BackgroundAcute otitis media (AOM) is a frequent complication of viral upper respiratory tract infection (URI). We hypothesized that severity of nasopharyngeal cellular injury during URI, as measured by lactate dehydrogenase (LDH) concentrations in nasopharyngeal secretions (NPS), is related to AOM complication.MethodsLDH concentrations were determined in NPS samples (n=594) which were collected at the initial visit for URI from 183 children who were followed for development of AOM. A subset of NPS samples (n= 134) were analyzed for interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF) α concentrations.ResultsAOM complication was independently predicted by LDH concentrations (median mU/ml with AOM = 2438 vs. without AOM = 1573, estimate=0.276; P=0.02). LDH effect on AOM development was highest during the first 4 days of URI. LDH concentrations were higher in URIs due to adenoviruses, bocaviruses, and rhinoviruses when compared to virus-negative samples (P <0.05). There was a positive correlation between concentrations of LDH and all cytokines (P< 0.001).ConclusionLDH concentrations in NPS are positively associated with AOM risk, suggesting that the severity of nasopharyngeal inflammatory injury during URI contributes to the development of AOM, and that reduction of inflammatory injury may reduce the risk for AOM.

Objectives Infants and children with upper respiratory tract infection (URI) often have concurrent acute otitis media (AOM). Young infants have less specific symptoms than older children. The purpose of this study was to evaluate the usefulness of symptoms and other risk factors in predicting the presence of AOM in infants. Methods Healthy infants, age ≤ four weeks, were enrolled and followed prospectively for up to age one year. Infants were scheduled for a research visit when their parents noted the onset of symptoms. At each URI visit, parents first reported the severity of symptoms. An investigator then diagnosed the presence or absence of concurrent AOM. Risk factors and symptom scores for infants with and without AOM were studied. Results Infants (N=193, mean age at first URI 3.9 ± 2.5 months) experienced 360 URI episodes and 63 AOM events. Symptoms consisting of fever, earache, poor feeding, restless sleep, and irritability together (ETG-5) were statistically associated with the prediction of AOM (P=0.006). A multiple variable statistical model (J-Score) that included day care attendance, age, severity of cough and earache best predicted AOM (P < 0.001), with 95% specificity. Both ETG-5 and J-score yielded relatively low sensitivity for AOM prediction. Conclusions : In infants with URI in the first year of life, severity of symptoms was significantly associated with concurrent AOM. Daycare attendance, presence and severity of earache and cough added to better correlation. These observations may have clinical application in identification of infants at risk for AOM.

Background Effect of the 2009 H1N1 influenza pandemic on viral epidemiology of upper and lower respiratory tract infections (URI and LRI) in healthy infants in the first year of life has not been well studied. Methods A total of 180 healthy infants were enrolled from birth and monitored for occurrences of URI and its LRI and acute otitis media (AOM) complications until the first AOM episode or between 6 and 12 months of age. Nasopharyngeal specimens collected during acute respiratory illnesses were tested for 18 viruses. Results Between October 2008 and April 2011, 373 URI episodes, including 20 with LRI, in 139 infants were documented. Viral studies were performed on 189 URI episodes; 87% were positive. Throughout the 31-month period (1386 patient-months), rhinovirus was the predominant virus causing URI (55%); RSV was the major cause of LRI (64%). While there was a significant increase in parent-initiated visit rate during the 15-month influenza pandemic as compared with pre- and post- pandemic periods, only 4 cases of influenza were detected (2 cases during and 2 cases pre- and post- pandemic). Conclusion The 2009 influenza A/H1N1 pandemic had no impact on the overall viral epidemiology of respiratory infections in healthy infants in the first year of life but resulted in increased parent-initiated visits due to respiratory symptoms. Maternal antibody and absence of co-morbidity may explain the low influenza burden while parental anxiety may explain the increased healthcare visit rate during the pandemic.

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