The problem of resistant bacteria for the management of acute otitis media

The Macromolecular Machines that Duplicate the Escherichia coli Chromosome as Targets for Drug Discovery

DNA replication is an essential process. Although the fundamental strategies to duplicate chromosomes are similar in all free-living organisms, the enzymes of the three domains of life that perform similar functions in DNA replication differ in amino acid sequence and their three-dimensional structures. Moreover, the respective proteins generally utilize different enzymatic mechanisms. Hence, the replication proteins that are highly conserved among bacterial species are attractive targets to develop novel antibiotics as the compounds are unlikely to demonstrate off-target effects. For those proteins that differ among bacteria, compounds that are species-specific may be found. Escherichia coli has been developed as a model system to study DNA replication, serving as a benchmark for comparison. This review summarizes the functions of individual E. coli proteins, and the compounds that inhibit them.

Specialist Pediatric Palliative Care Prescribing Practices: A Large 5-year Retrospective Audit

Introduction:

There is a gradual increasing trend in childhood cancers in India and pediatric palliative care in India is an emerging specialty. Prescribing pain and symptom control drugs in children with cancer requires knowledge of palliative care formulary, dosing schedules, and prescription guidelines. This study is a retrospective audit of prescribing practices of a specialist palliative care service situated in a tertiary cancer center.

Methods:

A total of 1135 medication records of children receiving specialist pediatric palliative care services were audited for 5 years (2010–2014) to evaluate prescribing practices in children with advanced cancer.

Results:

A total of 51 types of drugs were prescribed with an average of 4.2 drugs per prescription. 66.9% of the prescriptions had paracetamol, and 33.9% of the prescriptions had morphine. Most common nonsteroidal anti-inflammatory drugs prescribed was ibuprofen (23.9%), and more than 50% of the prescriptions had aperients. The most commonly prescribed aperient was a combination of liquid paraffin and sodium-picosulfate. Dexamethasone was prescribed in 51.9% of patients and in most cases this was part of oral chemotherapy regimen. Generic names in prescription were used only in 33% of cases, and adverse effects of the drugs were documented in only 9% of cases. In 25% of cases, noncompliance to the WHO prescription guidelines was seen, and patient compliance to prescription was seen in 40% of cases.

Conclusions:

Audit of the prescribing practices in specialist pediatric palliative care service shows that knowledge of pediatric palliative care formulary, rational drug use, dosing, and prescribing guidelines is essential for symptom control in children with advanced life-limiting illness. Noncompliance to WHO prescribing guidelines in one fourth of cases and using nongeneric names in two-thirds of prescription indicates poor prescribing practices and warrants prescriber education. Prescription noncompliance by almost two-thirds of patients is alarming and necessitates intense patient, family, and caregiver education and empowerment.

Once or twice daily versus three times daily amoxicillin with or without clavulanate for the treatment of acute otitis media

BACKGROUND

Acute otitis media (AOM) is a common problem in children, for which amoxicillin, with or without clavulanate, is frequently prescribed as a treatment of choice. The conventional recommendation is either three or four daily doses. However, nowadays it is frequently prescribed as once or twice daily doses. If once or twice daily amoxicillin, with or without clavulanate, is as effective for acute otitis media as three or four times a day, it may be more convenient to give the medication once or twice a day to children and hence improve compliance.

OBJECTIVES

To compare the effectiveness of one or two daily doses with three or four daily doses of amoxicillin, with or without clavulanate, for the treatment of AOM in children; and to compare complication rates and adverse reactions.

SEARCH METHODS

We searched CENTRAL 2013, Issue 2, MEDLINE (January 1950 to March week 1, 2013), EMBASE (1974 to March 2013) and the Science Citation Index (2001 to March 2013).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of children aged 12 years or younger with AOM, diagnosed by acute ear pain (otalgia) and inflamed ear drum (confirmed by positive tympanocentesis or tympanogram of type B or C).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on treatment outcomes from individual trials and assessed trial quality based on selection bias, performance bias and detection bias, attrition bias, reporting bias and other biases. We defined the quality grading as low risk of bias, high risk of bias or unclear risk of bias. We summarised the results as risk ratio (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included five studies with 1601 children in the review. Pooled analysis demonstrated that the following outcomes were comparable between the two groups: clinical cure at the end of therapy (RR 1.03, 95% CI 0.99 to 1.07); during therapy (RR 1.06, 95% CI 0.85 to 1.33) and at follow-up (RR 1.02, 95% CI 0.95 to 1.09); recurrent AOM (RR 1.21, 95% CI 0.52 to 2.81); compliance rate (RR 1.04, 95% CI 0.98 to 1.10) and overall adverse events (RR 0.92, 95% CI 0.52 to 1.63). When we performed subgroup analysis separately for trials with amoxicillin only and amoxicillin/clavulanate only, it showed that all important outcomes were comparable between once or twice daily groups and the three times daily group. The risk of bias amongst the five included studies was as follows: for random sequence generation we graded two studies as low and three unclear risk of bias; for allocation concealment all studies were at unclear risk of bias; for blinding (performance and detection bias) we graded four as high and one as unclear risk of bias; for incomplete outcome data (attrition bias) we graded two low, two high and one as unclear risk of bias; for reporting bias four were at low and one at high risk; and for 'other' bias four were at low and one at unclear risk of bias.

AUTHORS' CONCLUSIONS

This review showed that the results of using once or twice daily doses of amoxicillin, with or without clavulanate, were comparable with three doses for the treatment of AOM.

