Levofloxacin Pharmacokinetics in Children

Levofloxacin is a broad-spectrum fluoroquinolone antibiotic with activity against many pathogens that cause bacterial infections in children, including penicillin-resistant pneumococci. To provide dosing guidance for children, 3 single-dose, multicenter pharmacokinetic studies were conducted in 85 children in 5 age groups: 6 months to <2 years, 2 to <5 years, 5 to <10 years, 10 to <12 years, and 12 to 16 years. Each child received a single 7-mg/kg dose of levofloxacin (not to exceed 500 mg) intravenously or orally. Plasma and urine samples were collected through 24 hours after dose. Pharmacokinetic parameters were estimated and compared among the 5 age groups and to previously collected adult data. Levofloxacin absorption (as indicated by C(max) and t(max)) and distribution in children are not age dependent and are comparable to those in adults. Levofloxacin elimination (reflected by t1/2 and clearance), however, is age dependent. Children younger than 5 years of age clear levofloxacin nearly twice as fast (intravenous dose, 0.32+/-0.08 L/h/kg; oral dose, 0.28+/-0.05 L/h/kg) as adults and, as a result, have the total systemic exposure (area under the plasma drug concentration-time curve) approximately one half that of adults. The levofloxacin area under the plasma drug concentration-time curve (dose normalized) in children receiving a single dose of the oral liquid formulation is comparable to that in children receiving the intravenous formulation. To provide compatible levofloxacin exposures associated with clinical effectiveness and safety in adults, children > or =5 years need a daily dose of 10 mg/kg, whereas children 6 months to <5 years should receive 10 mg/kg every 12 hours.

Characteristics of Severe Bordetella pertussis Infection Among Infants ≤90 Days of Age Admitted to Pediatric Intensive Care Units - Southern California, September 2009-June 2011

BACKGROUND

Bordetella pertussis infection can cause severe illness and death among young infants.

METHODS

We collected demographic and clinical information from the medical records of infants who were ≤90 days of age and hospitalized for pertussis in 5 Southern California pediatric intensive care units (PICUs) from September 1, 2009 to June 30, 2011. Infants who died or were diagnosed with pulmonary hypertension were considered to have more severe pertussis.

RESULTS

Thirty-one infants were admitted to a participating PICU. Eight infants had more severe infections, 6 infants had pulmonary hypertension, and 4 infants died. The 8 infants with more severe infections had white blood cell counts that exceeded 30 000, heart rates that exceeded 170, and respiratory rates that exceeded 70 more rapidly after cough onset than the 23 infants with less severe illness.

CONCLUSIONS

Identifying higher-risk infants earlier might allow for more rapid implementation of interventions.

Oseltamivir pharmacokinetics, dosing, and resistance among children aged <2 years with influenza

BACKGROUND

Children <2 years of age are at high risk of influenza-related mortality and morbidity. However, the appropriate dose of oseltamivir for children <2 years of age is unknown.

METHODS

The National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group evaluated oseltamivir in infants aged <2 years in an age-de-escalation, adaptive design with a targeted systemic exposure.

RESULTS

From 2006 to 2010, 87 subjects enrolled. An oseltamivir dose of 3.0 mg/kg produced drug exposures within the target range in subjects 0-8 months of age, although there was a greater degree of variability in infants <3 months of age. In subjects 9-11 months of age, a dose of 3.5 mg/kg produced drug exposures within the target range. Six of 10 subjects aged 12-23 months receiving the Food and Drug Administration-approved unit dose for this age group (ie, 30 mg) had oseltamivir carboxylate exposures below the target range. Virus from 3 subjects developed oseltamivir resistance during antiviral treatment.

CONCLUSIONS

The appropriate twice-daily oral oseltamivir dose for infants ≤8 months of age is 3.0 mg/kg, while the dose for infants 9-11 months old is 3.5 mg/kg.

Genetic structure of community acquired methicillin-resistant Staphylococcus aureus USA300

Background

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a significant bacterial pathogen that poses considerable clinical and public health challenges. The majority of the CA-MRSA disease burden consists of skin and soft tissue infections (SSTI) not associated with significant morbidity; however, CA-MRSA also causes severe, invasive infections resulting in significant morbidity and mortality. The broad range of disease severity may be influenced by bacterial genetic variation.

Results

We sequenced the complete genomes of 36 CA-MRSA clinical isolates from the predominant North American community acquired clonal type USA300 (18 SSTI and 18 severe infection-associated isolates). While all 36 isolates shared remarkable genetic similarity, we found greater overall time-dependent sequence diversity among SSTI isolates. In addition, pathway analysis of non-synonymous variations revealed increased sequence diversity in the putative virulence genes of SSTI isolates.

Conclusions

Here we report the first whole genome survey of diverse clinical isolates of the USA300 lineage and describe the evolution of the pathogen over time within a defined geographic area. The results demonstrate the close relatedness of clinically independent CA-MRSA isolates, which carry implications for understanding CA-MRSA epidemiology and combating its spread.

Evaluation of an Interferon Gamma Release Assay to Detect Tuberculosis Infection in Children in San Diego, California

QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) results are reported in 23 children with active tuberculosis due to Mycobacterium tuberculosis and Mycobacterium bovis. Overall QFT-GIT (96%) was more sensitive than TST (74%) for detecting tuberculosis infection in these patients.

The California Pertussis Epidemic 2010: A Review of 986 Pediatric Case Reports From San Diego County

BACKGROUND

The California Department of Public Health (CDPH) declared a pertussis epidemic on 23 June 2010. More cases were reported in 2010 (9146) than in any year since 1947. We describe the characteristics of pertussis epidemiology and disease from 986 reported cases in children in San Diego County (population 3.2 million).

METHODS

Descriptive statistics were abstracted from CDPH pertussis case report forms that were completed by public health nurses investigating reports of positive laboratory results for pertussis and reports of illnesses compatible with pertussis.

