Effect of viral respiratory tract infection on outcome of acute otitis media

Respiratory and Gut Microbiome Modification during Respiratory Syncytial Virus Infection: A Systematic Review

BACKGROUND

Respiratory syncytial virus (RSV) infection is a major cause of lower respiratory tract infection, especially in infants, and increases the risk of recurrent wheezing and asthma. Recently, researchers have proposed a possible association between respiratory diseases and microbiome alterations. However, this connection has not been fully established. Herein, we conducted a systematic literature review to evaluate the reported evidence of microbiome alterations in patients with RSV infection.

METHODS

The systematic literature review on the association between RSV and microbiome in humans was conducted by searching PubMed, EMBASE, Scopus, and CINAHL from 2012 until February 2022. The results were analyzed qualitatively, focusing on the relationship between microbiome and RSV infection with available key microbiome-related parameters.

RESULTS

In the 405 articles identified by searching databases, 12 (Respiratory tract: 9, Gut: 2, Both: 1) articles in line with the research aims were eligible for this qualitative review. The types of samples for the respiratory tract microbiome and the sequencing methods utilized varied from study to study. This review revealed that the overall microbial composition in both the respiratory tract and gut in RSV-infected patients was different from that in healthy controls. Our generated results demonstrated an increase in the abundance of Haemophilus and Streptococcus, which could contribute to the distinctive separation based on the beta diversity in the respiratory tract.

CONCLUSIONS

The respiratory tract and gut microbiome changed in patients with RSV infection. Further research with a well-organized longitudinal design is warranted to clarify the impact of microbiome alterations on disease pathogenesis.

Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media (AOM) is one of the most common diseases in childhood for which antibiotics are commonly prescribed; a systematic review reported a pooled prevalence of 85.6% in high-income countries. This is an update of a Cochrane Review first published in the Cochrane Library in 1997 and updated in 1999, 2005, 2009, 2013 and 2015.

OBJECTIVES

To assess the effects of antibiotics for children with AOM.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Current Contents, CINAHL, LILACS and two trial registers. The date of the search was 14 February 2023.

SELECTION CRITERIA

We included randomised controlled trials comparing 1) antimicrobial drugs with placebo, and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened trials for inclusion and extracted data using the standard methodological procedures recommended by Cochrane. Our primary outcomes were: 1) pain at various time points (24 hours, two to three days, four to seven days, 10 to 14 days), and 2) adverse effects likely to be related to the use of antibiotics. Secondary outcomes were: 1) abnormal tympanometry findings, 2) tympanic membrane perforation, 3) contralateral otitis (in unilateral cases), 4) AOM recurrences, 5) serious complications related to AOM and 6) long-term effects (including the number of parent-reported AOM symptom episodes, antibiotic prescriptions and health care utilisation as assessed at least one year after randomisation). We used the GRADE approach to rate the overall certainty of evidence for each outcome of interest.

MAIN RESULTS

Antibiotics versus placebo We included 13 trials (3401 children and 3938 AOM episodes) from high-income countries, which we assessed at generally low risk of bias. Antibiotics do not reduce pain at 24 hours (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.78 to 1.01; 5 trials, 1394 children; high-certainty evidence), or at four to seven days (RR 0.76, 95% CI 0.50 to 1.14; 7 trials, 1264 children), but result in almost a third fewer children having pain at two to three days (RR 0.71, 95% CI 0.58 to 0.88; number needed to treat for an additional beneficial outcome (NNTB) 20; 7 trials, 2320 children; high-certainty evidence), and likely result in two-thirds fewer having pain at 10 to 12 days (RR 0.33, 95% CI 0.17 to 0.66; NNTB 7; 1 trial, 278 children; moderate-certainty evidence). Antibiotics increase the risk of adverse events such as vomiting, diarrhoea or rash (RR 1.38, 95% CI 1.16 to 1.63; number needed to treat for an additional harmful outcome (NNTH) 14; 8 trials, 2107 children; high-certainty evidence). Antibiotics reduce the risk of children having abnormal tympanometry findings at two to four weeks (RR 0.83, 95% CI 0.72 to 0.96; NNTB 11; 7 trials, 2138 children), slightly reduce the risk of experiencing tympanic membrane perforations (RR 0.43, 95% CI 0.21 to 0.89; NNTB 33; 5 trials, 1075 children) and halve the risk of contralateral otitis episodes (RR 0.49, 95% CI 0.25 to 0.95; NNTB 11; 4 trials, 906 children). However, antibiotics do not reduce the risk of abnormal tympanometry findings at six to eight weeks (RR 0.89, 95% CI 0.70 to 1.13; 3 trials, 953 children) and at three months (RR 0.94, 95% CI 0.66 to 1.34; 3 trials, 809 children) or late AOM recurrences (RR 0.94, 95% CI 0.79 to 1.11; 6 trials, 2200 children). Severe complications were rare, and the evidence suggests that serious complications do not differ between children treated with either antibiotics or placebo. Immediate antibiotics versus expectant observation We included six trials (1556 children) from high-income countries. The evidence suggests that immediate antibiotics may result in a reduction of pain at two to three days (RR 0.53, 95% CI 0.35 to 0.79; NNTB 8; 1 trial, 396 children; low-certainty evidence), but probably do not reduce the risk of pain at three to seven days (RR 0.75, 95% CI 0.50 to 1.12; 4 trials, 959 children; moderate-certainty evidence), and may not reduce the risk of pain at 11 to 14 days (RR 0.91, 95% CI 0.75 to 1.10; 1 trial, 247 children; low-certainty evidence). Immediate antibiotics increase the risk of vomiting, diarrhoea or rash (RR 1.87, 95% CI 1.39 to 2.51; NNTH 10; 3 trials, 946 children; high-certainty evidence). Immediate antibiotics probably do not reduce the proportion of children with abnormal tympanometry findings at four weeks and evidence suggests that immediate antibiotics may not reduce the risk of tympanic membrane perforation and AOM recurrences. No serious complications occurred in either group.

AUTHORS' CONCLUSIONS

This review reveals that antibiotics probably have no effect on pain at 24 hours, a slight effect on pain in the days following and only a modest effect on the number of children with tympanic perforations, contralateral otitis episodes and abnormal tympanometry findings at two to four weeks compared with placebo in children with AOM. In high-income countries, most cases of AOM spontaneously remit without complications. The benefits of antibiotics must be weighed against the possible harms: for every 14 children treated with antibiotics, one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have occurred if antibiotics were withheld. For most children with mild disease in high-income countries, an expectant observational approach seems justified. Therefore, clinical management should emphasise advice about adequate analgesia and the limited role for antibiotics.

