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Science Tuesday - Weight Loss, Hearing, Marriage, and a new disease!
Why Even Resolute Dieters Often Fail
By JANE E. BRODY, September 19, 2011, The New York Times
If you’ve been trying for years to lose unwanted pounds and keep them off, unrealistic goals may be the reason you’ve failed. It turns out that a long-used rule of weight loss — reduce 3,500 calories (or burn an extra 3,500) to lose one pound of body fat — is incorrect and can ultimately doom determined dieters.
That is the conclusion reached by Dr. Kevin D. Hall and his colleagues at the National Institute of Diabetes and Digestive and Kidney Diseases. Recently they created a more realistic model of how the body responds to changes in caloric intake and expenditure, basing their calculations on how people of different weights responded to caloric changes in a controlled setting like a metabolic unit.
Their work, spelled out in a new study published in The Lancet, explains how body weight can slowly rise even when people have not changed their eating and exercise habits.
Their research also helps to explain why some people can lose weight faster than others, even when all are eating the same foods and doing the same exercise, and why achieving permanent weight loss is so challenging for so many.
The model shows that lasting weight loss takes a long time to achieve and suggests that more effective weight loss programs might be undertaken in two phases: a temporary, more aggressive change in behavior at first, followed by a second phase of a more relaxed but permanent behavioral change that can prevent the weight regain that afflicts so many dieters despite their best intentions.
Debunking a Long-Used Rule
According to the researchers, it is easy to gain weight unwittingly from a very small imbalance in the number of calories consumed over calories used. Just 10 extra calories a day is all it takes to raise the body weight of the average person by 20 pounds in 30 years, the authors wrote.
Furthermore, the same increase in calories will result in more pounds gained by a heavier person than by a lean one — and a greater proportion of the weight gained by the heavier person will be body fat. This happens because lean tissue (muscles, bones and organs) uses more calories than the same weight of fat.
In an interview, Dr. Hall said the longstanding assumption that cutting 3,500 calories will produce a one-pound weight loss indefinitely is inaccurate and can produce discouraging results both for dieters and for policy changes like the proposed tax on sugar-sweetened beverages.
If the 3,500-calorie rule applied consistently in real life, it would result in twice the weight loss that the new model predicts, the authors wrote. This helps to explain why even the most diligent dieters often fail to reach weight loss goals that were based on the old rule.
A more realistic result, he said, is that cutting out 250 calories a day — the amount in a small bar or chocolate or half a cup of premium ice cream — would lead to a weight loss of about 25 pounds over three years, with half that loss occurring the first year.
Many people get discouraged when weight loss slows even though they are sticking religiously to their diets, but Dr. Hall said a gradual loss is nearly always more effective because it allows the new eating and exercise habits to become a lasting lifestyle.
Still, obese people would have to cut out more calories to lose weight than it took to gain the extra pounds. Although reaching a weight of 220 pounds may have been caused by consuming, say, 250 calories more than were used each day, losing that weight requires much larger reductions in calorie intake. According to Dr. Hall’s calculations, an extra 220 calories a day are now maintaining the new higher weight.
For the population to return to average body weights of the 1970s, obese individuals, who now represent 14 percent of the population, would have to cut out more than 500 calories a day, the new model shows.
Dr. Hall noted that typical weight-loss programs result in significant losses over a period of six to eight months, followed by gradual weight regain in the years that follow. When weight-loss plateaus at six to eight months — “which happens with all the diets,” he said — many dieters unconsciously start to eat a little more.
Although consuming an extra 100 calories a day would not show up right away as weight gain, it does over time. And it happens more slowly for the obese person than for someone who is lean, Dr. Hall said, because the obese person’s body requires more calories to maintain the extra pounds.
Role of Physical Activity
It is often said that increasing one’s physical activity does not have much, if any, effect on weight loss. But Dr. Hall’s model suggests otherwise.
If a man weighing 220 pounds ran an additional 12.5 miles a week at a moderate pace, he would lose more weight, and slightly faster, than if he cut the equivalent amount of calories from his diet, the authors calculated.
