Evaluation of potential factors contributing to microbiological treatment failure in Streptococcus pyogenes pharyngitis.

BACKGROUND: A cohort study of children with pharyngitis aged two to 16 years was conducted to assess the role of microbial and host factors in group A beta-hemolytic streptococcus (GABHS) microbiological treatment failure. METHODS: GABHS-infected children had pharyngeal swabs repeated two to five days after completing a 10-day course of penicillin V. M and T typing, and pulsed field gel electrophoresis were performed on the isolates, and the isolates were evaluated for tolerance. Patient characteristics and clinical features were noted and nasopharyngeal swabs for respiratory viruses were taken at enrolment. RESULTS AND CONCLUSIONS: Of 286 patients enrolled, 248 (87%) could be evaluated. GABHS was cultured from 104 patients (41.9%), of whom 33 (33.7%) had microbiological treatment failures on follow-up. Although there was a trend toward failure for younger children (mean 6.5+/-2.4 years versus 7.3+/-2.4 years, P=0.07) and M type 12 (24% versus 10%, P=0.08), no factors were associated with treatment failure.

Prevention of central venous catheter-related infections and thrombotic events in immunocompromised children by the use of vancomycin/ciprofloxacin/heparin flush solution: A randomized, multicenter, double-blind trial.

PURPOSE: To determine whether an antibiotic flush solution containing vancomycin, heparin, and ciprofloxacin (VHC) can prevent the majority of line infections. PATIENTS AND METHODS: A prospective double-blind study was performed comparing VHC to vancomycin and heparin (VH) to heparin alone in 126 pediatric oncology patients. RESULTS: The 153 assessable lines resulted in 36,944 line days studied. There were 58 blood stream infections (43 gram-positive, 14 gram-negative, and one fungal). Forty were defined as line infections (31 heparin, three VH, six VHC). The time to develop a line infection was significantly increased using either antibiotic flush (VH, P =.011; VHC, P =.036). The rate of total line infections (VH, P =.004; VHC, P =.005), gram-positive line infections (VH, P =. 028; VHC, P =.022), and gram-negative line infections (VH, P =.006; VHC, P =.003) was significantly reduced by either VH or VHC. Sixty-two (41%) of the lines developed 119 occlusion episodes (heparin, 3.99 per 1,000 line days; VHC, 1.75 per 1,000 line days; P =.0005). Neither antibiotic could be detected after flushing, and no adverse events were detected, including increased incidence of vancomycin-resistant Enterococcus colonization or disease. CONCLUSION: The use of either VH or VHC flush solution significantly decreased the complications associated with the use of tunneled central venous lines in immunocompromised children and would save significant health care resources.

Epidemiology and cost of infection with human parainfluenza virus types 1 and 2 in young children.

To determine the morbidity, costs, and epidemiological features of lower respiratory tract infections (LRIs) due to human parainfluenza virus types 1 and 2 (HPIV-1 and HPIV-2), we evaluated 1,213 children < 6 years of age who were seen for LRIs in the emergency room of the Children's Hospital of Wisconsin and/or were admitted to the hospital for LRIs during the fall quarter of 1991. The age, sex, race, and respiratory syndrome were recorded for each child; 158 patients (13%) had respiratory samples cultured for viruses and were followed clinically for the duration of their illness. Caucasian children had croup diagnosed more often than did African-American children (relative risk [RR] = 3.12; 95% confidence interval [CI], 2.43-4.00; P < .001), while African-American children more often had pneumonia (RR = 1.85; 95% CI, 1.36-2.5; P < .001). Forty-five of 70 viruses recovered were HPIV-1 (17 cases) or HPIV-2 (28 cases). Together these two viruses were recovered from 49% of children presenting with croup, 10% of those presenting with bronchiolitis, and 12% of those presenting with pneumonia. Gender- and race-associated differences were documented in the group of children infected with HPIV-2: specifically, this group included more girls than boys (RR = 1.99; 95% CI, 1.02-3.88; P < .04) and more Caucasian than African-American children (RR = 2.64; 95% CI, 1.05-6.63; P = .027). These data extrapolate nationally to approximately 250,000 emergency-room visits and approximately 70,000 hospitalizations due to HPIV-1 and HPIV-2, with a cost of $50 million for the former and $140 million for the latter.

Recovery of human parainfluenza virus types one and two.

The ability to recover human parainfluenza virus types 1 and 2 (HPIV-1, 2) from infected individuals has been highly variable. During the autumn of 1991, 158 nasal wash specimens collected from children with lower respiratory symptoms were split and cultured independently at two laboratories using different tissue culture techniques. Immunofluorescent antibody (IFA) and hemadsorption (HAd) assays were compared for their speed and efficiency in viral detection. 45 isolates [HPIV-1 (17) and HPIV-2 (28)] were recovered by one laboratory and only one (HPIV-2) by the other. IFA was the most sensitive assay detecting 87% of HPIV-1 and 70% of HPIV-2 by the fourth day of culture. HAd assay detected 87% of HPIV-1 isolates by the time they were positive by IFA, but only 35% of the HPIV-2 isolates. Significant methodologic differences between laboratories were then compared simultaneously for effect on virus recovery from culture positive frozen clinical specimens. Recovery of 100% of the isolates was achieved. Factors that contributed to differences in recovery of HPIV-1 and 2 were: (1) primary African green monkey (AGMK) cells were inferior to cynomolgus monkey kidney or LLC-MK2 cells, (2) addition of trypsin to culture medium for AGMK and LLC-MK2 cells enhanced recovery, (3) use of IFA was essential for rapid detection of HPIV-2, and (4) use of microtiter plate culture without specimen dilution enhanced virus recovery. A survey of clinical virology laboratories demonstrated considerable variability in the use of these techniques for routine respiratory virus culture.