CHICAGO—A vaccine that was distributed beginning in 2000 has reduced the incidence of childhood pneumonia and meningitis and has helped to decrease the excess incidence among black Americans, according to a study in the May 12 issue of the Journal of the American Medical Association (JAMA).

"Historically, blacks in the United States have higher incidence of invasive pneumococcal disease (i.e., pneumonia and meningitis) than whites, with the widest disparities occurring among children in the first 2 years of life and among adults 18 to 64 years old," according to background information in the article. Following recommendation of a new vaccine (7-valent pneumococcal conjugate vaccine) for children in October 2000, the incidence of invasive pneumococcal disease has declined dramatically, but the impact of vaccination on racial disparities in incidence of pneumococcal disease has not been known.

Brendan Flannery, Ph.D., of the Centers for Disease Control and Prevention, Atlanta, and colleagues analyzed data from the Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, an active, population-based surveillance system in 7 states. The data included 15,923 cases of invasive pneumococcal disease occurring between January 1, 1998, and December 31, 2002.

The researchers found that between 1998 and 2002, annual incidence rates for invasive pneumococcal disease decreased from 19.0 to 12.1 cases per 100,000 among whites and from 54.9 to 26.5 among blacks. "Due to these declines, 14,730 fewer cases occurred among whites and 8,780 fewer cases occurred among blacks in the United States in 2002, compared with the average number in two prevaccine years, 1998 and 1999. Before vaccine introduction, incidence among blacks was 2.9 times higher than among whites; in 2002, the black-white rate ratio had been reduced to 2.2. Incidence among black children younger than 2 years went from being 3.3 times higher than among white children in the prevaccine period to 1.6 times higher in 2002," the authors write.

By 2002, 74 percent of white children and 68 percent of black children aged 19 to 35 months in the 7 states had received at least 1 dose of pneumococcal conjugate vaccine; 43 percent of white and 39 percent of black children received three or more doses.

CHICAGO—Approximately 4 percent of young adults in the U.S. have chlamydial infection, with substantial racial/ethnic disparities present in the prevalence, according to a study in the May 12 issue of the Journal of the American Medical Association (JAMA).

According to background information in the article, the sexually transmitted diseases Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) cause substantial illness in the United States. In women, chlamydial and gonococcal infections may cause pelvic inflammatory disease, tubal infertility, chronic pelvic pain, and ectopic pregnancy. Chlamydial infection may also be linked to cervical cancer. Chlamydial and gonococcal infections may increase susceptibility to and transmission of human immunodeficiency virus in both men and women. Early detection and treatment of these infections is challenging because most women and men with chlamydial infection and many women with gonorrhea are asymptomatic. Although screening for chlamydia is widely recommended among young adult women, little information is available regarding the prevalence of chlamydial and gonococcal infections in the general young adult population.

William C. Miller, M.D., Ph.D., M.P.H., of the University of North Carolina at Chapel Hill, N.C., and colleagues conducted a study involving a nationally representative sample of 14,322 young adults aged 18 to 26 years. In-home interviews were conducted across the United States for Wave III of The National Longitudinal Study of Adolescent Health (Add Health) from April 2, 2001, to May 9, 2002. This study sample represented 66.3 percent of the original 18,924 participants in Wave I of Add Health. Urine specimens were available for 12,548 (87.6 percent) of the Wave III participants, and were tested for evidence of chlamydial and gonococcal infections.

The researchers found that the overall prevalence of chlamydial infection in this sample of young adults was 4.19 percent. Prevalence varied little by age, but was more common among women (4.74 percent) than men (3.67 percent). Prevalence was more than 2 times higher in the south (5.39 percent) than in the northeast (2.39 percent) region. The prevalence of chlamydial infection varied significantly by race/ethnicity. Prevalence was lowest in white young adults (1.94 percent) and more than 6 times higher in black young adults (12.54 percent). Intermediate prevalences were observed in Latino young adults (5.89 percent). The highest prevalence in any group was among black women (13.95 percent), followed by black men (11.12 percent). The lowest prevalences were among Asian American men (1.14 percent), white men (1.38 percent), and white women (2.52 percent).

Overall prevalence of gonorrhea was 0.43 percent. Among black men and women, the prevalence was 2.13 percent and among white young adults, 0.10 percent. Overall, the prevalence of co-infection with both chlamydial and gonococcal infections was 0.03 percent.

CHICAGO—Individuals who have a variation of the COX-2 gene have an associated lower risk for a heart attack or stroke, according to a study in the May 12 issue of the Journal of the American Medical Association (JAMA).

Although myocardial infarction (MI, or heart attack) and atherothrombotic ischemic stroke are thought to be caused by rupture of vulnerable atherosclerotic plaques, they are recognized to be complex disorders that likely result from multifaceted interactions between an individual's genetic makeup and environmental factors, according to background information in the article. The relation between COX-2 variations and the risk of MI and stroke has not been clear.

Francesco Cipollone, M.D., of the G. d'Annunzio University of Chieti and G. d'Annunzio University Foundation, Chieti, Italy and colleagues conducted a study to determine if there was a relationship between a variation in the COX-2 gene (termed the "-765G-C polymorphism") and clinically evident plaque rupture. The study was conducted between March 2002 and October 2003 among 864 patients with first MI or atherothrombotic ischemic stroke and 864 hospitalized controls. The groups were matched for age, sex, body mass index, smoking, hypertension, hypercholesterolemia, and diabetes.

The researchers found that the prevalence of this specific genetic variation (-765GC) was 2.41 times higher among the controls than among the MI and stroke patients. The prevalence of a different variant (-765CC) was 5.81 times higher among the controls than among the MI and stroke patients. Patients with the -765GC or -765CC genotype had a reduction in relative risk of MI and ischemic stroke of 52 percent and 67 percent, respectively, after adjustment for age, sex, smoking status, body mass index, hypercholesterolemia, hypertension, and diabetes.

CDC SAYS PNEUMOCOCCAL VACCINE PROVEN CAUSE OF DRAMATIC REDUCTION IN SERIOUS ILLNESS, ESPECIALLY IN BLACKS