Treatment and outcome of severe and non-severe acute otitis media

A rapid simultaneous antigen detection of Haemophilus influenzae and Streptococcus pneumoniae for predicting the prognosis of acute otitis media

BACKGROUND

Rapid identification of causative bacteria in treatment of acute otitis media (AOM) is of paramount importance for appropriate antibiotic use.

MATERIALS AND METHODS

This prospective observational study was conducted in 15 hospitals and clinics in Japan between 2018 and 2020. A new rapid antigen test kit (AOS-116), which simultaneously detects antigens for Streptococcus pneumoniae (Sp) and Haemophilus influenzae (Hi), was applied for middle ear fluids (MEFs) and nasopharyngeal secretions (NPSs) in patients with moderate to severe AOM. We investigated relationship between the results of rapid test, severity at initial visit, and clinical course.

RESULTS

Regarding performance accuracy based on culture results, AOS-116 showed 1) high (>80%) sensitivity, specificity, and negative predictive value (NPV) in MEFs for both antigens, 2) high sensitivity, specificity, and positive predictive value (PPV) in NPSs for Hi antigen, and 3) high specificity, and PPV in NPSs for Sp antigen. Regarding predictive value of nasopharyngeal culture and antigen detection for causative middle ear pathogens, similar results were observed between AOS-116 and culture, which was characterized with high sensitivity and NPV for both pathogens. MEFs/NPSs positive for Hi antigen were significantly associated with eardrum findings, and severity. MEFs/NPSs positive for pneumococcal antigen were significantly associated with severity of otalgia, fever, and otorrhea. Among patients with prior antimicrobial treatment, improvement tended to be slower in cases positive for Hi than in cases negative.

CONCLUSION

The rapid antigen detection test is useful as a decision-making tool for prescribing antimicrobial agents and may play an important role in promoting appropriate antimicrobial use.

Sex and Gender Differences in Bacterial Infections

There is a growing awareness of the importance of sex and gender in medicine and research. Women typically have stronger immune responses to self and foreign antigens than men, resulting in sex-based differences in autoimmunity and infectious diseases. In both animals and humans, males are generally more susceptible than females to bacterial infections. At the same time, gender differences in health-seeking behavior, quality of health care, and adherence to treatment recommendations have been reported. This review explores our current understanding of differences between males and females in bacterial diseases. We describe how genetic, immunological, hormonal, and anatomical factors interact to influence sex-based differences in pathophysiology, epidemiology, clinical presentation, disease severity, and prognosis, and how gender roles affect the behavior of patients and providers in the health care system.

Treatment failure in pediatric acute otitis media: How do you define?

INTRODUCTION

Reaching the point of treatment failure in the management of pediatric acute otitis media (AOM) is decision-changing, and is often associated with switching to a broader coverage antibiotic with/without middle ear surgical drainage. Yet, still there is no consensus on the definition of what is treatment failure, which may lead to confusion for clinical decision-making purposes. We sought to review the heterogeneity of treatment failure definitions in AOM.

METHODS

We searched for relevant English language manuscripts using the following key-words: ['otitis media' (OM) or (AOM)] AND ['treatment failure' or 'failure' or 'response failure' or 'response'] AND 'human' in various electronic databases from 1/1/2005 through 10/31/2020.

RESULTS

In the 60 retrieved papers, treatment failure was considered only when antibiotics had been prescribed beforehand, but not when watchful waiting had been adopted. We categorized the manuscripts into 5 major treatment failure definition subgroups, which occasionally overlapped: unimprovement or worsening of symptoms or signs of failure in otoscopy (n = 36), specialist(s) referral or hospital admission (n = 12), changing or adding antibiotic treatment (n = 22), failure to eradicate causative bacteria (n = 7) and failure as perceived by parents (n = 4).

CONCLUSIONS

We suggest a broader definition of AOM treatment failure including physical examination findings and degree of initial treatment response, which will enable an unbiased, uniform comparison of treatments for pediatric AOM.

Improvement in the appropriate antimicrobial usage for treating pediatric acute otitis media in Japan: A descriptive study using nation-wide electronic medical record data

OBJECTIVES

We investigated changes in prescriptions for antimicrobial agents to treat children with acute otitis media (AOM).

METHODS

A descriptive study using an electronic medical record database. Of 199,896 patients enrolled between 2001 and 2019, a total of 10,797 were aged <16 years and had AOM as their first and primary disease (overall pediatric AOM cohort). In addition, 4786 patients with AOM without other comorbidities (pediatric AOM cohort) were included.

RESULTS

In the overall pediatric AOM cohort, the age distribution ranged from 11% to 23% for those younger than 2 years and from 66% to 77% for those younger than 6 years, with no change over time. In the pediatric AOM cohort, the antimicrobial prescription rate was 91% in 2001 but declined to 40% by 2019. Antimicrobial use increased from 0% to 75% for penicillins, whereas use of cephalosporins decreased from 84% to 10%. The prescription rate for acetaminophen alone increased from 33% to 58%. There were no differences in the incidence of adverse reactions among the prescribed antimicrobials.

CONCLUSIONS

Due to education efforts and promotion of the proper use of antimicrobials through means such as the Clinical practice guidelines for the diagnosis and management of acute otitis media in children (2006) and the Manual of Antimicrobial Stewardship (2016), a change in the use of antimicrobials occurred, leading to a trend to more proper use of these agents.

Features predicting treatment failure in pediatric acute otitis media

OBJECTIVES

To facilitate better antibiotic stewardship, we conducted this clinical trial to identify the prognostic features of treatment failure in pediatric acute otitis media (AOM).

STUDY

Design: This is a randomized, parallel-group, open-label, comparative clinical trial.