RESULTS

Of 1144 reported adult and pediatric cases, 753 (66%) were confirmed and 391 were probable/suspect. Children aged <19 years comprised 86% of all reported cases in San Diego County; of these, 22% were aged 11-18 years, 29% were aged 6-10 years, 27% were aged 1-5 years, and 22% were aged <1 year (with 70% aged <6 months). Case rates were highest in infants aged <6 months (651 per 100 000 population). Of those aged >1 year, the highest attack rates were in preschool children aged 1-5 years (114 per 100 000) and elementary school children aged 6-10 years (141 per 100 000). Of 51 children hospitalized, 82% were aged <6 months; 2 deaths occurred in these young infants. Paroxysmal cough was noted in over 70% of children in all age groups; post-tussive vomiting occurred in 36% (aged 11-18 years) to 57% (aged <6 months) of children.

CONCLUSIONS

Pertussis vaccine efficacy may decrease more rapidly than previously believed, facilitating spread of pertussis in elementary school-aged children. The highest case rates and the only mortality occurred in infants aged <6 months.

Executive summary: the management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.

Oral acyclovir suppression and neurodevelopment after neonatal herpes

BACKGROUND

Poor neurodevelopmental outcomes and recurrences of cutaneous lesions remain unacceptably frequent among survivors of neonatal herpes simplex virus (HSV) disease.

METHODS

We enrolled neonates with HSV disease in two parallel, identical, double-blind, placebo-controlled studies. Neonates with central nervous system (CNS) involvement were enrolled in one study, and neonates with skin, eye, and mouth involvement only were enrolled in the other. After completing a regimen of 14 to 21 days of parenteral acyclovir, the infants were randomly assigned to immediate acyclovir suppression (300 mg per square meter of body-surface area per dose orally, three times daily for 6 months) or placebo. Cutaneous recurrences were treated with open-label episodic therapy.

RESULTS

A total of 74 neonates were enrolled--45 with CNS involvement and 29 with skin, eye, and mouth disease. The Mental Development Index of the Bayley Scales of Infant Development (in which scores range from 50 to 150, with a mean of 100 and with higher scores indicating better neurodevelopmental outcomes) was assessed in 28 of the 45 infants with CNS involvement (62%) at 12 months of age. After adjustment for covariates, infants with CNS involvement who had been randomly assigned to acyclovir suppression had significantly higher mean Bayley mental-development scores at 12 months than did infants randomly assigned to placebo (88.24 vs. 68.12, P=0.046). Overall, there was a trend toward more neutropenia in the acyclovir group than in the placebo group (P=0.09).

CONCLUSIONS

Infants surviving neonatal HSV disease with CNS involvement had improved neurodevelopmental outcomes when they received suppressive therapy with oral acyclovir for 6 months. (Funded by the National Institute of Allergy and Infectious Diseases; CASG 103 and CASG 104 ClinicalTrials.gov numbers, NCT00031460 and NCT00031447, respectively.).

The use of systemic and topical fluoroquinolones

Appropriate prescribing practices for fluoroquinolones are essential as evolving resistance patterns are considered, additional treatment indications are identified, and the toxicity profile of fluoroquinolones in children becomes better defined. Earlier recommendations for systemic therapy remain; expanded uses of fluoroquinolones for the treatment of certain infections are outlined in this report. Although fluoroquinolones are reasonably safe in children, clinicians should be aware of the specific adverse reactions. Use of fluoroquinolones in children should continue to be limited to treatment of infections for which no safe and effective alternative exists.

The management of community-acquired pneumonia in infants and children older than 3 months of age: clinical practice guidelines by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

Evidenced-based guidelines for management of infants and children with community-acquired pneumonia (CAP) were prepared by an expert panel comprising clinicians and investigators representing community pediatrics, public health, and the pediatric specialties of critical care, emergency medicine, hospital medicine, infectious diseases, pulmonology, and surgery. These guidelines are intended for use by primary care and subspecialty providers responsible for the management of otherwise healthy infants and children with CAP in both outpatient and inpatient settings. Site-of-care management, diagnosis, antimicrobial and adjunctive surgical therapy, and prevention are discussed. Areas that warrant future investigations are also highlighted.

Linezolid-associated peripheral and optic neuropathy in children

OBJECTIVE

Peripheral neuropathy (PN) and optic neuropathy (ON) associated with linezolid use are described in the adult literature; however limited information is available in pediatrics. The purpose of this communication is to summarize pediatric cases of linezolid-associated neuropathy and to increase awareness of these neurologic side effects so that clinicians can most appropriately balance the benefits and risks of linezolid in the pediatric population.

METHODS

A search of the FDA Adverse Events Reporting System was performed for all pediatric cases of neuropathy from April 2000-2009. AERS includes both inpatient and outpatient data. Inpatient utilization patterns for linezolid were also assessed from January 2000 to December 2008.

RESULTS

Eight pediatric cases of linezolid-associated neuropathy were identified. Treatment duration ranged from 4 weeks to 1 year. Five patients had PN alone, one had only ON and two had both. Symptoms of PN included pain, numbness, weakness, and paresthesias. Symptoms of ON included decreased visual acuity and color vision. Three children had other adverse events associated with linezolid including acidosis, anemia, and leukopenia. Outcomes were reported in 5 cases. Resolution of symptoms occurred between 2 weeks and 6 months after discontinuation of linezolid. Utilization data showed that during the study period, overall inpatient utilization of linezolid had increased.

CONCLUSIONS

While linezolid may be used to treat serious infections often needing extended courses of therapy, potential safety concerns should be kept in mind. In the circumstance of prolonged use of linezolid in children, it is likely that more cases of neuropathy may occur.

Considerations unique to pediatrics for clinical trial design in hospital-acquired pneumonia and ventilator-associated pneumonia

Background. A need exists for new antimicrobial agents to treat neonates, infants, and children for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) caused by nosocomial antibiotic-resistant pathogens. Current and clear guidance on approval of new agents for all pediatric age groups is lacking. Methods. Studies on HAP and VAP in the neonatal and pediatric age groups were collected using PubMed (National Library of Medicine). Published articles were reviewed for pediatric-specific definitions of HAP and VAP, diagnostic techniques, rates of disease, risk factors, characteristics, and outcomes. Results. Definitions of HAP and VAP in neonatal and pediatric age groups vary considerably. No well-studied, sensitive, and specific microbiologic testing techniques exist. Morbidity and mortality associated with VAP in neonates, infants, and children have been documented. Conclusions. Investigation and approval of new agents for HAP and VAP in all pediatric age groups is needed. A uniform definition of HAP and VAP is required that is relevant for clinical trials and balances the risks of experimental therapy and sampling procedures for study patients with potential benefits for both the patient under investigation and the hospitalized children who may develop nosocomial pneumonia.

Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003-2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Safety of oseltamivir compared with the adamantanes in children less than 12 months of age

BACKGROUND

When oseltamivir is administered in extremely high doses (500-1000 mg/kg) to young juvenile rats, central nervous system toxicity and death occurred in some animals. Mortality was not observed in older juvenile rats, suggesting a possible relationship between neurotoxicity and an immature blood-brain barrier. To assess potential neurologic adverse effects of oseltamivir use in infants, a retrospective chart review was performed in infants less than 12 months of age who received oseltamivir, amantadine, or rimantadine.

METHODS

The primary objective was to describe the frequency of neurologic adverse events among children less than 12 months of age who received oseltamivir compared with those receiving adamantanes. Medical record databases, emergency department databases, and/or pharmacy records at 15 medical centers were searched to identify patients.

RESULTS

Of the 180 infants identified as having received antiviral therapy, 115 (64%) received oseltamivir, 37 (20%) received amantadine, and 28 (16%) received rimantadine. The median dose of oseltamivir was 2.0 mg/kg/dose in 3- to 5-month-old and 2.2 mg/kg/dose in 9- to 12-month-old infants. The maximum dose administered was 7.0 mg/kg/dose. There were no statistically significant differences in the occurrence of adverse neurologic events during therapy among subjects treated with oseltamivir versus those treated with the adamantanes (P = 0.13).

CONCLUSIONS

This is the largest report to date of oseltamivir use in children less than 12 months of age. Neurologic events were not more common with use of oseltamivir compared with that of the adamantanes. Dosing of oseltamivir was variable, illustrating the need for pharmacokinetic data in this younger population.

Serotype 19A Is the most common serotype causing invasive pneumococcal infections in children

OBJECTIVE

The purpose of this study was to monitor the clinical and microbiologic features of invasive infections caused by Streptococcus pneumoniae among children before and after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7).

DESIGN

We conducted a 15-year prospective surveillance study of all invasive pneumococcal infections in children. The sample included infants and children at 8 children's hospitals in the United States with culture-proven invasive S pneumoniae infections.

RESULTS

Since the implementation of routine PCV7 immunization in 2000, invasive infections have decreased yearly from 2001 through 2004, to a nadir of 151 infections; the rate then increased from 2005 through 2008. Compared with the pre-PCV7 era, a greater proportion of children with invasive pneumococcal infection had an underlying condition in the post-PCV7 period. Compared with the total number of annual admissions, the number of 19A isolates increased significantly from 2001 to 2008 (P < .00001). In 2007 and 2008, only 16 isolates (4%) were vaccine serotypes; 19A accounted for 46% (168 of 369) of the non-PCV7 serotypes. Thirty percent of the 19A isolates were multidrug resistant. Serotypes 1, 3, and 7F accounted for 22% of the non-PCV7 serotypes. Among children with invasive pneumococcal infections, the likelihood of a 19A serotype increased with the number of preceding PCV7 doses.

CONCLUSIONS

Since 2005, the number of invasive pneumococcal infections in children has increased at 8 children's hospitals, primarily as a result of serotype 19A isolates, one third of which were resistant to multiple antibiotics in 2007 and 2008. Continued surveillance is necessary to detect emerging serotypes after the planned introduction of 13-valent or other pneumococcal vaccines.

Speech levels in meeting rooms and the probability of speech privacy problems

Speech levels were measured in a large number of meetings and meeting rooms to better understand their influence on the speech privacy of closed meeting rooms. The effects of room size and number of occupants on average speech levels, for meetings with and without sound amplification, were investigated. The characteristics of the statistical variations of speech levels were determined in terms of speech levels measured over 10 s intervals at locations inside, but near the periphery of the meeting rooms. A procedure for predicting the probability of speech being audible or intelligible at points outside meeting rooms is proposed. It is based on the statistics of meeting room speech levels, in combination with the sound insulation characteristics of the room and the ambient noise levels at locations outside the room.

Diagnosis and Management of Complicated Intra-abdominal Infection in Adults and Children: Guidelines by the Surgical Infection Society and the Infectious Diseases Society of America

Evidence-based guidelines for managing patients with intra-abdominal infection were prepared by an Expert Panel of the Surgical Infection Society and the Infectious Diseases Society of America. These updated guidelines replace those previously published in 2002 and 2003. The guidelines are intended for treating patients who either have these infections or may be at risk for them. New information, based on publications from the period 2003–2008, is incorporated into this guideline document. The panel has also added recommendations for managing intra-abdominal infection in children, particularly where such management differs from that of adults; for appendicitis in patients of all ages; and for necrotizing enterocolitis in neonates.

Evaluating signal-to-noise ratios, loudness, and related measures as indicators of airborne sound insulation

Subjective ratings of the audibility, annoyance, and loudness of music and speech sounds transmitted through 20 different simulated walls were used to identify better single number ratings of airborne sound insulation. The first part of this research considered standard measures such as the sound transmission class the weighted sound reduction index (R(w)) and variations of these measures [H. K. Park and J. S. Bradley, J. Acoust. Soc. Am. 126, 208-219 (2009)]. This paper considers a number of other measures including signal-to-noise ratios related to the intelligibility of speech and measures related to the loudness of sounds. An exploration of the importance of the included frequencies showed that the optimum ranges of included frequencies were different for speech and music sounds. Measures related to speech intelligibility were useful indicators of responses to speech sounds but were not as successful for music sounds. A-weighted level differences, signal-to-noise ratios and an A-weighted sound transmission loss measure were good predictors of responses when the included frequencies were optimized for each type of sound. The addition of new spectrum adaptation terms to R(w) values were found to be the most practical approach for achieving more accurate predictions of subjective ratings of transmitted speech and music sounds.