The diagnosis and management of acute otitis media

This evidence-based clinical practice guideline is a revision of the 2004 acute otitis media (AOM) guideline from the American Academy of Pediatrics (AAP) and American Academy of Family Physicians. It provides recommendations to primary care clinicians for the management of children from 6 months through 12 years of age with uncomplicated AOM. In 2009, the AAP convened a committee composed of primary care physicians and experts in the fields of pediatrics, family practice, otolaryngology, epidemiology, infectious disease, emergency medicine, and guideline methodology. The subcommittee partnered with the Agency for Healthcare Research and Quality and the Southern California Evidence-Based Practice Center to develop a comprehensive review of the new literature related to AOM since the initial evidence report of 2000. The resulting evidence report and other sources of data were used to formulate the practice guideline recommendations. The focus of this practice guideline is the appropriate diagnosis and initial treatment of a child presenting with AOM. The guideline provides a specific, stringent definition of AOM. It addresses pain management, initial observation versus antibiotic treatment, appropriate choices of antibiotic agents, and preventive measures. It also addresses recurrent AOM, which was not included in the 2004 guideline. Decisions were made on the basis of a systematic grading of the quality of evidence and benefit-harm relationships. The practice guideline underwent comprehensive peer review before formal approval by the AAP. This clinical practice guideline is not intended as a sole source of guidance in the management of children with AOM. Rather, it is intended to assist primary care clinicians by providing a framework for clinical decision-making. It is not intended to replace clinical judgment or establish a protocol for all children with this condition. These recommendations may not provide the only appropriate approach to the management of this problem.

Antimicrobial-resistant Streptococcus pneumoniae: trends and management

Management of pneumococcal infections has been challenged by the development of resistance and, more recently, the unexpected spread of resistant clones of serotypes, such as 19A, following the introduction of a conjugate pneumococcal vaccine for use in children in 2000. High-dose penicillin G and many other agents continue to be efficacious parenterally for pneumonia and bacteremia. However, treatment options for meningitis and for infections treated with oral agents, particularly in children, have been limited by resistance. Empiric treatment guidelines should reflect the emerging threats from increased drug resistance. Compliance with guidelines by physicians and patients is important to prevent further development of resistance as new classes of agents are unlikely to be available in the next decade.

Once or twice daily versus three times daily amoxicillin with or without clavulanate for the treatment of acute otitis media

BACKGROUND

Acute otitis media (AOM) is a common problem in children, for which the antibiotic amoxicillin, with or without clavulanate, is frequently prescribed.

OBJECTIVES

To compare the effectiveness of one or two daily doses with three or four daily doses of amoxicillin, with or without clavulanate, for the treatment of AOM in children.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 1), which contains the Acute Respiratory Infections (ARI) Group's Specialized Register; MEDLINE (January 1950 to March 2008); EMBASE (1974 to March 2008); the Science Citation Index (2001 to March 2008); and NLM Gateway (HSRProj) (March 2008).

SELECTION CRITERIA

We included studies if they met the following criteria: randomized controlled trials (RCTs) of children aged 12 years or younger with AOM, diagnosed by the following explicit criteria: acute ear pain (otalgia) and inflamed ear drum (confirmed by positive tympanocentesis or tympanogram of type B or C).

DATA COLLECTION AND ANALYSIS

We extracted data on treatment outcomes from individual trials. We assessed quality based on selection bias, performance bias, attrition bias and sample size calculation. The quality grading was defined as low risk of bias, moderate risk of bias or high risk of bias. The results were summarized as risk ratio (RR) and 95% confidence intervals (CI).

MAIN RESULTS

We included six studies with 1601 children in the review. Although the clinical cure rates at the end of therapy and at the follow-up periods of each study were shown to be comparable between the two groups, we did not perform pooled data analysis because of moderate to high risk of biases in the included studies. Most of the children were aged 2 months to 12 years. None of the studies had any consistently significant results either for benefit or harm. The outcomes were assessed at the end of therapy (often 10 days) and this may have been too late to measure any differences.

AUTHORS' CONCLUSIONS

This review showed insufficient evidence to judge whether once or twice daily doses of amoxicillin, with or without clavulanate, were comparable with three or four daily doses for the treatment of AOM. The evidence appears to be biased and therefore no firm conclusions can be drawn.

The effects of maternal employment on child injuries and infectious disease

This article presents estimates of effects of maternal paid work and nonmaternal child care on injuries and infectious disease for children aged 12 to 36 months. Mother-child fixed-effects estimates are obtained by using data from the NICHD Study of Early Child Care. Estimates indicate that maternal employment itself has no statistically significant adverse effects on the incidence of infectious disease and injury. However, greater time spent by children in center-based care is associated with increased rates of respiratory problems for children aged 12 to 36 months and increased rates of ear infections for children aged 12 to 24 months.

Implementing guidelines for the treatment of acute otitis media

The recently published Clinical Practice Guideline for the Diagnosis and Management of Acute Otitis Media represents a sincere effort by the AAP andthe AAFP to provide management guidelines for the practitioner based upon the best scientific evidence available. Despite many years of research and hundreds of clinical studies addressing various aspects of the epidemiology, clinical presentation, and treatment of acute otitis media, important questions remain unaddressed or have been addressed in a less than optimal fashion. These gaps in knowledge and deficiencies in several of the studies that formed the scientific basis for the proposed guidelines are the major reasons behind continued disagreement over certain recommendations. Until more comprehensive and careful analyses can be performed, disagreements are likely to persist. Even so, there is general agreement about most of the recommendations made in these guidelines, and these recommendations will provide a very valuable framework for the practicing physician as he or she cares for children with acute otitis media. To briefly review the major points, first is the critical importance of accurately diagnosing acute otitis media using a combination of clinical findings and observable abnormalities of the tympanic membrane and middle ear space. Particularly important is the differentiation of acute otitis media from otitis media with effusion. Second is the value of treating the pain associated with acute otitis media as a regular component of care, irrespective of any decision concerning antimicrobial treatment. Third is the option, for a select group of older patients with nonsevere disease, of withholding antimicrobial therapy for the first 48 to 72 hours, if close follow-up and active parental involvement can be guaranteed. Fourth is the recommendation that if an antimicrobial agent is used, high-dose amoxicillin (80 to 90 mg/kg/d) is the treatment of choice for most children at the time of initial presentation unless disease is particularly severe or the child has recently failed a previous course of the antibiotic. Finally highlighted is the importance of ongoing education efforts on the part of physicians in advising parents about the things they can do in their households to lessen the risk of future disease.