SUBJECTS AND METHODS

Children with AOM and aged between 1 month and 5 years were enrolled. Patients were randomly assigned to receive either amoxicillin alone (70 mg/kg) for five days, or the same with additional clarithromycin (15 mg/kg) for the initial three days. The clinical course of AOM was evaluated based on tympanic membrane scores. Failure of treatment for AOM was confirmed on day 14. Nasal conditions were also assessed by a clinical scoring system for acute rhinosinusitis.

RESULTS

Treatment failures occurred in 25 out of 129 (19.4%) children. The ratio of treatment failures by age was significantly higher in children younger than 2 years than in children older than 2 years. The tympanic membrane scores on day 3 (P = 0.0334) and day 5 (P < 0.0001) and acute rhinosinusitis scores on day 5 (P = 0.0004) were higher in failure cases than in cured cases. Multivariate logistic regression analysis indicated significant associations between the treatment failure with tympanic membrane scores and acute rhinosinusitis scores on day 5, and the antimicrobial treatment regimen.

CONCLUSIONS

Improvement of acute rhinosinusitis and tympanic membrane scores on day five were important predictive features in failure of treatment for pediatric AOM. These results will be useful when discussing the treatment decisions with the patient's parents.

Inhibitory effects of 2-methacryloyloxyethyl phosphorylcholine polymer on the adherence of bacteria causing upper respiratory tract infection

Objective

We aimed to investigate the inhibitory effect of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer on the adherence of Streptococcus pneumoniae (Spn) and nontypeable Haemophilus influenzae (NTHi) in vitro and in vivo.

Materials and Methods

Phosphorylcholine (PC) expression of 21 strains each of Spn and NTHi was evaluated using fluorescence-activated cell sorting; the adherence of bacteria to Detroit 562 cells and to the nasal mucosa of BALB/c mice was determined. MPC polymer-mediated inhibitory effects were compared with PC-keyhole limpet hemocyanin (PC-KLH)-mediated inhibitory effects.

Results

In vitro experiments showed that pretreatment with MPC polymer markedly inhibited the adherence of Spn and NTHi in a concentration dose–dependent manner independently of PC expression. No correlation was observed between PC expression and MPC polymer-mediated inhibitory effects. Contrarily, there was a significant negative correlation between PC-KLH-mediated inhibitory effects and PC expression in Spn and NTHi. The same results were obtained via in vivo experiments. The MPC polymer did not affect the histology of the nasal mucosa.

Conclusions

MPC polymer might be effective to reduce the occurrence of upper respiratory tract infection caused by Spn and NTHi and could be applied for the development of local treatments, such as topical gargles and nebulizer medications.

Clinical practice guidelines for the diagnosis and management of acute otitis media in children-2018 update

OBJECTIVE

"Clinical Practice Guidelines for the Diagnosis and Management of Acute Otitis Media in Children-2018 update (2018 Guidelines)" aim to provide appropriate recommendations about the diagnosis and management of children with acute otitis media (AOM), including recurrent acute otitis media (recurrent AOM), in children under 15 years of age. These evidence-based recommendations were created with the consensus of the subcommittee members, taking into consideration unique characteristics of bacteriology and antimicrobial susceptibilities of AOM pathogens in Japan, as well as global advances in vaccines.

METHODS

The subcommittee re-evaluated key clinical issues based on SCOPE (a master plan of the guidelines) and created clinical questions (CQ) about the diagnosis and management of AOM patients. A literature search of the publications from 2013 to 2016 were added to the Guidelines 2013, not only to assess the evidence on the effectiveness of vaccines, but also to provide up to date information of the bacteriology and antimicrobial susceptibilities of AOM causative pathogens in Japan.

RESULTS

We have proposed guidelines for disease severity-based management of AOM patients, after classifying AOM severity into mild, moderate, and severe, based on age, clinical manifestations, and otoscopic findings.

CONCLUSIONS

Precise otoscopic findings are essential for judging AOM severity, which can lead to appropriate management of AOM patients.

Updated Guidelines for the Management of Acute Otitis Media in Children by the Italian Society of Pediatrics: Diagnosis

BACKGROUND

In recent years, new progress has been made regarding the diagnosis, treatment and prevention of acute otitis media (AOM). The Italian Pediatric Society therefore decided to issue an update to the previous guidelines published in 2010.

METHODS

Literature searches were conducted on MEDLINE by Pubmed, including studies in children, in English or Italian, published between January 1, 2010, and December 31, 2018. The quality of the included studies was assessed using the grading of recommendations, assessment, development and evaluations (GRADE) methodology. In particular, the quality of the systematic reviews was evaluated using the AMSTAR 2 appraisal tool. The guidelines were formulated using the GRADE methodology by a multidisciplinary panel of experts.

RESULTS

The diagnosis of AOM is based on acute clinical symptoms and otoscopic evidence; alternatively, the presence of otorrhea associated with spontaneous tympanic membrane perforation allows the AOM diagnosis. The diagnosis of AOM must be certain and the use of a pneumatic otoscope is of fundamental importance. As an alternative to the pneumatic otoscope, pediatricians can use a static otoscope and a tympanometer. To objectively establish the severity of the episode for the formulation of a correct treatment program, an AOM severity scoring system taking into account clinical signs and otoscopic findings was developed.

CONCLUSIONS

The diagnosis of AOM is clinical and requires the introduction of specific medical training programs. The use of pneumatic otoscopes must be promoted, as they are not sufficiently commonly used in routine practice in Italy.

