Practice Guidelines - June 1, 2000 - American Academy of Family Physicians

Practice Guidelines

AAP Issues Recommendations on the Prevention and Treatment of Lyme Disease
Toni Lapp

The American Academy of Pediatrics (AAP) Committee on Infectious Diseases has issued recommendations for the prevention of Lyme disease. The recommendations appear in the January 2000 issue of Pediatrics.

Lyme disease, a disease transmitted by ticks carrying the spirochete Borrelia burgdorferi, is the most common vector-borne illness in the United States." The disease appears to be on the rise, with approximately 12,500 cases reported annually between 1993 and 1997. Ninety percent of cases originate in the northeastern and north-central United States. Lyme disease is carried by the black-legged tick, also known as the deer tick. [corrected]

Persons most at risk for Lyme disease are those whose activities put them in wooded, brushy or overgrown grassy areas, where ticks are most likely to be found. The highest rates of infection are reported in persons between two and 15 years of age and 30 to 55 years of age.

Prevention

Persons can lessen their risk of Lyme disease by reducing their exposure to ticks. Insect repellents that contain n,n-diethyl-m-toluamide (DEET) are effective but must be reapplied every one to two hours. Persons should be instructed in methods of examining themselves for ticks after being in tick-infested areas. Ticks often attach to hairy areas of the body, especially the head and neck.

Studies have shown that transmission of B. burgdorferi usually requires ticks to be attached for at least 48 hours; therefore, ticks should be removed promptly. The tick should not be squeezed when removing. Tweezers should be used to grasp the tick as close to the skin as possible and removed by firmly pulling straight out without twisting.

Treatment of Tick Bites

The AAP reports that routine use of antimicrobial prophylaxis is not recommended because of the potential for adverse reactions and associated costs. In highly endemic areas, at most 20 to 30 percent of deer ticks are infected with B. burgdorferi. The risk of infection after a bite by a deer tick in an endemic area is about 1.4 percent. Most persons who become infected develop erythema migrans at the site of the bite, which is diagnostic of early Lyme disease. Children can be treated easily and effectively at this stage of disease, with little risk of long-term complications.

Because it is unlikely for there to be detectable antibodies at the time of a tick bite, such testing would likely be misleading. The AAP does not recommend serologic testing for Lyme disease at the time of a tick bite. Presence of antibodies at the time of a tick bite would likely represent a false-positive result or evidence of an earlier infection, says the AAP.

Vaccination

According to the AAP, the decision to recommend vaccination should be based on a person's risk of being bitten by ticks infected with B. burgdorferi. Factors that should affect the decision include the density of ticks in the area, the prevalence of B. burgdorferi infection among those ticks and individual behavior. State and local health departments can provide information on the risk of infection in specific areas.

The AAP reports the results of animal studies on vaccines against Lyme disease. It has been shown that purified recombinant proteins, especially of outer surface proteins (Osp) of B. burgdorferi, such as Osp A, B and C, induce protective responses. In particular, the recombinant OspA (rOspA) is highly effective against challenge strains that are homologous or closely related to the isolate of OspA. The rOspA vaccine seems to have a unique mode of action, although the exact mechanism by which the antibody works is unknown. Early clinical trials on humans demonstrated that rOspA was immunogenic and well-tolerated. The vaccines have been produced by two manufacturers and field tested in humans. Only one vaccine, LYMErix, is licensed at this time by the U.S. Food and Drug Administration (FDA). The vaccine is administered intramuscularly in three doses of 0.5 mL (30 µg); the second dose is given one month after the first, and the third dose is given 11 months later, one year after the first dose. Dosages should be timed so that the second and third doses are given several weeks before the start of Lyme disease season, which begins in April.

The AAP reports on the efficacy of the vaccine in a controlled trial of 10,936 subjects. In the year after the first two injections, the vaccine efficacy against Lyme disease was 49 percent. In the second year after the third injection, efficacy rose to 76 percent. According to the AAP, it is unknown whether the protective immunity will last more than a year beyond the third dose. The data suggest that boosters may be necessary to extend protection. Adverse reactions to the vaccine usually occurred within 48 hours of injection. The most common reaction was soreness at the injection site, reported by 24 percent of recipients. Systemic symptoms such as myalgias, achiness, fever and chills were reported by fewer than 3 percent of subjects. Such symptoms were usually mild to moderate in severity.

