumbar punctures that showed they were free of infection. These slow-growing infections aren't as severe as meningitis, but worrying nonetheless.

“If you had an MRI in October, I don’t know that you’re out of the woods,” said Dr. Anurag Malani, an infectious disease expert at St. Joseph Mercy Hospital in Ann Arbor, Mich., the state that has seen the most cases -- 253 -- in the outbreak.

CDC officials issued a health alert this week urging clinicians to remain vigilant for new infections, even in people who show subtle symptoms -- or none at all.

“We are seeing some patients with very long incubation periods,” said Dr. Tom Chiller, associate director for epidemiological science in the CDC’s division of foodborne, waterborne and environmental diseases. “We expect to see people getting infections months after their injections.”

Nearly 14,000 people in 23 states were exposed to the contaminated drugs produced by the now-shuttered New England Compounding Center of Framingham, Mass. An estimated 11,000 actually received shots for back or neck pain, the CDC says. So far, 720 people in 20 states have fallen ill.

Most of the seriously ill people – those with fungal meningitis infections that caused strokes, for instance – showed up within several weeks or one to two months starting in late September.

Back then, CDC officials told worried patients that the greatest risk for meningitis was likely in the first 42 days -- six weeks -- after the shots, suggesting that they could breathe easy after the first week in November.

But patients have continued to become ill, most often not with meningitis, but with infections at the injection site, with epidural abscesses or with a condition called arachnoiditis, an inflammation of the nerves near the spine.

Though doctors have little experience with such fungal infections, the incubation period appears to be stretching longer than a previous outbreak in 2002, when a patient became ill 152 days – five months – after getting a steroid shot.

“I don’t think at this time we know how long the incubation period is,” Malani said.

That’s worrisome for people like John Horrell, 54, of Nashville, Tenn., who received a steroid shot for back pain from one of three tainted lots in September. He says he’s feeling “remarkably well” these days, with no signs of infection. Health officials told him the biggest worry was after 90 days or so, but now he’s not so sure.

“There’s people still having problems,” said Horrell, who owns a sound system firm. “We just keep our fingers crossed. I try not to worry about it.”

CDC officials want health workers to continue to monitor patients who got shots, particularly those whose have pain that is worse or different from the initial symptoms. But even patients who previously tested negative for infections and those with no apparent symptoms are at risk.

“These infections may be unrecognized because some patients have not continued to receive close clinical follow-up or because they have not recognized symptoms suggestive of a localized infection,” the new alert says.

CDC recommends that health workers have a low threshold for considering MRIs, or magnetic resonance imaging, to detect unseen infections.

Even patients who initially resisted MRIs because they didn’t want them or didn’t think they needed them have turned up with infections, said Malani.

The danger of not detecting the infections is that they only will get worse, Chiller said.

“Any untreated infection can sit there and smolder and spread,” he said, noting it can move beyond soft tissue to bone and the central nervous system, with devastating, even deadly, effects.

That, however, raises the next question in the ongoing meningitis puzzle: How long should infected patients be treated? Some patients say they’ve been told three months, then nine months -- then a year.

The primary drugs used to treat the fungus -- voriconazole and amphotericin B -- are both expensive and toxic, with a host of side effects ranging from hair loss and hallucinations to liver problems. 

Margaret Snopkowski, 51, of Fowlerville, Mich., has been on the drugs since early October, when she developed meningitis -- and later, arachnoiditis -- after getting a contaminated shot.

She's back home, but life is hardly back to normal, especially with the high doses of antifungal drugs necessary to keep her infection in check.

“She walks around like a zombie,” said her husband, Tom Snopkowski. “It just knocks her on her butt.”

Family members had hoped she’d be better by now, or at least looking to wean herself from the drugs. But that’s not happening, her husband said. Another MRI is scheduled for next week to see whether the infection has gotten worse.

“Now, they don’t even have an end date for that treatment," he added.

Related: 

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There’s more evidence that untreatable or tough-to-treat infections from a rare but deadly superbug are on the rise in U.S. hospitals, ratcheting up concerns about stopping the spread before it gets worse, health officials said Tuesday.

Last year, about 4 percent of U.S. acute-care hospitals and 18 percent of long-term acute care hospitals reported at least one case of dangerous CRE bacteria -- Carbapenem-resistant enterobacteriaceae -- germs resistant to most last-resort antibiotics.