Respiratory syncytial virus infection exacerbates pneumococcal pneumonia via Gas6/Axl-mediated macrophage polarization

Patients with respiratory syncytial virus (RSV) infection exhibit enhanced susceptibility to subsequent pneumococcal infections. However, the underlying mechanisms involved in this increased susceptibility remain unclear. Here, we identified potentially novel cellular and molecular cascades triggered by RSV infection to exacerbate secondary pneumococcal pneumonia. RSV infection stimulated the local production of growth arrest-specific 6 (Gas6). The Gas6 receptor Axl was crucial for attenuating pneumococcal immunity in that the Gas6/Axl blockade fully restored antibacterial immunity. Mechanistically, Gas6/Axl interaction regulated the conversion of alveolar macrophages from an antibacterial phenotype to an M2-like phenotype that did not exhibit antibacterial activity, and the attenuation of caspase-1 activation and IL-18 production in response to pneumococcal infection. The attenuated IL-18 production failed to drive both NK cell-mediated IFN-γ production and local NO and TNF-α production, which impair the control of bacterial infection. Hence, the RSV-mediated Gas6/Axl activity attenuates the macrophage-mediated protection against pneumococcal infection. The Gas6/Axl axis could be a potentially novel therapeutic target for RSV-associated secondary bacterial infection.

The yield of respiratory viruses detection testing is age-dependent in children with acute otitis media

Background:

Studies of nasopharyngeal secretions serve as reliable surrogate to evaluate the involvement of viruses in acute otitis media (AOM) and upper/lower respiratory tract infections (URIs/LRIs). We explored nasopharyngeal viral studies from children with uncomplicated AOM and examined their cost-effectiveness in relation to their age.

Methods:

We identified children aged 0–6 years admitted to our pediatrics department in a university-affiliated, secondary hospital with uncomplicated AOM and concurrent URI/LRI between 2012 and 2017, during October–April, when viral studies are performed. Studies were performed either using antigen detection tests, for respiratory syncytial virus (RSV) and influenza A/B (2012–2016) and for a variety of other common respiratory viruses, utilizing multiplex polymerase chain reaction assays (2017).

Results:

A total of 249 children were included (median age: 15 months). In 88 (35%) children, viral studies were positive, most of them in children ⩽24 months (78, 89%). RSV was positive in 52 (59%) children, followed by influenza A and B, in 11 (13%) and 5 (6%) children, respectively. First year switch to a molecular assay, 4.5-fold more expensive, resulted in a statistically significant higher yield: 69% positive results in ⩽24 months, and 66% in those aged ⩽12 months (p < 0.05). In those ⩽24 months, US$23 and US$95 were spent for one positive test in the antigen detection years and the polymerase chain reaction year, respectively, whereas in those >24 months, US$83 and US$878 were invested for one positive test in the same year, respectively.

Conclusion:

In cost-effectiveness terms, the greatest benefit of nasopharyngeal studies was highest in children ⩽24 months.

Comprehensive Detection of Respiratory Bacterial and Viral Pathogens in the Middle Ear Fluid and Nasopharynx of Pediatric Patients With Acute Otitis Media

BACKGROUND

Acute otitis media (AOM) is a common ear infection caused by respiratory viruses and bacteria of the nasopharynx. The present study aimed to detect various respiratory viruses and bacteria in middle ear fluid (MEF) and nasopharyngeal aspirates (NPA) using polymerase chain reaction (PCR).

METHODS

We collected MEF and NPA samples from 122 pediatric patients with AOM. Real-time PCR detected 11 types of respiratory viruses (respiratory syncytial virus A/B, parainfluenza virus 1/2/3, human metapneumovirus, influenza virus A/B, adenovirus, human bocavirus and rhino virus) and 7 types of bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Streptococcus pyogenes, Legionella pneumophila and Moraxella catarrhalis). MEF specimens were also examined using bacterial culture.

RESULTS

At least 1 respiratory viral or bacterial pathogen was detected in MEF of 120 cases (98%) by viral and bacterial PCR and of 93 cases (76%) by viral PCR and bacterial culture. Respiratory viruses were detected in NPA of 84 cases (69%) and MEF of 67 cases (55%). The most common virus detected in MEF was respiratory syncytial virus (21%), followed by parainfluenza virus (15%). All the viruses present in MEF were also detected in NPA specimens. Bacteria were detected by PCR in MEF of 109 cases (89%); H. influenzae was the most frequently detected (65%).

CONCLUSIONS

In many cases, pediatric AOM was found to constitute a respiratory polymicrobial infection. Multiplex PCR was useful to detect multiple respiratory viruses and bacteria in AOM. To understand intractable AOM, further studies regarding the clinical features of each viral and bacterial coinfection are required.

Epidemiology of Acute Otitis Media in the Postpneumococcal Conjugate Vaccine Era

OBJECTIVES

To study the epidemiology of acute otitis media (AOM), especially the otitis-prone condition, during the pneumococcal conjugate vaccines 7 and 13 era.

METHODS

Six hundred and fifteen children were prospectively managed from 6 to 36 months of life during a 10-year time frame (June 2006-June 2016). All clinical diagnoses of AOM were confirmed by tympanocentesis and bacterial culture of middle ear fluid.

RESULTS

By 1 year of age, 23% of the children experienced ≥1 episode of AOM; by 3 years of age, 60% had ≥1 episodes of AOM, and 24% had ≥3 episodes. The peak incidence occurred at 6 to 12 months of life. Multivariable analysis of demographic and environmental data revealed a significantly increased risk of AOM associated with male sex, non-Hispanic white race, family history of recurrent AOM, day care attendance, and early occurrence of AOM. Risk factors for stringently defined (tympanocentesis-confirmed) otitis proneness, in which children suffered at least 3 episodes of AOM in a 6-month period or at least 4 within a year, were male sex, day care attendance, and family history of AOM, whereas breastfeeding in the first 6 months of life was protective. Stringently defined otitis prone children were also likely to experience their first AOM episode at a younger age. The proportion of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis causing AOM had dynamic changes during the past decade.

CONCLUSIONS

We conclude that the epidemiology but not the risk factors for AOM have undergone substantial changes since the introduction of pneumococcal conjugate vaccines.

Non-typeable Haemophilus influenzae protects human airway epithelial cells from a subsequent respiratory syncytial virus challenge

Respiratory syncytial virus (RSV) and the common commensal and opportunistic pathogen, non-typeable Haemophilus influenzae (NTHi) both serve as a frequent cause of respiratory infection in children. Although it is well established that some respiratory viruses can increase host susceptibility to secondary bacterial infections, few studies have examined how commensal bacteria could influence a secondary viral response. Here, we examined the impact of NTHi exposure on a subsequent RSV infection of human bronchial epithelial cells (16HBE14o-). Co-culture of 16HBE14o- cells with NTHi resulted in inhibition of viral gene expression following RSV infection. 16HBE14o- cells co-cultured with heat-killed NTHi failed to protect against an RSV infection, indicating that protection requires live bacteria. However, NTHi did not inhibit influenza A virus replication, indicating that NTHi-mediated protection was RSV-specific. Our data demonstrates that prior exposure to a commensal bacterium such as NTHi can elicit protection against a subsequent RSV infection.

Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media (AOM) is one of the most common diseases in early infancy and childhood. Antibiotic use for AOM varies from 56% in the Netherlands to 95% in the USA, Canada and Australia. This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 1997 and previously updated in 1999, 2005, 2009 and 2013.

OBJECTIVES

To assess the effects of antibiotics for children with AOM.

