Rates Of Acute Otitis Media Research Articles

Bacterial etiology of acute otitis media and characterization of pneumococcal serotypes and genotypes among children in Moscow, Russia.

We aimed to describe bacterial etiology of acute otitis media (AOM) and characterize resistance, serotypes and genotype profiles of AOM-causing pneumococci recovered in Moscow children. Children with AOM and an available middle ear fluid specimen were prospectively enrolled in this study. Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae and Moraxella catarrhalis were considered as true otopathogens. All pneumococcal isolates were serotyped using the Quellung reaction; multidrug-resistant (MDR) pneumococci underwent multilocus sequence typing. In 172 of 541 enrolled AOM patients (32%) at least 1 otopathogen was recovered, with S. pneumoniae having the highest rate of 63% (109/172). When adjusted for antibiotic treatment before sampling, in untreated patients the rate of culture-positive AOM was 35% (124/352), S. pneumoniae had a prevalence of 69% (86/124), S. pyogenes 19% (24/124), H. influenzae 13% (16/124) and M. catarrhalis 9% (11/124). Among 107 examined pneumococci, 45% were penicillin-nonsusceptible, 34 and 30% were resistant to erythromycin and clindamycin, respectively; 30% had an MDR phenotype, but no amoxicillin-resistant isolates were found. Ten of 32 (31%) MDR pneumococci related to clonal complex 320, the remaining isolates belonged to 7 different clonal complex. Six leading serotypes were 19F (27%), 3 (12%), 6B (11%), 14 (11%), 19A (9%) and 23F (8%); overall polysaccharide conjugate vaccine13 coverage was 93%. S. pneumoniae, the leading bacterial AOM pathogen in Moscow children, is characterized by a substantial rate of antibiotic nonsusceptibility and clonality. A polysaccharide conjugate vaccine with expanded coverage seems to fit the current AOM pneumococcal serotype distribution in Russia better.

Symptomatic and Asymptomatic Respiratory Viral Infections in the First Year of Life: Association With Acute Otitis Media Development

Sensitive diagnostic assays have increased the detection of viruses in asymptomatic individuals. The clinical significance of asymptomatic respiratory viral infection in infants is unknown. High-throughput, quantitative polymerase chain reaction assays were used to detect 13 common respiratory viruses from nasopharyngeal specimens collected during 2028 visits from 362 infants followed from near birth up to 12 months of age. Specimens were collected at monthly interval (months 1-6 and month 9) and during upper respiratory tract infection (URTI) episodes. Subjects were followed closely for acute otitis media (AOM) development. Viruses were detected in 76% of 394 URTI specimens and 27% of asymptomatic monthly specimens. Rhinovirus was detected most often; multiple viruses were detected in 29% of the specimens. Generalized mixed-model analyses associated symptoms with increasing age and female sex; detection of respiratory syncytial virus (RSV), influenza, rhinovirus, metapneumovirus, and adenovirus was highly associated with symptoms. Increasing age was also associated with multiple virus detection. Overall, 403 asymptomatic viral infections in 237 infants were identified. Viral load was significantly higher in URTI specimens than asymptomatic specimens but did not differentiate cases of URTI with and without AOM complication. The rate of AOM complicating URTI was 27%; no AOM occurred following asymptomatic viral infections. AOM development was associated with increasing age and infection with RSV, rhinovirus, enterovirus, adenovirus, and bocavirus. Compared to symptomatic infection, asymptomatic viral infection in infants is associated with young age, male sex, low viral load, specific viruses, and single virus detection. Asymptomatic viral infection did not result in AOM.

