Infectious Diseases I Concurrent Session 1:30 PM Friday, February 2, 2007 279 THE EPIDEMIOLOGY OF EARLY-ONSET VERSUS LATE-ONSET BLOODSTREAM INFECTIONS IN A NEONATAL INTENSIVE CARE UNIT. R. Saisan, B. Afghani, E. Afghani, J. Sills, University of California, Irvine Medical Center, Irvine, CA. Bloodstream infections in neonates continue to be a significant ailment despite improvements in health care practice, most likely due to multiple risk factors affecting both early-onset and late-onset sepsis. Objective: To compare the epidemiologic characteristics of early-onset and late-onset bloodstream infections in neonates treated at the University of California, Irvine neonatal intensive care unit (UCI- NICU) over a 7-year period. Methods: All neonates with positive blood cultures treated at UCI-NICU between January 1998 and December 2004 were identified and their medical records were reviewed. Early-onset bacteremia was defined as an episode of bacteremia within the first 7 days of life. Results: We identified 56 episodes of early onset and 160 episodes of late-onset bloodstream infections (see Table). Organism Early Onset (n 5 56) Late Onset (n 5 160) p Value CONS 23 (41%) 121 (76%) , .01 Streptococcus 6 (10%) 4 (2%) .01 S. aureus 2 (4%) 11 (7%) Enterococcus 2 (4%) 3 (2%) E. coli 6 (11% 5 (3%) .03 Serratia/Pseudomonas/ Citrobacter/Enterobacter/ Proteus 14 (25%) 14 (9%) , .01 Other 3 (5%) 2 (1%) Gram-negative bacteria caused bloodstream infections more frequently in early onset compared with late onset, whereas coagulase-negative Staphylococcus (CONS) was more common in late-onset infections. Comparing risk factors for patients with early-onset and late-onset bloodstream infections, as expected, those with early-onset infections were less likely to have had surgeries (5.4% vs 38%), prior antibiotic therapy (37.5% vs 90%), shorter duration of intubation (2 days vs 13.7 days), and shorter duration of central lines (3.7 days vs 28.7 days). Conclusions: The predominant bacterial causes of early-onset and late-onset bloodstream infections are different. Elucidation of epidemiologic trends and risk factors associated with early- and late-onset bloodstream infections will have significant implications in developing measures to control the occurrence of these infections. 280 COMPARISON OF THE DRUG-SUSCEPTIBILITY PROFILE OF STAPHYLOCOCCUS AUREUS AMONG THE ADULT AND PEDIATRIC POPULATIONS, 2001–2006. V. Ebert, B. Afghani, University of California, Irvine Medical Center, Orange, CA. Drug-susceptibility profile of Staphylococcus aureus is changing rapidly. Comparative data on drug susceptibility patterns of S. aureus in adult and pediatric population are scant. Objective: To compare the drug-susceptibility profile of S. aureus in the adult and pediatric population hospitalized at the University of California, Irvine Medical Center (UCIMC). Methods: We analyzed drug susceptibility of all patient isolates of S. aureus recovered from various clinical sources for patients hospitalized at UCIMC between January 2001 and July 2006. Results: Drug susceptibility of 2,268 patient isolates was reviewed and compared for the pediatric (0–18 years old) and the adult (. 18 years old) population (see Table). 2001–2003 2004–2006 Adult (n 5 956) Pediatric (n 5 138) Adult (n 5 965) Pediatric (n 5 209) Methicillin-R 364 (38%) 27 (20%) 388 (40%) 53 (25%) Clindamycin-R 219 (23%) 17 (12%) 278 (29%) 65 (31%) Erythromycin–R 478 (50%) 56 (41%) 499 (52%) 121 (58%) Trimeth-sulfa-R 36 (4%) 4 (3%) 30 (3%) 3 (1%) Adults were more likely to have methicillin-resistant S. aureus (MRSA) isolates compared with the pediatric population for both periods (2001–2003 vs 2004–2006). Clindamycin resistance increased between the two periods, especially for the pediatric population (p , .05). When comparing MRSA and MSSA susceptibility profiles, MRSA isolates were more likely to be resistant to multiple antibiotics (p , .01). Of 832 MRSA, 96% were Erythro-R and 54% were Clinda-R, whereas for 1,436 MSSA isolates, 25% were Erthro-R and 9% were Clinda-R. D-test was performed on all isolates starting August 6, 2004. During this period, of 322 isolates (from all age groups) that tested Erythro-R and Clinda-S initially, 135 (42%) had inducible clindamycin resistance. For the pediatric population, D-test was positive for 26 (37%) of 71 Erythro-R isolates that initially tested Erythro-R and Clinda-S. Conclusions: At our center, the drugsusceptibility pattern of S. aureus is different in adult and pediatric populations and has changed over time. A significant proportion of the Erythro-R S. aureus has inducible clindamcycin resistance. Further analysis will include review of susceptibility profiles according to the specimen type and mode of transmission of S. aureus (community vs health care associated). 