SEARCH METHODS

We searched CENTRAL (2015, Issue 3), MEDLINE (1966 to April week 3, 2015), OLDMEDLINE (1958 to 1965), EMBASE (January 1990 to April 2015), Current Contents (1966 to April 2015), CINAHL (2008 to April 2015) and LILACS (2008 to April 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing 1) antimicrobial drugs with placebo and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

For the review of antibiotics against placebo, 13 RCTs (3401 children and 3938 AOM episodes) from high-income countries were eligible and had generally low risk of bias. The combined results of the trials revealed that by 24 hours from the start of treatment, 60% of the children had recovered whether or not they had placebo or antibiotics. Pain was not reduced by antibiotics at 24 hours (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.78 to 1.01) but almost a third fewer had residual pain at two to three days (RR 0.70, 95% CI 0.57 to 0.86; number needed to treat for an additional beneficial outcome (NNTB) 20). A quarter fewer had pain at four to seven days (RR 0.76, 95% CI 0.63 to 0.91; NNTB 16) and two-thirds fewer had pain at 10 to 12 days (RR 0.33, 95% CI 0.17 to 0.66; NNTB 7) compared with placebo. Antibiotics did reduce the number of children with abnormal tympanometry findings at two to four weeks (RR 0.82, 95% CI 0.74 to 0.90; NNTB 11), at six to eight weeks (RR 0.88, 95% CI 0.78 to 1.00; NNTB 16) and the number of children with tympanic membrane perforations (RR 0.37, 95% CI 0.18 to 0.76; NNTB 33) and halved contralateral otitis episodes (RR 0.49, 95% CI 0.25 to 0.95; NNTB 11) compared with placebo. However, antibiotics neither reduced the number of children with abnormal tympanometry findings at three months (RR 0.97, 95% CI 0.76 to 1.24) nor the number of children with late AOM recurrences (RR 0.93, 95% CI 0.78 to 1.10) when compared with placebo. Severe complications were rare and did not differ between children treated with antibiotics and those treated with placebo. Adverse events (such as vomiting, diarrhoea or rash) occurred more often in children taking antibiotics (RR 1.38, 95% CI 1.19 to 1.59; number needed to treat for an additional harmful outcome (NNTH) 14). Funnel plots do not suggest publication bias. Individual patient data meta-analysis of a subset of included trials found antibiotics to be most beneficial in children aged less than two years with bilateral AOM, or with both AOM and otorrhoea.For the review of immediate antibiotics against expectant observation, five trials (1149 children) from high-income countries were eligible and had low to moderate risk of bias. Four trials (1007 children) reported outcome data that could be used for this review. From these trials, data from 959 children could be extracted for the meta-analysis of pain at three to seven days. No difference in pain was detectable at three to seven days (RR 0.75, 95% CI 0.50 to 1.12). One trial (247 children) reported data on pain at 11 to 14 days. Immediate antibiotics were not associated with a reduction in the number of children with pain (RR 0.91, 95% CI 0.75 to 1.10) compared with expectant observation. Additionally, no differences in the number of children with abnormal tympanometry findings at four weeks, tympanic membrane perforations and AOM recurrence were observed between groups. No serious complications occurred in either the antibiotic or the expectant observation group. Immediate antibiotics were associated with a substantial increased risk of vomiting, diarrhoea or rash compared with expectant observation (RR 1.71, 95% CI 1.24 to 2.36; NNTH 9).Results from an individual patient data meta-analysis including data from six high-quality trials (1643 children) that were also included as individual trials in our review showed that antibiotics seem to be most beneficial in children younger than two years of age with bilateral AOM (NNTB 4) and in children with both AOM and otorrhoea (NNTB 3).

AUTHORS' CONCLUSIONS

This review reveals that antibiotics have no early effect on pain, a slight effect on pain in the days following and only a modest effect on the number of children with tympanic perforations, contralateral otitis episodes and abnormal tympanometry findings at two to four weeks and at six to eight weeks compared with placebo in children with AOM. In high-income countries, most cases of AOM spontaneously remit without complications. The benefits of antibiotics must be weighed against the possible harms: for every 14 children treated with antibiotics one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have occurred if antibiotics were withheld. Therefore clinical management should emphasise advice about adequate analgesia and the limited role for antibiotics. Antibiotics are most useful in children under two years of age with bilateral AOM, or with both AOM and otorrhoea. For most other children with mild disease in high-income countries, an expectant observational approach seems justified.

[Exudative otitis media in the childhood]

This review article was designed to systematize the literature data concerning etiology, pathogenesis, diagnostics and treatment of exudative otitis media (EOM) in the children. The review is focused on the prevailing current tendencies in the approaches to the problems of etiology, diagnostics, and treatment of EOM in the children as exemplified by the publications in the foreign and Russian-speaking literature. The special emphasis is laid on the description of the therapeutic and surgical methods for the management of EOM.

Influenza A virus alters pneumococcal nasal colonization and middle ear infection independently of phase variation

Streptococcus pneumoniae (pneumococcus) is both a widespread nasal colonizer and a leading cause of otitis media, one of the most common diseases of childhood. Pneumococcal phase variation influences both colonization and disease and thus has been linked to the bacteria's transition from colonizer to otopathogen. Further contributing to this transition, coinfection with influenza A virus has been strongly associated epidemiologically with the dissemination of pneumococci from the nasopharynx to the middle ear. Using a mouse infection model, we demonstrated that coinfection with influenza virus and pneumococci enhanced both colonization and inflammatory responses within the nasopharynx and middle ear chamber. Coinfection studies were also performed using pneumococcal populations enriched for opaque or transparent phase variants. As shown previously, opaque variants were less able to colonize the nasopharynx. In vitro, this phase also demonstrated diminished biofilm viability and epithelial adherence. However, coinfection with influenza virus ameliorated this colonization defect in vivo. Further, viral coinfection ultimately induced a similar magnitude of middle ear infection by both phase variants. These data indicate that despite inherent differences in colonization, the influenza A virus exacerbation of experimental middle ear infection is independent of the pneumococcal phase. These findings provide new insights into the synergistic link between pneumococcus and influenza virus in the context of otitis media.

Wet cough in children: infective and inflammatory characteristics in broncho-alveolar lavage fluid

Wet cough is a common feature of many disease processes affecting children. Our aim was to examine the relationships between cough nature, lower airway infection (bacterial, viral, and viral-bacterial) and severity of neutrophilic airway inflammation. We hypothesized that viral-bacterial co-infection of the lower airway would be associated with wet cough and heightened neutrophilic airway inflammation. We prospectively recruited 232 children undergoing elective flexible bronchoscopy. Participants were grouped using a cough nature symptom-based approach, into wet, dry or no cough groups. Broncho-alveolar lavage (BAL) and clinical data, including presence, nature, and duration of cough and key demographic factors, were collected. Children with wet cough (n = 143) were more likely to have lower airway bacterial infection (OR 2.6, P = 0.001), viral infection (OR 2.04, P = 0.045) and viral-bacterial co-infection (OR 2.65, P = 0.042) compared to those without wet cough. Wet cough was associated with heightened airway neutrophilia (median 19%) as compared to dry or no cough. Viral-bacterial co-infection was associated with the highest median %neutrophils (33.5%) compared to bacteria only, virus/es only and no infection (20%, 18%, and 6%, respectively, P < 0.0001). Children with wet cough had higher rates of lower airway infection with bacteria and viruses. Maximal neutrophilic airway inflammation was seen in those with viral-bacterial co-infection. Cough nature may be a useful indicator of infection and inflammation of the lower airways in children.