However, as activity and calorie reduction are increased, there comes a point at which the weight-loss benefit of diet exceeds that of physical activity, said the researchers, “because the energy expenditure of added physical activity is proportional to body weight itself.”
In other words, heavier people burn more calories in an equivalent amount of exercise; but as their weight drops, the number of calories used in exercise does, too.
The authors warned that when some people increase their level of physical activity, they compensate by eating more. Then, discouraged by a lack of progress, they may cut back on physical activity and gain even more weight.
Nonetheless, Dr. Hall said, physical activity remains important to weight loss and especially to weight maintenance. Studies of the more than 5,000 participants in the National Weight Control Registry have shown that those who lost a significant amount of weight and kept it off for many years relied primarily on two tactics: continuing physical activity and regular checks on body weight.
Some studies have indicated that low-carbohydrate diets that are relatively high in protein and fat are more effective for losing weight than a more balanced low-calorie diet. Dr. Hall said that while low-carbohydrate diets do a little more to reduce weight over the course of six months to a year, it remains to be shown that people are really eating what they say they are eating in these studies and that they can stick to a low-carbohydrate diet indefinitely.
Dr. Hall and his colleagues wrote that “all reduced-energy diets have a similar effect on body-fat loss in the short run” and that “some diets can lead to reduced hunger, improved satiety, and better overall diet adherence during a weight management intervention.”
But they added a caveat: Little is known about the long-term effect of diets that vary in their makeup of fat, protein and carbohydrate on either weight maintenance or health.
This is the second of two columns on new findings on obesity causes and weight loss.
Really? The Claim: Musicians Have a Greater Risk of Hearing Loss
By ANAHAD O'CONNOR, September 19, The New York Times
THE FACTS
To many musicians, hearing loss is just an unfortunate — and inevitable — consequence of pursuing a passion.
But a lifelong dedication to playing an instrument or being in a band may not be quite as hard on the ears as many assume. Some recent research suggests it may even benefit hearing.
In a study published this year, researchers examined professional musicians recruited from four classical orchestras. Their jobs often require multiple concerts each week, hours of practice and, in some cases, teaching others. Extensive tests analyzing factors that included blood cholesterol as well as noise exposure, the scientists found hearing loss among the musicians no worse than among the general population.
They did find a greater risk of hearing loss among musicians with the greatest exposure to higher-frequency noise (above three kilohertz) and a greater prevalence of tinnitus, or ringing in the ears, among musicians in general.
In another study, in the current issue of the journal Psychology and Aging, scientists gave hearing tests to 74 musicians and 89 nonmusicians.
The musicians showed far less age-related decline in certain aspects of hearing, among them the ability to discern frequencies, hear conversation against a noisy background and hear tones as they get quieter.
THE BOTTOM LINE
While chronic exposure to any loud noise can cause hearing damage, musicians may have better hearing than people in the general population.
In a Married World, Singles Struggle for Attention
By TARA PARKER-POPE, September 19, The New York Times
Here’s a September celebration you probably didn’t know about: It’s National Single and Unmarried Americans Week.
But maybe celebration isn’t the right word. Social scientists and researchers say the plight of the American single person is cause for growing concern.
About 100 million Americans, nearly half of all adults, are unmarried, according to the Census Bureau — yet they tend to be overlooked by policies that favor married couples, from family-leave laws to lower insurance rates.
That national bias is one reason gay people fight for the right to marry, but now some researchers are concerned that the marriage equality movement is leaving single people behind.
“There is this push for marriage in the straight community and in the gay community, essentially assuming that if you don’t get married there is something wrong with you,” says Naomi Gerstel, a sociologist at the University of Massachusetts in Amherst who has published a number of papers comparing the married and unmarried.
“But a huge proportion of the population is unmarried, and the single population is only going to grow. At the same time, all the movement nationally is to offer benefits to those who are married, and that leaves single people dry.”
