THE PHYSICIAN AND SPORTSMEDICINE - VOL 27 - NO. 4 - APRIL 99

Lyme Disease Vaccination: Who Needs It? How Effective?

The first Lyme disease vaccine was approved in December 1998, and now that tick season is near, physicians are likely to field questions about the vaccine from anxious patients who have seen it advertised.

The vaccine (Lymerix, SmithKline Beecham Pharmaceuticals, Philadelphia) was approved for people aged 15 to 70 who are at risk for Lyme disease. It is given in three doses spread over a year. In clinical trials, the vaccine was 50% effective after two doses and 78% effective after three doses, according to a report from the Centers for Disease Control and Prevention (CDC) (1).

Brian S. Schwartz, MD, associate professor and director of the Division of Occupational and Environmental Health at Johns Hopkins School of Public Health in Baltimore, says the vaccine combines a single recombinant protein from the infective organism with an adjuvant that stimulates the immune system to produce an antibody. "The antibody in the human's blood kills Lyme disease bacteria in the gut of the tick after the tick feeds," says Schwartz, who has researched the risk in outdoor workers for 10 years (2) and sees Lyme disease patients on referral.

A second Lyme disease vaccine is awaiting US Food and Drug Administration (FDA) approval. ImuLyme (Pasteur Mérieux Connaught USA, Swiftwater, Pennsylvania) is based on the same recombinant protein as Lymerix, according to Schwartz.

Who Should Be Vaccinated?

Clinical opinions vary on who should receive the vaccine. John Meyerhoff, MD, clinical scholar in rheumatology at Sinai Hospital in Baltimore, says he recommends the vaccine to anyone who lives in or travels to endemic areas: from Maryland up the Atlantic coast, Wisconsin and Minnesota, and the Pacific Northwest.

Schwartz recommends the vaccine for those who live in an endemic area and don't feel they can adequately protect themselves from tick bites. "But I'm not sure people who are diligent need the vaccine," he says.

The vaccine was not tested in people younger than 15 or older than 70, pregnant women, and people with rheumatic arthritis or certain heart conditions, according to the FDA. Safety data for those groups therefore are limited.

Meyerhoff says patient risk factors might influence whether or not insurance companies or managed care organizations will pay for the vaccine, which costs about $200 for the series. Schwartz says insurance companies may wait until the Advisory Committee on Immunization Practices, a division of the CDC, issues its report. Barbara Reynolds, a spokesperson for the CDC, said the committee is drafting some recommendations that will appear in an upcoming issue of Morbidity & Mortality Weekly Report. "The recommendations will be based on individual risk and geographic risk," she says.

Protection Takes Time

The vaccine is given in three doses: at 0, 1, and 12 months. It can cause pain at the injection site and possibly a fever. Researchers don't know how long protection lasts, and boosters may be needed.

Pharmaceutical companies are working to improve the dosing schedules so that patients are fully protected faster. "It's also an issue of patient compliance—the longer the time [between doses], the smaller the proportion of people who will finish the series," Schwartz says. Meyerhoff, who wrote the first review article on Lyme disease (3), says physicians can boost patient compliance by developing a "tickle" file, keeping a log of who has received the vaccine, or emphasizing the patient's responsibility for follow-up. He notes that the Lyme vaccine is given on the same schedule as the hepatitis B vaccine.

Patients need to know that they are never fully protected by the vaccine, and that protection doesn't reach 78% until they have received all three doses a year after their first dose. That means patients shouldn't abandon the usual Lyme disease preventive measures, which include wearing long pants and other protective clothing, wearing tick repellent, checking for ticks, and knowing tick removal methods. Another reason to continue preventive measures is that the vaccine does not prevent other tick-borne illnesses such as ehrlichiosis, babesiosis, and Rocky Mountain spotted fever.

The lag in protection could cloud the clinical picture if a recently vaccinated patient has Lyme disease symptoms, Schwartz says. "The vaccine will produce a positive blood test on the first-stage ELISA test, and it does produce one band on the Western blot," he says. "That might make Lyme disease trickier to diagnose." (See "New In-Office Test Speeds Lyme Disease Detection," below.)

Lisa Schnirring
Minneapolis

References

1. Centers for Disease Control and Prevention: Notice to readers: availability of Lyme disease vaccine. MMWR 1999;48(2):35-43
2. Schwartz BS, Goldstein MD: Lyme disease in outdoor workers: risk factors, preventive measures, and tick removal methods. Am J Epidemiol 1990;131(5):877-885
3. Meyerhoff J: Lyme disease. Am J Med 1983;75(4):663-670

New In-Office Test Speeds Lyme Disease Detection

In February the US Food and Drug Administration (FDA) approved a new blood test for Lyme disease that can produce initial results in an hour. The test will enable physicians to make a diagnosis without sending the sample to a lab and to start antibiotic treatment sooner, according to an FDA press release.