Large dosage amoxicillin/clavulanate, compared with azithromycin, for the treatment of bacterial acute otitis media in children

BACKGROUND

A large dosage pediatric formulation of amoxicillin/clavulanate with an improved pharmacokinetic/pharmacodynamic profile was developed to eradicate many penicillin-resistant strains of Streptococcus pneumoniae and Haemophilus influenzae (including beta-lactamase-producing strains).

METHODS

This randomized, investigator-blinded, multicenter trial examined treatment of bacterial acute otitis media (AOM) in children 6-30 months of age with amoxicillin/clavulanate (90/6.4 mg/kg/d in 2 divided doses for 10 days) versus azithromycin (10 mg/kg for 1 day followed by 5 mg/kg/d for 4 days). Tympanocentesis was performed at entry for bacteriologic assessment, at the on-therapy visit (day 4-6) to determine bacterial eradication and at any time before the end-of-therapy visit (day 12-14) if the child was categorized as experiencing clinical failure. Clinical assessments were performed at the on-therapy, end-of-therapy and follow-up (day 21-25) visits.

RESULTS

We enrolled 730 children; AOM pathogens were isolated at baseline for 249 of the amoxicillin/clavulanate group and 245 of the azithromycin group. For children with AOM pathogens at baseline, clinical success rates at the end-of-therapy visit were 90.5% for amoxicillin/clavulanate versus 80.9% for azithromycin (P < 0.01), and those at the on-therapy and follow-up visits were 94.9% versus 88.0% and 80.3% versus 71.1%, respectively (all P < 0.05). At the on-therapy visit, pretherapy pathogens were eradicated for 94.2% of children receiving amoxicillin/clavulanate versus 70.3% of those receiving azithromycin (P < 0.001). Amoxicillin/clavulanate eradicated 96.0% of S. pneumoniae (92.0% of fully penicillin-resistant S. pneumoniae) and 89.7% of H. influenzae (85.7% [6 of 7 cases] of beta-lactamase-positive H. influenzae). Corresponding rates for azithromycin were 80.4% (54.5%) for S. pneumoniae and 49.1% (100% [1 of 1 case]) for H. influenzae (all P < 0.01 for between-drug comparisons).

CONCLUSION

Amoxicillin/clavulanate was clinically and bacteriologically more effective than azithromycin among children with bacterial AOM, including cases caused by penicillin-resistant S. pneumoniae and beta-lactamase-positive H. influenzae.

Fluoroquinolone prescribing in the United States: 1995 to 2002

PURPOSE

To measure changes in the rate and type of fluoroquinolones prescribed in the United States from 1995 to 2002.

METHODS

We performed a longitudinal analysis of the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey of adult visits to physicians in ambulatory clinics and emergency departments throughout the United States from 1995 to 2002. The main outcomes were fluoroquinolone prescribing rates and prescribing in accordance with Food and Drug Administration approval as of December 2002.

RESULTS

Between 1995 and 2002, fluoroquinolones became the most commonly prescribed class of antibiotics to adults in the United States. Fluoroquinolone prescribing rose threefold, from 7 million visits in 1995 to 22 million visits in 2002 (P < 0.0001). Fluoroquinolone prescribing increased as a proportion of overall antibiotic prescribing (from 10% to 24%; P < 0.0001) and as a proportion of the U.S. population (from 39 to 106 prescriptions per 1000 adults; P < 0.001). These increases were due to the use of newer fluoroquinolones with activity against Streptococcus pneumoniae. Forty-two percent of fluoroquinolone prescriptions were for nonapproved diagnoses. Among patients receiving antibiotics, nonapproved fluoroquinolone prescribing increased over time (odds ratio = 1.18 per year; 95% confidence interval: 1.13 to 1.24).

CONCLUSION

Fluoroquinolone prescribing increased threefold in outpatient clinics and emergency departments in the United States from 1995 to 2002. Fluoroquinolones became the most commonly prescribed class of antibiotics to adults in 2002. Nonapproved fluoroquinolone prescribing was common and increased over time. Such prescribing patterns are likely to be followed by an increasing prevalence of fluoroquinolone-resistant bacteria.

Mechanisms of resistance among respiratory tract pathogens

Antimicrobial resistance among respiratory tract pathogens represents a significant health care threat. Identifying the antimicrobial agents that remain effective in the presence of resistance, and knowing why, requires a thorough understanding of the mechanisms of action of the various agents as well as the mechanisms of resistance demonstrated among respiratory tract pathogens. The primary goal of antimicrobial therapy is to eradicate the pathogen, via killing or inhibiting bacteria, from the site of infection; the defenses of the body are required for killing any remaining bacteria. Targeting a cellular process or function specific to bacteria and not to the host limits the toxicity to patients. Currently, there are four general cellular targets to which antimicrobials are targeted: cell wall formation and maintenance, protein synthesis, DNA replication, and folic acid metabolism. Resistance mechanisms among respiratory tract pathogens have been demonstrated for all four targets. In general, the mechanisms of resistance used by these pathogens fall into one of three categories: enzymatic inactivation of the antimicrobial, prevention of intracellular accumulation, and modification of the target site to which agents bind to exert an antimicrobial effect. Resistance to some agents can be overcome by modifying the dosage regimens (e.g., using high-dose therapy) or inhibiting the resistance mechanism (e.g., b-lactamase inhibitors), whereas other mechanisms of resistance can only be overcome by using an agent from a different class. Understanding the mechanisms of action of the various agents and the mechanisms of resistance used by respiratory tract pathogens can help clinicians identify the agents that will increase the likelihood of achieving optimal outcomes.