Yet as she and other experts note, single people often contribute more to the community — because once people marry, they tend to put their energy and focus into their partners and their own families at the expense of friendships, community ties and extended families.
In a report released this week by the Council on Contemporary Families, Dr. Gerstel notes that while 68 percent of married women offer practical or routine help to their parents, 84 percent of the never-married do. Just 38 percent of married men help their parents, compared with 67 percent of never-married men. Even singles who have children are more likely than married people to contribute outside their immediate family.
“It’s the unmarried, with or without kids, who are more likely to take care of other people,” Dr. Gerstel said. “It’s not having children that isolates people. It’s marriage.”
The unmarried also tend to be more connected with siblings, nieces and nephews. And while married people have high rates of volunteerism when it comes to taking part in their children’s activities, unmarried people often are more connected to the community as a whole. About 1 in 5 unmarried people take part in volunteer work like teaching, coaching other people’s children, raising money for charities and distributing or serving food.
Unmarried people are more likely to visit with neighbors. And never-married women are more likely than married women to sign petitions and go to political gatherings, according to Dr. Gerstel.
The demographics of unmarried people are constantly changing, and more Americans are spending a greater percentage of their lives unmarried than married. While some people never marry, other adults now counted as single are simply delaying marriage longer than people of their parents’ generation did. And many people are single because of divorce or the death of a spouse. About one-sixth of all unmarried adults are 65 and older; nearly one-eighth of unmarried people are parents.
The pressure to marry is particularly strong for women. A 2009 study by researchers at the University of Missouri and Texas Tech University carried the title “I’m a Loser, I’m Not Married, Let’s Just All Look at Me.” The researchers conducted 32 interviews with middle-class women in their 30s who felt stigmatized by the fact that they had never married.
“These were very successful women in their careers and their lives, yet almost all of them felt bad about not being married, like they were letting someone down,” said Lawrence Ganong, a chairman of human development and family studies at the University of Missouri.
“If a person is happy being single,” he said, “then we should support that as well.”
Bella DePaulo, a visiting professor of psychology at the University of California, Santa Barbara, has a term for discrimination against single people, which she calls one of the last accepted prejudices. It is the title of her new book, “Singlism: What It Is, Why It Matters and How to Stop It.”
As an example, Dr. DePaulo cites the Family and Medical Leave Act. Because she is single and has no children, nobody in her life can take time off under the law to care for her if she becomes ill. Nor does it require that she be given time off to care for a sibling, nephew or close friend.
Stephanie Coontz, director of research for the Council on Contemporary Families, says policy makers often neglect the needs of single people because their view is outdated — based on the way they themselves grew up.
In researching her latest book, “A Strange Stirring: The Feminine Mystique in American Women at the Dawn of the 1960s,” Ms. Coontz found that in the past single people were often called “deviant,” “neurotic” and “selfish.”
“We do have the tendency to think that there is something special about married people, and that they are the ones who keep community and family going,” she said. “I thought it was important to point out that single people keep our community going, too.”
New Tick-Borne Disease Is Discovered
By DONALD G. McNEIL Jr., September 19, 2011, The New York Times
A new tick-borne disease that may be stealthily infecting some Americans has been discovered by Yale researchers working with Russian scientists.
The disease is caused by a spirochete bacterium called Borrelia miyamotoi, which is distantly related to Borrelia burgdorferi, the spirochete that causes Lyme disease.
B. miyamotoi has been found — albeit relatively rarely — in the same deer tick species that transmit Lyme, and the Yale researchers estimate that perhaps 3,000 Americans a year pick it up from tick bites, compared with about 25,000 who get Lyme disease.
But there is no diagnostic test for it in this country, so it is not yet known whether it has actually made any Americans sick.
The same short course of antibiotics that normally cures Lyme also seems to cure it.
In Russia, where a team in the Siberian city of Yekaterinburg developed a test that can distinguish miyamotoi from other tick-borne spirochetes, it caused higher fevers than Lyme disease typically does. In about 10 percent of cases, the fevers repeatedly disappear and return after a week or two.