The Centers for Disease Control and Prevention recommends a two-step procedure for Lyme disease testing: A positive ELISA test should be confirmed by a Western blot test. The new test, Pre Vue B. burgdorferi Antibody Detection Assay (Chembio Diagnostic Systems, Medford, New York) is simply a quicker version of the ELISA test, says John Meyerhoff, MD, clinical scholar in rheumatology at Sinai Hospital in Baltimore.

In its press release the FDA said approval of the test was based on studies that showed a 3% false-positive rate, similar to the rate for other tests for Lyme disease.

Meyerhoff says the availability of a quicker, easier test for Lyme disease may raise some problems. He notes that the tests are "reasonably" sensitive and specific, but that more false-positives could skew the results if physicians are testing patients with a low likelihood of having Lyme disease. "The test is only as good as the people who are using it, and physicians need to learn to use the tests selectively," he says. Patients who have the classic bull's-eye skin rash don't need the test because Lyme disease is highly likely, he says, and the tests are negative in patients who have been infected in the previous 2 to 3 weeks.

News From the AAOS Annual Meeting

The 66th annual meeting of the American Academy of Orthopaedic Surgeons (AAOS) was held in February in Anaheim, California. Here are some highlights of the meeting as described in press releases and news reports from the AAOS.

• Certain arm positions can cause injuries in baseball pitchers, according to a study done at the Steadman-Hawkins Sports Medicine Foundation in Vail, Colorado. The study was presented and coauthored by Thomas J. Gill, MD, an orthopedic surgeon at Massachusetts General Hospital in Boston. Researchers videotaped 40 professional baseball pitchers to analyze their motion. The motions that led to injuries were: (1) inadequate shoulder rotation—instability can occur when the arm is positioned too far behind the body; (2) improper elbow angle—the elbow should be positioned away from the body at ball release to prevent injury; (3) arm lag during ball release—limiting fatigue can help prevent the arm from lagging behind the body; and (4) fastball pitching—coaches should limit the number of fastballs, particularly in younger players. The authors suggested that daily workouts for pitchers should include exercises that strengthen the shoulder, such as cross-body arm curls, light dumbbell exercises, and wall push-ups.
  
  
• A single steroid injection may predict the success of conservative treatment of subacromial impingement syndrome, according to a study presented by Robert Rupp, MD, an orthopedic surgeon at Edwards Air Force Hospital in Edwards, California. The study included 40 patients with impingement syndrome that did not respond to 6 weeks of nonsteroidal anti-inflammatory drugs and physical therapy. All received a subacromial injection of 1 mL of triamcinolone (40 mg/mL) and 5 mL of 1% lidocaine. Twenty-two patients had a positive response to the injection lasting at least 4 weeks; of 18 who reported an unsuccessful response after 3 weeks, 17 required surgery (average follow-up was 37.6 months). "No patient with less than 4 weeks of beneficial response time to the injection successfully responded to continued conservative therapy," Rupp said (see "Subacromial Space Injection: Pain Reliever, Diagnostic Tool," page 119.)
  
  
• Hyaluronate sodium injections at the shoulder appear to provide the same relief as steroid injections while causing less tissue damage in patients with rotator cuff tears, according to a poster presented by Yozo Shibata, MD, representing a research group from Fukuoka University School of Medicine in Fukuoka, Japan. (The US Food and Drug Administration has not approved hyaluronate sodium injections for joints other than the knee.) The researchers evaluated the effects of hyaluronate sodium and steroid injections in 78 patients with rotator cuff tears. The steroid group received five 2-mg dexamethasone injections and the hyaluronate group received a 25-mg injection of hyaluronate sodium. Of the 78 patients, 15 (38%) from the steroid group and 16 (42%) from the hyaluronate group eventually required surgery. Analysis of histologic specimens from cuff stumps in these patients showed that only 16% of specimens in the steroid group were dense, compared with 54.5% of specimens in the hyaluronate group. Shibata said that hyaluronate-treated patients will be more responsive to surgical cuff repair. "Repeated [steroid] injections are associated with a softer residual cuff, and it seems reasonable to assume that poor surgical results are due to the giving way of this soft tissue," he said.