Sex Bias in Asthma Prevalence and Pathogenesis

Sex-related differences in asthma prevalence are well established and change through the reproductive phases of life. As children, boys have increased prevalence of asthma compared to girls. However, as adults, women have increased prevalence of asthma compared to men. Many factors, including genetics, environment, immunological responses, and sex hormones, affect the sex disparity associated with the development and control of asthma and other allergic diseases. Fluctuations of hormones during puberty, menstruation, pregnancy, and menopause, alter asthma symptoms and severity. In this article, we review clinical and epidemiological studies that examined the sex disparity in asthma and other allergic diseases as well as the role of sex hormones on asthma pathogenesis.

Remote evaluation of video-otoscopy recordings in an unselected pediatric population with an otitis media scale

BACKGROUND

A recently validated image-based grading scale for acute otitis media (OMGRADE) can be used to assess tympanic membrane (TM) status. The aim of this study was to evaluate the validity and reliability of this scale for remote assessments of TM status using video-otoscopy recordings in an unselected pediatric population.

METHOD

Children 2-16 years attending a South African primary health clinic were offered an ear examination by an otologist using otomicroscopy. An ear and hearing telehealth facilitator then made video-otoscopy recordings (9-33s) of the ears and uptakes were uploaded to a secure server for remote assessments in Sweden by an otologist and general practitioner at four- and eight-weeks post onsite assessment. TM appearance was judged according to the OMGRADE scale. Concordance between onsite otomicroscopy and asynchronous assessments of video-otoscopy recordings was calculated together with intra- and inter-rater agreements.

RESULTS

One hundred and eighty ears were included. Concordance of TM classifications using the OMGRADE scale was found to be substantial (weighted kappa range 0.66-0.79). Intra- and inter-rater agreement (test-retest) was found to be substantial to almost perfect (weighted kappa range 0.85-0.88 and 0.69-0.72, respectively).

CONCLUSION

The OMGRADE scale can be used to accurately assess the normal TM and secretory otitis media (SOM) remotely using video-otoscopy recordings in an unselected pediatric population.

Development and validation of a new grading scale for otitis media

BACKGROUND

Grading of acute otitis media (AOM) is important in clinical situations as well as in research. Current grading scales for AOM have used a 6 to 9 point scoring system primarily based on variation of redness and bulging of the tympanic membrane (TM). This study aimed to develop and validate a new scale for grading AOM.

METHOD

The scale was developed in 3 stages based on 32 patients with images taken of the TM when a child attended healthcare centre with othalgia and at follow-up visits. Content validity was used as the method for the first 2 stages. An expert panel reviewed the scale and repeated the process on a revised scale. Reliability was tested with a different expert panel that used the final scale on a sample of TM images in a test-retest and inter-rater and intra-rater agreements were calculated.

RESULTS

The scale was developed in 3 steps using expert committees. During the process the description of vascularization was judged to be of insufficient importance for our scale. Inter-rater agreement was moderate (κ = 0.52) and intra-rater agreement was good (κ = 0.66 to 0.89) in the test-retest of the final scale.

CONCLUSIONS

The developed AOM image-based grading scale demonstrates substantial inter- and intra-rater reliability with potential use in clinical research and telemedicine applications. Furthermore, the parameter "redness of TM" is of less importance in our scale as compared with other available grading systems.

Korean clinical practice guidelines: otitis media in children

Acute otitis media (AOM) and otitis media with effusion (OME) are common infections in children, and their diagnosis and treatment have significant impacts on the health of children and the costs of providing national medical care. In 2009, the Korean Otologic Society organized a committee composed of experts in the field of otolaryngology, pediatrics, and family medicine to develop Korean clinical practice guidelines (CPG) for otitis media in children with the goal of meeting regional medical and social needs in Korea. For this purpose, the committee adapted existing guidelines. A comprehensive literature review was carried out primarily from 2004 to 2009 using medical search engines including data from Korea. A draft was written after a national questionnaire survey and several public audits, and it was editorially supervised by senior advisors before publication of the final report. These evidence-based guidelines for the management of otitis media in children provide recommendations to primary practitioners for the diagnosis and treatment of children younger than 15 yr old with uncomplicated AOM and OME. The guidelines include recommendations regarding diagnosis, treatment options, prevention and parent education, medical records, referral, and complementary/alternative medicine for treating pediatric otitis media.

A review of the burden of disease due to otitis media in the Asia-Pacific

OBJECTIVE

The burden of disease due to otitis media (OM) in Asia Pacific countries was reviewed to increase awareness and raise understanding within the region.

METHODS

Published literature and unpublished studies were reviewed.

RESULTS

In school-age children, OM prevalence varied between 3.25% (Thailand) and 12.23% (Philippines) being highest (42%) in Aboriginal Australian children. OME prevalence at school age varied between 1.14% (Thailand) and 13.8% (Malaysia). Higher prevalence was reported in children with hearing impairment, HIV, pneumonia and rhinitis. CSOM prevalence was 5.4% in Indonesia (all ages), 15% in Aboriginal Australian children and 2-4% in Thailand, Philippines, Malaysia and Vietnam (WHO estimate). OM prevalence/incidence and service utilisation were highest in children 2-5 years of age. The disease burden was substantially higher in Pacific Island children living in New Zealand (25.4% with OME), and was highest in indigenous Australians (>90% with any OM). Streptococcus pneumoniae and Haemophilus influenzae dominated as primary causes of AOM in all studies. Few studies examined pneumococcal serotype distribution. Health-related cost estimates for OM, when available, were substantial. In developing countries, significant investment is needed to provide facilities for detection and treatment of ear disease in children, if long term hearing deficits and other sequelae are to be prevented.

CONCLUSION

The available evidence suggests an important burden of disease and economic cost associated with OM in most Asia Pacific countries and a potential benefit of prevention through vaccination. Large, prospective community-based studies are needed to better define the prevalence of ear disease in children, and to predict and track pneumococcal conjugate vaccine impacts. AOM prevention through vaccination may also provide a means of reducing antibiotic use and controlling antibiotic-resistant disease in children. This review highlights the need for additional research, and provides a basis on which to build and develop regional guidelines for OM management.

