Randomized trial of "bleach baths" plus routine hygienic measures vs. routine hygienic measures alone for prevention of recurrent infections.

Children with probable community-associated Staphylococcus aureus skin and soft tissue or invasive infections were randomized to routine daily hygienic measures with or without "bleach baths" twice a week for 3 months. Within 12 months, a medically attended recurrence occurred in 84 of 495 (17%) children using bleach baths compared to 103 of 492 (21%) of control participants (P = .15).

Recurrent community-associated Staphylococcus aureus infections in children presenting to Texas Children's Hospital in Houston, Texas.

BACKGROUND: There are limited data characterizing recurrent staphylococcal disease in children. We sought to define the clinical features and laboratory findings of children with recurrent community-associated Staphylococcus aureus infections presenting to Texas Children's Hospital in Houston, TX. METHODS: Medical records of children with recurrent, culture-proven community-associated S. aureus infections at Texas Children's Hospital from 8/1/2001 to 7/29/2009 were reviewed, and antibiotic susceptibility patterns were obtained for all S. aureus isolates. RESULTS: Six hundred ninety-four otherwise healthy patients presented to Texas Children's Hospital with 2-7 episodes of community-associated S. aureus infection, accounting for 1495 encounters, 823 hospitalizations and 3337 inpatient days. In 90% of patients with ≤12 months separating their initial and recurrent infections, the methicillin susceptibility of the initial and recurrent isolates was the same, compared with 79% of patients with > 12 months separating their infections. The overall antibiotic susceptibility pattern did not change between isolates in 71% of otherwise healthy children compared with only 33% of children with eczema. Ninety-two percent of otherwise healthy children had only recurrent skin and soft tissue infections; 8% had ≥1 non-skin and soft tissue infections. The location of skin and soft tissue infections varied by age, with children≤36 months of age being more likely to have ≥1 S. aureus infection located in the diaper area. CONCLUSIONS: Our study demonstrates that recurrent staphylococcal disease requiring emergency center or inpatient care is common, accounting for significant utilization of hospital resources. Children with recurrent staphylococcal infections are likely to have repeated infections from the same staphylococcal strain (by antibiotic susceptibility pattern), indicating that persistent colonization, frequent exposure to others who are chronically colonized, or environmental contamination is playing a role in recurrent disease. Finally, our study emphasizes the need for repeat cultures in children with recurrent disease, as 29% of healthy children and 67% of children with a predisposing risk factor (such as eczema) have a change in the antibiotic susceptibility pattern between S. aureus isolates.

Staphylococcus aureus infections in pediatric patients with diabetes mellitus.

OBJECTIVES: To describe Staphylococcus aureus infections in children with diabetes mellitus (DM). METHODS: Children with DM (cases) and S. aureus infections (2/02-6/10) were identified from a surveillance database. Patient charts were reviewed, and S. aureus isolates were characterized by molecular methods. Cases were compared to age-matched controls without DM but with CA-S. aureus skin and soft tissue infections (SSTI) using conditional logistic regression. RESULTS: Forty-seven cases were identified; 41 were matched with 123 controls. Four cases had osteomyelitis and 43 had SSTI. Mean age was 14.2 years and 63% of cases had hemoglobin (Hb) A1c levels above 10%. Cases and controls differed by gender (85% vs. 45% female, P < 0.001), BMI% (median 87% vs. 72%, P = 0.04), methicillin-resistant S. aureus (MRSA) infection (49% vs. 68%, P = 0.04), and recurrent infections (22% vs. 4%, P = 0.001). Among cases, 88% of recurrences were caused by MRSA. CONCLUSIONS: The majority of cases had poor glycemic control, more recurrences, fewer primary MRSA infections and were more likely to be female compared to a control group. Improved glycemic control may reduce the risk for infection, and decrease hospitalizations due to S. aureus infections.

Nasal Staphylococcus aureus colonization among mothers of term and late preterm previously healthy neonates with community-acquired Staphylococcus aureus infections.

