Borrelioosiin sairastuneiden määrä on kasvussa eri puolilla maailmaa. Nykyiset borrelioositestit eivät kykene kertomaan onko taudinaiheuttaja elimistössä vai ei. Siksi olisi nopeasti kehitettävä uusia tutkimusmenetelmiä.
Rise in Lyme cases highlights need for new tests
Current methods can?t tell if disease is alive in body, which may delay care
James Gathany / AP
WASHINGTON - President Bush?s recently revealed treatment for Lyme disease makes him part of an unfortunate trend: The tick-borne infection is on the rise, with cases more than doubling in the past 15 years.
The good news is that most patients, like Bush, take antibiotics for a few weeks and are cured, especially if they were diagnosed early.
But people who aren?t treated promptly can develop painful arthritis, meningitis and other serious illnesses. If they don?t experience, or notice, Lyme?s hallmark round, red rash, they can struggle to be diagnosed, as other early symptoms are flulike and vague.
And a small fraction of patients report pain and fatigue that linger for months or years after treatment. Do they still have Lyme, or something else? No one knows, although desperate patients often try repeated antibiotics despite little evidence that the drugs do more good than harm.
The central problem: No test can tell when someone has active Lyme disease ? when Lyme-causing bacteria are alive in the body. Today?s tests instead spot infection-fighting antibodies, which can take weeks to form but then linger long after Lyme is gone.
A push is on for better Lyme tests, with parallel hunts getting started by the National Institutes of Health and, separately, by patient advocacy groups angry that modern medicine hasn?t found an answer.
?The time is right to take a closer look,? says Dr. Dennis M. Dixon, chief of bacteria research at the NIH?s National Institute for Allergy and Infectious Diseases, which plans to gather leading scientists later this year to determine the best approaches. ?We would not rule out any avenue.?
?We have a lot of new tools? to explore, adds Dr. Brian Fallon, who directs Columbia University?s new Lyme and Tick-borne Diseases Research Center, funded by the advocacy groups Time for Lyme and the Lyme Disease Association. ?Science is going to bridge the gap.?
Among the research:
* A newer antibody test seems to indicate when antibiotics are working in early Lyme stages, offering the possibility of tracking treatment response.
* Hunting markers of active infection, including bits of Lyme-related protein in the blood or spinal fluid.
* Fallon is using brain imaging to try to distinguish when Lyme penetrates the nervous system.
Many cases go unreported
About 20,000 new cases of Lyme disease are reported to the government every year, says a June analysis from the Centers for Disease Control and Prevention.
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The CDC acknowledges that?s a fraction of the true toll, as many cases go unreported. Experts say it may be five times higher.
Still, the figure is more than double the count in 1991, when official tracking began, and the CDC says it?s not due just to better awareness of Lyme. The rise is expected to continue as suburbia expands into the woodland home of black-legged tick species, commonly called deer ticks, that carry Lyme-causing ?Borrelia burgdorferi? bacteria in the Northeast, mid-Atlantic, north-central states and Pacific Coast.
The only human vaccine was pulled off the market in 2002 for lack of consumer interest. It was partly protective; better, next-generation vaccines are years away.
CONTINUED: Overshadowing treatment success