Diagnosis and management of acute otitis media

This evidence-based clinical practice guideline provides recommendations to primary care clinicians for the management of children from 2 months through 12 years of age with uncomplicated acute otitis media (AOM). The American Academy of Pediatrics and American Academy of Family Physicians convened a committee composed of primary care physicians and experts in the fields of otolaryngology, epidemiology, and infectious disease. The subcommittee partnered with the Agency for Healthcare Research and Quality and the Southern California Evidence-Based Practice Center to develop a comprehensive review of the evidence-based literature related to AOM. The resulting evidence report and other sources of data were used to formulate the practice guideline recommendations. The focus of this practice guideline is the appropriate diagnosis and initial treatment of a child presenting with AOM. The guideline provides a specific definition of AOM. It addresses pain management, initial observation versus antibacterial treatment, appropriate choices of antibacterials, and preventive measures. Decisions were made based on a systematic grading of the quality of evidence and strength of recommendations, as well as expert consensus when definitive data were not available. The practice guideline underwent comprehensive peer review before formal approval by the partnering organizations. This clinical practice guideline is not intended as a sole source of guidance in the management of children with AOM. Rather, it is intended to assist primary care clinicians by providing a framework for clinical decision-making. It is not intended to replace clinical judgment or establish a protocol for all children with this condition. These recommendations may not provide the only appropriate approach to the management of this problem.

Amoxicillin tablets for oral suspension in the treatment of acute otitis media: a new formulation with improved convenience

Acute otitis media (AOM) is the most common cause of pediatric office visits in the United States and the most frequent bacterial infection in children. Antimicrobials are often prescribed and amoxicillin continues to be the first-line treatment for AOM. Recently, amoxicillin tablets that disperse in water to form an oral suspension have become available in the United States for the treatment of AOM. This formulation retains the efficacy, safety, and tolerability features of conventional amoxicillin formulations while providing the additional potential benefits of improved portability, patient convenience and compliance, and dosing accuracy.

Does a paediatric after-hours clinic use evidence-based guidelines in the management of acute otitis media?

OBJECTIVE

To determine whether a paediatric after-hours clinic uses evidence-based management in the treatment of acute otitis media, and compare this management with that provided in a paediatric emergency department and a general hospital emergency department.

METHODS

A retrospective chart review of 573 patients (aged six months to five years) with a discharge diagnosis of acute otitis media was conducted in three after-hours settings: a paediatric after-hours clinic, a tertiary paediatric hospital emergency department and a secondary general hospital emergency department. The patients' age, weight, sex and allergy to antibiotics were recorded as baseline characteristics. The physicians' antibiotic choice, dose and duration, and the use of investigations were recorded as outcome variables.

RESULTS

Amoxicillin was prescribed to 68% of patients at both the paediatric after-hours clinic and the paediatric hospital emergency department, compared with 53% of patients at the general hospital emergency department (P<0.01). The mean dose of amoxicillin prescribed at the paediatric after-hours clinic and the paediatric hospital emergency department were similar (43.4±9.7 mg/kg per day and 42.4±14.3 mg/kg per day, respectively) and higher than that prescribed at the general hospital emergency department (38.6±8.8 mg/kg per day, P<0.01). The paediatric after-hours clinic used investigations less often than did emergency departments (0.5% of cases compared with 9% and 20%, P<0.01).

CONCLUSION

The paediatric after-hours clinic provided a high level of adherence to a clinical practice guideline and had a low utilization of resource intensive investigations.

Bacterial otitis media: current vaccine development strategies

Otitis media is the most common reason for children less than 5 years of age to visit a medical practitioner. Whilst the disease rarely results in death, there is significant associated morbidity. The most common complication is loss of hearing at a critical stage of the development of speech, language and cognitive abilities in children. The cause and pathogenesis of otitis media is multifactorial. Among the contributing factors, the single most important are viral and bacterial infections. Infection with respiratory syncytial virus, influenza viruses, para-influenza viruses, enteroviruses and adenovirus are most commonly associated with acute and chronic otitis media. Streptococcus pneumoniae, non-typeable Haemophilus influenzae and Moraxella catarrhalis are the most commonly isolated bacteria from the middle ears of children with otitis media. Treatment of otitis media has largely relied on the administration of antimicrobials and surgical intervention. However, attention has recently focused on the development of a vaccine. For a vaccine to be effective against bacterial otitis media, it must, at the very least, contain antigens that induce a protective immune response in the middle ear against the three most common infecting bacteria. Whilst over the past decade there has been significant progress in the development of vaccines against invasive S. pneumoniae disease, these vaccines are less efficacious for otitis media. The search for candidate vaccine antigens for non-typeable H. influenzae are well advanced whilst less progress has been made for M. catarrhalis. No human studies have been conducted for non-typeable H. influenzae or M. catarrhalis and the concept of a tribacterial vaccine remains to be tested in animal models. Only when vaccine antigens are determined and an understanding of the immune responses induced in the middle ear by infection and immunization is gained will the formulation of a tribacterial vaccine against otitis media be possible.

Otitis media: diagnosis, management, and judicious use of antibiotics

Otitis media continues to present a major challenge to practitioners in the clinical setting. With the ever-increasing trend toward the use of a sound research-structured approach to health care and the use of evidence-based guidelines, it is important to have an understanding of these findings related to otitis media. A review of research-supported literature regarding the diagnosis and management of this disease, and suggestions for the judicious use of antibiotics, are presented in this paper.

Random amplified polymorphic DNA analysis applied to acute otitis media caused by penicillin non-susceptible Streptococcus pneumoniae

The spread of penicillin non-susceptible Streptococcus pneumoniae (PNSSP) is an emerging problem for the treatment of acute otitis media (AOM). Attendance of children at day care centers, as well as the spread of PNSSP, is a risk factor for AOM. The status of the spread of PNSSP during the acute infection phase of AOM has not been evaluated. We examined the clonality of samples from seven children in a day care center who simultaneously developed AOM caused by PNSSP. The seven isolates from the children, and six control samples were grouped by serotyping, by determining resistance to antimicrobial agents, and by genotyping, carried out by sequencer-based random amplified polymorphic DNA (RAPD), and validated by bootstrap analysis. There was no evidence to indicate the direct dissemination of PNSSP among these patients in the day care center, although the simultaneous occurrence of PNSSP AOM had initially suggested a clonal outbreak. The possible presence of a common ancestral strain suggested the importance of surveillance during the carrier state. The result of RAPD genotyping was highly reproducible, as validated by the high bootstrap score. The use of an automated sequencer, in combination with a careful choice of primers, and commercially established kits, played a significant role in the reproducibility of the studies.