That’s according to new figures released by the Centers for Disease Control and Prevention, which analyzed data from about 3,900 U.S. hospitals in the first six months of 2012.

"CRE are nightmare bacteria," CDC Director Dr. Tom Frieden told reporters.

Figures may show that CRE are still rare, but analysis from three different data pools revealed a big jump in the infections during the past decade. The percentage of certain bacteria reported to be resistant to carbapenem antibiotics -- often the drugs of last resort -- climbed from 1.2 percent in 2001 to 4.2 percent in 2011, a spike of about 250 percent.

“The message that we’re trying to send is there’s an opportunity here,” the CDC’s Dr. Arjun Srinivasan, associate director for healthcare-associated prevention programs said in an interview before Tuesday's press conference. “It’s an uncommon issue, but it’s concerning. There’s an opportunity to act while it’s still uncommon.”

CREs increased most for the worrisome Klebsiella pneumoniae, jumping from 1.6 percent to 10.4 percent between 2001 and 2011, a rise of 550 percent. That’s the bug that made headlines last summer after reports that it was part of an outbreak that swept through the National Institutes of Health Clinical Center near Washington, D.C., killing seven people, including a 16-year-old boy.

CDC relied on CRE data collected from the National Nosocomial Infection Surveillance System, or NNIS, and its successor, the National Healthcare Safety Network, or NHSN. More data came from another source called the Surveillance Network-USA, known as TSN.

CREs are part of a family of drug-resistant germs that have shown up in growing numbers of U.S. health care settings. They’re named for their ability to fight off carbapenem antibiotics, which have been the big gun drugs used to treat serious infections. CRE infections typically show up in people who’ve been hospitalized frequently, who have been taking antibiotics and who may require devices such as ventilators or catheters.

They often present as hard-to-treat bloodstream or urinary tract infections.

CRE infections tied to Klebsiella now have been detected in 42 U.S. states and Puerto Rico, the CDC reports. That's particularly worrisome because the mortality rate for CRE bloodstream infections can be as high as 50 percent and CRE infections can spread like wildfire through a hospital.

CDC

CDC microbiologist Kitty Anderson holds up a 96-well plate used to test the ability of bacteria to grow in the presence of antibiotics. CDC officials report that Carbapenem-resistant enterobacteriaceae are on the rise in U.S. hospitals.

No one knows exactly how many cases there have been in the U.S. or how many deaths may be tied to CREs, Srinivasan said.

CDC has launched an all-out campaign -- a "detect and protect" strategy to urge hospitals and other health care facilities to be on guard for CREs. The agency issued a health alert last month warning that the number of unusual forms of CRE has nearly doubled since last July. That includes the notorious NDM bug -- New Delhi metallo-beta-lactamase -- which produces an enzyme that renders antibiotics virtually useless.

Health care providers should be alert for evidence of CRE in their facilities, CDC says, and act promptly to detect and contain the bug. Patients exposed to the germ should be kept together, away from others. Hospital staff should be vigilant about hand hygiene and exposing patients to potentially contaminated materials. Some states and some sites have better systems in place to catch CREs, including places such as Colorado and Florida, which have had outbreaks and grappled with the problem of stopping them.

“The actions right now are uneven,” Srinivasan said.

Patients worried about catching a CRE infection can take certain precautions, too, he suggested. Risk may be higher in people who are hospitalized frequently or who are transferred from one type of hospital to another. For instance, someone who suffers a stroke may be treated at an acute-care hospital, but then transferred for longer-term critical care at another site.

Patients or family members should ask about the risk of CRE, especially in people who require ventilators or catheters or those who show signs of infection, such as a fever. Check with the staff about the steps they take to prevent hospital-acquired infections, Srinivasan said.

“Ask: What are you doing to keep me safe from CRE?” he suggested.

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More Americans know about and smoke electronic cigarettes in the U.S., the Centers for Disease Control and Prevention reported on Thursday -- something that highlights the need for government regulation and evaluation, the head of CDC's office on smoking and health said.

The CDC found the number of smokers who have tried them doubled in just a year amid heavy marketing -- from 10 percent in 2010 to about 21 percent in 2011. The numbers grew from 2.5 percent to 7.4 percent for former smokers, the report,  published in the journal Nicotine & Tobacco Research, finds.