A challenge to appropriate antibiotic use in children with respiratory infections: a 5-year single-institution experience

BACKGROUND

We have studied the rate of emergence of antibiotic-resistant Streptococcus pneumoniae (S. pneumoniae) and Haemophilus influenzae (H. influenzae) and the subsequent antibiotic use in host patients of those isolates at the Department of Pediatrics, Soma General Hospital, Fukushima. Moreover, we carried out several studies investigating the risks and benefits of antibiotic-free treatment for children with respiratory infections. In this report, we summarize our research and suggest better treatment options for pediatric patients with respiratory infections.

METHODS

We investigated the necessity of antibiotic use in the treatment of pediatric inpatients with respiratory syncytial virus (RSV) infection, and tested our hypothesis that antibiotic-free treatment for common cold will reduce the number of resistant S. pneumoniae strains in the pediatric nasopharynx. Therefore, we restricted prescribing antibiotics for pediatric patients with respiratory infections. The rates of resistant S. pneumoniae and H. influenzae and the medication history of the host patients before and after the intervention were compared.

RESULTS

We found that most of the RSV-infected patients recovered without antibiotic treatment, and that the antibiotic-free treatment inhibited the emergence of antibiotic-resistant strains. The rate of penicillin-resistant S. pneumoniae decreased but the rate of ampicillin-resistant H. influenzae did not change significantly during the study.

CONCLUSION

We concluded that patients with respiratory infections can be treated without antibiotics, under careful examination and observation. Continued monitoring of such new interventions as well as recommending their use to other caregivers and physicians will help inhibit the spread of resistant strains.

Long-term follow-up of chronic suppurative otitis media in a high-risk children cohort

OBJECTIVE

Chronic suppurative otitis media (CSOM) is the leading cause of mild to moderate hearing impairment in children worldwide and a major public health problem in many indigenous populations. There is a lack of basic epidemiological facts and knowledge on the development of CSOM, as the disease primarily affects developing countries where research capacities often are limited. The purpose of this study was to determine the long-term outcome of CSOM in a high-risk population and to identify risk factors.

METHODS

Follow-up study (2008) on a population-based cohort of 465 children in Greenland, initially examined (1996-8) between the ages 0 and 4 years. Follow-up was attempted among 307 children living in the two major towns. Binomial logistic regression analysis was made to identify risk factors for developing CSOM and for maintaining disease in to adolescence (odds ratios). Log linear binomial regression was used to estimate risk ratios and absolute risks.

RESULTS

At follow-up 236 participated (77% of those available). The prevalence of CSOM was 32/236 (14%) at age group 0-4 years and 21/236 (9%) at age group 11-15 years. Thirteen had disease debut after the initial study. Of those with CSOM in the initial study 24/32 (75%) healed spontaneously. Risk factors for the development of CSOM at any time in childhood was the mother's history of CSOM OR 2.55 (95% CI 1.14-5.70; p=0.02), and mothers with low levels of schooling OR 1.57 (1.03-2.40; p=0.04). Once CSOM had developed boys were more likely to have persistent disease OR 5.46 (95% CI 1.47-20.37; p=0.01). The absolute risk of CSOM if the mother had both a history of CSOM and low schooling was for boys 45.4% (95% CI 26.5-77.7) and for girls 30.7% (95% CI 17.8-53.10). The cumulative risk of CSOM was 19% at follow-up.

CONCLUSIONS

Even though a large number of CSOM cases seemed to heal spontaneously, the prevalence of untreated CSOM among school-age children in Greenland remained high as new cases were found at follow-up. Increased focus on prevention and identification of children at special risk could reduce the high prevalence of CSOM.

Association between the use of antibiotics in the first year of life and pediatric inflammatory bowel disease

OBJECTIVES

The development of commensal flora in infants has been shown to be sensitive to antibiotic use. Altered intestinal flora is thought to contribute to the etiology of inflammatory bowel disease (IBD), an idiopathic chronic condition. We aimed to determine if early use of antibiotics was associated with the development of IBD in childhood.

METHODS

Nested case-control analysis of the population-based University of Manitoba Inflammatory Bowel Disease Epidemiologic Database was carried out. IBD status was determined from a validated administrative database definition. A total of 36 subjects diagnosed between 1996 and 2008 were matched to 360 controls, on the basis of age, sex, and geographic region. Antibiotic data were drawn from the Manitoba Drug Program Information Network, a comprehensive population-based database of all prescription drugs for all Manitobans dating back to 1995. Antibiotic use in the first year of life was compared between IBD cases and controls.

RESULTS

The mean age at IBD diagnosis was 8.4 years. Twenty-one cases (58%) had one or more antibiotic dispensations in their first year of life compared with 39% of controls. Crohn's disease was diagnosed in 75% of IBD cases. Those receiving one or more dispensations of antibiotics were at 2.9 times the odds (95% confidence interval: 1.2, 7.0) of being an IBD case.

CONCLUSIONS

Subjects diagnosed with IBD in childhood are more likely to have used antibiotics in their first year of life.