Antimicrobial agents for complicated skin and skin-structure infections: justification of noninferiority margins in the absence of placebo-controlled trials

BACKGROUND

The United States Food and Drug Administration requires clinical trial noninferiority margins to preserve a fraction (eg, 50%) of the established comparator drug's efficacy versus placebo. Lack of placebo-controlled trials for many infections complicates noninferiority margin justification for and, hence, regulatory review of new antimicrobial agents. Noninferiority margin clarification is critical to enable new antimicrobial development. In the absence of placebo-controlled trials, we sought to define the magnitude of efficacy of antimicrobial agents and resulting noninferiority margins for studies of complicated skin and skin-structure infection (SSSI).

METHODS

We systematically reviewed literature on complicated SSSI published during 1900-1950 (before widespread penicillin resistance) to define treatment outcomes and confidence intervals (CIs). Antimicrobial efficacy was calculated as the lower limit CI of the cure rate with antimicrobials minus the upper limit CI of the cure rate without antimicrobials.

RESULTS

We identified 90 articles describing >28,000 patients with complicated SSSI. For cellulitis/erysipelas, cure rates were 66% (95% CI, 64%-68%) without antibiotics and 98% (95% CI, 96%-99%) for penicillin-treated patients, and penicillin reduced mortality by 10%. Cure rates for wound/ulcer infections were 36% (95% CI, 32%-39%) without antibiotics and 83% (95% CI, 81%-85%) for penicillin-treated patients. For major abscesses, cure rates were 76% (95% CI, 71%-80%) without antibiotics and 96% (95% CI, 94%-98%) for penicillin-treated patients; penicillin reduced mortality by 6%.

CONCLUSION

Systematic review of historical literature enables rational noninferiority margin justification in the absence of placebo-controlled trials and may facilitate regulatory review of noninferiority trials. Noninferiority margins of 14% for cellulitis/erysipelas, 21% for wound/ulcer infections, and 7% for major abscesses would preserve >or= 50% of antibiotic efficacy versus placebo for these complicated SSSI subsets.

Evaluating standard airborne sound insulation measures in terms of annoyance, loudness, and audibility ratings

This paper reports the results of an evaluation of the merits of standard airborne sound insulation measures with respect to subjective ratings of the annoyance and loudness of transmitted sounds. Subjects listened to speech and music sounds modified to represent transmission through 20 different walls with sound transmission class (STC) ratings from 34 to 58. A number of variations in the standard measures were also considered. These included variations in the 8-dB rule for the maximum allowed deficiency in the STC measure as well as variations in the standard 32-dB total allowed deficiency. Several spectrum adaptation terms were considered in combination with weighted sound reduction index (R(w)) values as well as modifications to the range of included frequencies in the standard rating contour. A STC measure without an 8-dB rule and an R(w) rating with a new spectrum adaptation term were better predictors of annoyance and loudness ratings of speech sounds. R(w) ratings with one of two modified C(tr) spectrum adaptation terms were better predictors of annoyance and loudness ratings of transmitted music sounds. Although some measures were much better predictors of responses to one type of sound than were the standard STC and R(w) values, no measure was remarkably improved for predicting annoyance and loudness ratings of both music and speech sounds.

Some spatial and temporal effects on the speech privacy of meeting rooms

This paper reports on initial experiments concerning how key spatial and temporal effects in rooms influence the speech privacy provided by enclosed rooms. The first part of the work demonstrates that for the same signal-to-noise ratio, the intelligibility of speech and the threshold of intelligibility are significantly different for transmission between real rooms than in the previous results in approximately free-field conditions [B. N. Gover and J. S. Bradley, J. Acoust. Soc. Am. 116, 3480-3490 (2004)]. The second part investigates the influence of aspects of the spatial and temporal components of sound fields in typical rooms, to explain these differences for transmission between real rooms. These components included the separate effects of early-arriving and later-arriving reflected speech sounds. They also included the effects of spatially separated speech and noise sources as well as more diffuse noise representative of typical meeting rooms. In realistic combinations these effects are of practical importance and can change privacy criteria by 5 dB or more. Ignoring them could lead to costly over-design of the sound insulation required to achieve adequate speech privacy.

Seasonal influenza in adults and children--diagnosis, treatment, chemoprophylaxis, and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America

Guidelines for the treatment of persons with influenza virus infection were prepared by an Expert Panel of the Infectious Diseases Society of America. The evidence-based guidelines encompass diagnostic issues, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal (interpandemic) influenza. They are intended for use by physicians in all medical specialties with direct patient care, because influenza virus infection is common in communities during influenza season and may be encountered by practitioners caring for a wide variety of patients.

Influenza estacional en adultos y niños—Diagnóstico, tratamiento, quimioprofilaxis y control de brotes institucionales: Guías de práctica clínica de la Sociedad de Enfermedades Infecciosas de Estados Unidos de América

Un Grupo de Expertos de la Sociedad de Enfermedades Infecciosas de los Estados Unidos de América elaboró las guias para el tratamiento de personas infectadas por el virus de la influenza. Estas guias basadas en datos y pruebas cientificas comprenden el diagnóstico, el tratamiento y la quimioprofilaxis con medicamentos antivirales, además de temas relacionados con el control de brotes de influenza estacional (interpandémicas) en ámbitos institucionales. Están destinadas a los médicos de todas las especialidades a cargo de la atención directa de pacientes porque los médicos generales que atienden una gran variedad de casos son los que se enfrentan con la influenza, frecuente en el ámbito comunitario durante la temporada de influenza.

Intravenous ceftriaxone and calcium in the neonate: assessing the risk for cardiopulmonary adverse events

OBJECTIVES

Unsolicited reports regarding potentially serious adverse drug reactions in neonates and young infants were reported to the Food and Drug Administration, leading to changes in the package label for ceftriaxone. This report describes and summarizes the reported cases that led to safety concerns regarding the concurrent administration of intravenous ceftriaxone and calcium in this age group.