We enrolled 35 case neonates with community-acquired Staphylococcus aureus infection and their mothers and 19 control mother-neonate pairs. We obtained neonatal and maternal anterior nasal cultures, and clinical isolates. S. aureus nasal colonization was greater in case than control pairs. Neonates were more often infected with their nasal strain than their mother's nasal strain.

Staphylococcus aureus sinus infections in children.

OBJECTIVE: Staphylococcus aureus can cause sinusitis in children. The predominant MRSA clone in the United States, USA300, has been associated with skin and soft tissue as well as invasive diseases. USA300 has increased among CA methicillin-susceptible S. aureus (CA-MSSA) isolates. We describe the clinical characteristics of pediatric patients with S. aureus cultured from sinus specimens, treated at Texas Children's Hospital (TCH), and characterized their isolates by molecular methods. METHODS: This was a retrospective study of children with endoscopic sinus surgery (ESS) cultures positive for S. aureus between 01/2005 and 12/2008 at TCH. Medical records were reviewed and associated S. aureus isolates were characterized by pulsed field gel electrophoresis (PFGE). Data were analyzed by Mann-Whitney U, Chi-square, Fisher's exact test, and Chi-square for trend. RESULTS: We identified 56 patients with S. aureus sinus infections; 12 (21%) were MRSA. Seven of 12 (58%) MRSA vs. 5/44 (11%) MSSA were USA300 (p<0.01). All MRSA isolates were non-susceptible to erythromycin compared to 30% of MSSA (p<0.01); 75% of the USA300 strains were non-susceptible to erythromycin compared to 36% of the non-USA300 strains (p<0.04). Co-pathogens were isolated from 77% (43/56) of the patient specimens. Both MRSA and USA300 isolates were associated with Haemophilus influenzae co-isolation (p<0.05). Patients with USA300 strains were significantly younger (p=0.02) and more likely to experience snoring as a symptom associated with their sinusitis (p=0.03) than those infected with non-USA300 strains. Children with MRSA (4/12) tended to have a greater recurrence rate than children with MSSA isolates (5/44) (p=0.09). No significant differences were observed between groups for fever or complications such as neck cellulitis, nasal abscess, meningitis, subdural empyema, and orbital cellulitis. CONCLUSION: MSSA was more commonly isolated than MRSA from sinus cultures of children who underwent ESS at TCH. The majority of ESS cultures positive for S. aureus, were mixed with other respiratory pathogens, principally H. influenzae. USA300 was the major clone among the MRSA sinusitis isolates, but was not associated with more complications than other S. aureus isolates.

Hospital-acquired Staphylococcus aureus infections at Texas Children's Hospital, 2001-2007.

OBJECTIVE: To document the introduction of the methicillin-resistant Staphylococcus aureus (MRSA) USA300 clone into a children's hospital. Current molecular epidemiology of infections due to the USA300 strain of MRSA in the pediatric healthcare setting remains obscure. DESIGN: Retrospective study of patients with hospital-acquired S. aureus infection during the period from August 1, 2001, through July 31, 2007, at Texas Children's Hospital in Houston. METHODS: Patients with hospital-acquired S. aureus infection from whom an isolate was available for molecular analysis were included. Clinical information was obtained from patient medical records and the electronic hospital information system. S. aureus isolates underwent antimicrobial susceptibility testing, pulsed-field gel electrophoresis, and polymerase chain reaction testing for staphylococcal cassette chromosome (SCC) mec, agr, the diamine N-acetyltransferase gene, and the Panton-Valentine leukocidin genes (pvl). RESULTS: Of 242 patients with hospital-acquired S. aureus infection, 147 (61%) had methicillin-susceptible S. aureus infection. Of the 95 MRSA isolates causing hospital-acquired infection, 69 (73%) were USA300 isolates, and that rate did not increase over time. Skin and soft tissue infection (P < .001), onset of infection less than 10 days after admission (P = .007), and lack of comorbidities (P < .001) were associated with hospital-acquired MRSA infection caused by the USA300 strain, compared with other isolates (hereafter referred to as non-USA300 isolates). Nine of 10 patients with a S. aureus infection at the time of death were infected with a non-USA300 strain. USA300 carried SCCmec IV, agr I, the diamine N-acetyl transferase gene, and pvl. USA300 isolates were more susceptible to clindamycin, gentamicin, and trimethoprim-sulfamethoxazole than were other non-USA300 isolates (P < .01). CONCLUSIONS: In our patient population, the annual numbers of observed cases of hospital-acquired S. aureus infection have remained constant. USA300 was the most common clone and, compared with other non-USA300 MRSA isolates, was associated with skin and soft tissue infection, early onset of infection after admission, and greater susceptibility to antimicrobial agents.