[A clinical study of acute mastoiditis and mastoid lesions associated with pediatric otitis media]

Increased otitis media rendering acute mastoiditis and mastoid lesions severe or intractable appear to be related to dominant drug-resistant strains and the dissemination of nursery school attendance. Acute mastoiditis involves middle-ear inflammation spreading to the antrum mastoideum and accompanied by subcutaneous abscess. This emergency condition risks progression to subperiosteal abscess and meningitis. Mastoid cavity opacity in computed tomography (CT) scan often occurs with recurrent or intractable otitis media similar to that with mastoiditis. Four of the 8 cases of mastoiditis we treated were infant in whom upper respiratory tract pneumococcus and group A streptococcus were detected. Treatment involved antibiotics and myringotomy in all cases and surgery in two. Nine of the 10 cases of mastoid lesions with otitis media we saw were infant. All had pneumococcus detected, with accociated sinusitis.

Nontypeable Haemophilus influenzae isolated from intractable acute otitis media internalized into cultured human epithelial cells

OBJECTIVES

The aim of this study is to examine the internalization of nontypeable Haemophilus influenzae (NTHi) into human epithelial cells.

METHODS

Bactericidal assay was applied to examine the effects of antibiotics against cell-adherent NTHi using HEp-2 cells. A trans-well chamber assay was applied to examine the internalization and penetration of NTHi using Detroit562 cells.

RESULTS

The adherence of NTHi to HEp-2 cells was noted after 2h of incubation. Azithromycin had a strong bactericidal effect against both cell-associated and non-adherent NTHi, while ceftriaxone did not show bactericidal effects on NTHi adhered to the HEp-2 cells. Three (60.0%) out of five NTHi isolates from the nasopharynx of children with intractable acute otitis media (AOM) internalized into and subsequently penetrated through the epithelial cells at various degrees. Azithromycin had a strong bactericidal effect against the cell-internalized NTHi, while ceftriaxone was bactericidal only against extracellular NTHi.

CONCLUSION

The potential of NTHi as the intracellular pathogen may contribute to the persistent existence of this pathogen that result in the prolonged and intractable clinical course of AOM. Azithromycin may be a therapeutically significant antibiotic for patients with prolonged respiratory tract infections due to NTHi.

Formation of biofilm by Haemophilus influenzae isolated from pediatric intractable otitis media

OBJECTIVES

The aims of this study are to evaluate biofilm formation by nontypeable Haemophilus influenzae (NTHi) isolated from children with acute otitis media (AOM) and its relation with clinical outcome of the disease.

METHODS

Biofilm formations by NTHi clinical isolates from pediatric AOM patients were evaluated by a crystal violet microtiter plate and a 98 well pin-replicator assay with a confocal laser scanning microscopy (CLSM). Optical density values of clinical isolates were compared with a positive control and the ratio of clinical isolates to a positive control was defined as biofilm formation index (BFI).

RESULTS

84.3% clinical isolates of NTHi were biofilm forming strains (BFI> or =0.4). The BFI represented the levels of biofilm formation and adherence on the surface. The identical strains isolated from both middle ear fluids (MEFs) and nasopharynx showed biofilm formation at the same level. The prevalence of biofilm forming isolates was significantly higher among the susceptible strains than resistant strains. The level of biofilm formation of NTHi isolated from AOM cases who was not improved by amoxicillin (AMPC) was significantly higher than that of NTHi isolated from AOM cases who was improved by AMPC.

CONCLUSION

We clearly showed the biofilm formation of clinical NTHi isolates from AOM children. In addition, the biofilm formed by NTHi would play an important role in persistent or intractable clinical course of AOM as a result of lowered treatment efficacy of antibiotics.

Detection of respiratory viruses in nasopharyngeal secretions and middle ear fluid from children with acute otitis media

CONCLUSIONS

Our results suggest that various respiratory viruses contribute to the pathogenesis of acute otitis media (AOM).

OBJECTIVE

AOM is one of the most common complications of viral upper respiratory tract infections in children. Recently, the importance of respiratory viruses has been stressed as causative agents of AOM.

SUBJECTS AND METHODS

A total of 1092 children < or =10 years old (average age 1.38 years) diagnosed as having AOM between 2002 and 2004 were studied. Bacterial and viral cultures of both nasopharyngeal secretions (NPS) and middle ear fluid (MEF) were performed for all 1092 children. Body temperature, changes of the tympanic membrane, and the number of days from the onset of illness were analyzed.

RESULTS

Respiratory viruses were detected in 360 of 1092 NPS specimens, including 157 isolates of respiratory syncytial virus and 88 of influenza virus. Among 1092 MEF specimens, 102 were virus-positive, including 43 for respiratory syncytial virus and 29 for influenza virus. In 75 children, respiratory viruses were only detected in MEF. The viral detection rate was higher in children with fever at an early stage of their illness. The tympanic membrane changes associated with viral infection tended to be less severe, while changes were more severe in cases with bacterial infection, especially co-infection with bacteria and viruses.

Age inconsistency in the American Academy of Pediatrics guidelines for acute otitis media

OBJECTIVE

The American Academy of Pediatrics acute otitis media guidelines could reduce antibiotic use. The objective was to compare strategies for diagnosing and treating otitis: (1) a commonly used, 2-criteria strategy, (2) the guidelines' 3-criteria algorithm, and (3) initially watching without antibiotics.

METHODS

A decision analysis was performed with literature-based parameter. The target population was children presenting to primary care physicians with possible otitis media. Main outcomes were antibiotic use, sick days, mild adverse drug events, and number needed to treat/avoided sick day.