Nearly six in 10 adults in the U.S. are aware of the battery-powered devices that heat a liquid nicotine solution and create vapor that users inhale, according the first study to assess the change in awareness and use of electronic cigarettes on a national level.

"These finding sort of tantalizingly underscore the need for more rigorous study of patterns of use of e-cigarettes and impacts," the CDC's Dr. Tim McAfee said in an interview with The Associated Press. "Until there's regulatory authority and oversight, it's going to be more difficult to be certainly reassuring around things like toxic effects."

Some of the nation's largest tobacco companies have gotten into the e-cig market as part of the industrywide push to diversify beyond the traditional cigarette business. Reynolds American Inc., the second-biggest U.S. cigarette maker, has begun limited distribution of its first electronic cigarette under the Vuse brand. Lorillard Inc., the nation's third-biggest tobacco company, acquired e-cigarette maker Blu Ecigs in April. Some e-cigarettes are made to look like a cigarette with a tiny light on the tip that glows like the real thing.

The Food and Drug Administration says e-cigarettes have not been fully studied. The federal agency is expected to assert regulatory authority over e-cigarettes later this year to treat them the same as traditional cigarettes and other tobacco products.

The FDA has said its tests found that the liquid in some electronic cigarettes contained toxins besides nicotine as well as cancer-causing substances that occur naturally in tobacco. But some public health experts say the level of carcinogens was comparable to those found in nicotine replacement therapy, because the nicotine in all of the products is extracted from tobacco.

According to the results of a series of online surveys, the CDC reported, awareness of electronic cigarettes increased from 40 percent in 2010 to nearly 60 percent in 2011, and use among adults doubled to 6 percent during that time. 

McAfee said the motivations behind e-cigarette use remain unclear. For example, a former smoker could be experimenting with them as a new nicotine delivery system, or could have used an electronic cigarette to quit smoking regular cigarettes. Current smokers might be using e-cigs in places where tobacco smoking isn't allowed.

More than 45 million Americans smoke cigarettes, and about half of smokers try to quit each year.

First marketed overseas in 2002, e-cigarettes didn't become easily available in the U.S. until late 2006. Now, the industry has grown from the thousands of users in 2006 to several million worldwide. Analysts estimate sales could double to $1 billion in 2013. Some companies have even started running TV commercials.

Devotees tout e-cigs as a way to break addiction to real cigarettes. They say the devices address both the nicotine addiction and the behavioral aspects of smoking — the holding of the cigarette, the puffing and exhaling something that looks like smoke — without the more than 4,000 chemicals found in cigarettes.

"The bottom line is ... the impact of e-cigarettes on public health remains uncertain," McAfee said.

By Rachael Rettner
MyHealthNewsDaily

A salmonella outbreak linked to pet hedgehogs has sickened 20 people in eight states, according to a new report from the Centers for Disease Control and Prevention (CDC).

All the patients were infected with a strain of bacteria called Salmonella typhimurium. Fourteen of the ill people reported direct contact with hedgehogs, the CDC said.

The outbreak began in December 2011, and has continued into 2013. So far, four people have been hospitalized, and one has died. Many of the affected have been children, the CDC said.

Related story: Pet hedgehogs sicken 14 with salmonella, CDC says

Washington state has reported the most cases, seven, followed by Michigan, Minnesota and Ohio, which have each reported three cases. Other states that have reported infections are Alabama, Illinois, Indiana and Oregon.

Although the most common source of salmonella infections is food poisoning, animals can spread the disease as well. Besides hedgehogs, salmonella outbreaks have also been linked to pet turtles.

To reduce the risk of infection, it's important to wash your hands after handling hedgehogs, or anything the animals come in contact with, the CDC said. Adults should supervise children around hedgehogs and make sure the youngsters wash their hands after touching the animal or anything the hedgehog has been in contact with.

The report will be published this week in the CDC's Morbidity and Mortality Weekly Report.

Follow Rachael Rettner on Twitter@RachaelRettner, or MyHealthNewsDaily@MyHealth_MHND. We're also onFacebook&Google+.