Antibiotics for acute otitis media in children

BACKGROUND

Acute otitis media (AOM) is one of the most common diseases in early infancy and childhood. Antibiotic use for AOM varies from 56% in the Netherlands to 95% in the USA, Canada and Australia.

OBJECTIVES

To assess the effects of antibiotics for children with AOM.

SEARCH METHODS

We searched CENTRAL (2012, Issue 10), MEDLINE (1966 to October week 4, 2012), OLDMEDLINE (1958 to 1965), EMBASE (January 1990 to November 2012), Current Contents (1966 to November 2012), CINAHL (2008 to November 2012) and LILACS (2008 to November 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing 1) antimicrobial drugs with placebo and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

For the review of antibiotics against placebo, 12 RCTs (3317 children and 3854 AOM episodes) from high-income countries were eligible. However, one trial did not report patient-relevant outcomes, leaving 11 trials with generally low risk of bias. Pain was not reduced by antibiotics at 24 hours (risk ratio (RR) 0.89; 95% confidence interval (CI) 0.78 to 1.01) but almost a third fewer had residual pain at two to three days (RR 0.70; 95% CI 0.57 to 0.86; number needed to treat for an additional beneficial outcome (NNTB) 20) and fewer had pain at four to seven days (RR 0.79; 95% CI 0.66 to 0.95; NNTB 20). When compared with placebo, antibiotics did not alter the number of abnormal tympanometry findings at either four to six weeks (RR 0.92; 95% CI 0.83 to 1.01) or at three months (RR 0.97; 95% CI 0.76 to 1.24), or the number of AOM recurrences (RR 0.93; 95% CI 0.78 to 1.10). However, antibiotic treatment did lead to a statistically significant reduction of tympanic membrane perforations (RR 0.37; 95% CI 0.18 to 0.76; NNTB 33) and halved contralateral AOM episodes (RR 0.49; 95% CI 0.25 to 0.95; NNTB 11) as compared with placebo. Severe complications were rare and did not differ between children treated with antibiotics and those treated with placebo. Adverse events (such as vomiting, diarrhoea or rash) occurred more often in children taking antibiotics (RR 1.34; 95% CI 1.16 to 1.55; number needed to treat for an additional harmful outcome (NNTH) 14). Funnel plots do not suggest publication bias. Individual patient data meta-analysis of a subset of included trials found antibiotics to be most beneficial in children aged less than two with bilateral AOM, or with both AOM and otorrhoea.For the review of immediate antibiotics against expectant observation, five trials (1149 children) were eligible. Four trials (1007 children) reported outcome data that could be used for this review. From these trials, data from 959 children could be extracted for the meta-analysis on pain at days three to seven. No difference in pain was detectable at three to seven days (RR 0.75; 95% CI 0.50 to 1.12). No serious complications occurred in either the antibiotic group or the expectant observation group. Additionally, no difference in tympanic membrane perforations and AOM recurrence was observed. Immediate antibiotic prescribing was associated with a substantial increased risk of vomiting, diarrhoea or rash as compared with expectant observation (RR 1.71; 95% CI 1.24 to 2.36).

AUTHORS' CONCLUSIONS

Antibiotic treatment led to a statistically significant reduction of children with AOM experiencing pain at two to seven days compared with placebo but since most children (82%) settle spontaneously, about 20 children must be treated to prevent one suffering from ear pain at two to seven days. Additionally, antibiotic treatment led to a statistically significant reduction of tympanic membrane perforations (NNTB 33) and contralateral AOM episodes (NNTB 11). These benefits must be weighed against the possible harms: for every 14 children treated with antibiotics, one child experienced an adverse event (such as vomiting, diarrhoea or rash) that would not have occurred if antibiotics had been withheld. Antibiotics appear to be most useful in children under two years of age with bilateral AOM, or with both AOM and otorrhoea. For most other children with mild disease, an expectant observational approach seems justified. We have no trials in populations with higher risks of complications.

Viral-bacterial interactions in acute otitis media

Acute otitis media (AOM) is a polymicrobial disease, which usually occurs as a complication of viral upper respiratory tract infection (URI). While respiratory viruses alone may cause viral AOM, they increase the risk of bacterial middle ear infection and worsen clinical outcomes of bacterial AOM. URI viruses alter Eustachian tube (ET) function via decreased mucociliary action, altered mucus secretion and increased expression of inflammatory mediators among other mechanisms. Transient reduction in protective functions of the ET allows colonizing bacteria of the nasopharynx to ascend into the middle ear and cause AOM. Advances in research help us to better understand the host responses to viral URI, the mechanisms of viral-bacterial interactions in the nasopharynx and the development of AOM. In this review, we present current knowledge regarding viral-bacterial interactions in the pathogenesis and clinical course of AOM. We focus on the common respiratory viruses and their established role in AOM.

Otitis media

Otitis media represents a broad spectrum of disease, which include acute otitis media and otitis media with effusion. As immunization with the pneumococcal conjugate vaccine has become more widespread, the microbiological landscape of otitis media has changed, which affects the treatment options facing clinicians worldwide. This review discusses the diagnosis and medical management of acute and chronic suppurative otitis media, the changes noted over the past decade, and briefly expounds on the surgical management of their severe complications.

Presence of viral nucleic acids in the middle ear: acute otitis media pathogen or bystander?

Viruses play an important role in acute otitis media (AOM) pathogenesis, and live viruses may cause AOM in the absence of pathogenic bacteria. Detection of AOM pathogens generally relies on bacterial culture of middle ear fluid. When viral culture is used and live viruses are detected in the middle ear fluid of children with AOM, the viruses are generally accepted as AOM pathogens. Because viral culture is not sensitive and does not detect the comprehensive spectrum of respiratory viruses, polymerase chain reaction assays are commonly used to detect viral nucleic acids in the middle ear fluid. Although polymerase chain reaction assays have greatly increased the viral detection rate, new questions arise on the significance of viral nucleic acids detected in the middle ear because nucleic acids of multiple viruses are detected simultaneously, and nucleic acids of specific viruses are detected repeatedly and in a high proportion of asymptomatic children. This article first reviews the role of live viruses in AOM and presents the point-counterpoint arguments on whether viral nucleic acids in the middle ear represent an AOM pathogen or a bystander status. Although there is evidence to support both directions, helpful information for interpretation of the data and future research direction is outlined.

Risk of acute otitis media in relation to acute bronchiolitis in children

OBJECTIVE

A prospective study was carried out to evaluate the prevalence and the etiology of acute otitis media (AOM) in children with acute bronchiolitis. Also to determine whether AOM occurring with acute bronchiolitis is accompanied with another pathogens or not.

SUBJECTS AND METHODS

One hundred and eighty children with acute bronchiolitis aged 3-18 months who were admitted to pediatrics department, Minia University hospital, were included in the study done in the winter and spring of 2009. In patients with AOM at entry or developed AOM within 14 days, Gram-stained smears, bacterial cultures, and enzyme-linked immunosorbent assay (ELISA) were performed on middle-ear aspirates to detect the presence of bacterial pathogens and RSV respectively.