Vancomycin MICs for Staphylococcus aureus vary by detection method and have subtly increased in a pediatric population since 2005.

Vancomycin MICs for Staphylococcus aureus isolates in a pediatric hospital with a high rate of staphylococcal infections were examined for any increase over a 7-year period. A broth microdilution scheme allowed direct comparison of the MICs generated by this method to MICs generated by Etest. MICs generated by both methods were determined with the same inoculum suspension. One hundred sixty-five S. aureus isolates were selected on the basis of the patients having been bacteremic or having received vancomycin as the definitive therapy for their infections. Of the 165 isolates, 117 were methicillin-resistant S. aureus and 48 were methicillin-susceptible S. aureus. Forty-seven were acquired in the hospital (nosocomial), 56 were community acquired, and 62 were community onset-health care associated. All but one isolate tested by broth microdilution had MICs of < 1.0 microg/ml, while 96% of these same isolates tested by Etest had MICs of > or = 1 microg/ml. A significant increase in MICs that occurred after study year 4 (2004 to 2005) was demonstrated by the Etest (P < 0.00007) but not by broth microdilution. MICs were not different for isolates of community or health care origin, regardless of methodology. The proportion of isolates with Etest MICs of < 1 and > or = 1 microg/ml between children with bacteremia for < or = 5 days and > 5 days (P = 0.3) was not different. We conclude that MICs for pediatric isolates have increased slightly since 2005 and therapeutic decisions based on vancomycin MICs need to be made by considering the methodology used.

Evaluation and treatment of community-acquired Staphylococcus aureus infections in term and late-preterm previously healthy neonates.

OBJECTIVE: We describe the evaluation and treatment of neonatal community-acquired Staphylococcus aureus disease in the era of community-acquired methicillin-resistant S. aureus. METHODS: We retrospectively reviewed the evaluation and treatment of 126 community-acquired S. aureus infections of term and late-preterm previously healthy neonates who were < or = 30 days of age between August 2001 and July 2006 at Texas Children's Hospital. RESULTS: S. aureus infections included 43 pustulosis, 68 cellulitis/abscess, and 15 invasive infections. We found 84 methicillin-resistant and 42 methicillin-susceptible S. aureus isolates. Twenty-one patients received outpatient antibiotics before hospital presentation. Systemic infection evaluation included urine, blood, and cerebrospinal fluid cultures in 79, 102, and 84 neonates, respectively. Culture revealed S. aureus urinary tract infections in 1, S. aureus bacteremias in 6, and aseptic cerebrospinal fluid pleocytosis of unclear cause in 11 neonates. Physicians admitted 106, transferred 5 to other hospitals, and discharged 15 afebrile patients with topical or oral antibiotics. Clindamycin was the predominant antistaphylococcal intravenous and oral antibiotic for pustulosis and cellulitis/abscess infections. One patient with systemic S. aureus and herpes simplex virus infection died. At discharge after inpatient treatment, physicians prescribed no antibiotics for 43 patients and oral or topical antibiotics for 62 patients. Outpatient treatment failed for 1 patient who was discharged after intravenous therapy and was readmitted. Eighty percent (16 of 20) of patients with mastitis alone completed treatment with outpatient oral antibiotics. CONCLUSIONS: Evaluation and treatment strategies for neonatal community-acquired S. aureus disease are varied at our hospital. Prospective studies are needed to determine optimal management strategies.

Community-acquired Staphylococcus aureus infections in term and near-term previously healthy neonates.

BACKGROUND: Community-acquired, methicillin-resistant Staphylococcus aureus infections are increasing among children. OBJECTIVE: Our goal is to describe the clinical presentation of neonatal community-acquired S aureus disease and provide molecular analyses of the infecting isolates. PATIENTS AND METHODS: We retrospectively reviewed the demographics and hospital course of term and near-term previously healthy neonates, < or = 30 days of age, with community-acquired S aureus infections presenting after nursery discharge between August 2001 and March 2005 at Texas Children's Hospital. Prospectively collected isolates were characterized by pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec type, and the presence of PVL genes. RESULTS: Of 89 S aureus infections, 61 were methicillin-resistant S aureus; S aureus infections increased each year. Methicillin-resistant S aureus infections increased from 10 of 20 to 30 of 36 infections from 2002 to 2004. Most subjects, 65 of 89, were male. Symptoms began at 7 to 12 days of age for 26 of 45 male infants with methicillin-resistant S aureus. Most infections, 77 of 89, involved skin and soft tissue; 28 of 61 methicillin-resistant S aureus versus 7 of 28 methicillin-susceptible S aureus infections required drainage. Invasive manifestations included shock, musculoskeletal and urinary tract infection, perinephric abscess, bacteremia, empyema/lung abscess, and a death. Maternal S aureus or skin-infection history occurred with 13 of 61 methicillin-resistant S aureus versus 1 of 28 methicillin-susceptible S aureus infections. The predominant community clone, USA300 (PVL genes +), accounted for 55 of 57 methicillin-resistant S aureus and 3 of 25 methicillin-susceptible S aureus isolates. CONCLUSIONS: Community-acquired methicillin-resistant S aureus is a substantial and increasing proportion of S aureus infections in previously healthy neonates. Male infants 7 to 12 days of age are affected most often. Neonatal community-acquired S aureus infection may be associated with concurrent maternal infection. USA300 is the predominant clone among these neonatal isolates in our region.

Venous thrombosis associated with staphylococcal osteomyelitis in children.

BACKGROUND: Venous thrombosis (VT) in children with Staphylococcus aureus osteomyelitis occurs rarely. We describe clinical features of infections and molecular characterization of isolates of children at Texas Children's Hospital with S aureus osteomyelitis and VT. METHODS: We reviewed records and imaging studies (chest radiographs, ultrasound, computed tomography, and MRI) of 9 patients at Texas Children's Hospital with acute S aureus osteomyelitis and new onset VT between August 1999 and December 2004. Isolates were fingerprinted by pulsed-field gel electrophoresis and tested for the presence of genes encoding selective virulence factors. RESULTS: The mean age of the patients was 10.6 years. All 9 of the patients had osteomyelitis with sites of infection adjacent to the VT. The femoral and popliteal veins were most commonly affected. Two patients had VTs develop on the same side in which a central line had been in place. Four patients had chest radiographs consistent with septic emboli; inferior vena cava filters were placed in 3. Evaluation for hypercoagulable state revealed 3 patients with lupus anticoagulant, 1 with anticardiolipin IgG antibody, and 5 with no defect. Most laboratory abnormalities had resolved at follow-up. Seven patients had infections caused by methicillin-resistant S aureus belonging to the same clonal group (USA300); all were community acquired. Seven isolates carried the Panton-Valentine leukocidin (luk-S-PV and luk-F-PV) genes. CONCLUSIONS: The predominant community-acquired, methicillin-resistant S aureus clone in Houston, Texas, (USA300) may have a unique propensity to cause VT in association with osteomyelitis. Management of the venous thrombosis in this setting may be complicated by the rapid evolution of septic emboli.

Three-year surveillance of community onset health care-associated staphylococcus aureus infections in children.

BACKGROUND: Staphylococcus aureus causes skin and soft tissue or invasive infections in children in the community, in the hospital or in other ways associated with the health care system (HCA). METHODS: Prospective community-acquired S. aureus infection surveillance at Texas Children's Hospital was initiated on August 1, 2001. Community onset HCA (CO HCA) infections were identified. Demographic and clinical data were collected. Antibiotic susceptibilities were determined. Data were analyzed by chi or Student's t test. CO HCO-isolates were characterized by pulsed field gel electrophoresis and staphylococcal chromosomal cassette carrying the mecA methicillin-resistant gene (SCCmec) typing. RESULTS: From August 1, 2001 to July 31, 2004, 61.5% of 322 in year 1, 62.9% of 259 in year 2 and 56.9% of 318 in year 3 of CO HCA isolates were methicillin-resistant S. aureus (MRSA). Among the CO HCA-MRSA isolates, 8.9% of 542 were from children with invasive infections compared with 24.1% of 357 CO HCA-methicillin-susceptible S. aureus (MSSA; P < 0.001). Sixty-six percent of children with CO HCA-S. aureus isolates were admitted to the hospital. Clindamycin resistance increased over the 3 years (CO HCA-MRSA, from 3.5% to 18.8%, P < 0.001; CO HCA-MSSA, from 3.2% to 10.2%, P = 0.053). Thirty-three of 35 (94.3%) CO HCA-MRSA carried SCCmecIV; 30 were USA300. Only 3 of 35 MSSA were related to USA300 by pulsed field gel electrophoresis. CONCLUSIONS: CO HCA-S. aureus infections remained steady over the 3-year study at Texas Children's Hospital. Clindamycin resistance increased >4-fold for CO HCA-S. aureus isolates over the 3 years and is no longer appropriate for empiric treatment of invasive infections suspected to be caused by CO HCA-MRSA at our hospital. In our setting, CO HCA-MRSA infections are steady in number despite substantial increases in community-acquired MRSA infections and both being related to the same clone.

Panton-Valentine leukocidin genes are associated with enhanced inflammatory response and local disease in acute hematogenous Staphylococcus aureus osteomyelitis in children.

BACKGROUND: Staphylococcus aureus strains carrying the genes encoding Panton-Valentine leukocidin (pvl-positive [pvl+]) are associated with more febrile days and higher complication rates of osteomyelitis in children than are pvl-negative (pvl-) strains. OBJECTIVES: Selected clinical, laboratory, and radiographic findings in children with osteomyelitis caused by pvl+ and pvl- S aureus strains were compared. METHODS: The demographics, selected clinical features, laboratory values, and radiographic findings of children with community-acquired S aureus osteomyelitis prospectively identified at Texas Children's Hospital between August 2001 and July 2004 were reviewed. Polymerase chain reaction was performed to detect the genes for pvl (luk-S-PV and luk-F-PV) and fibronectin-binding protein (fnbB) in S aureus isolates. Chi2, 2-sample t test, and multiple logistic regression were used for statistical analysis. RESULTS: Methicillin-susceptible and methicillin-resistant S aureus (MSSA and MRSA, respectively) caused osteomyelitis in 33 and 56 children, respectively. Twenty-six isolates were pvl- (26 MSSA), 59 were pvl+ (3 MSSA, 56 MRSA), and 4 were not available for analysis (4 MSSA). On univariate analysis, patients with pvl+ S aureus isolates had significantly higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level both at presentation and as a maximum value during hospitalization and were more likely to have a blood culture positive for S aureus during their admission. Patients with pvl+ S aureus isolates were significantly more likely to have concomitant myositis or pyomyositis compared with patients with pvl- S aureus isolates on MRI. In a multivariate analysis pvl remained significantly associated with ESR and CRP levels at presentation and blood culture positive for S aureus. pvl+ status and younger age were associated with myositis on MRI. CONCLUSIONS: Osteomyelitis caused by pvl+ S aureus strains were associated with more severe local disease and a greater systemic inflammatory response compared with osteomyelitis caused by pvl- S aureus.

Pulmonary manifestations in children with invasive community-acquired Staphylococcus aureus infection.

BACKGROUND: Primary pneumonia and metastatic pulmonary infection have become more common in patients with invasive community-acquired Staphylococcus aureus disease at Texas Children's Hospital (TCH; Houston). METHODS: In this study, we sought to describe pulmonary involvement in children with community-acquired S. aureus invasive infection and to determine whether the presence of genes encoding Panton-Valentine leukocidin (PVL) (luk-S-PV and luk-F-PV) and collagen adhesin (cna) is correlated with pulmonary manifestations. Patients with invasive staphylococcal infections admitted to TCH between 1 August 2001 and 30 June 2004 were studied. Chest imaging and postmortem examination reports were reviewed. Isolates were tested for the presence of genes encoding PVL and collagen adhesin by PCR. RESULTS: A total of 47 of 70 patients with community-acquired methicillin-resistant S. aureus (MRSA) infection had abnormal pulmonary imaging findings, compared with 12 of 43 patients with community-acquired methicillin-susceptible S. aureus (MSSA) infection (P < .001). Pneumonia and/or empyema, in addition to septic emboli, were the most common findings. Metastatic pulmonary disease occurred more frequently among patients with osteomyelitis. Severe necrotizing pneumonia was present in 3 children coinfected with influenza and parainfluenza virus. The presence of genes encoding PVL was investigated in 67 MRSA and 36 MSSA isolates. Abnormal chest imaging findings were observed for 51 of 80 patients with PVL-positive isolates, compared with 2 of 23 patients with PVL-negative isolates (P < .001). Only 2 isolates (both of which were MSSA) from patients with abnormal chest radiograph findings carried cna. PVL remained independently associated with abnormal chest imaging findings in patients with secondary pneumonia in a multivariate analysis (P = .03). CONCLUSIONS: Pulmonary involvement is commonly observed in patients with invasive community-acquired S. aureus infections. Community-acquired MRSA may cause primary community-acquired pneumonia, as well as metastatic pulmonary disease. The presence of genes encoding PVL is highly associated with pulmonary involvement by S. aureus.

Three-year surveillance of community-acquired Staphylococcus aureus infections in children.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) isolates are increasingly frequent causes of skin and soft-tissue infections or invasive infections in many communities. METHODS: Prospective surveillance for community-acquired S. aureus infections at Texas Children's Hospital was initiated on 1 August 2001. Infections meeting the definition of community-acquired were identified. Demographic and clinical data were collected. Antibiotic susceptibilities, including inducible resistance to macrolide, lincosamide, and streptogramin B (MLSB), were determined in the clinical microbiology laboratory with the methodology of the NCCLS. All data were entered into a computer database. Data were analyzed by chi2 tests. RESULTS: From 1 August 2001 to 31 July 2004, the percentage of community-acquired S. aureus isolates that were methicillin resistant increased from 71.5% (551 of 771 isolates) in year 1 to 76.4% (1193 of 1562 isolates) in year 3 (P = .008). The number of both community-acquired MRSA (CA-MSRA) isolates and community-acquired methicillin-susceptible S. aureus (CA-MSSA) isolates increased yearly, but the rate of increase was greater for the CA-MRSA isolates. Among the CA-MRSA isolates, 2542 (95.6%) were obtained from children with skin and soft-tissue infections, and 117 (4.4%) were obtained from children with invasive infections. Overall, 62% of children with CA-MRSA isolates and 53% of children with CA-MSSA isolates were admitted to the hospital (P = .0001). The rate of clindamycin resistance increased significantly for both CA-MRSA isolates (P = .003) and CA-MSSA isolates (P = .00003) over the 3 years. MLSB inducible resistance was found in 27 (44%) of 62 clindamycin-resistant CA-MSSA isolates, compared with 6 (4.5%) of 132 clindamycin-resistant CA-MRSA isolates (P < .000001). CONCLUSIONS: CA-MRSA isolates account for an increasing percentage and number of infections at Texas Children's Hospital. Clindamycin resistance increased among community-acquired S. aureus isolates. Community surveillance of community-acquired S. aureus infections is critical to determine the appropriate empiric antibiotic treatment for either local or invasive infections.

Severe Staphylococcal sepsis in adolescents in the era of community-acquired methicillin-resistant Staphylococcus aureus.

