Comparison of incidence of invasive Streptococcus pneumoniae disease among children before and after introduction of conjugated pneumococcal vaccine.

OBJECTIVES: The objective was to determine whether there has been a significant decrease in the incidence of invasive Streptococcus pneumoniae disease in the Louisville, KY, area since heptavalent pneumococcal conjugate vaccine was introduced in the winter of 1999-2000. A secondary objective was to collect demographic data regarding invasive S. pneumoniae disease in the Louisville, KY, area during the 1997-2002 period. METHODS: Data on cases of invasive S. pneumoniae disease (defined by a positive culture for S. pneumoniae from the blood, pleural fluid or cerebrospinal fluid) were collected from the microbiology laboratories and medical records departments of all hospitals that treat children in the Louisville area, for 1997-2002. Trends in case rates for all cases of invasive S. pneumoniae disease from 1999 to 2002 were observed, and demographic and other factors regarding this illness were recorded for each patient. RESULTS: The trend for rates of invasive pneumococcal disease showed a significant decrease during the study period for all ages combined (P < 0.001), for children younger than 2 years of age (P = 0.002) and for children 2 to 5 years of age (P = 0.002). The mean age for children was 2.22 years, with a male/female ratio of 1.8:1. The most common final diagnoses for the patients were bacteremia without focus, pneumonia and meningitis. Forty-eight percent of the organisms were resistant to penicillin. There was a significantly higher rate of resistance to penicillin among S. pneumoniae strains that caused cerebrospinal fluid infection than among strains that caused non-cerebrospinal fluid infection (P < 0.001). The case fatality rate was 2.6%. CONCLUSION: Case rates for invasive S. pneumoniae disease among children decreased significantly in the 2-year period after introduction of the heptavalent S. pneumonia protein conjugate vaccine into this community.

Hybrid external fixation of the proximal tibia: strategies to improve frame stability.

OBJECTIVE: To determine the specific frame construction strategies that can increase the stability of hybrid (ring with tensioned wires proximally connected by bars to half-pins distally) external fixation of proximal tibia fractures. DESIGN Repeated measures biomechanical testing. SETTING: Laboratory. SPECIMENS: Composite fiberglass tibias. METHODS: Using the Heidelberg and Ilizarov systems, external fixators were tested on composite fiberglass tibias with a 1-cm proximal osteotomy (OTA fracture classification 41-A3.3) in seven frame configurations: unilateral frames with 5-mm diameter half-pins and 6-mm diameter half-pins; hybrid (as described above), with and without a 6-mm anterior proximal half-pin; a "box" hybrid (additional ring group distal to the fracture connected by symmetrically spaced bars to the proximal rings) with and without an anterior, proximal half-pin; and a full, four-ring configuration. Each configuration was loaded in four positions (central, medial, posterior, and posteromedial). MAIN OUTCOME MEASUREMENTS: Displacement at point of loading of proximal fragment. RESULTS: The "box" hybrid was stiffer than the standard hybrid for all loading positions. The addition of an anterior half-pin stiffened the standard hybrid and the "box" hybrid. CONCLUSIONS: The most dramatic improvements in the stability of hybrid frames used for proximal tibial fractures result from addition of an anterior, proximal half-pin.