NBA Team Physicians Cope With Lockout Fallout

Settlement of the National Basketball Association (NBA) lockout in early January meant that players—some out of shape and overweight—were thrust into an intense 2-week training camp. Then they embarked on a rigorous, condensed schedule that often requires teams to play three games in three nights.

What are NBA team physicians' impressions of the medical consequences of the lockout and schedule, and what are the teams doing to keep players healthy and on the court?

Sheldon Burns, MD, medical director, Minnesota Timberwolves:
"Prevention of injuries and illnesses is critical and for some teams may decide the outcome of the season. We're emphasizing nutrition, and we feed the players right after the game to reload their glycogen stores. We gave them all flu shots. Mental fatigue is a larger factor because players are sacrificing even more time away from their family and friends. The conditions this year require even more aggressive care. More care has to be delivered on the road, and our physician colleagues around the league are really helping out."

Glenn Perry, MD, team physician, Charlotte Hornets, president of the NBA Team Physicians Society:
"It's dangerous to draw conclusions about injuries this far into the season. We won't get the data until the end of the year. At the beginning of the season there was great concern among the players, teams, and physicians about the risk of increased injuries. Some injuries are unavoidable because of the nature of the game, but a conditioned muscle is less likely to strain. The fatigue factor may be real. The coaches and trainers are more aware of this, and they will possibly rotate more players. As a result, we may see an impact on performance. There might be fewer minutes for starters, and coaches may not practice [teams] as intensely."

Harlan Selesnick, MD, team physician, Miami Heat:
"We're beginning to see an increase in overuse injuries such as hamstring pulls and tendinitis. The players who arrived out of shape seem to be getting more injuries. I haven't seen a difference in upper-respiratory infections."

Field Notes

Does Smokeless Tobacco Improve Performance?
Because they believe it enhances their performance, some athletes who use smokeless tobacco are reluctant to quit. But a recent study suggests that smokeless tobacco can hurt performance, according to an article in the October 1998 issue of Medicine & Science in Sports & Exercise.

Researchers investigated the effects of smokeless tobacco on reaction time and strength in Division III college athletes. The researchers compared 20 athletes who used smokeless tobacco with 20 who did not use any form of tobacco (the tobacco users were tested during use and while abstaining). The results showed that smokeless tobacco had no effect on reaction time but may have impaired strength.

Let Patients Know About Fitness Week
One way to rally patients to become more active is to promote National Running and Fitness Week, scheduled for May 16 to 23. The educational campaign is sponsored by the American Running and Fitness Association, the American Medical Athletic Association, and the National Recreation and Park Association. Educational materials that can help promote National Running and Fitness Week can be found on the Web at http://www.arfa.org/programs/runfitweek.htm.

FDA Urges Supplement Recall
The US Food and Drug Administration (FDA) is requesting that dietary supplement makers voluntarily recall products that contain gamma butyrolactone (GBL).

According to an FDA press release, products containing GBL purportedly build muscles, improve physical performance, enhance sex, reduce stress, and induce sleep. Brand names include Renewtrient, Revivarant, Blue Nitro, GH Revitalizer, Gamma G, and Remforce. Sold in liquid and powder forms, the products are marketed on the Web, in health food stores, and in some gyms and fitness centers.

When taken orally, GBL converts to gamma hydroxybutyrate, a drug currently under study for the treatment of narcolepsy. GBL-related products have been associated with at least 55 adverse events, including one death, according to the FDA. In 19 cases, consumers became unconscious or comatose. Other reported effects include seizures, vomiting, slow breathing, and bradycardia.

Dietary Supplement Data on the Web
The National Institutes of Health (NIH) recently launched a free Web database of published international scientific literature on dietary supplements. The purpose of the database is to provide professionals and the public with credible information on dietary supplements. The Web address is http://dietary-supplements.info.nih.gov.

Study Sheds New Light on Women's ACL Injuries
The increased risk for anterior cruciate ligament (ACL) injuries in women may be intrinsic, according to a report presented by David E. Gwinn, MD, an orthopedic surgeon at the US Naval Academy in Annapolis, Maryland. A study of men and women at the academy from 1991 to 1997 found that the overall risk of ACL injury in athletics and military training was more than twice as high in women.

Incidence rates per 1,000 exposures were 0.0055 in men and 0.0135 in women, giving women a relative risk of 2.44. Gwinn noted that the higher risk in women has been attributed to several intrinsic and extrinsic factors, but that this study suggests intrinsic causes because female and male midshipmen met athletic competence standards upon admission and had the same training programs and facilities while at the academy. "This is of particular concern and deserves further study," Gwinn said.