Bacteriologic and clinical efficacy of high dose amoxicillin/clavulanate in children with acute otitis media

OBJECTIVES

To determine the bacteriologic and clinical efficacy of high dose amoxicillin/clavulanate (90/6.4 mg/kg/day) against common bacterial pathogens causing acute otitis media (AOM), including penicillin-resistant Streptococcus pneumoniae (PRSP).

METHODS

In this open label multicenter study, 521 infants and children with AOM [mean age, 18.6 months; age < 24 months, n = 375 (72%)] were treated with amoxicillin/clavulanate 90/6.4 mg/kg/day in two divided doses for 10 days. Bilateral otitis media, previous episodes of AOM, antibiotic treatment within 3 months and day-care attendance were recorded in 60.1, 35.7, 50.2 and 38.2% of the children, respectively. Tympanocentesis was performed before the first dose and repeated on Days 4 to 6 for all children with S. pneumoniae at 22 centers and for all children with any pathogen at 3 centers. Clinical response was assessed at end of therapy.

RESULTS

Pathogens were isolated from 355 (68%) of 521 enrolled children; 180 children underwent repeat tympanocentesis and were bacteriologically evaluable. Baseline pathogens were S. pneumoniae (n = 122 enrolled/93 bacteriologically evaluable), Haemophilus influenzae (n = 160/51), both (n = 37/32) and others (n = 36/4). Pathogens were eradicated from 172 (96%) of 180 bacteriologically evaluable children. Overall 122 (98%) of 125 isolates of S. pneumoniae were eradicated, including 31 (91%) of 34 PRSP isolates (penicillin MICs 2 to 4 micrograms/ml). Seventy-eight (94%) of 83 isolates of H. influenzae were eradicated. Symptoms and otoscopic signs of acute inflammation were completely resolved or improved on Days 12 to 15 in 263 (89%) of 295 clinically evaluable children with bacteriologically documented AOM.

CONCLUSIONS

On the basis of bacteriologic outcome on Days 4 to 6 and clinical outcome on Days 12 to 15, we found that high dose amoxicillin/clavulanate (90/6.4 mg/kg/day) was highly efficacious in children with AOM, including those most likely to fail treatment, namely children < 24 months of age and those with infectious caused by PRSP.

Increasing prevalence of multidrug-resistant Streptococcus pneumoniae in the United States

BACKGROUND

The emergence of drug-resistant strains of bacteria has complicated treatment decisions and may lead to treatment failures.

METHODS

We examined data on invasive pneumococcal disease in patients identified from 1995 to 1998 in the Active Bacterial Core Surveillance program of the Centers for Disease Control and Prevention. Pneumococci that had a high level of resistance or had intermediate resistance according to the definitions of the National Committee for Clinical Laboratory Standards were defined as "resistant" for this analysis.

RESULTS

During 1998, 4013 cases of invasive Streptococcus pneumoniae disease were reported (23 cases per 100,000 population); isolates were available for 3475 (87 percent). Overall, 24 percent of isolates from 1998 were resistant to penicillin. The proportion of isolates that were resistant to penicillin was highest in Georgia (33 percent) and Tennessee (35 percent), in children under five years of age (32 percent, vs. 21 percent for persons five or more years of age), and in whites (26 percent, vs. 22 percent for blacks). Penicillin-resistant isolates were more likely than susceptible isolates to have a high level of resistance to other antimicrobial agents. Serotypes included in the 7-valent conjugate and 23-valent pneumococcal polysaccharide vaccines accounted for 78 percent and 88 percent of penicillin-resistant strains, respectively. Between 1995 and 1998 (during which period 12,045 isolates were collected), the proportion of isolates that were resistant to three or more classes of drugs increased from 9 percent to 14 percent; there also were increases in the proportions of isolates that were resistant to penicillin (from 21 percent to 25 percent), cefotaxime (from 10 percent to 15 percent), meropenem (from 10 percent to 16 percent), erythromycin (from 11 percent to 16 percent), and trimethoprim-sulfamethoxazole (from 25 percent to 29 percent). The increases in the frequency of resistance to other antimicrobial agents occurred exclusively among penicillin-resistant isolates.

CONCLUSIONS

Multidrug-resistant pneumococci are common and are increasing. Because a limited number of serotypes account for most infections with drug-resistant strains, the new conjugate vaccines offer protection against most drug-resistant strains of S. pneumoniae.

Judicious use of antibiotics for common pediatric respiratory infections

BACKGROUND

Antibiotic resistance among common respiratory infection-producing bacteria such as Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis has become a major global public health problem. The use of antibiotics, whether or not medically justified for a particular illness, contributes to the development of resistant bacteria. To help to contain the proliferation of drug-resistant bacteria, members of the CDC and the American Academy of Pediatrics (AAP) recently published principles for the judicious use of antibiotics in common pediatric respiratory infections including the common cold, otitis media, sinusitis and tonsillopharyngitis. This article reviews the CDC/AAP principles for management of these illnesses and describes results of clinical practice studies in which efforts to improve the judicious use of antibiotics were undertaken.

CONCLUSIONS

The success of the CDC/AAP principles in containing the increase in antimicrobial resistance depends upon their being practiced. Results of clinical practice studies indicate that judicious use of antimicrobial therapy in pediatric respiratory infections can be realized through education and persistence. More widespread educational and behavior modification efforts are necessary to reduce unnecessary prescription of antibiotics and to curtail the still burgeoning problem of bacterial resistance.