RESULTS

For children 2 to <6 months of age, compared with the 2-criteria strategy, guideline use predicted 21% less antibiotic use, 13% more sick days, and 23% fewer adverse drug events; the number needed to treat for the 2-criteria strategy versus the American Academy of Pediatrics strategy was 1.2 children per avoided sick day. For children 6 to <24 months of age, guideline use, compared with the 2-criteria strategy, predicted 26% less antibiotic use, 14% more sick days, and 28% fewer adverse drug events; the number needed to treat for the 2-criteria strategy versus the American Academy of Pediatrics strategy was 1.4 children per avoided sick day. For children >2 years of age, guideline use, compared with the 2-criteria strategy, predicted 67% less antibiotic use, 4% more sick days, and 68% fewer adverse drug events. The number needed to treat for the guideline strategy versus the watch strategy was 6.3 children per avoided sick day; that for the 2-criteria strategy versus the guideline strategy was 12.3. Guideline use for children <2 years implies that our number needed to treat to avoid a sick day is <1.4; for children >2, guideline use implies we are willing to treat at least 6.3 children to avoid a sick day. Thus, the guidelines imply a greater willingness to treat older children, compared with younger children.

CONCLUSIONS

The American Academy of Pediatrics guidelines are inconsistent in their outcomes across age groups. Guideline implementation under age 2 reduces antibiotic use but at a relatively heavy cost of sick days and parental missed work days. This trade-off may be particularly unfavorable for working parents, who might reasonably prefer greater antibiotic use.

Valuing reduced antibiotic use for pediatric acute otitis media

OBJECTIVE

The 2004 American Academy of Pediatrics acute otitis media guidelines urge parents to weigh the benefits of reduced antibiotic use, adverse drug events, and future resistance versus risks of extra costs and sick days resulting from guideline use. The value of decreased antibiotic resistance has not been quantified. The objective was to perform cost-utility analysis, estimating the resistance value of implementing the guidelines for acute otitis media treatment for children <2 years of age. Outcomes were described with a common denominator and the value of avoiding resistance was estimated using a parental perspective.

METHODS

Decision analysis results were used for outcome probabilities. Published utilities were used to describe outcomes in quality-adjusted life-day units. The minimum resistance benefit value, where the benefits of the American Academy of Pediatrics guidelines would at least balance their costs, was defined as the guidelines' incremental costs minus their other benefits.

RESULTS

For a child 2 to <6 months of age presenting to a primary care physician with possible otitis media, parents would need to value the resistance benefit at 0.77 quality-adjusted life-days per antibiotic prescription avoided for the guidelines' benefits to balance their costs. For the 6- to <24-month-old group, results were 0.67 quality-adjusted life-days per prescription avoided. Results were sensitive to the dollar cost utility; when willingness to pay ranged from $20,000 to $200,000 per quality-adjusted life-year, results ranged from 0.36 and 0.30 quality-adjusted life-days up to 4.10 and 3.57 quality-adjusted life-days for the 2- to <6-month-old and 6- to <24-month-old groups, respectively. Costs were driven by missed parent work days.

CONCLUSIONS

From a societal perspective, trading 0.30 to 4 quality-adjusted life-days to avoid 1 antibiotic course might be desirable; from a parental perspective, this may not be as desirable. Parent demand for antibiotics may be rational when driven by the value of parent time. Other approaches that have the potential to reduce antibiotic use, such as wider use of influenza vaccine and improved rapid viral diagnostic techniques, might be more successful.

Sex differences in the incidence and severity of respiratory tract infections

Sex is a significant epidemiological factor for several diseases. However, the role of sex in the development and outcome of various infections has not been extensively studied with the notable exception of urinary tract infections. We searched in the PubMed database to identify articles that could provide relevant data regarding sex differences in the incidence and severity of respiratory tract infections (RTIs). We extracted data from 84 relevant studies that provided information regarding sex differences in the incidence and severity of RTIs. Females are more commonly affected with infections of the upper respiratory tract, specifically sinusitis, tonsillitis, and otitis externa. On the other hand, males are more commonly affected with otitis media, croup, and most important, lower RTIs. It is also evident from the reviewed evidence that the course of most RTIs is more severe in males than in females, leading to higher mortality in males, especially in community-acquired pneumonia. In conclusion, the available data suggest that males are more susceptible than females to most types of RTIs in all age groups (adults and children). Overall, it seems that males develop RTIs more frequently than females, except for sinusitis, otitis externa, and probably tonsillitis. Anatomic, lifestyle, behavioural, and socioeconomic differences between males and females may explain the observed findings. The role of sex hormones in the regulation of the immune system may also contribute to the reported sex differences in the incidence and severity of the various types of RTIs, especially in adolescents and adults.

What is new in otitis media?

The "wait and see" approach in acute otitis media (AOM), consisting of postponing the antibiotic administration for a few days, has been advocated mainly to counteract the increased bacterial resistance in respiratory infections. This approach is not justified in children less than 2 years of age and this for several reasons. First, AOM is an acute inflammation of the middle ear caused in about 70% of cases by bacteria. Redness and bulging of the tympanic membrane are characteristic findings in bacterial AOM. Second, AOM is associated with long-term dysfunction of the inflamed eustachian tube (ET), particularly in children less than 2 years of age. In this age group, the small calibre of the ET together with its horizontal direction result in impaired clearance, ventilation and protection of the middle ear. Third, recent prospective studies have shown poor long-term prognosis of AOM in children below 2 years with at least 50% of recurrences and persisting otitis media with effusion (OME) in about 35% 6 months after AOM. Viruses elicit AOM in about 30% of children. A prolonged course of AOM has been observed when bacterial and viral infections are combined because viral infection is also associated with ET dysfunction in young children. Bacterial and viral testing of the nasopharyngeal aspirate is an excellent tool both for initial treatment and recurrence of AOM. Antibiotic treatment of AOM is mandatory in children less than 2 years of age to decrease inflammation in the middle ear but also of the ET particularly during the first episode. The best choice is amoxicillin because of its superior penetration in the middle ear. Streptococci pneumoniae with intermediary bacterial resistance to penicillin are particularly associated with recurrent AOM. Therefore the dosage of amoxicillin should be 90 mg/kg per day in three doses. In recurrent AOM with beta-lactamase-producing bacilli, amoxicillin should be associated with clavulanic acid at a dose of 6.4 mg/kg per day. The duration of the treatment is not established yet but 10 days is reasonable for a first episode of AOM. OME may be a precursor initiating AOM but also a complication thereof. OME needs a watchful waiting approach. When associated with deafness for 2-3 months in children over 2 years of age, an antibiotic should be given according to the results of the bacterial resistance in the nasopharyngeal aspirate. The high rate of complications of tympanostomy tube insertion outweighs the beneficial effect on hearing loss. The poor results of this procedure are due to the absence of effects on ET dysfunction. Pneumococcal vaccination has little beneficial effects on recurrent AOM and its use in infants needs further studies. Treatment with amoxicillin is indicated in all children younger than 2 years with a first episode of AOM presenting with redness and bulging of the tympanic membrane. Combined amoxicillin and clavulanic acid should be given in patients with beta-lactamase-producing bacteria. The duration of treatment is estimated to be at least 10 days depending on the findings by pneumo-otoscopy and tympanometry. Bacterial and viral testing of the nasopharyngeal aspirate is highly recommended particularly in children in day care centres as well as for regular follow-up. The high recurrence rate is due to the long-lasting dysfunction of the eustachian tube and the immune immaturity of children less than 2 years of age.

