A Stony Brook scientist has helped map the genetic family tree of the bacterial strains that cause Lyme disease, a finding that raises hopes for faster diagnosis and new vaccines, scientists said Tuesday.
Dr. Benjamin Luft and colleagues have been on the trail of Lyme disease for years, aiming to discover why some people are affected by symptoms that last a few weeks, while others develop invasive infections that attack major organ systems. The mapping of more than a dozen bacterial strains moves science a step closer to finding out.
The availability of such precise genetic information is expected to help develop diagnostic tests sensitive to the exact strain that has caused a patient's infection, said Luft, a professor of medicine at Stony Brook University's medical school. He presented his research Monday in Washington, D.C., at the Institute of Medicine, an arm of the National Academy of Sciences.
Of the varying strains, Luft said some cause only a skin rash, while others, which he characterized as more serious, "go into the blood stream and spread throughout."
Lyme disease, the most frequently transmitted tick-borne infection in North America, is endemic on Long Island, particularly in Suffolk County, where several hundred cases are reported annually. According to the U.S. Centers for Disease Control and Prevention, cases of severe forms of Lyme disease have been rising for two decades.
Luft said he believes the new genetic information eventually could play a role in the development of vaccines. One vaccine - the first against Lyme disease, and developed before the findings were announced this week - is slated for human trials in January.
Working with a team of researchers from across the country, Luft and colleagues parsed the entire genetic codes of 13 types of the Borrelia burgdorferi bacteria that cause Lyme disease.
A renowned Lyme disease investigator, who was not connected with the study, said the work "is of enormous value" - an important advance with practical applications.
The researcher, Dr. Brian Fallon, director of Columbia University's Lyme and Tick-borne Disease Research Center in Manhattan, said Tuesday that the current method of screening for Lyme is notorious for "being far too insensitive for early Lyme disease and for neurologic Lyme disease."
He added: "Mapping of these 13 strains will help us to learn more about the invasiveness and virulence of these particular strains, as well as whether they have unique clinical profiles."
Luft said the finding "is already stirring a lot of discussion and a lot of ideas." Two years ago, he discovered that a single strain of B. burgdorferi was causing severe cases of the disease in the United States and Europe.
In the new research, published online in the Journal of Bacteriology, scientists scanned the genomes of more than 100 strains of the bacterium to identify the 13 subtypes that play the most prominent roles in Lyme disease infections seen frequently in North America.
For years, scientists have known about the existence of multiple Lyme bacterial strains but were unable to delineate the symptoms each caused, said Dr. Steven Schutzer, a Lyme disease expert at the University of Medicine and Dentistry of New Jersey, who was Luft's collaborator and lead author of the study.
"Six of these strains we studied were taken from patients, not ticks," added Schutzer, which provided more precise clinical information on how infections manifest.
New York State has the highest number of cases in the United States. More than 77,000 cases have been identified to the state Department of Health since 1986, when the disease became reportable.
Bacteria transmitted by the deer tick.
How it's spread
By the bite of an infected tick that stays attached to the skin, typically for 36 hours or more.
In most cases, a rash resembling a bull's eye appears around the bite. Early symptoms include chills and fever, headache, fatigue, stiff neck, muscle and/or joint pain, and swollen glands.
Periods of high risk
The chances of being bitten are highest when the ticks are most active:
Adult ticks, March to mid-May and mid-August to November
Young deer ticks (nymphs), mid-August to November and mid-May to mid-August.
Sources: NYS Department Of Health, U.S. Centers For Disease Control and Prevention