RESULTS

One hundred children (55.6%) with acute bronchiolitis had AOM at entry or developed AOM within 14 days, 45 patients (25%) had developed otitis media with effusion, and only 35 patients (19.4%) remained free throughout the 2-week observation period. Of 135 middle-ear aspirates (65 unilateral and 35 bilateral), bacterial pathogens were isolated in 86 patients (86%) [37 bacteria alone "37%" and 49 mixed bacteria and RSV "49%"], RSV was identified in 56 patients (56%) of middle ear aspirates [mixed with bacteria in 49 patients and RSV alone in 7 cases (7%).

CONCLUSION

We concluded that bacterial AOM is a complication in most children with acute bronchiolitis. Streptococcus pneumonia and Haemophilus influenza were the commonest organisms isolated from middle ear aspirate. RSV is identified in 56% of acute otitis media with bronchiolitis.

Evaluation of potential factors contributing to microbiological treatment failure in Streptococcus pyogenes pharyngitis

BACKGROUND

A cohort study of children with pharyngitis aged two to 16 years was conducted to assess the role of microbial and host factors in group A beta-hemolytic streptococcus (GABHS) microbiological treatment failure.

METHODS

GABHS-infected children had pharyngeal swabs repeated two to five days after completing a 10-day course of penicillin V. M and T typing, and pulsed field gel electrophoresis were performed on the isolates, and the isolates were evaluated for tolerance. Patient characteristics and clinical features were noted and nasopharyngeal swabs for respiratory viruses were taken at enrolment.

RESULTS AND CONCLUSIONS

Of 286 patients enrolled, 248 (87%) could be evaluated. GABHS was cultured from 104 patients (41.9%), of whom 33 (33.7%) had microbiological treatment failures on follow-up. Although there was a trend toward failure for younger children (mean 6.5+/-2.4 years versus 7.3+/-2.4 years, P=0.07) and M type 12 (24% versus 10%, P=0.08), no factors were associated with treatment failure.

The efficacy of live attenuated influenza vaccine against influenza-associated acute otitis media in children

BACKGROUND

Acute otitis media (AOM) is a frequent complication of influenza in young children. Influenza vaccination is known to protect against AOM by preventing influenza illness. We sought to determine the efficacy of the live attenuated influenza vaccine (LAIV) against influenza-associated AOM compared with placebo and trivalent inactivated influenza vaccine (TIV). LAIV is approved for eligible children aged ≥ 2 years in the United States and in several other countries.

METHODS

AOM incidence data from 6 randomized, double-blind, placebo-controlled trials and 2 randomized, double-blind, TIV-controlled trials in children 6 to 83 months of age were pooled and analyzed.

RESULTS

A total of 290 cases of AOM were identified in 24,046 study subjects. LAIV efficacy against influenza-associated AOM was 85.0% (95% confidence interval [CI], 78.3%-89.8%) compared with placebo and 54.0% (95% CI, 27.0%-71.7%) compared with TIV. Efficacy trended higher in those ≥ 24 months of age compared with those aged 6 to 23 months. In placebo-controlled trials, among children who acquired influenza despite vaccination, AOM was diagnosed in 10.3% of LAIV recipients and 16.8% of placebo recipients, representing a 38.2% (95% CI, 11.0%-58.2%) relative reduction in the development of AOM. In TIV-controlled studies, among subjects with breakthrough influenza illness, the proportions of LAIV and TIV recipients who developed AOM were similar.

CONCLUSIONS

Children receiving LAIV had a high level of protection against influenza-associated AOM when compared with placebo or TIV. This was most evident in children older than 2 years, for whom LAIV is indicated. LAIV recipients who contracted breakthrough influenza illness despite vaccination developed AOM at a significantly lower rate than did unvaccinated children who developed influenza.

Clinical and microbiological impact of human bocavirus on children with acute otitis media

Human Bocavirus (HBoV) as a newly discovered parvovirus has been commonly detected in respiratory tract infections. However, its role in acute otitis media (AOM) has not been well studied. We examined HBoV in Japanese children with AOM and evaluated the virus prevalence together with clinical manifestations and bacterial findings. Overall, 222 nasopharyngeal swabs and 176 middle ear fluids (MEF) samples were collected from 222 children with AOM (median age, 19 months) between May 2006 and April 2007. HBoV detection was performed by PCR and bacterial isolation by standard culture methods. HBoV was found in the nasopharyngeal aspirates of 14 children (6.3%) and in the MEF of six children (2.7%). When HBoV detection results were evaluated with clinical characteristics of children, resolution time of AOM was significantly longer (p=0.04), and rate of fever symptom was also higher in HBoV-positive group (p=0.04). Furthermore, we found positive correlation between detection of HBoV and Streptococcus pneumoniae in the MEF (p=0.004). Nevertheless, nasopharyngeal proportion of S. pneumoniae was similar between virus positive and negative groups. Furthermore, S. pneumoniae was detected as a single pathogen in all MEF of HBoV-positive cases but one, while it presents mixed with other pathogenic bacteria in nasopharynx. In conclusion, HBoV may worsen the clinical symptoms and prolong the clinical outcome of AOM in pediatric population. Finally, HBoV may prime the secondary bacterial infection in the middle ear in favor of S. pneumoniae.

Immunopathogenesis of polymicrobial otitis media

The synergistic relationship between URT viruses and bacteria in OM pathogenesis is not fully understood, but overall is predicated on viral impairment of airway defenses.

OM, or inflammation of the middle ear, is a highly prevalent infection in children worldwide. OM is a multifactorial disease with multiple risk factors, including preceding or concurrent viral URT infection. Hence, OM is also a polymicrobial disease. The mechanisms by which viruses predispose to bacterial OM are replete; however, all are predicated on the general principle of compromise of primary host airway defenses. Thus, despite an as‐yet incomplete understanding of the molecular mechanisms involved in bacterial superinfection of a virus‐compromised respiratory tract, the URT viruses are known to induce histopathology of airway mucosal epithelium, up‐regulate expression of eukaryotic receptors used for bacterial adherence, alter the biochemical and rheological properties of airway mucus, and affect innate and acquired host immune functions, among others. Although discussed here in the context of OM, during preceding or concurrent viral infection of the human respiratory tract, viral impairment of airway defenses and the resulting predisposition to subsequent bacterial coinfection are also known to be operational in the mid and lower airway as well.

Microbial interactions in the respiratory tract

Upper respiratory tract infections are caused by the synergistic and antagonistic interactions between upper respiratory tract viruses and 3 predominant bacterial pathogens: Streptococcus pneumoniae, nontypeable Haemophilus influenzae (NTHi), and Moraxella catarrhalis, which are members of the commensal flora of the nasopharynx. For many bacterial pathogens, colonization of host mucosal surfaces is a first and necessary step in the infectious process. S. pneumoniae and H. influenzae have intricate interactions in the nasopharynx. The host innate immune response may influence these interactions and therefore influence the composition of the colonizing flora and the invading bacteria. S. pneumoniae, nontypeable H. influenzae, and M. catarrhalis can behave as opportunistic pathogens of the middle ear when conditions are optimal. Chronic otitis media (OM) and recurrent OM include a biofilm component. Each of the 3 predominant pathogens of OM can form a biofilm and have been shown to comprise biofilms present on middle ear mucosa specimens recovered from children with recurrent or chronic OM. Some of these characterized biofilms are of mixed bacterial etiology, suggesting that progress made on single-microbe directed strategies for treatment and/or prevention of OM, although highly encouraging, are likely to be inadequate. A significantly greater understanding about microbial physiology is required as it relates to the involvement of biofilms in OM, to identify points in the natural course of the disease that are perhaps more amenable to treatment strategies, as well as to identify biofilm-relevant antigenic targets that would be helpful in the rational design of vaccines to prevent OM.