The study by the two teams is to be published soon in the journal Emerging Infectious Diseases. Since the disease was only recently discovered, it is unknown whether it does serious long-term damage, as untreated Lyme disease can.
The Yale medical school researchers — Durland Fish, an entomologist, and Dr. Peter J. Krause, an epidemiologist — have recently won a grant from the National Institutes of Health to study the symptoms and develop a rapid diagnostic kit.
Dr. Fish found B. miyamotoi in American ticks 10 years ago, but was repeatedly refused a study grant until the Russians proved it caused illness. “It’s been like pulling teeth,” he said. “Go ask the N.I.H. why.”
The discovery will no doubt add to the controversy surrounding Lyme disease. While most Lyme victims are cured by a two-week course of antibiotics, some have symptoms that go on for years and believe they have persistent infections that the antibiotics did not reach.
Most medical authorities, including the Centers for Disease Control and Prevention and the Infectious Disease Society of America, take the position that “chronic Lyme disease” does not exist and that those victims either have other illnesses or are hypochondriacs. They oppose the solution demanded by some self-proclaimed victims: long-term intravenous antibiotics.
Dr. Krause said it was unlikely that the new spirochete could be responsible for chronic Lyme, because the symptoms do not match: Most of those who think they have chronic Lyme complain of fatigue and joint pain, not repeated fevers.
But he said doctors might consider the new infection, especially in patients who think they have been bitten by ticks, come up negative on Lyme tests and have recurrent episodes of fever.
B. miyamotoi does not appear to cause the “bull’s-eye rash” that helps doctors diagnose Lyme disease, the Russian team found.
“People shouldn’t panic,” Dr. Krause said. “And they also should not jump to the conclusion that we’ve found the cause of chronic Lyme disease. It’s not highly likely, but it’s possible. We just don’t know.”
The miyamotoi spirochete was discovered in Japan in 1995. It was at first believed to be limited to those islands.
In 2001, Dr. Fish found it in about 2 percent of the deer ticks in the Northeast and Upper Midwest and proved that mice could pick it up from tick bites.
By JANE E. BRODY, September 19, 2011, The New York Times
If you’ve been trying for years to lose unwanted pounds and keep them off, unrealistic goals may be the reason you’ve failed. It turns out that a long-used rule of weight loss — reduce 3,500 calories (or burn an extra 3,500) to lose one pound of body fat — is incorrect and can ultimately doom determined dieters.
That is the conclusion reached by Dr. Kevin D. Hall and his colleagues at the National Institute of Diabetes and Digestive and Kidney Diseases. Recently they created a more realistic model of how the body responds to changes in caloric intake and expenditure, basing their calculations on how people of different weights responded to caloric changes in a controlled setting like a metabolic unit.
Their work, spelled out in a new study published in The Lancet, explains how body weight can slowly rise even when people have not changed their eating and exercise habits.
Their research also helps to explain why some people can lose weight faster than others, even when all are eating the same foods and doing the same exercise, and why achieving permanent weight loss is so challenging for so many.
The model shows that lasting weight loss takes a long time to achieve and suggests that more effective weight loss programs might be undertaken in two phases: a temporary, more aggressive change in behavior at first, followed by a second phase of a more relaxed but permanent behavioral change that can prevent the weight regain that afflicts so many dieters despite their best intentions.
Debunking a Long-Used Rule
According to the researchers, it is easy to gain weight unwittingly from a very small imbalance in the number of calories consumed over calories used. Just 10 extra calories a day is all it takes to raise the body weight of the average person by 20 pounds in 30 years, the authors wrote.
Furthermore, the same increase in calories will result in more pounds gained by a heavier person than by a lean one — and a greater proportion of the weight gained by the heavier person will be body fat. This happens because lean tissue (muscles, bones and organs) uses more calories than the same weight of fat.
In an interview, Dr. Hall said the longstanding assumption that cutting 3,500 calories will produce a one-pound weight loss indefinitely is inaccurate and can produce discouraging results both for dieters and for policy changes like the proposed tax on sugar-sweetened beverages.