Dominance of Haemophilus influenzae in ear discharge from Indigenous Australian children with acute otitis media with tympanic membrane perforation

BackgroundIndigenous Australian children living in remote communities experience high rates of acute otitis media with tympanic membrane perforation (AOMwiP). Otitis media in this population is associated with dense nasopharyngeal colonization of three primary otopathogens; Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Little is known about the relative abundance of these pathogens during infection. The objective of this study was to estimate the abundance and concordance of otopathogens in ear discharge and paired nasopharyngeal swabs from children with AOMwiP (discharge of not more than 6 weeks’ duration and perforation size <2%).MethodsCulture and quantitative PCR (qPCR) estimation of H. influenzae, S. pneumoniae, M. catarrhalis and total bacterial load were performed on paired nasopharyngeal and ear discharge swabs from 55 Indigenous children with AOMwiP aged 3.5 – 45.6 months and resident in remote communities.ResultsBy culture, H. influenzae, S. pneumoniae, and M. catarrhalis were detected in 80%, 84% and 91% of nasopharyngeal swabs, and 49%, 33% and 4% of ear discharge swabs, respectively. Using qPCR, H. influenzae, S. pneumoniae, and M. catarrhalis were detected in 82%, 82%, and 93% of nasopharyngeal swabs, and 89%, 41% and 18% of ear discharge swabs, respectively. Relative abundance of H. influenzae in ear discharge swabs was 0-68% of the total bacterial load (median 2.8%); whereas S. pneumoniae and M. catarrhalis relative abundances were consistently <2% of the total bacterial load. S. pneumoniae and M. catarrhalis abundances were significantly lower in ear discharge compared with nasopharyngeal swabs (p = 0.001, p < 0.001); no significant difference was observed in H. influenzae mean abundance at the two sites.ConclusionsH. influenzae was the dominant otopathogen detected in ear discharge swabs collected from children with AOMwiP. High prevalence and abundance of S. pneumoniae and M. catarrhalis in the nasopharynx did not predict ear discharge prevalence and abundances of these pathogens. PCR was substantially more sensitive than culture for ear discharge, and a necessary adjunct to standard microbiology. Quantitative methods are required to understand species abundance in polymicrobial infections and may be needed to measure accurately the microbiological impact of interventions and to provide a better understanding of clinical failure in these children.

Role of Human Bocavirus in Upper Respiratory Tract Infections and Acute Otitis Media.

BackgroundHuman bocavirus (HBoV) is a newly described parvovirus. HBoV1 has been associated with respiratory infections, including acute otitis media (AOM), but the knowledge on the significance of HBoV1 in upper respiratory tract infections (URI) and AOM in relation to other respiratory viruses is limited. The objective of this study was to compare the rate of detection of HBoV1 to that of other respiratory viruses in specimens from children with URI, with and without AOM complication.MethodsNasopharyngeal secretions (NPS) were collected during URI from healthy children (6–35 months) followed prospectively for 1 year; specimens have been previously analyzed for broad spectrum of respiratory viruses. Archived NPS were analyzed for HBoV1 using a high-throughput, quantitative polymerase chain reaction method.ResultsSeven hundred and seven NPS samples collected during URI episodes from 201 children were studied for HBoV1. A total of 94 (47%) children tested positive for HBoV1 DNA during 172 (24%) URI episodes; HBoV1 was present as the only virus in 44 (6%) URI episodes. Overall, 37% of URI episodes were complicated by AOM. Of URI associated with single virus (n = 303), the rate of AOM complicating URI associated with HBoV1 only was 52% (23 of 44); this was a higher AOM rate, compared to that of other respiratory viruses.ConclusionsAmong URI associated with single respiratory virus, HBoV1-URI was commonly associated with AOM complication. The important role of HBoV1 on AOM pathogenesis needs to be studied further.

Improvement Rate of Acute Otitis Media Caused by Haemophilus influenzae at 1 Week Is Significantly Associated with Time to Recovery