Antimicrobial resistance

Antimicrobial resistance is not a new concept. For over half a century, health care providers have been faced with this problem. The overuse and misuse of antimicrobial therapy by health care providers has contributed largely to the problem, but several other factors have also been associated with antimicrobial resistance. This article reviews current literature regarding antimicrobial resistance in an effort to educate health care providers to make judicious decisions in the treatment of bacterial infections and stem the rise of antibiotic resistance by carefully scrutinizing prescribing practices. Contributing factors to antimicrobial resistance and recommendations for the control of antimicrobial resistance will be reviewed. Treatment recommendations for common health ailments (i.e., acute otitis media, rhinitis, sinusitis, and pharyngitis) are provided.

Nonsusceptible Streptococcus pneumoniae in children with chronic otitis media with effusion and recurrent otitis media undergoing ventilating tube placement

CONTEXT

Children with chronic otitis media are at risk for nonsusceptible Streptococcus pneumoniae (NSP) infection. If these children undergo ventilating tube placement, there is an opportunity to culture middle ear fluid and the nasopharynx to determine carriage of NSP.

OBJECTIVE

To determine the incidence of NSP carriage, NSP antibiotic susceptibility and risk factors for NSP carriage in children with chronic otitis media undergoing tube placement.

DESIGN AND SETTING

Prospective cohort study in an academic medical center with recruitment of patients from an otolaryngology private practice and clinic.

PATIENTS

Children < 18 years of age undergoing tube placement for chronic otitis media.

INTERVENTIONS

Myringotomy and tube placement, with culture of middle ear fluid and nasopharynx.

MAIN OUTCOME MEASURES

The incidence of NSP cultured from the middle ears and nasopharynx of recruited subjects with the use of the minimum inhibitory concentration break points for penicillin susceptibility recommended by the National Committee for Clinical Laboratory Standards.

RESULTS

S. pneumoniae was identified in at least 1 site from 23 of 300 study subjects (7.6%); of these 23, 12 case subjects (52.2%) harbored NSP. Of the risk factors assessed by preoperative questionnaire, only younger age was associated with NSP colonization (P < 0.0001). Of the six oral cephalosporins studied, cefpodoxime and cefuroxime showed good in vitro activity against S. pneumoniae isolates with intermediate penicillin resistance.

CONCLUSIONS

Children with chronic otitis media undergoing tube placement may carry NSP and provide a means of monitoring the incidence of NSP and antibiotic susceptibilities for children with ear infections in their communities. Younger age is a risk factor for NSP carriage in this population.

Clinical significance of resistant organisms in otitis media

BACKGROUND

Otitis media is an important health care problem of childhood. The bacteriology of otitis media comprises three main pathogens: Streptococcus pneumoniae, nontypable Haemophilus influenzae and Moraxella catarrhalis. Although the prevalence of resistant strains varies geographically and temporally, antimicrobial resistance is widespread and increasing.

RESISTANCE TO ANTIBIOTIC DRUGS

Among the risk factors for development of resistance in otitis media are antimicrobial use, young age, day-care attendance and prior hospitalization. The increasing rate of resistance to antibiotic drugs is associated with a decreased rate of successful eradication of pathogens from middle ear fluid, which is associated with clinical failure. A bacteriologic cure rate of 80 to 85% is observed for S. pneumoniae and nontypable H. influenzae when serum concentrations exceed the MIC for 40 to 50% of dosing interval. Comparative trials indicate that some of the beta-lactams can achieve bacteriologic eradication in acute otitis media, although major differences in outcome exist among agents based on pathogen, beta-lactamase status and MIC values.

ANTIBIOTIC CHOICE

Overall the choice of antibiotics for treatment of otitis media should take into consideration their in vitro activity against the locally prevalent organisms, especially resistant organisms, and results obtained from studies in which bacteriologic outcome was used as the endpoint.

Therapeutic effects of parenteral beta-lactam antibiotics on experimental otitis media caused by penicillin-resistant Streptococcus pneumoniae in guinea-pigs

The therapeutic effects of parenteral beta-lactam antibiotics were evaluated in experimental acute otitis media caused by penicillin-resistant Streptococcus pneumoniae (PRSP) in guinea-pigs. Cefotaxime, ceftriaxone and piperacillin significantly reduced viable cell counts of PRSP in the middle ear at a dose of 50 mg/kg bd for 3 days (P < 0.01 compared with control). The therapeutic effects of cefotaxime, ceftriaxone and piperacillin were superior to those of cefotiam and ceftazidime. These therapeutic effects reflected both in vitro activity and pharmacokinetic properties of the drugs.

Bacteriologic efficacies of oral azithromycin and oral cefaclor in treatment of acute otitis media in infants and young children

A prospective, open-label, randomized study was conducted in order to determine the bacteriologic efficacies of cefaclor and azithromycin in acute otitis media (AOM). Tympanocentesis was performed on entry into the study and 3 to 4 days after initiation of treatment. Bacteriologic failure after 3 to 4 days of treatment with both drugs occurred in a high proportion of culture-positive patients, especially in those in whom AOM was caused by Haemophilus influenzae (16 of 33 [53%] of those treated with azithromycin and 13 of 34 [52%] of those treated with cefaclor). Although a clear correlation of the persistence of the pathogen with increased MICs of the respective drugs could be demonstrated for Streptococcus pneumoniae, no such correlation was found for H. influenzae. It is proposed that susceptibility breakpoints for H. influenzae should be considerably lower than the current ones for both cefaclor and azithromycin for AOM caused by H. influenzae.

Parents, physicians, and antibiotic use

BACKGROUND

Emergence of resistant bacterial pathogens has increased concerns about antibiotic prescribing patterns. Parent expectations and pressure may influence these patterns.

OBJECTIVE

To understand how parents influence the prescribing patterns of physicians and what strategies physicians believe are important if we are going to reduce inappropriate use of oral antimicrobial agents.