Nontypeable Haemophilus influenzae as a pathogen in children

Nontypeable Haemophilus influenzae is a significant pathogen in children, causing otitis media, sinusitis, conjunctivitis, pneumonia, and occasionally invasive infections. H. influenzae type b conjugate vaccines have no effect on infections caused by nontypeable strains because nontypeable strains are nonencapsulated. Approximately, one-third of episodes of otitis media are caused by nontypeable H. influenzae and the bacterium is the most common cause of recurrent otitis media. Recent progress in elucidating molecular mechanisms of pathogenesis, understanding the role of biofilms in otitis media and an increasing understanding of immune responses have potential for development of novel strategies to improve prevention and treatment of otitis media caused by nontypeable H. influenzae. Feasibility of vaccination for prevention of otitis media due to nontypeable H. influenzae was recently demonstrated in a clinical trial with a vaccine that included the surface virulence factor, protein D.

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.

Prevention of influenza: recommendations for influenza immunization of children, 2007-2008

The American Academy of Pediatrics recommends annual influenza immunization for all children with high-risk conditions who are 6 months of age and older, for all healthy children ages 6 through 59 months, for all household contacts and out-of-home caregivers of children with high-risk conditions and of healthy children younger than 5 years, and for all health care professionals. To more fully protect against the morbidity and mortality of influenza, increased efforts are needed to identify and immunize all children at high risk and all healthy children ages 6 through 59 months and to inform their parents when annual immunizations are due. Previously unimmunized children who are at least 6 months of age but younger than 9 years should receive 2 doses of influenza vaccine, given 1 month apart, beginning as soon as possible on the basis of local availability during the influenza season. If children in this cohort received only 1 dose for the first time in the previous season, it is recommended that 2 doses be administered in the current season. This recommendation applies only to the influenza season that follows the first year that a child younger than 9 years receives influenza vaccine. A child who then also fails to receive 2 doses the next year should be given only 1 dose per year from that point on. Influenza vaccine should also continue to be offered throughout the influenza season, even after influenza activity has been documented in a community. On the basis of global surveillance of circulating virus strains, the influenza vaccine may change from year to year; indeed, 1 of the 3 strains in the 2007-2008 vaccine is different from the previous year's vaccine. All health care professionals, influenza campaign organizers, and public health agencies should develop plans for expanding outreach and infrastructure to immunize all children for whom influenza vaccine is recommended. Appropriate prioritization of administering influenza vaccine will also be necessary when vaccine supplies are delayed or limited. Because the influenza season often extends into March, immunization against influenza is recommended to continue through late winter and early spring. Lastly, it is recommended that for the 2007-2008 season, and likely beyond, health care professionals do not prescribe amantadine or rimantadine for influenza treatment or chemoprophylaxis, because widespread resistance to these antiviral medications now exists among influenza A viral strains. However, oseltamivir and zanamivir can be prescribed for treatment or chemoprophylaxis, because influenza A and B strains remain susceptible.

Acute otitis media associated with cytomegalovirus infection in infants and children

OBJECTIVE

Acute otitis media (AOM) is one of the most common complications of viral respiratory tract infections in children, but the role of each virus is still to be elucidated. We analyzed AOM associated with infection by cytomegalovirus (CMV), which is known as one of the major causes of viral respiratory tract infection.

METHODS

Four hundred and ninety-five children (292 boys and 203 girls) diagnosed as having AOM in 2002 were studied. All of the children were under 6 years old, with the average age being 1.31+/-1.36 years. Bacterial and viral culture of both nasopharyngeal secretions (NPS) and middle ear fluid (MEF) was performed in all 495 children. The levels of glutamyl pyruvic transaminase (GPT) and the serum IgM antibody for CMV were measured. CMV infection was defined on the basis of isolation of this virus by culture and/or positive anti-CMV IgM antibody. NPS and MEF specimens of the subjects diagnosed as having CMV infection were tested for the virus by nested PCR.

RESULTS

Twelve of the 495 children were found to have CMV infection. They included 6 boys and 6 girls aged from 3 to 25 months, with the average age being 11+/-7 months. Among 10 children in whom CMV infection was diagnosed by viral culture, CMV was isolated from NPS alone in nine cases and from both NPS and MEF in one case. Nested PCR was performed in all 12 subjects diagnosed as having CMV infection, and all NPS samples were positive, as were 8 MEF samples. We obtained serum samples from 205 children under 2 years of age, including 9 with CMV infection. The mean serum GPT level of 124 children in whom no viruses were detected was 20.7+/-14.4 IU/L. While, the serum GPT levels of 9 children with CMV infection ranged from 10 to 280 IU/L with the average titer being 78.4+/-81.9 IU/L, and the GPT levels of the children with CMV infection were significantly higher than those of the children in whom no viruses were detected (p<0.05).

CONCLUSION

Our results suggested that CMV is a causative pathogen of AOM, and that CMV infection should be suspected in patients with AOM and liver dysfunction.

Vaccine development for non-typeable Haemophilus influenzae and Moraxella catarrhalis: progress and challenges

An urgent need exists for vaccines to prevent infections caused by nontypeable Haemophilus influenzae and Moraxella catarrhalis. These bacteria cause otitis media in children, a clinical problem associated with enormous morbidity and cost. H. influenzae and M. catarrhalis also cause lower respiratory tract infections in adults with chronic lung disease. Infections in this clinical setting are associated with disability and death. Recent progress in identifying potential vaccine antigens in both bacteria raises great promise in developing effective vaccines. This paper reviews the key issues in vaccine development for H. influenzae and M. catarrhalis, including areas where progress has been stalled, and proposes areas that deserve investigation in the next 5 years.

Laterality of acute otitis media: different clinical and microbiologic characteristics

BACKGROUND

A large individual patient data meta-analysis recently showed that children aged less than 2 years with bilateral, as compared with unilateral, acute otitis media (AOM) were at higher risk for persistent symptoms without antibiotic treatment. Prior studies have shown a propensity for children with bilateral AOM to be infected with bacterial pathogens, specifically Haemophilus influenzae. The objectives of this study were to further characterize risk factors for bilateral AOM and to assess the propensity for specific viral and bacterial pathogens to predispose to bilateral versus unilateral AOM.

METHODS

We performed a secondary data analysis on 1216 cases of AOM diagnosed and treated at our institution: 566 subjects underwent tympanocentesis and middle ear fluid (MEF) culture. We compared subjects with bilateral and unilateral AOM for demographic characteristics, clinical findings, parent/clinician perception of AOM severity, and MEF study results for bacteria and viruses.

RESULTS

When compared with children who have unilateral AOM, children with bilateral AOM were more likely to be younger (P < 0.001), have H. influenzae isolated from one or both MEFs (P < 0.0001), and have more severe inflammation of the tympanic membrane on otoscopic examination (P < 0.0001).