The value of nasopharyngeal culture in predicting the etiology of acute otitis media in children less than two years of age

BACKGROUND

In selecting treatment of acute otitis media (AOM), knowledge of its etiology would be valuable. We revisited the possibility to use the nasopharyngeal culture of Streptococcus pneumoniae (Pnc) and Haemophilus influenzae (Hi) for predicting their presence in the middle ear fluid (MEF) during AOM.

METHODS

The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of bacterial culture of the nasopharyngeal aspirate (NPA) in predicting the presence of the same pathogen in the MEF were assessed during AOM events among children followed from 2 to 24 months of age.

RESULTS

The data comprised 586 AOM events. For Pnc, the sensitivity and NPV were high, 99% (95% confidence interval = 95-100%) and >99% (97-100%), respectively. The specificity and PPV were relatively low, 63% (57-68%) and 50% (43-56%). For Hi, the sensitivity and the NPV were lower (77%, 69-83% and 93%, 90-95%) than for Pnc, but the specificity and the PPV were higher (88%, 85-91% and 64%, 56-71%). The quantity of Pnc and Hi in the NPA was clearly related to their presence in the MEF. If both Pnc and Hi were found in the nasopharynx, Hi was more likely cultured from MEF.

CONCLUSION

Together with clinical and epidemiologic features of AOM, the nasopharyngeal culture can be helpful in selecting specific antimicrobial therapy.

Efficacy of a novel oral carbapenem, tebipenem pivoxil (TBM-PI), against experimental otitis media caused by penicillin resistant Streptococcus pneumoniae in chinchilla

An animal model of otitis media using chinchillas was developed to evaluate the efficacy of tebipenem pivoxil (TBM-PI) against experimental otitis media. Chinchillas inoculated via the transbullar approach with Streptococcus pneumoniae serogroup 6 were included in the efficacy study with TBM-PI, amoxicillin (AMX) or untreated as controls. TBM-PI resulted in survival rate of 83%, compared with 25% survival for AMX and 0% survival for controls (p<0.01). Quantitative cultures in the middle ear effusions at day 5 of the TBM-PI group yielded 3.5+/-2.4log(10)CFUs/ml. TBM-PI is a promising antibiotic for the treatment of acute otitis media.

High Prevalence of Streptococcus pneumoniae with Mutations in pbp1a, pbp2x, and pbp2b Genes of Penicillin-Binding Proteins in the Nasopharynx in Children in Japan

OBJECTIVE

To evaluate the resistances of Streptococcus pneumoniae to beta-lactams developed by stepwise alterations in high-molecular-weight penicillin-binding proteins (PBPs) with a reduced binding affinity of beta-lactams. Among the numerous mutations in pbp genes that alter the affinity for beta-lactams, the decreased affinity of PBP1A, 2X and 2B is especially important in the development of resistances to beta-lactams.

STUDY DESIGN

Retrospective review.

METHODS

In this study, we investigated the mutations in pbp1a, pbp2x, and pbp2b genes evaluated by polymerase chain reaction (PCR) in 866 pneumococcal isolates collected from the nasopharynx of Japanese children with acute otitis media.

RESULTS

210 strains (24.3%) exhibited no mutations in the three pbp genes. 333 strains (38.5%) had mutations in the three pbp genes, 78 (9.0%) in two pbp genes, whereas 245 (28.3%) displayed mutations in only one pbp gene. Among the 656 strains with mutations in pbp genes, 620 (94.5%) strains had mutations in pbp2x. The annual prevalence of antimicrobial-resistant S. pneumoniae showed a gradual increase in strains with mutations in the three pbp genes and a parallel decrease in strains without mutations.

CONCLUSIONS

PCR-based genotyping can characterize the antimicrobial resistances in pneumococci along with minimal inhibitory concentrations (MICs). Physicians should pay attention to the recent increase in antimicrobial-resistant S. pneumoniae when treating pediatric acute otitis media.

Antimicrobial resistance of Haemophilus influenzae isolated from the nasopharynx of Japanese children with acute otitis media

CONCLUSION

A high prevalence of penicillin-binding protein gene-mutated (PGM) strains of Haemophilus influenzae should be taken into account when treating otitis media in children.

OBJECTIVE

To evaluate the prevalence of beta-lactamase-non-producing ampicillin-resistant strains of H. influenzae with mutations in the ftsI gene encoding penicillin-binding protein 3 (PBP3) among children with otitis media.