DESIGNS AND METHODS

One thousand pediatricians who are members of the American Academy of Pediatrics were asked to complete a semi-structured questionnaire. The physicians were chosen randomly by the American Academy of Pediatrics.

RESULTS

Nine hundred fifteen pediatricians were eligible and 610 surveys were analyzable, for a response rate of 67%. The majority of respondents were male (56%), worked in a group practice (51%), saw an average of 114 patients per week and were in practice for 14 years. Forty percent of the pediatricians indicated that 10 or more times in the past month a parent had requested an antibiotic when the physician did not feel it was indicated. Forty-eight percent reported that parents always, most of the time, or often pressure them to prescribe antibiotics when their children are ill but antibiotics are not indicated. In follow-up questions, approximately one-third of physicians reported they occasionally or more frequently comply with these requests. Seventy-eight percent felt that educating parents would be the single most important program for reducing inappropriate oral antibiotic use and 54% indicated that parental pressure, in contrast to concerns about legal liability (12%) or need to be efficient in practice (19%), contributed most to inappropriate use of oral antibiotics.

CONCLUSIONS

Pediatricians acknowledge prescribing antimicrobial agents when they are not indicated. Pediatricians believe educating parents is necessary to promote the judicious use of antimicrobial agents.

Pharmacokinetics and pharmacodynamics of new and old antimicrobial agents for acute otitis media

Selection of appropriate antibiotic treatment for children with acute otitis media (AOM) is challenging. Although the diagnosis is relatively easy for experienced clinicians, the distinction between AOM and otitis media with effusion is often more subtle. In general therapy is empiric and the pathogen causing disease in a given patient remains unknown. However, this situation is made even more difficult by the dynamic nature of the pathogenesis of AOM. Both the proportion of patients infected with one of the three primary pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, and the antimicrobial susceptibility patterns of these pathogens are changing. Currently there are 16 antibiotics labeled for use in AOM. Only 2 are reliably effective against penicillin-resistant pneumococcus: high dose amoxicillin (80 to 100 mg/kg/day) and im ceftriaxone. Among the others all are beta-lactamase-stable and have proven clinical effectiveness in AOM patients infected with H. influenzae or M. catarrhalis. Even with the high spontaneous resolution rate reported for AOM, antimicrobial therapy remains the standard of care in the United States. Recognition of the fundamental determinants of effective therapy should permit rational antibiotic selection for each patient.

Antibiotic resistance in community-acquired respiratory tract infections: current issues

OBJECTIVE

In recent years, antibiotic resistance has emerged as an important global problem. The major goal of this review is to update important issues pertaining to antibiotic resistance, with an emphasis on antibiotic resistance involving community-acquired respiratory pathogens. In addition, this review examines potential reasons why antibiotic resistance has increased in recent years, how clinicians can better understand commonly used laboratory antibiotic resistance tests, and possible solutions to the increasing problem of antibiotic resistance. The article emphasizes the diagnosis, therapy, and prevention of antibiotic-resistant infections.

DATA SOURCES

We identified relevant English-language articles through MEDLINE search (1966 to March 1998). All articles related to antibiotic resistance and the scope of the articles included original investigative articles, reviews, letters, and editorials. In addition, we selected additional references from the bibliographies of the identified articles.

STUDY SELECTION

We selected articles for detailed review if they provided direct insight into the cause of antibiotic resistance, testing for antibiotic resistance, or the treatment of antibiotic resistance. Most, but not all, of the articles selected pertained to antibiotic resistance and respiratory tract infections. We performed a detailed review on approximately 40% of the originally selected articles.

RESULTS

Multiple factors that play a significant role in the development of antibiotic resistance include the overuse of antibiotics in both humans and animals, situations such as day care that enhance transmission via frequent close personal contact, and widespread dissemination of resistant strains via global travel. Most respiratory pathogens have developed resistance to commonly used antibiotics either by producing beta-lactamase or by altering binding site proteins.

CONCLUSIONS

In many regions of the United States, the level of antibiotic resistance has impacted the clinical management of common respiratory pathogens. Future efforts to curtail antibiotic resistance will require a concerted effort in multiple areas, particularly enhanced epidemiologic surveillance to better detect resistance trends, judicious use of antibiotics, and new drug development.

Otitis media health status evaluation: a pilot study for the investigation of cost-effective outcomes of recurrent acute otitis media treatment

There are no reliable and valid instruments that measure otitis media clinical or functional health status in children ages 1 to 3 years. This study develops and tests three new instruments of clinical and functional otitis health status: the Otitis Media Clinical Severity Index (OM-CSI), the Otitis Media Functional Status Questionnaire (OM-FSQ), and the Otitis Media Diary (OMD). The OM-CSI was found to be a reliable measure of clinical acute otitis media (AOM) severity, with high internal consistency (Cronbach's alpha) scores, as well as an accurate indicator of AOM severity. The OM-FSQ and OMD were demonstrated to be reliable and valid measures of otitis-specific functional health status, with reproducible scores over time, high internal consistency alpha scores, and high correlation with measures of AOM clinical severity and other functional health status instruments. These three new instruments were also sensitive and specific indicators of AOM episodes.

Parents' and physicians' views on antibiotics

OBJECTIVE

To describe parents' opinions and concerns about antibiotics and to contrast these opinions with those of pediatricians.

DESIGN

Parents were surveyed using an interviewer-administered questionnaire and pediatricians were mailed a self-administered questionnaire.