CONCLUSION

Compared with children who have unilateral AOM, children with bilateral AOM are more likely to have bacteria in the MEF and have more severe inflammation of the tympanic membrane. This may help explain why children with bilateral AOM are more likely to experience persistent symptoms without antibiotic treatment. Laterality of AOM should be considered when discussing treatment options with parents.

Role of respiratory syncytial virus in acute otitis media: implications for vaccine development

We summarize herein the results of various virologic studies of acute otitis media (AOM) conducted at our site over a 10-year period. Among 566 children with AOM, respiratory syncytial virus (RSV) was the most common virus identified in either middle ear fluid or nasal wash; it was found in 16% of all children and 38% of virus-positive children. Seventy-one percent of the children with RSV were 1 year of age or older, which was significantly older than all other viruses combined (P=0.045). RSV infection was associated with the common bacterial pathogens causing AOM. Past efforts to develop vaccines for RSV have emphasized prevention of lower respiratory tract infection in infants, which is a more serious problem but less common than AOM. Our results suggest that RSV vaccines that work only against infection in older children may have value in preventing AOM, the most common pediatric disease.

Presence of herpesviruses in middle ear fluid of children with otitis media with effusion

BACKGROUND

Otitis media with effusion (OME) is a disease that frequently occurs in children. Etiopathogenesis of the diseases has not been completely elucidated. There are limited numbers of studies on the presence of herpesviruses in otitis media cases with OME. The present study was undertaken to determine the rate of some herpesviruses in OME cases of children.

METHODS

A total of 92-middle ear fluids were collected from 51 children. The samples were analyzed using polymerase chain reaction (PCR) for detection of herpesviruses including Herpes simplex virus (HSV), cytomegalovirus (CMV), Varicella zoster virus (VZV), and Epstein-Barr virus (EBV).

RESULTS

PCR analysis of the 92 samples showed that genomes of EBV in 12 (13.04%), HSV in seven (7.60%), CMV in five (5.43%), and VZV in three (3.26%) were present. Two of these samples were positive for both HSV and EBV genomes. Therefore, 25 (27.17%) of the samples were determined to be infected with any of the herpesviruses tested.

CONCLUSIONS

In the present study, herpesviruses were determined at a high rate in middle ear fluids of children with OME. However, the present study is a preliminary study and more extensive studies, especially experimental studies, are required to elucidate the role of herpesviruses in pathogenesis of OME and whether there is a relation between rate of herpesviruses in OME cases, and the reactivation of latent infections.

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.

Isolation of measles virus from middle ear fluid of infants with acute otitis media

Measles virus was isolated from the middle ear fluid (MEF) of two infant cases of acute otitis media (AOM) associated with measles. This is the first report on the isolation of measles virus from the MEF in patients with AOM, and possibility of the measles virus as a causative agent of AOM was suggested.

Microbiology of acute otitis media in children with tympanostomy tubes: prevalences of bacteria and viruses

Background. Bacteria are found in 50%–90% of cases of acute otitis media (AOM) with or without otorrhea, and viruses are found in 20%–49% of cases. However, for at least 15% of patients with AOM, the microbiological etiology is never determined. Our aim was to specify the full etiology of acute middle ear infection by using modern microbiological methods concomitantly for bacterial and viral detection.

Methods. The subjects were 79 young children having AOM with new onset (<48 h) of otorrhea through a tympanostomy tube. Middle ear fluid samples were suctioned from the middle ear through the tympanostomy tube. Bacteria were sought by culture and polymerase chain reaction; viruses were analyzed by culture, antigen detection, and polymerase chain reaction.

Results. At least 1 respiratory tract pathogen was noted in 76 children (96%). Bacteria were found in 73 cases (92%), and viruses were found in 55 (70%). In 52 patients (66%), both bacteria and viruses were found. Bacteria typical of AOM were detected in 86% of patients. Picornaviruses accounted for 60% of all viral findings.

Conclusions. In the great majority of children, AOM is a coinfection with bacteria and viruses. The patent tympanostomy tube does not change the spectrum of causative agents in AOM. A microbiological etiology can be established in practically all cases.

Otitis media today: a challenge for physicians and the community

Acute otitis media is one of the most common causes of medical consultation worldwide, and has a high economic impact. In this review, a clear definition between acute otitis media and otitis media with effusion is presented. The microbiology and characterization of the main bacterial isolates in acute otitis media and the susceptibility patterns are reviewed, and the latest concepts in antimicrobial treatment are discussed. The need for courses that improve the capability of primary care physicians to diagnose acute otitis media using pneumatic otoscopy, and for parental education is also discussed.

A high prevalence of new onset otitis media during parent diagnosed common colds

INTRODUCTION

Past studies suggest that the majority of new otitis media (OM) diagnoses is a complication of a colds/flu. A prospective format was used to determine the coincidence of otitis media and parent diagnosed cold/flu episodes in young children followed over a typical cold/flu season.

METHODS

Eighteen families with children aged 1-8 years were followed from October 1 to April 30 using parent-completed daily diaries focused on cold/flu signs and weekly examinations using pneumatic otoscopy for diagnosis of the presence/absence of otitis media.

RESULTS

Overall, 108 cold episodes were documented in 36 enrolled children with 20 colds (19%) occurring during a pre-existing OM episode and 40 colds (37%) complicated by a new OM episode. Conversely, there were 82 new OM episodes, 40 (49%) were associated with a cold in the individual child and 18 (22%) with a concurrent cold in a family member. The median duration of the OM episodes was approximately 2 weeks but this was longer for OM episodes where earache was reported.

CONCLUSION

The results confirm past observation relating new OM episodes to a concurrent cold/flu but show these episodes to usually be of short duration. Two sources of potential bias were identified for point prevalence study formats: the presence of a pre-existing OM for a new onset cold/flu and the possibility of subclinical colds in patients with new OM episodes. These biases reinforce the need for longitudinal study formats to address this important relationship.

Association of human metapneumovirus with acute otitis media

OBJECTIVE

Human metapneumovirus (hMPV) is a recently described paramyxovirus that has been associated with acute upper and lower respiratory infection (LRI) in infants and children worldwide. We previously observed that one-third of the children with hMPV-associated LRI had been diagnosed with a concomitant acute otitis media (AOM). In the current study, we sought to investigate an association between hMPV and children presenting with AOM as a primary diagnosis.

METHODS

We used realtime RT-PCR for hMPV to retrospectively test 144 paired nasal wash (NW) and middle ear fluid (MEF) specimens that had been prospectively collected from children with AOM during a 3-year period from 1990-1992. RNA was extracted from archived, frozen samples and realtime RT-PCR for hMPV was performed.

RESULTS

We detected hMPV in 8/144 (6%) NW and 1/144 MEF. Several of the children still tested positive for hMPV in NW 3 days later, showing persistent virus shedding. All were detected from November-May and six had bacterial co-pathogens. Two of the eight (25%) hMPV-infected children had no bacterial pathogen isolated, suggesting that hMPV may be associated with AOM as a sole pathogen.

CONCLUSIONS

These data show that hMPV is associated with a proportion of AOM and thus has additional morbidity and healthcare impact related to these illnesses.