Acute otitis media (AOM) is the most common upper respiratory tract infection in childhood. Children with AOM were enrolled at Tohoku Rosai Hospital between July 2006 and June 2011 if their middle ear fluid cultures after tympanocentesis yielded only Haemophilus influenzae. The susceptibilities of the isolates to ampicillin were determined, and microtiter biofilm assays and invasion assays using BEAS-2B cells were performed. The association between these bacterial characteristics and clinical relapses of AOM and treatment failures was evaluated. Seventy-four children (39 boys and 35 girls) with a median age of 1 year (interquartile range [IQR], 0.25 to 2 years) were enrolled. Among 74 H. influenzae isolates, 37 showed intermediate resistance or resistance to ampicillin (MIC, ≥ 2 μg/ml). In the microtiter biofilm assay, the median optical density at 600 nm (OD600) was 0.68 (IQR, 0.24 to 1.02), and 70 isolates formed biofilms. The median invasion rate was 15% (IQR, 0 to 10%), and 46 isolates invaded BEAS-2B cells. Relapses and treatment failures occurred in 19 and 6 children, respectively. There was no significant difference in the invasion rates between patients with and those without relapses or treatment failures. Also, there was no significant association between biofilm formation and relapse or treatment failure. The improvements in the severity scores after 1 week were significantly associated with the recovery time (P < 0.0001). We did not identify any significant association between relapse or treatment failure and bacterial factors. AOM has a multifactorial etiology, and this may explain why we could not find a significant association. An improvement in the severity score after 1 week of treatment may be a useful predictor of the outcome of AOM.

What is the role of tympanostomy tubes in the treatment of recurrent acute otitis media?

What is the role of tympanostomy tubes in the treatment of recurrent acute otitis media?

Burden of acute otitis media in primary care pediatrics in Italy: a secondary data analysis from the Pedianet database

BackgroundThe incidence of acute otitis media (AOM) vary from country to country. Geographical variations together with differences in study designs, reporting and settings play a role. We assessed the incidence of AOM in Italian children seen by primary care paediatricians (PCPs), and described the methods used to diagnose the disease.MethodsThis secondary data analysis from the Pedianet database considered children aged 0 – 6 years between 01/2003 and 12/2007. The AOM episodes were identified and validated by means of patient diaries. Incidence rates/100 person-years (PY) were calculated for total AOM and for single or recurrent AOM.ResultsThe 92,373 children (52.1% males) were followed up for a total of 227,361 PY: 23,039 (24.9%) presented 38,241 episodes of AOM (94.6% single episodes and 5.4% recurrent episodes). The total incidence rate of AOM in the 5-year period was 16.8 episodes per 100 PY (95% CI: 16.7-16.9), including single AOM (15.9 episodes per 100 PY; 95% CI: 15.7-16.1) and recurrent AOM (0.9 episodes per 100 PY; 95% CI: 0.9-0.9). There was a slight and continuously negative trend decrease over time (annual percent change −4.6%; 95%CI: -5.3, -3.9%). The AOM incidence rate varied with age, peaking in children aged 3 to 4 years (22.2 episodes per 100 PY; 95% CI 21.8-22.7). The vast majority of the AOM episodes (36,842/38,241, 96.3%) were diagnosed using a static otoscope; a pneumatic otoscope was used in only 3.7%.ConclusionsOur data fill a gap in our knowledge of the incidence of AOM in Italy, and indicate that AOM represents a considerable burden for the Italian PCP system. Educational programmes concerning the diagnosis of AOM are needed, as are further studies to monitor the incidence in relation to the introduction of wider pneumococcal conjugate vaccines.

Effectiveness of pandemic influenza A/H1N1 vaccine for prevention of otitis media in children

Our aim was to evaluate effectiveness of pandemic influenza A/H1N1 vaccine in preventing acute otitis media (AOM) and/or otitis media with effusion (OME), in a randomized, prospective and single-blind study conducted in the children aged of 6-60 months. This study was done between December 1, 2009 and April 30, 2010 during the pandemia between June 2009 and May 2010. On the healthy children, vaccinated against pandemic influenza A/H1N1 and age-matched unvaccinated controls, the rate of AOM, OME, and any otitis media (OM) attack (sum of AOM and OME attacks) confirmed by otoscopic and tympanometric examination, and their associations with risk factors were looked for. Otoscopic and tympanometric evaluation was done twice within the follow-up period of 4-8 weeks. Totally 46 vaccinated and 46 unvaccinated healthy children were enrolled. No difference in rates of AOM, OME, or OM was found between vaccinated and unvaccinated children. But logistic regression analysis revealed that unvaccinated children had 2.9-folds more risk for OME and OM, but not for AOM. Further, male gender and bottle feeding and/or using pacifier revealed significant relationships with AOM. We conclude that pandemic influenza A/H1N1 vaccine prevented OME rather than AOM attacks in children with 6-60 months of age.