Recommendations

The AAP's recommendations are as follows:

Attempts to minimize exposure to vector ticks in residential areas is encouraged. Heavily tick-infested areas should be avoided, if possible. If not possible, then personal protective measures (e.g., wearing specific types of clothing, use of repellents, frequent checks for ticks), and early detection and treatment of disease manifestations are encouraged.

Routine use of antimicrobial agents to prevent Lyme disease after a deer tick bite, even in highly endemic areas, is not recommended. Serologic testing for Lyme disease at the time of a recognized tick bite is also not recommended.

Use of Lyme disease vaccine is recommended in the following cases:

Administration of the vaccine should be considered for the following persons who are 15 years of age or older: those who spend time in geographic areas of high risk and whose activities result in frequent or prolonged exposure to vector ticks; and those who visit geographic areas of high risk during the peak Lyme disease transmission season and whose activities result in frequent or prolonged exposure to vector ticks.

The vaccine may be given to persons who reside, work or recreate in areas of high or moderate risk and whose activities result in some, but neither frequent nor prolonged, exposure to vector ticks. However, the benefits of vaccination for these persons compared with those of personal protective measures and early treatment of Lyme disease are unclear.

The vaccine is not recommended for the following: persons who reside, work or recreate in areas of high or moderate risk but who have minimal or no exposure to infected ticks; persons who reside, work and recreate in geographic areas of low or no risk; and children younger than 15 years until data about the safety and immunogenicity of the vaccine in this age group are available and the FDA has labeled the product for use in this age group.

Immunization should be considered for persons with a history of Lyme disease who are at continued high risk. However, persons with antibiotic-resistant Lyme arthritis should not be immunized because of the association between this condition and immune reactivity to OspA. Persons with chronic joint or neurologic illness related to Lyme disease, as well as those with second or third degree atrioventricular block, were excluded from the phase III safety and efficacy trial; thus, the safety and efficacy of Lyme disease vaccine for such persons is unknown.

The safety and efficacy of the simultaneous administration of rOspA vaccine with other vaccines have not been established. Administration of rOspA vaccine should not interfere with the administration of routinely recommended immunizations. If rOspA vaccine is to be given concurrently with other vaccines, each should be administered in a separate syringe at a separate site.

Data are lacking on the safety and efficacy of rOspA vaccines in persons with immunodeficiencies. General guidelines for administration of inactivated or subunit vaccines should be followed (see the current edition of Red Book).

Because the safety of rOspA vaccine administered during pregnancy has not been established, immunization of women known to be pregnant is not recommended. A vaccine pregnancy registry has been established by the manufacturer. In the event that a pregnant woman is immunized, health care professionals are encouraged to register this immunization by calling 800-366-8900, extension 5231.

AHRQ Releases Evidence Report on Brain Injury in Children
Sharon Scott Morey

The Agency for Healthcare Research and Quality (AHRQ; formerly the Agency for Health Care Policy and Research) has released an evidence-based report on the rehabilitation of children and adolescents with traumatic brain injury. The report is the product of the AHRQ evidence-based practice program. This program compiles and analyzes scientific information on which to base clinical guidelines, performance measures and other tools for improving the quality of health care. AHRQ contracts with institutions to review all relevant scientific literature on a particular clinical topic and produce evidence reports and technology assessments, conduct research on the effectiveness of various methods of clinical care and participate in technical assistance activities.

The AHRQ evidence report on rehabilitation after traumatic brain injury in children and adolescents was developed at the Oregon Health Sciences University, Portland, which is one of the AHRQ's evidence-based practice centers.

The five-page summary of the evidence report is available on the AHRQ Web site (http://www.ahrq.gov/ clinic/). Print copies are available from the AHRQ Clearinghouse, P.O. Box 8547, Silver Spring, MD 20907; phone: 800-358-9295 in the United States; 410-381-3150 from outside the United States. The following summarizes the AHRQ evidence-based report on rehabilitation after traumatic brain injury in children and adolescents.

Key Questions to Answer

The evidence report, titled "Rehabilitation for Traumatic Brain Injury in Children and Adolescents" (AHRQ Publication No. 99-E025), identifies five key questions for assessing the effectiveness of rehabilitation interventions in children and adolescents with traumatic brain injury. The five questions are as follows:

1. Does early, intensive medical rehabilitation in the hospital improve outcomes in children with traumatic brain injury?

2. How many children with traumatic brain injury receive special education designed to accommodate their needs as a result of the brain injury?