MATERIAL AND METHODS

A total of 644 nasopharyngeal isolates of H. influenzae were collected from pediatric acute otitis media patients with or without otitis media with effusion at the clinics of the Department of Otolaryngology-Head and Neck Surgery, Wakayama Medical University Hospital and 6 affiliated hospitals in Wakayama Prefecture between January 1999 and December 2003. MICs to ampicillin (AMP), cefdinir (CFD), cefaclor (CCL), cefpodoxime (CPD) and cefcapene (CFPN) were determined by a microbroth dilution method according to the recommendations of the National Committee for Clinical Laboratory Standards. Types of mutations in the PBP3 gene (ftsI) were evaluated by means of a polymerase chain reaction (PCR)-based genotyping method. The beta-lactamase gene (bla) was also identified by means of PCR.

RESULTS

Beta-lactamase-producing (BLP) strains having the bla gene were identified in 16 isolates (2.5%). PGM strains were identified in 279 isolates (43.3%). There were 242 PGM1-non-BLP strains (37.6%) with mutations in the variable mutated locus of ftsI, 35 PGM2-non-BLP strains (5.4%) with mutations in the highly mutated locus of ftsI and 2 BLP-PGM strains (0.3%) with mutations in ftsI that produced beta-lactamase. BLP-non-PGM strains producing beta-lactamase without mutations in ftsI were identified in 14 isolates (2.2%). MICs of PGM1-non-BLP strains to AMP were 0.5-2.0 microg/ml. The MIC90 of CDN to the PGM1-non-BLP strains was the lowest (0.06 microg/ml). The proportion of PGM1-non-BLP strains increased rapidly during 1999-2002 and then decreased in 2003. In contrast, the proportion of PGM2-non-BLP strains increased in 2003.

Antimicrobial resistance in Haemophilus influenzae isolated from the nasopharynx among Japanese children with acute otitis media

CONCLUSION

High prevalence of penicillin-binding protein (PBP) gene mutated (PGM) strains of H. influenzae should be taken into account when treating otitis media in children.

OBJECTIVE

To evaluate prevalence of ss-lactamase nonproducing ampicillin-resistant (BLNAR) strains of Haemophilus influenzae with mutations in ftsI gene encoding penicillin-binding protein 3 (PBP3) among children with otitis media.

METHODS

A total of 644 nasopharyngeal isolates of H. influenzae was collected from pediatric acute otitis media (AOM) patients with or without otitis media with effusions (OME) at the clinics of Otolaryngology-Head and Neck Surgery, Wakayama Medical University Hospital and six affiliated hospitals in Wakayama prefecture between January 1999 and December 2003. Minimal inhibitory concentrations (MICs) of ampicillin (AMP), cefditoren (CDN), cefdinir (CFD), cefaclor (CCL), cefpodoxime (CPD), and cefcapene (CFPN) were determined by the microbroth dilution method according to the recommendations of the National Committee for Clinical Laboratory Standards (NCCLS). Types of mutations in PBP3 gene (ftsI) were evaluated by a polymerase chain reaction (PCR)-based genotyping method. ss-Lactamase gene (bla) was also identified by PCR.

RESULTS

ss-Lactamase-producing (BLP) strains with the bla gene were identified in 16 (2.5%) of isolates. PGM strains were identified in 279 (43.3%) isolates. There were 242 (37.6%) PGM1-nonBLP strains with mutations in variable mutated locus of ftsI, 35 (5.4%) PGM2-nonBLP strains with mutations in highly mutated locus of ftsI, 2 (0.3%) BLP-PGM strains with mutations in ftsI and producing ss-lactamase. BLP-nonPGM strains producing ss-lactamase without mutations in ftsI were identified in 14 (2.2%) isolates. MICs of PGM1-nonBLP strains to AMP were 0.5-2.0 microg/ml. The MIC(90) of CDN to the PGM1-nonBLP strains was lowest (0.06 microg/ml). Proportions of PGM1-nonBLP strains rapidly increased during 1999 to 2002 and then decreased in 2003. In contrast, PGM2-nonBLP strains increased in 2003.

Study of nasopharyngeal bacterial flora. Second report. Variations in nasopharyngeal bacterial flora in children aged 6 years or younger when administered antimicrobial agents. Part 2

This report focuses on changes in the nasopharyngeal bacterial flora before and after administration of antimicrobial agents in 172 cases of acute upper respiratory infection in patients aged 6 years or younger. The antimicrobial agents administered were amoxicillin (AMPC) (34%), clavulanic acid/amoxicillin compound (11%), cefditren pivoxil (CDTR-PI) (43%), and others (12%). Changes in nasopharyngeal bacterial flora were investigated with reexaminations conducted after 2-5 days (day 2-5 subgroup), 6-10 days (day 6-10 subgroup), and 11 days and thereafter. There was a significant reduction in the Streptococcus pneumoniae detected in the group administered AMPC (AMPC group) in the day 2-5 subgroup and the day 6-10 subgroup. There was also a significant decrease in H. influenzae in the group administered CDTR-PI (CDTR-PI group) in the day 2-5 subgroup. From this it was inferred that for the most part significant changes in infectious nasopharyngeal bacteria occurred in the day 2-5 subgroups. However, a significant improvement in the degree of inflammation, as indicated by leukocyte infiltration images for the AMPC group, was observed in the day 2-5 subgroup, and for the CDTR-PI group in the day 6-10 subgroup. On the other hand, in both the antimicrobial agent groups, S. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were newly detected at reexamination. Furthermore, a difference in the incidence of these bacteria was observed between the 2 antimicrobial agent groups. It was suggested that such phenomena related to the survival of resistant strains or a recurrence otitis media.