The incidence of acute otitis media in New Zealand children under five years of age in the primary care setting

Acute otitis media (AOM) is a common childhood infection. Baseline data are required to evaluate potential changes in the epidemiology of AOM with new public health measures. To estimate the incidence of AOM in children under five years of age in primary care in New Zealand. Using a cohort study design, consultation notes from 1 November 2008 to 31 October 2009 from 63 primary care facilities were analysed for new and recurrent episodes of AOM, complications, antimicrobial use and outcome. There were 19 146 children in the sample. The raw incidence of AOM was 273 per 1000 children (27.3%; 95% CI 216-330). Of the 3885 children, 2888 (74%) had one episode of AOM and 152 (4%) of these children developed recurrent AOM. Incidence declined with age. There was no difference in incidence between Maori, Pacific and 'Other' ethnicities. Antibiotics were used to treat 2653 (51%) AOM episodes and 113 (4.3%) of these children re-presented within three days of antibiotic therapy for persistent symptoms. Tympanic membrane perforation was the only complication noted, observed in 62 (1%) episodes. These data indicate that AOM is an important and frequent childhood infection in New Zealand. The show a significant decline in the use of antibiotics to manage AOM in concordance with accepted best practice. The complication rate of AOM is likely under-represented. This study enables future research into the effectiveness of current and future immunisations and changing management practices in New Zealand.

ENT problems in Dutch children: Trends in incidence rates, antibiotic prescribing and referrals 2002–2008

Background. Ear, nose, and throat (ENT) problems are common in childhood and are important reasons to visit the general practitioner. Objective. To examine trends in incidence rates, antibiotic prescribing, and referrals of five common ENT problems in children. Design. Netherlands Information Network of General Practice (LINH), a nationally representative general practice database. Setting. A total of 50 000 children, aged 0–17 years, registered in Dutch general practice over the period 2002–2008. Methods. Incidence rates were calculated and trends were analysed using linear regression analysis, with incidence rates per age group, proportion treated with antibiotics, and referrals as dependent variables and year of observation as independent variable. Results. In general, incidence rates of acute otitis media, serous otitis, sinusitis, tonsillitis, and tonsil hypertrophy remained stable over the period 2002–2008. An increasing trend was observed for serous otitis media in children aged 0–4 years (RR = 1.04, p < 0.001). A decreasing trend was observed for sinusitis in children aged 5–11 and for tonsillitis in children aged 11–17 years (RR 0.99, p < 0.001 and RR 0.94, p < 0.001, respectively). Antibiotics were prescribed in 10–60% of the diagnoses. An increasing trend for antibiotic prescription was found for acute otitis media (beta = 0.07, p < 0.001), mainly on account of amoxicillin. Although antibiotic treatment of tonsillitis remained stable, pheneticillin prescriptions showed a downward trend (beta = −0.10, p < 0.001). First-choice antibiotics were prescribed in >80% of cases. Conclusions. This study showed remarkably stable trends in incidence rates, antibiotic prescribing, and referrals of common ENT problems. The low proportion of antibiotic treatment in ENT problems did not show negative consequences.

WITHDRAWN: Decongestants and antihistamines for acute otitis media in children.