RESULTS

Parents from two private practices (N = 300) were largely white (84%) and had completed college (81%). The parents from a community health center (N = 100) were mostly black (80%) and had not completed college (91%). Twenty-nine percent of parents were worried that their children were receiving too many antibiotics. Eighty-five percent believed there were problems with receiving too many antibiotics, with 55% mentioning resistance or immunity as concerns. Eighteen percent of parents had given their child an antibiotic at home before consulting a physician. Parents believed that antibiotics were always or sometimes required for ear infections (93%), throat infections (83%), colds (32%), cough (58%), and fever (58%). Fourteen percent of parents believed that their child had required an antibiotic when the doctor did not prescribe one, with clinic parents significantly more likely to report this issue (22%) than private practice parents (12%). Nine percent believed that their doctor had prescribed an antibiotic unnecessarily (private practice = 12%, community health center = 3%). Parents from the private practices were also more likely to report requesting a specific antibiotic (34%) in comparison with 19% of clinic parents. Sixty-one percent of the physician surveys were returned after two mailings and a follow-up phone call. The pediatricians had been in practice for a median of 12 years, seeing a median of 110 patients per week. Fifty-eight percent of pediatricians reported that some, many, or most of the parents in their practices were worried that their children were receiving too many antibiotics. Seventy-one percent indicated that four or more times during the previous month, a parent had requested an antibiotic when the physician believed it was unnecessary, and 35% said that at least occasionally they went along with these requests. Sixty-one percent reported that parents requested a different antibiotic from the one they were going to prescribe at least four times in the previous month, and 30% of pediatricians said that they agreed to parents' requests often or most of the time.

CONCLUSIONS

Both the parent and the physician surveys suggest that parents are concerned about the overuse of antibiotics, but often request them when their physicians believe they are unnecessary. Parents often administer antibiotics without physician knowledge, and many parents have misconceptions about which illnesses warrant antibiotic therapy. Understanding parents' concerns and beliefs about antibiotics and the range of physician practice styles with respect to antibiotics may direct the development of intervention strategies to reduce the inappropriate use of oral antibiotics.

Acute otitis media in children

Acute otitis media (AOM) is the most common reason parents bring children into the primary care physician's office. It is diagnosed by clinical symptoms of otalgia and often fever and irritability and by clinical otoscopy. Organisms common to the nasopharynx usually cause AOM. Many episodes of AOM resolve spontaneously. Because it is uncertain how many and which children will resolve without therapy, it is reasonable to treat all children with AOM with antibiotics. The first choice of antibiotics is amoxicillin. Other choices rest on a variety of factors.

Impaired bacteriologic response to oral cephalosporins in acute otitis media caused by pneumococci with intermediate resistance to penicillin

BACKGROUND

Penicillin resistance of Streptococcus pneumoniae, one of the most common causes of acute otitis media, has recently increased and is now highly prevalent in many regions. However, its contribution to clinical failure still must be proved. Because the role of antibiotics in acute otitis media is to eradicate the pathogens present in the middle ear fluid, we conducted a randomized controlled study to determine bacterial eradication of pathogens in acute otitis media by two commonly used oral cephalosporins, cefuroxime axetil (30 mg/kg/day) and cefaclor (40 mg/kg/day).

METHODS

Patients 6 to 36 months old with pneumococcal otitis media seen in the Pediatrics Emergency Room were studied. An initial middle ear fluid culture was obtained at enrollment, and a second culture was obtained on Day 4 or 5 during treatment. Follow-up was done also on Days 10, 17 and 42 after initiation of treatment. In cases of clinical relapse a third culture was obtained.

RESULTS

In total 78 patients were enrolled, 41 in the cefuroxime axetil group and 37 in the cefaclor group. Of the 78 S. pneumoniae isolates 31 (40%) were intermediately penicillin-resistant (MIC 0.125 to 1.0 microgram/ml). Of the 47 patients with penicillin-susceptible organisms 3 (6%) had bacteriologic failure vs. 4 of 19 (21%) and 7 of 11 (64%) of those with MIC of 0.125 to 0.25 microgram/ml and 0.38 to 1.0 microgram/ml, respectively (P < 0.001). For intermediately resistant pneumococci, in 7 of 12 (58%) of those receiving cefaclor the isolate was not eradicated vs. only 4 of 19 (21%) of those receiving cefuroxime axetil (P = 0.084). MIC to the administered cephalosporin of > 0.5 microgram/ml was associated with bacteriologic failure. Clinical failure was observed in 9 of 14 (64%) patients with bacteriologic failure vs. 10 of 52 (19%) patients with bacteriologic eradication (P = 0.003).

CONCLUSION

Intermediately penicillin-resistant S. pneumoniae is associated with an impaired bacteriologic and clinical response of acute otitis media to cefaclor and cefuroxime axetil. This effect was more pronounced with cefaclor than with cefuroxime axetil.

Emerging resistance to antibiotics: impact on respiratory infections in the outpatient setting

OBJECTIVE

To review the major mechanisms of antibiotic resistance and provide an overview of currently available oral antibiotics. This article discusses the impact of antibiotic resistance on respiratory infections (eg, otitis media, sinusitis, and pneumonia) encountered in the outpatient setting and appropriate management strategies for these infections are proposed.

DATA SOURCES

A Medline search was performed to identify recent references from the English language pertinent to this topic. Proposed management schemes for infections due to antibiotic-resistant bacteria were derived from current literature as well as the opinion of the authors.

RESULTS

Currently available oral antibiotics including penicillins, cephalosporins, macrolides, trimethroprim/sulfamethoxazole, and clindamycin continue to provide effective therapeutic options despite the increasing importance of antibiotic resistance in bacteria causing respiratory tract infections in the outpatient setting. The effectiveness of a given agent may no longer be assured, leading to the need for development of updated management strategies for patients experiencing treatment failure with antibiotics. Diagnostic strategies (ie, tympanocentesis) and novel treatment algorithms (eg, use of amoxicillin in combination with amoxicillin/clavulanate) for patients experiencing clinical failures potentially due to antibiotic-resistant bacteria are proposed.

CONCLUSIONS

The increasing prevalence of antibiotic resistant bacteria (especially penicillin-resistant Streptococcus pneumoniae) is leading to new approaches to the management of common respiratory infections in the outpatient setting. Additional experience and careful clinical trials are necessary to identify optimal management strategies for these infections.