– 6 hours ago
WASHINGTON — More than 3,000 people a day have a heart attack. If you're one of them the day after your swine flu shot, will you worry the vaccine was to blame and not the more likely culprit, all those burgers and fries?
The government is starting an unprecedented system to track possible side effects as mass flu vaccinations begin next month. The idea is to detect any rare but real problems quickly, and explain the inevitable coincidences that are sure to cause some false alarms.
"Every day, bad things happen to people. When you vaccinate a lot of people in a short period of time, some of those things are going to happen to some people by chance alone," said Dr. Daniel Salmon, a vaccine safety specialist at the Department of Health and Human Services.
Health authorities hope to vaccinate well over half the population in just a few months against swine flu, which doctors call the 2009 H1N1 strain. That would be a feat. No more than 100 million Americans usually get vaccinated against regular winter flu, and never in such a short period.
How many will race for the vaccine depends partly on confidence in its safety. The last mass inoculations against a different swine flu, in 1976, were marred by reports of a rare paralyzing condition, Guillain-Barre syndrome.
"The recurring question is, 'How do we know it's safe?'" said Dr. Gregory Poland of the Mayo Clinic.
Enter the intense new monitoring. On top of routine vaccine tracking, there are these government-sponsored projects:
_Harvard Medical School scientists are linking large insurance databases that cover up to 50 million people with vaccination registries around the country for real-time checks of whether people see a doctor in the weeks after a flu shot and why. The huge numbers make it possible to quickly compare rates of complaints among the vaccinated and unvaccinated, said the project leader, Dr. Richard Platt, Harvard's population medicine chief.
_Johns Hopkins University will direct e-mails to at least 100,000 vaccine recipients to track how they're feeling, including the smaller complaints that wouldn't prompt a doctor visit. If anything seems connected, researchers can call to follow up with detailed questions.
_The Centers for Disease Control and Prevention is preparing take-home cards that tell vaccine recipients how to report any suspected side effects to the nation's Vaccine Adverse Event Reporting system.
"We don't have any reason to expect any unusual problems with this vaccine," said Dr. Neal Halsey, director of Hopkins' Institute for Vaccine Safety, who is directing the e-mail surveillance.
After all, the new H1N1 vaccine is a mere recipe change from the regular winter flu shot that's been used for decades in hundreds of millions of people without serious problems. Nor have there been any red flags in the few thousand people given test doses in studies to determine the right H1N1 dose. They've gotten the same sore arms and occasional headache or fever that's par for a winter flu shot.
But because this H1N1 flu targets the young more than the old, this may be the year that unprecedented numbers of children and pregnant women are vaccinated.
Then there's the glare of the Internet — where someone merely declaring on Facebook that he's sure the shot did harm could cause a wave of similar reports. Health authorities will have to tell quickly if there really do seem to be more cases of a particular health problem than usual.
So the CDC is racing to compile a list of what's normal: 25,000 heart attacks every week; 14,000 to 19,000 miscarriages every week; 300 severe allergic reactions called anaphylaxis every week.
Any spike would mean fast checking to see if the vaccine really seems to increase risk and by how much, so health officials could issue appropriate warnings.
Very rare side effects by definition could come to light only after large-scale inoculations begin — making this the year scientists may finally learn if flu vaccine truly is linked to Guillain-Barre, an often reversible but sometimes fatal paralysis. It's believed to strike between 1 and 2 of every 100,000 people. It often occurs right after another infection, such as food poisoning or even influenza.
But the vaccine concern stems from 1976, when 500 cases were reported among the 45 million people vaccinated against that year's swine flu. Scientists never could prove if the vaccine really caused the extra risk. The CDC maintains that if the regular winter flu vaccine is related, the risk is no more than a single case per million vaccinated.
So the question becomes, Is the risk of disease greater than that?
Mayo's Poland cites a study in Chicago that found the rate of preschoolers being hospitalized for the new H1N1 flu last spring was 2 1/2 times higher than that possible Guillain-Barre risk.
However the flu season turns out, the extra vaccine tracking promises a lasting impact.
"Part of what we hope is that it will teach us something about how to monitor the safety of all medical products quickly," said Harvard's Platt.
On the Net:
* CDC: http://www.cdc.gov/H1N1FLU/
October 23, 2009
AUSTRALIAN medical experts have warned doctors worldwide to be on the alert for a rare but alarming complication of swine flu after a teenage boy suffered "muscle melting" so severe his urine turned almost black.
The unnamed 16-year-old suffered fever and other flu symptoms for three days before his urine went dark and intense pain meant he could no longer stand or move his arms and legs.
He was admitted to Melbourne's Monash Medical Centre, where tests showed he was suffering a condition called rhabdomyolysis -- a condition caused when muscles are damaged and dissolve, flooding the bloodstream with their by-products.
Shortly after admission one blood test for creatine kinase -- an enzyme produced when muscles break down -- returned a reading of 164,149 international units per litre (IU/L), more than 700 times above a normal reading of less than 230 IU/L.
He was given antiviral drugs, morphine and large amounts of fluids, but his creatine kinase levels continued to soar and after four days in hospital peaked at 1,127,000 IU/L, before gradually declining.
He recovered and was discharged after eight days, and a follow-up two weeks later showed no lasting muscle weakness or significant other ill-effects.
The incident happened at the height of the swine flu outbreak in June, but has just been revealed in a paper published by five of the hospital's doctors in the Pediatric Infectious Disease Journal.
Rhabdomyolysis can be caused by factors including crush injuries, muscle overuse and alcohol abuse, but it can also be triggered by various infections including, rarely, seasonal flu. But this is the first time it has been noted in a swine flu patient.
The boy knew swine flu was circulating at his school, and he tested positive for the disease after his admission to hospital.
Jim Buttery, who was the boy's treating consultant and is senior author of the journal article, said doctors performed tests to make sure the muscle breakdown was not adversely affecting his heart.
Instead, the tests showed the damage was mostly confined to the boy's arms and legs. "His main complaint was pain -- he had a huge amount of muscle breakdown according to his biochemistry tests," said Dr Buttery, a pediatric infectious diseases physician at the Monash Children's Hospital and the Murdoch Childrens Research Institute.
"He had the highest creatine kinase I have ever seen in over 20 years of practice -- over 1 million.
"It's a tribute to how young people cope with significant disease. In older people that (degree of muscle breakdown) is associated with causing kidney failure, but he sailed through it."
Dr Buttery said the boy's pain was so severe it was unlikely he would have been able to remain at home, but had he attempted to do so he would have been at high risk of kidney damage.
"We believe that one of the reasons he stayed away from kidney trouble was that we flooded him with fluids to flush the muscle proteins out," he said.
"It took us a bit by surprise -- it's a rare complication of normal influenza that you don't see very often."
The journal article says rhabdomyolysis "should be considered" in any patient with flu-like symptoms who also has severe muscle weakness or pain, and warns doctors to expect "severe clinical manifestations of infection with this novel influenza virus in the coming respiratory virus season".
"We would expect to see further cases like this rarely, but we would still expect them to occur, either with swine flu or the normal flu," Dr Buttery said.
April 9, 2009
April 9, 2009
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