Acute otitis media (AOM) is a common and important source of morbidity in children, although the majority of cases resolve spontaneously. While frequently recommended, decongestant and antihistamine therapy is of unclear benefit. To determine the efficacy of decongestant and antihistamine therapy in children with AOM on outcomes of AOM resolution, symptom resolution, medication side effects, and complications of AOM. In this updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2); MEDLINE (January 2004 to May 2007); and EMBASE (July 2003 to May 2007). Randomized controlled trials (RCTs) evaluating decongestant or antihistamine treatment for children with AOM were included. Patient-oriented outcomes were considered most relevant. The review authors independently evaluated studies for inclusion, performed validity assessments and completed data extraction. Dichotomous data were pooled to generate relative risks; homogeneity was assessed using approximate chi-square tests. No new studies were included following this updated search. Fifteen trials involving 2695 people were included. Only the combined decongestant-antihistamine group demonstrated statistically lower rates of persistent AOM at the two week period (fixed relative risk (RR) 0.76; 95% confidence interval (CI) 0.60 to 0.96; number needed to treat (NNT) 10). No benefit was found for early cure rates, symptom resolution, prevention of surgery or other complications. There was a five to eight -fold increased risk of side effects for those receiving an intervention, which reached statistical significance for all decongestant groupings. Validity sub analyses demonstrated that lower quality studies found benefit, while analysis of those studies with higher validity scores found no benefit of treatment. Given lack of benefit and increased risk of side effects, these data do not support the use of decongestant treatment in children with AOM. There was a small statistical benefit from combination medication use but the clinical significance is minimal and study design may be biasing the results. Thus, the routine use of antihistamines for treating AOM in children cannot be recommended.

Incidence and recurrence of acute otitis media in Taiwan's pediatric population

OBJECTIVE:To report the incidence and recurrence of acute otitis media (AOM) in Taiwan's pediatric population.METHODS:Information from children (aged< = 12 years) with a diagnosis of AOM was retrieved from the 2006 National Healthcare Insurance claims database. We calculated the cumulative incidence rate and the incidence density rate of recurrent AOM within one year after the initial diagnosis in 2006. We used a multivariate logistic regression model to assess the predictors for recurrence of AOM.RESULTS:The annual incidence rate of AOM was estimated to be 64.5 cases per 1,000 children. The overall one-year cumulative incidence rate of recurrence was 33.1%, and the incidence density rate was 33.5 cases per 100 person-years, with the highest figure (41.2 cases per 100 person-years) noted for children aged 0-2 years. Recurrence was significantly associated with age, gender, place of treatment, and physician specialty.CONCLUSION:AOM remains a major threat to children's health in Taiwan. Male children and very young children require more aggressive preventive strategies to reduce the risk of recurrence.

Treatment Failure, Recurrence, and Antibiotic Prescription Rates for Different Acute Otitis Media Treatment Methods

In an era of increasing antibiotic resistance, reliance on empirical antibiotic therapy for management of acute otitis media (AOM) will eventually become an untenable strategy. New research efforts are needed to identify effective treatment alternatives. In this retrospective analysis, we assessed AOM treatment failure (AOMTF), recurrent AOM (RAOM), and antibiotic prescription rates for groups of AOM episodes managed with either immediate antibiotics (ABX), tympanocentesis + observation (Tap + OBS), or tympanocentesis + immediate antibiotics (Tap + ABX). No significant differences in rates of AOMTF or RAOM were observed between any of the treatment groups. The 30-day rate of antibiotic prescriptions written for AOM was significantly lower in the TAP + OBS group (1 prescription per 3.8 episodes) than in the immediate antibiotic therapy groups (1.2 prescriptions per episode), P < .001. The comparative risk of AOMTF was slightly higher among AOM episodes caused by Streptococcus pneumoniae (OR 2.523; CI 1.070-5.944; P = 0.056). Neither the presence of other particular otopathogens, nor the presence of drug-resistant otopathogens, nor the choice of any particular AOM antibiotic therapy correlated with increased risk of either AOMTF or RAOM. The observed absence of significant differences in clinical outcomes between the various treatment groups in this study is consistent with findings published by other authors: alternative AOM therapies can help reduce reliance on antibiotics without inviting significant increases in rates of clinical failure.