3. Do children who receive special education designed to accommodate their needs have better outcomes than children who do not receive such individualized special education or who receive no special education at all?

4. Does identification of the child's developmental stage at the time of the brain injury and at the time of assessment help predict the child's outcome? Does the extent to which the injury has arrested the child's normal development increase the ability to predict when the child will exhibit the needs, behaviors and problems resulting from the brain injury?

5. Does support of the families of children with brain injury enhance the family's ability to cope and reduce the burden of illness?

The report notes that any research question about childhood brain injury must be oriented to the relevant developmental category and age group of the child, including the child's age at the time of injury, the child's age at evaluation and the interval between the injury and the assessment.

In an attempt to answer the five key questions, a total of 356 articles were reviewed. Of these articles, one study was found for the first question, 15 for the second question, eight for the third question, 61 for the fourth question and three for the fifth question. The remaining 268 articles described interventions but did not provide data on the patients/students.

Question 1: How Effective Is Early Rehabilitation?

According to the report, no randomized controlled trials and no comparative studies have investigated the efficacy of early, intensive rehabilitation following traumatic brain injury in children and adolescents. Inferences about early intervention in children have been drawn from studies of adults.

Three studies were reviewed for indirect information. One study suggested that early, thorough evaluation, including bone scans, may identify undetected musculoskeletal trauma and heterotopic ossification. The authors of the study indicated that special methods for detecting physical trauma are important in patients with traumatic brain injury.

Question 2: How Many Children Receive Special Education?

The AHRQ report notes that three retrospective studies and one cross-sectional statewide study revealed that between 9 and 38 percent of students with identified brain injury are referred to special education. Whether the reported referral rates represent adequate referral, underreferral or overreferral could not be determined. Students with traumatic brain injury who did not receive special education were not included in the studies. Thus, data are not available on the number of children who are functioning well without special education services.

Question 3: Does Special Education Improve Outcome?

Data about the effects of special education programs are limited, according to the AHRQ report. One nonrandomized comparative study, one small case series, one survey and five case studies provide varied results. The report notes that the methodology of the comparative study is flawed because the control group performed significantly better than the treatment group at pretesting, suggesting that the control group was not as impaired as the treatment group. In the five case studies, all of the patients showed improvement over baseline measures.

Question 4: Can Deficits Predict Subsequent Needs and Problems?

A review of the literature uncovered 61 studies that provided data on the predictability of deficits based on developmental issues. The seven studies with the highest methodologic scores were selected for analysis.

In a study of language acquisition, predictable patterns of delays and deficits in language acquisition were demonstrated in children up to three years of age. Two cross-sectional studies established the base rate measures of brain growth at each stage of development that are necessary to detect the developmental effects of injury. Two comparative studies revealed subtle, hidden deficits in children who appeared to perform normally. Two studies demonstrated changes in growth that were strongly related to brain injury variables.

Question 5: Does Family Support Reduce the Burden of Illness?

No randomized controlled trials have been performed to compare the effects of support to families with the effects of no support. According to the AHRQ report, a randomized trial on the effects of two forms of support for the family suggest that intervention for parents of children with brain injury may be more effective in reducing the burden of illness if it focuses on the needs of the parents as opposed to the needs of the child. In a prospective observational study, a direct correlation was found between the presence of social support and measures of family functioning three years after the injury occurred. In addition, a number of studies have demonstrated a relationship between higher levels of family functioning and better outcomes for the injured child.

Conclusion

The AHRQ evidence-based report on rehabilitation following traumatic brain injury ends with the statement that no studies have been conducted to provide evidence of the effectiveness of rehabilitation interventions in children and adolescents. The published literature contains information on descriptions of intervention programs that are widely accepted but their effectiveness has not been validated. The report suggests that future research could be guided by themes that have emerged across many disability groups. While traumatic brain injury is unique, it also shares features of other disabilities.

Analysis of the literature revealed three gaps in the literature, which, according to the report, serve to identify priorities for future research. One gap is the insufficient evidence about the natural history of traumatic brain injury in children and adolescents. Another is the absence of experimental studies to assess effectiveness of different interventions. The third gap relates to the failure to incorporate concepts of child and adolescent development in longitudinal and experimental studies of traumatic brain injury.

This is a corrected version of the item that appeared in print.

Copyright © 2000 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact afpserv@aafp.org for copyright questions and/or permission requests.

June 1, 2000 Contents | AFP Home Page | AAFP Home | Search