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Salad greens make the most people sick, but contaminated poultry kills the most Americans, federal researchers report in the first comprehensive look at the foods that cause foodborne illnesses. And there are a few surprises -- the bug most likely to be lurking in a salad is norovirus, and it probably came from the hands of the person who made it.

This doesn’t mean salad is more dangerous, the team at the Centers for Disease Control and Prevention stresses: It just shows what foods are most involved and may reflect how often people eat them.

“When the average American looks at this data, they need to know that we are not trying to make estimates of the risk of illness per serving of any of the food categories,” says the CDC’s  Dr. Patricia Griffin, who heads the agency’s branch that investigates stomach bugs.

“We are just providing information on what are the food categories that are the major sources of illness ... so regulators can take action to make food safer.”

Food poisoning is extremely common.  The CDC estimates that 48 million Americans get some sort of foodborne illness every year, 128,000 of them are sick enough to go to the hospital and 3,000 die. Most of the time, the bacteria, virus or parasite responsible is never identified, and usually the particular food isn’t, either.

Griffin’s team analyzed all the data they could get on every outbreak of foodborne illness reported between 1998 and 2008 in which both the food source and the microbe responsible were known. They broke the food down into 17 categories.

“We attributed 46 percent of illnesses to produce and found that more deaths were attributed to poultry than to any other commodity,” they wrote in their report, published in the journal Emerging Infectious Diseases on Tuesday.

“(The data ) indicate that efforts are particularly needed to prevent contamination of produce and poultry.”

This doesn't mean people should swap out salads for, say, fries.

“We certainly would not want people to avoid any category of food,” Griffin said. “We know that the vast majority of meals are safe. As far as fruits and vegetables in particular, CDC is well aware and promotes the fact that they are an important part of a healthy diet. They are linked to reduced risk of heart attacks, strokes and cancer. “

Cooking food is one of the best ways to prevent illness, as proper cooking will kill most disease-causing agents. As raw meat and eggs are often contaminated, proper food handling techniques are also important.

It’s harder to protect against germs on raw food, however. “Our data found that produce items were a common cause of illness, accounting for almost half of illnesses,” Griffin said in a telephone interview. “Most of those produce items that caused those illnesses were consumed raw.”

And norovirus – also known as Norwalk virus, which causes gastrointestinal upset commonly known as stomach flu or winter vomiting disease – was a major cause of illness contracted from raw vegetables, the CDC finds.

Contaminated meat and poultry accounted for 22 percent of illness but 29 percent of deaths, while dairy and eggs accounted for 20 percent of illnesses and 15 percent of deaths.

Last week, CDC reported 1,527 foodborne disease outbreaks in 2009 and 2010. They said 29,444 people got sick and 23 died in these outbreaks. Norovirus or Salmonella -- especially in eggs, sprouts, tomatoes and peppers -- caused most, while Campylobacter in unpasteurized dairy products, Salmonella in eggs, and E. coli 0157 in beef were also very common causes of food poisoning outbreaks. And nearly half -- 48 percent -- of all outbreaks from a single place were traced to restaurants or delis.

News reports have focused a great deal on outbreaks of diseases such as salmonella, listeria and E. coli, and the Food and Drug Administration, US Department of Agriculture and other regulators have focused on protecting food from animal contamination such as bird droppings and manure from pigs and cows, which carry these agents.

But norovirus is carried and spread only by humans.

“The way that you get it from food is when a food handler doesn’t wash his hands after an episode of diarrhea or vomiting and then prepares food,” Griffin said. This is an area that may require extra focus, she says.

“Washing hands is very, very important,” she added.  Norovirus can be spread before a person feels sick and for days after he or she recovers, also.

Adding to the risk is the issue of sick leave. Many food preparers, restaurant workers and food handlers do not get paid sick leave, and thus are encouraged to work while they are ill.  One study published in 2011 in the American Journal of Public Health projected that workers who did not get paid time off for illness helped spread 5 million cases of respiratory disease during the 2009 H1N1 swine flu pandemic.

The Bureau of Labor Statistics says 39 percent of private sector workers have no paid sick leave, and this number rises to 70 percent for food and hotel workers.

There’s a bill in Congress that would mandate sick leave for many employers,  supported by President Barack Obama and groups including  the National Women’s Health Network, the AFL-CIO,  Families USA and others. It was last considered in 2009.