281 EPIDEMIOLOGIC CHARACTERISTICS OF GRAM-POSITIVE AND GRAM-NEGATIVE BLOODSTREAM INFECTIONS IN A TERTIARY NEONATAL INTENSIVE CARE UNIT. E. Afghani, B. Afghani, R. Saisan, J. Sills, University of California, Irvine, Orange, CA. Background: Bacteremia remains a major cause of morbidity and mortality in neonatal units. Objective: To analyze the epidemiologic characteristics of bloodstream infections at the University of California, Irvine Neonatal Intensive Care Unit (UCI-NICU) over a 7-year period. Methods: All neonates with positive blood cultures within the first month of life treated at the UCI-NICU between January 1998 and December 2004 were identified and their medical records were reviewed. The risk factors prior to the onset of bacteremia caused by gram-positive and gram-negative organisms were compared. Results: These are summarized in the table. Of 216 episodes of bacteremia, 176 (81%) were caused by gram-positive organisms and 40 (19%) were caused by gram-negative organisms. Risk Factor Gram Positive (n 5 176) Gram Negative (n 5 40) p Value Mean birth weight (g) 1,110 1,647 .002 Mean age at onset (d) 22.7 13.0 , .01 Central line (mean no. of days) 25.0 8.4 , .01 Intubation (mean no. of days) 11.8 4.1 , .01 C/S (%) 58.5 40.0 PROM (%) 28.4 27.5 Surgery (%) 32.4 20.0 , .01 Cephal use (%) 43.8 35.0 Penicillin-class use (%) 83.0 50.0 .03 Vancomycin use (%) 34.7 17.5 .07 Conclusions: Gram-positive organisms were the predominant cause of bacteremia in neonates at the UCI-NICU during the first month of life, and risk factors such as intubation, central line placement, surgical procedures, and antibiotic use were more common in patients with gram-positive bacteremia. Because of changing epidemiology of bloodstream infections, continuous surveillance studies to identify risk factors associated with bloodstream infections in neonates will be helpful in developing strategies to prevent and treat such infections. 282 EDUCATING HIGH SCHOOL ATHLETES AND COACHES ON COMMUNITY-ACQUIRED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS. G. Luettgen, University of Washington, Seattle, WA. Purpose: Columbus, MT, has experienced an epidemic of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in recent months, particularly in adolescent youth. A community- based education program targeting junior high and high school–aged athletes was developed to inform them on prevention and treatment. Methods: Since high school sports fit many of the risk factors associated with CA-MRSA, high school athletes seemed an appropriate target population. A search of the medical literature on CA-MRSA was performed and a PowerPoint presentation was developed emphasizing different aspects of transmission and prevention such as risk factors, common disease manifestations, and recent CA-MRSA case studies from the local area. This was presented to junior high and high school students during their annual sports physical at the Columbus Clinic. In addition, a pamphlet emphasizing prevention of disease spread within the high school sports setting was created and distributed to each athlete at the conclusion of their physical. An educational seminar on CA- MRSA was also presented to the local high school football and wrestling coaches. Summary: Many athletes and parents in attendance showed great interest in the topic and were surprised that such infections can occur in healthy youth. They asked multiple cogent questions. The coaches displayed a willingness to implement suggestions and appeared to take the situation seriously. We also discussed other areas of possible implementation within the school, such as physical education classes, as an additional means to control cases of CA-MRSA within the town of Columbus. 283 INCREASING RATE OF INTRAVENOUS IMMUNOGLOBULIN NONRESPONDERS AMONG CHILDREN WITH ACUTE KAWASAKI SYNDROME IN SAN DIEGO COUNTY. S. Song, S.L. Wang, B.M. Best, E. Corinaldesi, J.R. Eichenfield, J.C. Burns, Departments of Pediatrics and Pharmacy, University of California, San Diego, San Diego, CA. Purpose: To determine annual response rates to intravenous immunoglobulin (IVIG) among Kawasaki syndrome (KS) patients and to compare characteristics of IVIG responder and nonresponder patients. Methods: All patients met the AHA 2004 diagnostic criteria for KS and were first treated within 10 days of illness onset. Nonresponse to IVIG was defined as a rectal or oral temperature $ 100.4uF at 36 hours to 7 days following the end of IVIG infusion. Coronary artery dilatation was defined as Z-score for the left anterior descending or right coronary artery $ 2.5. We determined annual response rates from 1998 to 2006 and compared IVIG brands and lots used to treat nonresponder and responder patients in 2006. We compared demographic and laboratory data and clinical signs between responder and nonresponder patient groups treated in 2006. Continuous variables were analyzed by Wilcoxon rank sum test and categorical variables by Fisher’s exact and chi-square as appropriate. Results: The IVIG nonresponse rate was significantly higher in 2006 than in all previous years (p , .01). The percentage of patients with each of the KS clinical signs was similar between 2005 and 2006. Nonresponders in 2006 were more likely than responders to have been diagnosed earlier (median day 5 S122 Journal of Investigative Medicine