Inner ear and facial nerve complications of acute otitis media with focus on bacteriology and virology

CONCLUSION

Among 20 patients with inner ear complications and/or peripheral facial palsy secondary to acute otitis media (AOM) a proven or probable bacteriological cause was found in 13 (65%). In seven patients (35%), a proven or probable viral cause was found. Only two of the patients (10%), with a proven bacterial AOM and a clinical picture of a purulent labyrinthitis in both, together with a facial palsy in one, had a substantial degree of dysfunction. Although the number of patients in this study is relatively low our findings show that inner ear complications and facial palsy due to AOM can be of both bacterial and viral origin. Severe sequelae were found only where a bacterial origin was proven.

OBJECTIVES

Inner ear complications and/or peripheral facial palsy secondary to AOM are rare. The general understanding is that they are due to bacterial infections. However, in some of these patients there are no clinical or laboratory signs of bacterial infections and they have negative bacterial cultures. During recent years different viruses have been isolated from the middle ear or serologically proven in AOM patients and are thought to play a pathogenetic role. We suggest that in some cases of AOM complications from the inner ear and the facial nerve can be caused by viruses. The purpose of our study was to analyze infectious agents present in patients with inner ear complications and/or facial palsy arising from AOM.

PATIENTS AND METHODS

The medical records of 20 patients who had inner ear complications and/or facial palsy following AOM ( unilateral in 18, bilateral in 2) between January 1989 and March 2003 were evaluated. Bacterial cultures were carried out for all patients. Sera from 12 of the patients were stored and tested for a battery of specific viral antibodies. In three patients, investigated between November 2002 and March 2003, viral cultures were also performed on samples from the middle ear and nasopharynx.

RESULTS

Nineteen patients had inner ear symptoms. Eight of them had a unilateral sensorineural hearing loss and vertigo, three had vertigo as an isolated symptom and one, with bilateral AOM, had bilateral sensorineural hearing loss. Seven patients had a combination of facial palsy and inner ear symptoms (unilateral sensorineural hearing loss in three, unilateral sensorineural hearing loss and vertigo in two, bilateral sensorineural hearing loss and vertigo in one, with bilateral AOM, and vertigo alone in one). One patient had an isolated facial palsy. Healing was complete in 11 of the 20 patients. In seven patients a minor defect remained at follow-up (a sensorineural hearing loss at higher frequencies in all). Only two patients had obvious defects (a pronounced hearing loss in combination with a moderate to severe facial palsy (House-Brackman grade 4) in one, distinct vestibular symptoms and a total caloric loss in combination with a high-frequency loss in the other. Eight patients had positive bacteriological cultures from middle ear contents: Streptococcus pneumoniae in two, beta-hemolytic Streptococcus group A in two, beta-hemolytic Streptococcus group A together with Staphylococcus aureus in one, Staph. aureus alone in one and coagulase-negative staphylococci (interpreted as pathogens) in two. In the 12 patients with negative cultures, there was a probable bacteriological cause due to the outcome in SR/CRP and leukocyte count in five. In four patients serological testing showed a concomitant viral infection that was interpreted to be the cause (varicella zoster virus in two, herpes simplex virus in one and adenovirus in one.) In three there was a probable viral cause despite negative viral antibody test due to normal outcome in SR/CRP, normal leukocyte count, serous fluid at myringotomy and a relatively short pre-complication antibiotic treatment period.

Nuevas indicaciones de la vacuna inactivada antigripal en la población infantil (2004-2005)

Several epidemiological studies have indicated that, in all countries and in distinct epidemic years, the highest rates of influenza infection (between 15% and 42%) occur in the pediatric population, especially in school-aged children. Over various influenza seasons, the rates of annual outpatient visits attributable to influenza vary from 6-29% of children. Influenza and its complications have been reported to result in a 10-30% increase in the number of antibiotic courses prescribed to children during the influenza season. Current percentages of influenza vaccination in children are very low, although the hospitalization rates for infectious complications in children under 5 years are at least equal to those observed in individuals aged more than 65 years. The reasons for these low immunization rates are unknown, but many factors could be involved, especially the need for annual revaccination. In 2003 the Advisory Committee on Immunization Practices (ACIP) recommended influenza immunization only in children at high risk for influenza complications and in those living with someone in a high-risk group. However, they encouraged vaccination of all children aged 6-23 months old. After a review of various epidemiological studies, in 2004 both the ACIP and the American Academy of Pediatrics recommended systematic immunization of all healthy children within this age group. However, both institutions advise that before the routine introduction of influenza immunization in all children aged 6-23 months old, immunization programs in high-risk children need to be implemented.

Vaccines for otitis media: proposals for overcoming obstacles to progress

Otitis media is a common problem with enormous morbidity worldwide. The development of vaccines to prevent otitis media would have an important human and economic impact. A striking lack of progress in the development, production and clinical testing of vaccines to prevent otitis media has occurred in the past decade. This review outlines a series of specific proposals intended to advance vaccine development for otitis media.

Chinchilla and murine models of upper respiratory tract infections with respiratory syncytial virus

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in infants and the elderly. While the primary infection is the most serious, reinfection of the upper airway throughout life is the rule. Although relatively little is known about either RSV infection of the upper respiratory tract or host mucosal immunity to RSV, recent literature suggests that RSV is the predominant viral pathogen predisposing to bacterial otitis media (OM). Herein, we describe mouse and chinchilla models of RSV infection of the nasopharynx and Eustachian tube. Both rodent hosts were susceptible to RSV infection of the upper airway following intranasal challenge; however, the chinchilla proved to be more permissive than the mouse. The chinchilla model will likely be extremely useful to test the role of RSV in bacterial OM and the efficacy of RSV vaccine candidates designed to provide mucosal and cytotoxic T-lymphocyte immunity. Ultimately, we hope to investigate the relative ability of these candidates to potentially protect against viral predisposal to bacterial OM.

Antimicrobial resistance in the nasopharyngeal flora of children with acute otitis media and otitis media recurring after amoxicillin therapy

The objective of this study was to investigate the antimicrobial susceptibility of the organisms isolated from the nasopharynx of children who presented with acute otitis media (AOM) or otitis media that recurred after amoxicillin therapy. Nasopharyngeal cultures obtained from 72 patients, 40 with AOM and 32 with recurrent otitis media (ROM), were analysed. Thirty-six potentially pathogenic organisms were recovered in 34 (85 %) of the children from the AOM group, and 42 were isolated from 29 (91 %) of the children from the ROM group. The organisms isolated were Streptococcus pneumoniae (n = 26), Haemophilus influenzae non-type b (n = 22), Moraxella catarrhalis (n = 13), Streptococcus pyogenes (n = 8) and Staphylococcus aureus (n = 9). Resistance to the eight antimicrobial agents used was found in 37 instances in the AOM group as compared to 99 instances in the ROM group (P < 0.005). The difference between AOM and ROM was significant with Streptococcus pneumoniae resistance to amoxicillin (P < 0.005), to amoxicillin/clavulanate (P < 0.005), to trimethoprim/sulfamethoxazole (P < 0.01), to cefixime (P < 0.01) and to azithromycin (P < 0.01), and for H. influenzae resistance to amoxicillin (P < 0.025). These data illustrate the higher recovery rate of antimicrobial-resistant Streptococcus pneumoniae and H. influenzae from the nasopharynx of children who had otitis media that recurred after amoxicillin therapy than those with AOM.