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.

BACKGROUND: Viral upper and lower respiratory tract infections (URI, LRI) are common in infants. We determined the prevalence of viral URI and its complications, including acute otitis media (AOM) and LRI, and assessed the effect of bacterial-viral interactions, and genetic and environmental risks on AOM development.

WHAT'S KNOWN ON THIS SUBJECT: Rhinoviruses are commonly detected in both acutely ill and asymptomatic infants and children. The finding may represent new infection or prolonged presence of rhinovirus RNA in the respiratory tract. WHAT THIS STUDY ADDS:In young, otherwise healthy infants, shedding of RNA from the same rhinovirus strain rarely persisted longer than 30 days. abstract BACKGROUND: Current molecular diagnostic methods have detected rhinovirus RNA in a high proportion of asymptomatic infants and children, raising the question of the clinical significance of these findings. This study investigates the prevalence of prolonged rhinovirus RNA presence in the upper respiratory tract of infants during the first year of life. METHODS:In a longitudinal study, infants were followed from birth up to 12 months. Nasopharyngeal specimens were collected monthly (months 1-6 and month 9) and during an upper respiratory infection. Rhinoviruses were detected by quantitative reverse-transcription polymerase chain reaction. Presence of repeated rhinovirus RNA was evaluated by nucleotide sequence analysis. RESULTS:A total of 2153 specimens from 362 infants were studied; 341 distinct rhinovirus infections in 216 infants were identified. Follow-up specimens were available within 30 days for 179 infections, creating the sample set to assess prolonged rhinovirus presence. Of the 179 infections, 46 involved the detection of the same rhinovirus strain in repeated specimens, including 8 events of prolonged presence of the same strain (detected in specimens collected .30 days apart), representing 4.5% of the evaluable rhinovirus infections. There were 26 events in which a rhinovirus strain was replaced by a different strain within a 30-day interval, representing 14.5% of the 179 infections. CONCLUSIONS:Although rhinovirus infections are common in healthy infants, prolonged presence of rhinovirus RNA in the respiratory tract after an upper respiratory infection was uncommon (,5%). Detection of rhinovirus RNA in an infant most likely represents an infection within a 30-day period. Dr Loeffelholz co-conceptualized and co-designed the study and wrote the initial manuscript; Dr Trujillo coordinated data collection; Dr Pyles conceptualized and supervised molecular virology studies and reviewed and revised the manuscript; Mr Miller performed molecular virology studies and provided interpretation of the data for inclusion in the manuscript; Dr Alvarez-Fernandez supervised data collection; Dr Pong performed molecular virology studies and performed data collection and analysis; Dr Chonmaitree conceptualized and designed the study, provided overall study supervision, and revised the manuscript; and all authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. 4,5 A study in adult volunteers showed that cultivatable rhinoviruses were routinely recovered for ∼2 weeks after infection. 6 Recurrent rhinovirus infection has been described in patients with asthma 7 and in those at risk of developing...

Background Acute bacterial sinusitis (ABS) is a common complication of viral upper respiratory tract infections (URI). Clinical characteristics of URIs complicated by ABS in young children have not been well studied. Methods We identified ABS episodes in a prospective, longitudinal cohort study of 294 children (6 to 35 months of age at enrollment), who were followed-up for one year to capture all URI episodes and complications. At the initial URI visit seen by the study personnel (median day=4 from symptoms onset), nasopharyngeal samples were obtained for bacterial cultures and viral studies. Results Of 1295 documented URI episodes, 103 (8%) episodes (in 73 children) were complicated by ABS, 32 of which were concurrent with acute otitis media. The majority (72%) of ABS episodes were diagnosed based on persistent symptoms or a biphasic course. Average age at ABS diagnosis was 18.8±7.2 months; white children were more likely to have ABS episodes than blacks (p=0.01). