Recommendations on Screening for Chlamydia
Sexually active women aged 25 and younger should be screened routinely forChlamydia trachomatis,according to the U.S. Preventive Services Task Force (USPSTF). The task force's new recommendations on screening for chlamydia are available online atwww.ahcpr.gov/clinic/uspstf/uspschlm.htm.
Rates of chlamydial infection vary widely among communities and patient populations. Although women younger than 21 years are at highest risk, most data indicate that infection is prevalent among women aged 20 to 25 years. Women older than 25 years should be screened if they have risk factors, which include not using condoms consistently and correctly, and having new or multiple sexual partners, or a history of a sexually transmitted disease.
The optimal timing for screening pregnant women is unclear. Screening early in pregnancy potentially can improve outcomes such as low birth weight and premature delivery. However, screening and treatment in the third trimester might be more effective at preventing transmission of chlamydial infection to the infant during birth.
The interval for rescreening women with a previous negative screening test also is unclear. Timing should be based on factors such as changes in sexual partners, age, and other risk factors. If a woman is at low risk of infection (e.g., in a mutually monogamous relationship and with a history of negative screening tests for chlamy-dial infection), frequent screening might be unnecessary.
Pneumococcal Conjugate Vaccine Shortage Resolved
Vaccine production and deliveries of Prevnar, a 7-valent pneumococcal conjugate vaccine manufactured by Wyeth Lederle Vaccines and licensed for use among infants and children, is now considered adequate to permit a return to the routine vaccination schedule, according to the Centers for Disease Control and Prevention (CDC).
Beginning in August 2001, the supply of Prevnar failed to meet demand, resulting in shortages. To conserve the limited supply and ensure protection of children at highest risk, the CDC published interim recommendations for vaccination that called for withholding vaccine from healthy children two years of age and older, and deferring some doses for healthy children less than two years of age.
According to the original Advisory Committee on Immunization Practices recommendations, and more recent guidance from the CDC, all children less than 24 months of age and 24 to 59 months of age who are at increased risk of pneumococcal disease (e.g., children with sickle cell disease or anatomic asplenia, chronic illness, a cerebrospinal fluid leak, a cochlear implant, or an immuno-compromising condition) should be administered the pneumococcal conjugate vaccine. In addition, physicians should consider vaccine for all other children 24 to 59 months of age, with priority given to children 24 to 35 months of age, American Indian/Alaska Native and black children, and those who attend group child care.
A catch-up schedule for children who are incompletely vaccinated is available atwww.cdc.gov. The highest priority for catch-up vaccination is to ensure that children less than five years of age at high risk of invasive pneumococcal disease because of medical conditions have received a complete series. Second priorities include vaccination of healthy children less than 24 months of age who have not received any doses of pneumococcal conjugate vaccine, and healthy children less than 12 months of age who have not yet received three doses.
Because of the frequency of physician visits for children during their first 18 months, catch-up vaccination might occur at regularly scheduled visits for most children who receive vaccines from their primary care physician; special notification should be considered for children who have completed their 15-month visit and are not scheduled to be seen again before the visit at age two years. Programs that provide vaccinations but do not see children routinely for other reasons also should consider a notification process to contact undervaccinated or unvaccinated children.
The CDC is investigating situations in which invasive pneumococcal disease occurs despite vaccination. Physicians are encouraged to report invasive pneumococcal disease occurring in children less than five years of age who have received more than one dose of pneumococcal conjugate vaccine to the CDC through state health departments. If pneumococcal isolates are available from vaccinated children, the CDC will perform serotyping to determine whether the strain is a type included in the vaccine. Additional information is available atwww.cdc.gov/nip/diseases/pneumo/PCV-survrpts/default.htm.
Toxic Substance Fact Sheets Available Online
The Agency for Toxic Substances and Disease Registry has new fact sheets available atwww.atsdr.cdc.gov/toxfaq.html. Visitors to the site can look up contaminants, including asbestos and pentachlorophenol, to find out, for example, a substance's effects on the environment, methods of exposure to the substance, whether it causes cancer or has other adverse effects on health, and methods for testing exposure. In addition to the toxicologic profiles, the site indexes public health statements and other resources.
Diabetes and Cardiovascular Risk in Children
Although there is strong evidence that risk factors for cardiovascular disease are present during childhood, there is no consensus on the optimal assessment and treatment of insulin resistance syndrome (i.e., obesity, hypertension, dyslipidemia, and hyper-insulinemia). The American Heart Association has issued a statement reviewing risk factors for these conditions in children. “Obesity, Insulin Resistance, Diabetes, and Cardiovascular Risk in Children” was published in the March 18, 2003 issue of Circulation. The statement is based on expert opinion and does not provide a description of the strength of the evidence that underlies the recommendations.
Type 2 diabetes is becoming a major public health problem for adolescents. The early onset suggests that patients will be at risk of cardiovascular disease at a young age. If the current trend continues, it is likely that the prevalence of type 2 diabetes will increase in the pediatric age group as well.
The first step in assessment is identifying children who may benefit from intervention. Testing is recommended for children who are overweight or have a family history of type 2 diabetes, signs of insulin resistance, or a predisposition based on race or ethnicity (e.g., American Indians, blacks, Hispanics, Asian/Pacific Islanders). Fasting plasma glucose or the two-hour value on an oral glucose tolerance test can be used for diagnosis, but the fasting glucose method is preferred. Sufficient data are not available to recommend the use of glycosylated hemoglobin A1c (HbA1ctesting).
Children who do not have elevated blood glucose levels may have other signs of insulin resistance syndrome, such as obesity, hypertension, or high cholesterol levels. These children remain at high risk for cardiovascular disease and diabetes. Body size measurements (e.g., body mass index [BMI], waist circumference), blood pressure, and cholesterol levels should be monitored in any child at high risk.
Lifestyle modification and weight control in childhood may reduce the risk of developing insulin resistance syndrome, type 2 diabetes, and cardiovascular disease. Adolescents with type 2 diabetes are almost always obese, with mean BMI in clinical series ranging from 26 to 38 kg per m2. Although studies in adults have found that weight loss of 10 to 15 percent can improve cardiovascular risk, it is not known what level of weight loss is necessary for adolescents to achieve improved glucose handling. Patients may need to be treated with oral agents, and some adolescents with type 2 diabetes may require insulin.