If the 3,500-calorie rule applied consistently in real life, it would result in twice the weight loss that the new model predicts, the authors wrote. This helps to explain why even the most diligent dieters often fail to reach weight loss goals that were based on the old rule.
A more realistic result, he said, is that cutting out 250 calories a day — the amount in a small bar or chocolate or half a cup of premium ice cream — would lead to a weight loss of about 25 pounds over three years, with half that loss occurring the first year.
Many people get discouraged when weight loss slows even though they are sticking religiously to their diets, but Dr. Hall said a gradual loss is nearly always more effective because it allows the new eating and exercise habits to become a lasting lifestyle.
Still, obese people would have to cut out more calories to lose weight than it took to gain the extra pounds. Although reaching a weight of 220 pounds may have been caused by consuming, say, 250 calories more than were used each day, losing that weight requires much larger reductions in calorie intake. According to Dr. Hall’s calculations, an extra 220 calories a day are now maintaining the new higher weight.
For the population to return to average body weights of the 1970s, obese individuals, who now represent 14 percent of the population, would have to cut out more than 500 calories a day, the new model shows.
Dr. Hall noted that typical weight-loss programs result in significant losses over a period of six to eight months, followed by gradual weight regain in the years that follow. When weight-loss plateaus at six to eight months — “which happens with all the diets,” he said — many dieters unconsciously start to eat a little more.
Although consuming an extra 100 calories a day would not show up right away as weight gain, it does over time. And it happens more slowly for the obese person than for someone who is lean, Dr. Hall said, because the obese person’s body requires more calories to maintain the extra pounds.
Role of Physical Activity
It is often said that increasing one’s physical activity does not have much, if any, effect on weight loss. But Dr. Hall’s model suggests otherwise.
If a man weighing 220 pounds ran an additional 12.5 miles a week at a moderate pace, he would lose more weight, and slightly faster, than if he cut the equivalent amount of calories from his diet, the authors calculated.
However, as activity and calorie reduction are increased, there comes a point at which the weight-loss benefit of diet exceeds that of physical activity, said the researchers, “because the energy expenditure of added physical activity is proportional to body weight itself.”
In other words, heavier people burn more calories in an equivalent amount of exercise; but as their weight drops, the number of calories used in exercise does, too.
The authors warned that when some people increase their level of physical activity, they compensate by eating more. Then, discouraged by a lack of progress, they may cut back on physical activity and gain even more weight.
Nonetheless, Dr. Hall said, physical activity remains important to weight loss and especially to weight maintenance. Studies of the more than 5,000 participants in the National Weight Control Registry have shown that those who lost a significant amount of weight and kept it off for many years relied primarily on two tactics: continuing physical activity and regular checks on body weight.
Some studies have indicated that low-carbohydrate diets that are relatively high in protein and fat are more effective for losing weight than a more balanced low-calorie diet. Dr. Hall said that while low-carbohydrate diets do a little more to reduce weight over the course of six months to a year, it remains to be shown that people are really eating what they say they are eating in these studies and that they can stick to a low-carbohydrate diet indefinitely.
Dr. Hall and his colleagues wrote that “all reduced-energy diets have a similar effect on body-fat loss in the short run” and that “some diets can lead to reduced hunger, improved satiety, and better overall diet adherence during a weight management intervention.”
But they added a caveat: Little is known about the long-term effect of diets that vary in their makeup of fat, protein and carbohydrate on either weight maintenance or health.
This is the second of two columns on new findings on obesity causes and weight loss.
Really? The Claim: Musicians Have a Greater Risk of Hearing Loss
By ANAHAD O'CONNOR, September 19, The New York Times
THE FACTS
To many musicians, hearing loss is just an unfortunate — and inevitable — consequence of pursuing a passion.
But a lifelong dedication to playing an instrument or being in a band may not be quite as hard on the ears as many assume. Some recent research suggests it may even benefit hearing.