Recent Advances in Otitis Media

Otitis media (OM) is a pervasive illness in infants and children, and many children suffer multiple episodes during the first years of life. High rates of acute otitis media (AOM) are reported in developed and emerging countries. Early onset is common in both settings. Recurrent OM is associated with several factors, including early onset of disease, having a sibling with a history of AOM and absence of breast-feeding. Early onset disease has been hypothesized to result from Eustachian tube dysfunction, immunologic naivete and immaturity, and viral upper respiratory tract infection. Nasopharyngeal colonization with bacterial otopathogens increases the likelihood of AOM and the disease is most frequent in children with viral respiratory tract infection colonized with multiple otopathogens (Streptococcus pneumoniae, nontypeable Haemophilus influenzae [NTHi], Moraxella catarrhalis), potentially as a result of inflammation resulting from competition among the bacterial species within the nasopharynx. Epidemiologic observations and studies of pathogenesis suggest that successful strategies for reducing the burden of disease will be best accomplished by targeting multiple viral and/or bacterial pathogens and preventing early onset disease. Guidelines (2004) for the treatment of AOM in children establish a clear hierarchy among the various antibacterials for the treatment of this disease. Failure to achieve early bacterial eradication during antibiotic therapy for AOM increases the clinical failure rates in AOM in young children. Most recurrent AOM episodes occurring within 1 month after successful completion of antibiotic therapy are due to new otopathogens. Failure to eradicate middle ear and/or nasopharyngeal pathogens is associated with higher rates of clinical recurrent AOM, even when the patients show clinical improvement or cure at the end of therapy for the initial episode. Optimal strategy for the prevention of AOM recurrences requires sterilization of the middle ear and eradication of nasopharyngeal carriage of otopathogens during antimicrobial therapy.

Association between Cytokine Gene Polymorphisms and Risk for Upper Respiratory Tract Infection and Acute Otitis Media

We previously reported an association between tumor necrosis factor alpha (TNFalpha)(-308)and interleukin (IL)-6(-174) polymorphisms and otitis susceptibility by history. Acute otitis media occurs most commonly as a complication of upper respiratory tract infection (URI); it is not clear why some children develop acute otitis media after URI and others do not. Our objective was to prospectively evaluate the association of TNFalpha(-308)and IL-6(-174) polymorphisms with URI and with acute otitis media development after URI. Children aged 6-35 months were prospectively followed for occurrences of URI and acute otitis media. Blood or buccal mucosa samples were collected for DNA extraction to determine cytokine genotypes. Active and passive surveillance was used to capture all URI episodes during the 1-year follow-up period in order to study the rate of acute otitis media following URI. Data were analyzed using SAS software (SAS Institute) and general estimating equations modeling. Two hundred forty-two children were followed over 2689 patient-months and had DNA genotyped; 1235 URI episodes occurred, and 392 (32%) were complicated by acute otitis media. Children who had IL-6(-174) polymorphism had a higher susceptibility to URI during the study period (incidence density ratio, 1.24) and were more likely to meet established otitis susceptibility criteria (P < .01). Presence of TNFalpha(-308) polymorphism was associated with increased risk for acute otitis media after an episode of URI (odds ratio, 1.43). TNFalpha(-308) and IL-6(-174) genotypes are associated with increased risk for symptomatic URI and acute otitis media following URI. Future studies may be designed to carefully look at the interaction of these genetic polymorphisms with modifiable environmental risk factors.

Acute otitis media in the first two months of life: characteristics and diagnostic difficulties

Objective:To assess the clinical and laboratory features of acute otitis media (AOM) in infants younger than 2 months, to look for factors predicting bacterial otitis, and to evaluate the accuracy...

Neonatal Vitamin A Deficiency and Its Impact on Acute Respiratory Infections among Preschool Inuit Children

To assess if vitamin A concentration in umbilical cord blood is associated with incidence and severity of respiratory infections in preschool Inuit children from Nunavik (Quebec, Canada). The medical charts of 305 children were reviewed from 0 to 5 years of age. The association between vitamin A concentration in umbilical cord plasma and the incidence rates of acute otitis media (AOM), lower respiratory tract infections (LRTIs) and hospitalization rates for LRTIs was evaluated using Poisson regression. Compared to children with vitamin A concentration >-20 μg/dl, adjusted rate ratios (RR) for children below 20 μg/dl ranged between 1.06–1.62 for AOM, 1.12–1.34 for LRTIs, and 1.09–1.43 for hospitalization for LRTIs. Most RRs were statistically significant for AOM and LRTIs, but not for hospitalization for LRTIs. Neonatal vitamin A deficiency appears to be a significant risk factor for AOM and LRTIs in this population.