So besides cooking meat and making sure greens are washed well, how can people protect themselves? “I would advise people to avoid eating raw foods of animal origin, and that includes raw milk,” Griffin said.  Shellfish? “You have to make a decision about raw shellfish and how much you love them, how much risk you want to take and what your risk might be,” she said.

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Sixteen people in five states have been sickened with salmonella infections, including several who ate raw ground beef, government health officials said. 

No one has died, but half of the people have been hospitalized. Nine of the victims are in Michigan, but three were reported in Wisconsin, two in Illinois and one each in Arizona and Iowa, the Centers for Disease Control and Prevention reported. 

The illnesses were caused by the same rare strain of salmonella Typhimurium, CDC officials said. This strain has a genetic fingerprint rarely seen previously. 

Tracking by state and federal officials indicated that the ground beef was produced by Jouni Meats, Inc., of Sterling Heights, Mich., and Gab Halal Food of Troy, Mich., which together recalled more than 1,000 pounds of ground beef last week. 

Seven of the victims indicated they had eaten a raw ground beef dish called kibbeh at the same restaurant, which had acquired beef from the two retailers. Kibbeh is a dish typically made of finely ground meat, minced onions and bulgur wheat.

CDC officials say people should not eat raw or undercooked ground beef. Anyone who has products made by the companies should discard them or return them to the place of purchase. 

Salmonella infections can be serious for children under age 5, older adults and those with weakened immune systems. 

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A nasty new strain of norovirus, a highly contagious gut bug, has circled the globe and landed in the U.S., where it’s now the leading cause of what’s known indelicately as “winter vomiting disease.”

Health officials at the Centers for Disease Control and Prevention said Thursday that the GII.4 Sydney strain of norovirus was responsible for more than half of outbreaks of the illness during the last four months of 2012. The new norovirus spread amid a particularly harsh flu season that's also causing misery. 

Of 266 outbreaks of norovirus between September and December, 141 were caused by the bug that was first detected in Australia in March 2012, according to data from CaliciNet, which tracks norovirus outbreaks. The proportion of outbreaks caused by the new strain jumped dramatically from 19 percent in September to 58 percent in December, the CDC says in its weekly report on death and disease.

“Right now, it’s too soon to tell whether the new strain of norovirus will lead to more outbreaks than in previous years. However, CDC continues to work with state partners to watch this closely and see if the strain is associated with more severe illness,” said Dr. Aron Hall, a CDC epidemiologist specializing in viruses.

Like the virus that causes the flu, norovirus mutates quickly, resulting in a new strain every few years, Schaffner said. When that happens, people who’ve already had previous versions of the bug that can cause profuse vomiting and diarrhea are more likely to get it again. “What that means is more of us are susceptible,” said Dr. William Schaffner, a infectious disease expert at Vanderbilt University in Nashville, Tenn.

That can be a particular problem in enclosed spaces, such as cruise ships, nursing homes or other gatherings where people share close quarters.

The virus spreads ridiculously easily, often carried in the air after projectile vomiting, or lingering on surfaces where it infects the next victim, Schaffner said.

“It’s very contagious,” he said. “It takes only a few viral particles.”

In the U.S., norovirus is the leading cause of acute gastroenteritis, affecting more than 21 million people a year and leading to about 800 deaths, CDC said.

Though the worst part of the infection usually lasts only a few days, young children and the elderly are most at risk of serious complications, typically because of the danger of dehydration from rapid fluid loss.

Another danger is that dehydration can cause blood pressure to drop, resulting in fainting that can lead to falls. Schaffner said when he heard that U.S. Secretary of State Hillary Clinton suffered a concussion after fainting following a stomach virus in December, his first thought was norovirus.

“She’s a global traveler; she could have picked it up anywhere,” he said.

CDC officials advised health workers to be vigilant for increases in norovirus outbreaks this winter because of the new GII.4  Sydney strain. They should follow standard infection control practices to prevent norovirus.

In addition, the general public ought to be aware that the new bug is out there and take precautions including washing hands with soap and water, disinfecting surfaces, rinsing fruits and vegetables, cooking shellfish thoroughly and not preparing food or caring for others while ill.

CDC officials said it’s too early to tell whether the new strain will lead to more outbreaks or more serious illness, but they’re watching the situation closely.

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