METHODS

Nine reported cases were assessed. The Food and Drug Administration Adverse Event Reporting System database was searched for potential drug interactions in patients who were receiving concomitant ceftriaxone and calcium therapy.

RESULTS

Eight of the reported 9 cases (7 were < or =2 months of age) represented possible or probable adverse drug events. There were 7 deaths. None of the cases were reported from the United States. The dosage of ceftriaxone that was administered to 4 of 6 infants for whom this information was available was between 150 and 200 mg/kg per day. The rate of occurrence of these serious adverse drug reactions cannot be accurately determined from available data.

CONCLUSIONS

The concurrent use of intravenous ceftriaxone and calcium-containing solutions in the newborn and young infant may result in a life-threatening adverse drug reaction. Contributing factors for infants in this report may include the use of ceftriaxone at dosages higher than those approved by the Food and Drug Administration, intravenous "push" administration, and administration of the total daily dosage as a single infusion.

Effects of room acoustics on the intelligibility of speech in classrooms for young children

This paper reports new measurements of the intelligibility of speech in conditions representative of elementary school classrooms. The speech test material was binaurally recorded in simulated classroom conditions and played back to subjects over headphones. Subjects included grade 1, 3, and 6 students (6, 8, and 11 year olds) as well as adults. Recognizing that reverberation time is not a complete descriptor of room acoustics conditions, simulated conditions included realistic early-to-late arriving sound ratios as well as varied reverberation time. For conditions of constant signal-to-noise ratio, intelligibility scores increased with decreasing reverberation time. However, for conditions including realistic increases in speech level with varied reverberation time for constant noise level, intelligibility scores were near maximum for a range of reverberation times. Young children's intelligibility scores benefited from added early reflections of speech sounds similar to adult listeners. The effect of varied reverberation time on the intelligibility of speech for young children was much less than the effect of varied signal-to-noise ratio. The results can be used to help to determine ideal conditions for speech communication in classrooms for younger listeners.

Bad bugs, no drugs: no ESKAPE! An update from the Infectious Diseases Society of America

The Infectious Diseases Society of America (IDSA) continues to view with concern the lean pipeline for novel therapeutics to treat drug-resistant infections, especially those caused by gram-negative pathogens. Infections now occur that are resistant to all current antibacterial options. Although the IDSA is encouraged by the prospect of success for some agents currently in preclinical development, there is an urgent, immediate need for new agents with activity against these panresistant organisms. There is no evidence that this need will be met in the foreseeable future. Furthermore, we remain concerned that the infrastructure for discovering and developing new antibacterials continues to stagnate, thereby risking the future pipeline of antibacterial drugs. The IDSA proposed solutions in its 2004 policy report, "Bad Bugs, No Drugs: As Antibiotic R&D Stagnates, a Public Health Crisis Brews," and recently issued a "Call to Action" to provide an update on the scope of the problem and the proposed solutions. A primary objective of these periodic reports is to encourage a community and legislative response to establish greater financial parity between the antimicrobial development and the development of other drugs. Although recent actions of the Food and Drug Administration and the 110th US Congress present a glimmer of hope, significant uncertainly remains. Now, more than ever, it is essential to create a robust and sustainable antibacterial research and development infrastructure--one that can respond to current antibacterial resistance now and anticipate evolving resistance. This challenge requires that industry, academia, the National Institutes of Health, the Food and Drug Administration, the Centers for Disease Control and Prevention, the US Department of Defense, and the new Biomedical Advanced Research and Development Authority at the Department of Health and Human Services work productively together. This report provides an update on potentially effective antibacterial drugs in the late-stage development pipeline, in the hope of encouraging such collaborative action.

The intelligibility of speech in elementary school classrooms

This is the second of two papers describing the results of acoustical measurements and speech intelligibility tests in elementary school classrooms. The intelligibility tests were performed in 41 classrooms in 12 different schools evenly divided among grades 1, 3, and 6 students (nominally 6, 8, and 11 year olds). Speech intelligibility tests were carried out on classes of students seated at their own desks in their regular classrooms. Mean intelligibility scores were significantly related to signal-to-noise ratios and to the grade of the students. While the results are different than those from some previous laboratory studies that included less realistic conditions, they agree with previous in-classroom experiments. The results indicate that +15 dB signal-to-noise ratio is not adequate for the youngest children. By combining the speech intelligibility test results with measurements of speech and noise levels during actual teaching situations, estimates of the fraction of students experiencing near-ideal acoustical conditions were made. The results are used as a basis for estimating ideal acoustical criteria for elementary school classrooms.

Evaluation of acoustical conditions for speech communication in working elementary school classrooms

Detailed acoustical measurements were made in 41 working elementary school classrooms near Ottawa, Canada to obtain more representative and more accurate indications of the acoustical quality of conditions for speech communication during actual teaching activities. This paper describes the room acoustics characteristics and noise environment of 27 traditional rectangular classrooms from the 41 measured rooms. The purpose of the work was to better understand how to improve speech communication between teachers and students. The study found, that on average, the students experienced: teacher speech levels of 60.4 dB A, noise levels of 49.1 dB A, and a mean speech-to-noise ratio of 11 dB A during teaching activities. The mean reverberation time in the occupied classrooms was 0.41 s, which was 10% less than in the unoccupied rooms. The reverberation time measurements were used to determine the average absorption added by each student. Detailed analyses of early and late-arriving speech sounds showed these sound levels could be predicted quite accurately and suggest improved approaches to room acoustics design.

Evaluating airborne sound insulation in terms of speech intelligibility

This paper reports on an evaluation of ratings of the sound insulation of simulated walls in terms of the intelligibility of speech transmitted through the walls. Subjects listened to speech modified to simulate transmission through 20 different walls with a wide range of sound insulation ratings, with constant ambient noise. The subjects' mean speech intelligibility scores were compared with various physical measures to test the success of the measures as sound insulation ratings. The standard Sound Transmission Class (STC) and Weighted Sound Reduction Index ratings were only moderately successful predictors of intelligibility scores, and eliminating the 8 dB rule from STC led to very modest improvements. Various previously established speech intelligibility measures (e.g., Articulation Index or Speech Intelligibility Index) and measures derived from them, such as the Articulation Class, were all relatively strongly related to speech intelligibility scores. In general, measures that involved arithmetic averages or summations of decibel values over frequency bands important for speech were most strongly related to intelligibility scores. The two most accurate predictors of the intelligibility of transmitted speech were an arithmetic average transmission loss over the frequencies from 200 to 2.5 kHz and the addition of a new spectrum weighting term to R(w) that included frequencies from 400 to 2.5 kHz.

Management of complicated shunt infections: a clinical report

OBJECTIVES

The authors present their experience with a protocol for the treatment of patients with complicated shunt infections.

METHODS

Complicated shunt infections are defined for the purpose of this protocol as multiple compartment hydrocephalus, multiple organism shunt infection, severe peritonitis, or infections in other sites of the body. The initial treatment protocol for these patients was 3 weeks of intravenous antibiotic therapy and 2 weeks of twice daily intraventricular/intrashunt antibiotic therapy. Cerebrospinal fluid (CSF) cultures were monitored during therapy and obtained again 48 hours after completion. The shunt was completely replaced. Additionally, follow-up cultures were obtained in all patients 3-6 months after therapy was completed.

RESULTS

A cure of the infection was achieved in all patients as defined by negative cultures obtained at completion of antibiotic therapy and in follow-up studies. The follow-up period was 2-11 years (mean 4.4 +/- 2.5 years). The treatment protocol was modified in the patients treated after 1991, and 18 patients were treated with this modified treatment regime. In these patients, intraventricular antibiotics were administered only once daily for 14 days, and the CSF was cultured 24 hours after antibiotic therapy had been stopped instead of after 48 hours. The results were similar to those obtained with the initial protocol.

CONCLUSIONS

Based on their prospective nonrandomized series, the authors believe that patients with complicated shunt infections can be successfully treated with 2 weeks of intraventricular antibiotic therapy administered once daily, concurrent with 3 weeks of intravenous antibiotic therapy. This protocol reduces length of treatment and hospital stay, and avoids recurrence of infection.

Optimizing therapy with antibacterial agents: use of pharmacokinetic-pharmacodynamic principles in pediatrics

The appropriate dosage of antibacterial agents is essential in achieving both clinical and microbiologic success in the treatment of infections in children. By using in vitro experimental data and animal model outcome data, the pharmacokinetic-pharmacodynamic (PK-PD) parameters predictive of antibacterial effect have been elucidated. For time-dependent drugs such as beta-lactams, the PK-PD parameter of interest is the percentage of time in a dosage interval for which drug concentrations remain above the minimum inhibitory concentration (MIC) of the infecting organism. For concentration-dependent drugs such as aminoglycosides, the PK-PD parameter of interest is the ratio of the area under the plasma concentration-time curve to the MIC. Recent studies using data on clinical and microbiologic outcomes from infected adults and children, combined with data on drug exposure, have confirmed the importance of these parameters and provided estimates of the PK-PD goals of therapy for various antibacterial agents. Application of these PK-PD principles allows rational dosage regimen selection, both for serious infections in critically ill children and for non-life-threatening community-acquired infections.

Aggressive management of shunt infection: combined intravenous and intraventricular antibiotic therapy for twelve or less days

OBJECTIVE

This report is limited to patients with a single cerebrospinal fluid (CSF) shunt infected by a single organism, and compares two treatment protocols.

METHODS

In the initial protocol (1975-1991), patients underwent removal of the shunt system and received intravenous and intraventricular antibiotics. Intraventricular antibiotics were administered twice daily to those with external ventricular drainage. When CSF was cultured 48 h off all antibiotics and found to be sterile at 24 h of incubation, a new shunt was inserted. Follow-up CSF cultures were obtained in all patients between 1-6 months following placement of the new shunt.

RESULTS

There were 25 patients (ages 1 month to 16 years; mean +/- SD: 23 +/- 4.0 months). CSF obtained from the shunt yielded the following: Staphylococcus epidermidis (19), Staphylococcus aureus (2), Streptococcus species (2), Serratia marcescens (1), and Propionebacterium species (1). The duration of intravenous antibiotics was 7-12 days (mean +/- SD: 9.7 +/- 1.3 days), and intraventricular antibiotic therapy was 6.2 +/- 1.7 days. Total hospital stay was 15.2 +/- 2.3 days. The follow-up period was 7.7 +/- 3.6 years. Following the initial protocol in another 15 patients (1992-2004), the treatment regime was modified in that intraventricular antibiotics were administered once daily in patients with external ventricular drainage, and the CSF was cultured at 24 h off antibiotics, instead of 48 h. Results were similar to the initial protocol with respect to days of antibiotic therapy and hospital stay.

CONCLUSION

Based on our retrospective nonrandomized series, we believe patients with a single shunt and noncompartmentalized hydrocephalus can be successfully treated without a prolonged antibiotic course and lengthy hospital stay.

Comparative study of levofloxacin in the treatment of children with community-acquired pneumonia

BACKGROUND

Levofloxacin has established efficacy and safety in the treatment of community-acquired pneumonia (CAP) in adults, and its use as an alternative therapy for children with CAP has been proposed.

OBJECTIVE

Assess the clinical efficacy and safety of levofloxacin compared with standard of care antibiotic therapy in the treatment of CAP in children aged 6 months to 16 years.

METHODS

In an open-label, multicenter, noninferiority trial, children with CAP were randomized 3:1 to receive levofloxacin or comparator antimicrobial therapy (0.5 to <5 years: amoxicillin/clavulanate or ceftriaxone; > or =5 years: clarithromycin or ceftriaxone with clarithromycin or erythromycin lactobinate) for 10 days. The primary outcome was cure rates at the test-of-cure visit (10-17 days after completing treatment) as determined by symptoms, physical examination, and chest radiography.