Acute otitis media during the first two years of life in a rural community in Bangladesh: a prospective cohort study.

The study investigated the burden of acute otitis media (AOM) during the first two years of life in a cohort of 252 newborns in rural Bangladesh using data collected on occurrences of AOM. Trained community health workers (CHWs) conducted household surveillance and picked up cases of AOM using the study algorithm. The incidence rate was 0.9 episodes per child-year observed. Forty-six percent (n=115) of the 252 subjects developed AOM: 36% (n=91) during the first year of life and 10% (n=24) during the second year of life (p<0.001). The age-specific incidence rates of AOM varied; peaks occurred in the 6-12-month age-group and the lowest in the first three months of life. In total, 20% (n=49) of the study subjects had single, 26% (n=66) recurrent, and 54% (n=137) no episode of AOM. Perforation with discharge developed in 85% (n=322) of 375 episodes. The duration of discharge from the ears was < or =6 weeks in 95% of the episodes, but in 5% of the episodes, discharge from the ears continued for >6 weeks. The incidence of AOM was higher in the monsoon season compared to the summer season (p<0.003). The study documented AOM as an important cause of morbidity among rural children up to two years of age in Bangladesh and should be addressed with strategies to overcome the burden of disease.

Incidence of Acute Otitis Media and Sinusitis Complicating Upper Respiratory Tract Infection: The Effect of Age

Infants and young children are prone to developing upper respiratory tract infections, which often result in bacterial complications such as acute otitis media and sinusitis. We evaluated 623 upper respiratory tract infection episodes in 112 children (6-35 months of age) to determine the proportion of upper respiratory tract infection episodes that result in acute otitis media or sinusitis. Of all upper respiratory tract infections, 30% were complicated by acute otitis media and 8% were complicated by sinusitis. The rate of acute otitis media after upper respiratory tract infection declined with increasing age, whereas the rate of sinusitis after upper respiratory tract infection peaked in the second year of life. Risk for acute otitis media may be reduced substantially by avoiding frequent exposure to respiratory viruses (eg, avoidance of day care attendance) in the first year of life.

Mathematical model comparisons of potential non-typeable Haemophilus influenzae vaccine effects

Vaccines to prevent acute otitis media (AOM) caused by non-typeable Haemophilus influenzae (NTHi) are under development. Because NTHi is highly variable and colonization rates are high, special vaccine characteristics and trial designs might be needed. We examined in mathematical models the equilibrium NTHi-caused AOM rate given hypothetical vaccines that generated immunity identical to corresponding maximal naturally acquired immunity. Vaccines were examined with single effects and combinations of immunity affecting (1) AOM rates given colonization (pathogenicity), (2) susceptibility to colonization, and (3) contagiousness given colonization. Percent reductions in AOM across all preschool children were (1) 34%, (2) 31%, (3) 9%, (1 and 2) 57%, (2 and 3) 50%, and (1, 2, and 3) 75%. Effects on children in daycare vs. not in daycare were (1) 18 vs. 48%, (2) −1 vs. 57%, (3) 13 vs. 5%, (1 and 2) 30 vs. 79%, (2 and 3) 33 vs. 60%, and (1, 2, and 3) 64 vs. 85%. Pure pathogenicity effects (1 alone) will need to be supplemented by transmission effects. The effects of susceptibility (2 alone) are diminished or negative because children protected against colonization have lower levels of immunity to (1) and (3) than unvaccinated children. For trials to predict population effects, both colonization and AOM outcomes must be studied and all three effects must be evaluated. This need arises because, unlike H. influenzae type B, high NTHi exposure diminishes cumulative vaccine effects and high colonization rates generate rapid accumulation of natural immunity that alters the indirect effects of vaccine immunity on transmission differently by age and daycare status.