OBJECTIVE: More than 70% of the community-acquired (CA) staphylococcal infections treated at Texas Children's Hospital are caused by methicillin-resistant Staphylococcus aureus (MRSA). Since September 2002, an increase in the number of severely ill patients with S aureus infections has occurred. This study provides a clinical description of severely ill adolescent patients and an analysis of their isolates using molecular methods. METHODS: We identified adolescent patients meeting criteria for severe sepsis requiring admission to the PICU. Patient records were reviewed, and isolates were obtained for susceptibility testing and DNA extraction. Isolates were tested for the presence of virulence genes (cna, tst, lukS-PV, and lukF-PV) and enterotoxin genes (sea, seb, sec, sed, seh, and sej) by polymerase chain reaction. Genomic fingerprints were determined by repetitive-element polymorphism polymerase chain reaction and pulse-field gel electrophoresis. SCCmec cassette type was determined. RESULTS: Fourteen adolescents with severe CA S aureus infections were identified between August 2002 and January 2004. All were admitted to the PICU with sepsis and coagulopathy. Twelve patients had CA-MRSA infections; 2 had CA methicillin-susceptible Staphylococcus aureus (MSSA) infections. The mean age was 12.9 years (range: 10-15 years). Thirteen patients had pulmonary involvement and/or bone and joint infection; 10 patients had > or =2 bones or joints infected (range: 2-10); 4 patients developed vascular complications (deep venous thrombosis); and 3 patients died. All isolates were identical or closely related to the previously reported predominant clone in Houston, Texas (multilocus sequence type 8, USA300), and carried lukS-PV and lukF-PV genes as well as the SCCmec type IVa cassette (12 MRSA isolates) but did not contain cna or tst. Only 1 strain carried enterotoxin genes (sed and sej). CONCLUSIONS: Severe staphylococcal infections in previously healthy adolescents without predisposing risk factors have presented more frequently at Texas Children's Hospital since September 2002. CA MRSA and clonally related CA MSSA characterized as USA300 and sequence type 8 have been isolated from these patients.

Clindamycin treatment of invasive infections caused by community-acquired, methicillin-resistant and methicillin-susceptible Staphylococcus aureus in children.

BACKGROUND: Community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA) is an established pathogen in several areas of the United States, but experience with clindamycin for the treatment of invasive MRSA infections is limited. We compared the outcome of therapy for MRSA with that of methicillin-susceptible (MSSA) invasive infections in children treated with clindamycin, vancomycin or beta-lactam antibiotics. METHODS: The demographics, hospital course and outcome of children at Texas Children's Hospital between February and November 2000 and between August 2001 and August 2002 with invasive S. aureus infections were reviewed from medical records in this retrospective study. RESULTS: CA-MRSA and community-acquired methicillin-susceptible S. aureus (MSSA) caused invasive infections in 46 and 53 children, respectively. The median ages (range) of the children were: MRSA, 3.5 years (2 months to 18.6 years); MSSA, 4.8 years (3 months to 19.8 years). The sites of infection for MRSA vs. MSSA isolates, respectively, were: bacteremia, 3 vs. 6; osteomyelitis, 14 vs. 14; septic arthritis, 5 vs. 7; pneumonia, 11 vs. 3; lymphadenitis, 7 vs. 14; other, 5 vs. 8. Among MRSA patients 39 (20 received clindamycin only, 18 had vancomycin initially and 8 were treated with a beta-lactam initially) received clindamycin and 6 received vancomycin as primary therapy. Among MSSA patients, clindamycin, nafcillin or other beta-lactam antibiotics were used in 24, 18 and 9, respectively. The median number of febrile days was 3 (0 to 14) and 2 (0 to 6) for MRSA and MSSA patients, respectively (P = 0.07). The median number of days with positive blood cultures was 2 for the MRSA (n = 16) and 1 for the MSSA (n = 18) patients (P = 0.04). CONCLUSION: Clindamycin was effective in treating children with invasive infections caused by susceptible CA-MRSA isolates.