RESULTS

Seven hundred and thirty-eight children were enrolled and 539 (405 levofloxacin-treated, 134 comparator-treated) were clinically evaluable at test-of-cure visit. Clinical cure rates were 94.3% (382 of 405) in levofloxacin-treated and 94.0% (126 of 134) in comparator-treated children. Cure rates were also similar for levofloxacin and comparator for each age group (<5 years, 92.2% versus 90.8%; > or =5 years, 96.5% versus 97.1%; respectively) and for children categorized as being at higher risk for severe disease. Mycoplasma pneumoniae was the most frequently identified cause of pneumonia (230 children). Levofloxacin was as well tolerated as comparators, with similar type and incidence of adverse events.

CONCLUSIONS

Levofloxacin was as well tolerated and effective as standard-of-care antibiotics for the treatment of CAP in infants and children.

Comparative safety profile of levofloxacin in 2523 children with a focus on four specific musculoskeletal disorders

BACKGROUND

Fluoroquinolones, including levofloxacin, have not been recommended for use in children largely because studies in juvenile laboratory animals suggest there may be an increased risk of fluoroquinolone-associated cartilage lesions. A large prospective trial is needed to assess the risks associated with using levofloxacin in children.

OBJECTIVE

Assess the safety and tolerability of levofloxacin therapy in children based on observations for 1 year after therapy.

METHODS

Safety data were collected in children who participated in 1 of 3 efficacy trials (N = 2523) and a subset of these children who also subsequently participated in a long-term 1-year surveillance trial (N = 2233). Incidence of adverse events in children randomized to receive levofloxacin versus nonfluoroquinolone antibiotics was compared. Based on assessments by treating physicians and an independent data safety monitoring committee, events related to the musculoskeletal system were further categorized as 1 of 4 predefined musculoskeletal disorders (arthralgia, arthritis, tendinopathy, gait abnormality) considered most likely clinical correlates of fluoroquinolone-associated cartilage lesions observed in laboratory animals.

RESULTS

Levofloxacin was well tolerated during and for 1 month after therapy as evidenced by similar incidence and character of adverse events compared with nonfluoroquinolone antibiotics. However, incidence of at least 1 of the 4 predefined musculoskeletal disorders (largely due to reports of arthralgia) was greater in levofloxacin-treated compared with nonfluoroquinolone-treated children at 2 months (2.1% vs. 0.9%; P = 0.04) and 12 months (3.4% vs. 1.8%; P = 0.03) after starting therapy.

CONCLUSIONS

The incidence of 1 or more of the 4 predefined musculoskeletal disorders identified in nonblinded, prospective evaluations, was statistically greater in levofloxacin-treated compared with comparator-treated children.

Recurrent systemic pneumococcal disease in children

BACKGROUND

Recurrent systemic pneumococcal infection usually occurs in immunocompromised patients and patients with underlying conditions.

METHODS

Between 1993 and 2006, investigators at 8 pediatric hospitals prospectively identified cases of invasive pneumococcal disease (IPD) and retrospectively documented demographics and clinical information. Antibiotic susceptibility was determined for penicillin and ceftriaxone by microbroth dilution. Isolates were serotyped and molecular relatedness determined using pulse field gel electrophoresis (PFGE).

RESULTS

Four thousand sixty-seven children were diagnosed with IPD over 12.3 years. One hundred and 8 episodes of recurrent disease were seen in 90 children (2.6%); 75 experienced 2 infections, 12 experienced 3 infections and 3 experienced 4 infections. Fourteen of the 15 children with >2 episodes of infection had underlying conditions. The mean duration between 1st and 2nd infection was 22.9 weeks for children with no known underlying condition and 43.0 weeks for children with an underlying condition (P = 0.001). Seventy episodes of IPD among the 90 patients were caused by a different serotype or a different genotype as demonstrated by the PFGE. Sixteen children had intervals <30 days between infections; 7 were caused by different strains.

CONCLUSIONS

Approximately 80% of the children with recurrent invasive pneumococcal disease had underlying conditions. Seven of 16 children with recurrent infection <30 days apart were caused by acquisition of a new strain. Relapse of infection requires documentation that the pneumococcal isolates are not only the same serotype but also have the same PFGE patterns.

Single-dose pharmacokinetics of intravenous itraconazole and hydroxypropyl-beta-cyclodextrin in infants, children, and adolescents

This investigation was designed to evaluate the single-dose pharmacokinetics of itraconazole, hydroxyitraconazole, and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) after intravenous administration to children at risk for fungal infection. Thirty-three children aged 7 months to 17 years received a single dose of itraconazole (2.5 mg/kg in 0.1-g/kg HP-beta-CD) administered over 1 h by intravenous infusion. Plasma samples for the determination of the analytes of interest were drawn over 120 h and analyzed by high-pressure liquid chromatography, and the pharmacokinetics were determined by traditional noncompartmental analysis. Consistent with the role of CYP3A4 in the biotransformation of itraconazole, a substantial degree of variability was observed in the pharmacokinetics of this drug after IV administration. The maximum plasma concentrations (C(max)) for itraconazole, hydroxyitraconazole, and HP-beta-CD averaged 1,015 +/- 692 ng/ml, 293 +/- 133 ng/ml, and 329 +/- 200 mug/ml, respectively. The total body exposures (area under the concentration-time curve from 0 to 24 h) for itraconazole, hydroxyitraconazole, and HP-beta-CD averaged 4,922 +/- 6,784 ng.h/ml, 3,811 +/- 2,794 ng.h/ml, and 641.5 +/- 265.0 mug.h/ml, respectively, with no significant age dependence observed among the children evaluated. Similarly, there was no relationship between age and total body clearance (702.8 +/- 499.4 ml/h/kg); however, weak associations between age and the itraconazole distribution volume (r(2) = 0.18, P = 0.02), C(max) (r(2) = 0.14, P = 0.045), and terminal elimination rate (r(2) = 0.26, P < 0.01) were noted. Itraconazole infusion appeared to be well tolerated in this population with a single adverse event (stinging at the site of infusion) deemed to be related to study drug administration. Based on the findings of this investigation, it appears that intravenous itraconazole can be administered to infants beyond 6 months, children, and adolescents using a weight-normalized approach to dosing.

Best in class: a good principle for antibiotic usage to limit resistance development?