In a study published this year, researchers examined professional musicians recruited from four classical orchestras. Their jobs often require multiple concerts each week, hours of practice and, in some cases, teaching others. Extensive tests analyzing factors that included blood cholesterol as well as noise exposure, the scientists found hearing loss among the musicians no worse than among the general population.
They did find a greater risk of hearing loss among musicians with the greatest exposure to higher-frequency noise (above three kilohertz) and a greater prevalence of tinnitus, or ringing in the ears, among musicians in general.
In another study, in the current issue of the journal Psychology and Aging, scientists gave hearing tests to 74 musicians and 89 nonmusicians.
The musicians showed far less age-related decline in certain aspects of hearing, among them the ability to discern frequencies, hear conversation against a noisy background and hear tones as they get quieter.
THE BOTTOM LINE
While chronic exposure to any loud noise can cause hearing damage, musicians may have better hearing than people in the general population.
In a Married World, Singles Struggle for Attention
By TARA PARKER-POPE, September 19, The New York Times
Here’s a September celebration you probably didn’t know about: It’s National Single and Unmarried Americans Week.
But maybe celebration isn’t the right word. Social scientists and researchers say the plight of the American single person is cause for growing concern.
About 100 million Americans, nearly half of all adults, are unmarried, according to the Census Bureau — yet they tend to be overlooked by policies that favor married couples, from family-leave laws to lower insurance rates.
That national bias is one reason gay people fight for the right to marry, but now some researchers are concerned that the marriage equality movement is leaving single people behind.
“There is this push for marriage in the straight community and in the gay community, essentially assuming that if you don’t get married there is something wrong with you,” says Naomi Gerstel, a sociologist at the University of Massachusetts in Amherst who has published a number of papers comparing the married and unmarried.
“But a huge proportion of the population is unmarried, and the single population is only going to grow. At the same time, all the movement nationally is to offer benefits to those who are married, and that leaves single people dry.”
Yet as she and other experts note, single people often contribute more to the community — because once people marry, they tend to put their energy and focus into their partners and their own families at the expense of friendships, community ties and extended families.
In a report released this week by the Council on Contemporary Families, Dr. Gerstel notes that while 68 percent of married women offer practical or routine help to their parents, 84 percent of the never-married do. Just 38 percent of married men help their parents, compared with 67 percent of never-married men. Even singles who have children are more likely than married people to contribute outside their immediate family.
“It’s the unmarried, with or without kids, who are more likely to take care of other people,” Dr. Gerstel said. “It’s not having children that isolates people. It’s marriage.”
The unmarried also tend to be more connected with siblings, nieces and nephews. And while married people have high rates of volunteerism when it comes to taking part in their children’s activities, unmarried people often are more connected to the community as a whole. About 1 in 5 unmarried people take part in volunteer work like teaching, coaching other people’s children, raising money for charities and distributing or serving food.
Unmarried people are more likely to visit with neighbors. And never-married women are more likely than married women to sign petitions and go to political gatherings, according to Dr. Gerstel.
The demographics of unmarried people are constantly changing, and more Americans are spending a greater percentage of their lives unmarried than married. While some people never marry, other adults now counted as single are simply delaying marriage longer than people of their parents’ generation did. And many people are single because of divorce or the death of a spouse. About one-sixth of all unmarried adults are 65 and older; nearly one-eighth of unmarried people are parents.
The pressure to marry is particularly strong for women. A 2009 study by researchers at the University of Missouri and Texas Tech University carried the title “I’m a Loser, I’m Not Married, Let’s Just All Look at Me.” The researchers conducted 32 interviews with middle-class women in their 30s who felt stigmatized by the fact that they had never married.
“These were very successful women in their careers and their lives, yet almost all of them felt bad about not being married, like they were letting someone down,” said Lawrence Ganong, a chairman of human development and family studies at the University of Missouri.
“If a person is happy being single,” he said, “then we should support that as well.”