The causes of antibiotic resistance are often complex and it is difficult to identify strategies to prevent or delay its emergence. One strategy has been to use less active members of a drug class, so that when resistance develops the more active members will still prevail. This strategy may often fail because this resistance may form the basis of resistance to the whole class. Often, less active drugs are the first to be discovered and more active versions follow, so we have had no choice; however, increasingly less active drugs are available to deal with specific infections and this may have a detrimental effect on the class as a whole.

Effect of oseltamivir on the risk of pneumonia and use of health care services in children with clinically diagnosed influenza

OBJECTIVE

To evaluate the effectiveness of oseltamivir in reducing the rate of complications of influenza in children.

RESEARCH DESIGN AND METHODS

Anonymous, patient-level data from Medstat's MarketScan Research Database between 2000 and 2004 were used to identify children with influenza, aged 1-12 years. Patients who received a prescription for oseltamivir within 1 day of influenza diagnosis were compared with those who received no antiviral therapy.

MAIN OUTCOME MEASURES

Primary and secondary study outcomes included occurrence of pneumonia within 14 days of onset of influenza, rates of hospitalization for pneumonia, antibiotic use, numbers of healthcare services utilized, and healthcare expenditures.

RESULTS

In total, 4447 (17.9%) children received a prescription for oseltamivir within 1 day of when they were first clinically diagnosed with influenza, and 20 407 (82.1%) children received no antiviral treatment. Overall, children who received oseltamivir for the treatment of physician-diagnosed influenza were 51.7% less likely to be clinically diagnosed with pneumonia at a subsequent medical encounter (relative risk 0.483; 95% CI: 0.326, 0.717). This benefit was associated with reductions in antibiotic use, outpatient and emergency room visits, and savings in outpatient medical expenditures. Net expenditures per patient were not significantly different between children receiving oseltamivir and those who received no antiviral treatment (-$16; 95% CI: -13 dollars , +40 dollars) although pharmacy expenditures were higher. Wide regional variations in oseltamivir use were noted.

LIMITATIONS

The study was restricted to patients with employer-sponsored health insurance. The lack of a virologic diagnosis of influenza, and an index date based on the first diagnosis of influenza rather than first exposure or symptom onset, may have resulted in a conservative estimate of treatment effect.

CONCLUSIONS

Oseltamivir may reduce the risk of influenza-related morbidity in children when prescribed upon presentation of clinically diagnosed influenza. The use of oseltamivir in children may play an important role in managing influenza outbreaks.

Population pharmacokinetic model for gatifloxacin in pediatric patients

The broad spectrum of antimicrobial activity, oral bioavailability, extensive tissue distribution, and once-daily intravenous or oral dosing of gatifloxacin, an expanded-spectrum 8-methoxy fluoroquinolone, make it a potentially useful agent for the treatment of pediatric infections. A population pharmacokinetic model was developed to describe the pharmacokinetics of gatifloxacin in children. Data for analysis were obtained from a single-dose safety/pharmacokinetic study utilizing intensive blood sampling in patients aged 6 months to 16 years. Each subject received a single oral dose of gatifloxacin as a suspension, at doses of 5, 10, or 15 mg/kg of body weight. A total of 845 samples were obtained from 82 patients. A one-compartment model with first-order absorption and elimination was the most appropriate to describe the gatifloxacin concentrations. Covariate analysis using forward selection and backward elimination found that apparent clearance was related to body surface area, and apparent volume of distribution was related to body weight. No effect of age on drug clearance could be identified once clearance was corrected for body surface area. Based on pharmacokinetic simulations, the 10-mg/kg (maximum, 400 mg) once-daily dose of gatifloxacin is expected to provide drug exposure similar to that in healthy adults. The population pharmacokinetic model described herein will be used for Bayesian analyses of sparse pharmacokinetic sampling in phase II/III clinical trials and for Monte Carlo simulation experiments. The success of this strategy provides a model for future pediatric drug development programs.

Multicentre surveillance of the prevalence and molecular epidemiology of macrolide resistance among pharyngeal isolates of group A streptococci in the USA

OBJECTIVES

Rates of macrolide resistance in group A streptococci (GAS) were reported to be low in the US in the 1990s. However, we documented an unexpectedly high rate of macrolide resistance among GAS in Pittsburgh, PA, in 2001 and 2002. In an effort to define the current prevalence of macrolide-resistant GAS in the US, a multicentre surveillance project was initiated.

METHODS

Between October 2002 and May 2003, 50 pharyngeal GAS isolates per month were requested from each of the nine participating sites representing a wide geographical distribution. Standard susceptibility testing was performed and the macrolide resistance phenotype was assessed using double-disc diffusion testing. Monthly and annual rates of macrolide resistance were calculated for each site. An adjusted overall rate of macrolide resistance was determined to account for differences in the numbers of GAS isolates sent from each centre.

RESULTS

Overall, 171 of the 2797 collected isolates of GAS (6.1%) were resistant to erythromycin. The adjusted overall resistance rate was 5.2%. Rates of macrolide resistance varied by site (range 3.0-8.7%) and also by month (<2% to >10%). The M phenotype of macrolide resistance accounted for >60% of all macrolide-resistant isolates recovered in this study.

CONCLUSIONS

These data suggest an increasing prevalence and broad geographical distribution of macrolide-resistant GAS in the US, indicating the need for ongoing local and national longitudinal surveillance to define the extent of this problem.

Pharmacodynamics and the prediction of efficacy in short-course antibiotic therapy: pediatric studies to validate the model

Short-course antibiotic therapy for specific pediatric infections allows the clinician to minimize toxicities related to antibiotic exposure, to limit antibiotic resistance, and to improve compliance and cost without compromising microbiologic efficacy. Future studies of short-course therapy in children should address the pharmacokinetics of antibiotic exposure to the pathogen at the site of infection, the pharmacodynamics of pathogen eradication, and the many host factors involved in clinical and microbiologic outcomes. By using a mathematic model that integrates all important variables, one may be able to predict the probability of a cure with short-course therapy for each pathogen, antibiotic, site of infection, and host interaction.