Bella DePaulo, a visiting professor of psychology at the University of California, Santa Barbara, has a term for discrimination against single people, which she calls one of the last accepted prejudices. It is the title of her new book, “Singlism: What It Is, Why It Matters and How to Stop It.”
As an example, Dr. DePaulo cites the Family and Medical Leave Act. Because she is single and has no children, nobody in her life can take time off under the law to care for her if she becomes ill. Nor does it require that she be given time off to care for a sibling, nephew or close friend.
Stephanie Coontz, director of research for the Council on Contemporary Families, says policy makers often neglect the needs of single people because their view is outdated — based on the way they themselves grew up.
In researching her latest book, “A Strange Stirring: The Feminine Mystique in American Women at the Dawn of the 1960s,” Ms. Coontz found that in the past single people were often called “deviant,” “neurotic” and “selfish.”
“We do have the tendency to think that there is something special about married people, and that they are the ones who keep community and family going,” she said. “I thought it was important to point out that single people keep our community going, too.”
New Tick-Borne Disease Is Discovered
By DONALD G. McNEIL Jr., September 19, 2011, The New York Times
A new tick-borne disease that may be stealthily infecting some Americans has been discovered by Yale researchers working with Russian scientists.
The disease is caused by a spirochete bacterium called Borrelia miyamotoi, which is distantly related to Borrelia burgdorferi, the spirochete that causes Lyme disease.
B. miyamotoi has been found — albeit relatively rarely — in the same deer tick species that transmit Lyme, and the Yale researchers estimate that perhaps 3,000 Americans a year pick it up from tick bites, compared with about 25,000 who get Lyme disease.
But there is no diagnostic test for it in this country, so it is not yet known whether it has actually made any Americans sick.
The same short course of antibiotics that normally cures Lyme also seems to cure it.
In Russia, where a team in the Siberian city of Yekaterinburg developed a test that can distinguish miyamotoi from other tick-borne spirochetes, it caused higher fevers than Lyme disease typically does. In about 10 percent of cases, the fevers repeatedly disappear and return after a week or two.
The study by the two teams is to be published soon in the journal Emerging Infectious Diseases. Since the disease was only recently discovered, it is unknown whether it does serious long-term damage, as untreated Lyme disease can.
The Yale medical school researchers — Durland Fish, an entomologist, and Dr. Peter J. Krause, an epidemiologist — have recently won a grant from the National Institutes of Health to study the symptoms and develop a rapid diagnostic kit.
Dr. Fish found B. miyamotoi in American ticks 10 years ago, but was repeatedly refused a study grant until the Russians proved it caused illness. “It’s been like pulling teeth,” he said. “Go ask the N.I.H. why.”
The discovery will no doubt add to the controversy surrounding Lyme disease. While most Lyme victims are cured by a two-week course of antibiotics, some have symptoms that go on for years and believe they have persistent infections that the antibiotics did not reach.
Most medical authorities, including the Centers for Disease Control and Prevention and the Infectious Disease Society of America, take the position that “chronic Lyme disease” does not exist and that those victims either have other illnesses or are hypochondriacs. They oppose the solution demanded by some self-proclaimed victims: long-term intravenous antibiotics.
Dr. Krause said it was unlikely that the new spirochete could be responsible for chronic Lyme, because the symptoms do not match: Most of those who think they have chronic Lyme complain of fatigue and joint pain, not repeated fevers.
But he said doctors might consider the new infection, especially in patients who think they have been bitten by ticks, come up negative on Lyme tests and have recurrent episodes of fever.
B. miyamotoi does not appear to cause the “bull’s-eye rash” that helps doctors diagnose Lyme disease, the Russian team found.
“People shouldn’t panic,” Dr. Krause said. “And they also should not jump to the conclusion that we’ve found the cause of chronic Lyme disease. It’s not highly likely, but it’s possible. We just don’t know.”
The miyamotoi spirochete was discovered in Japan in 1995. It was at first believed to be limited to those islands.
In 2001, Dr. Fish found it in about 2 percent of the deer ticks in the Northeast and Upper Midwest and proved that mice could pick it up from tick bites.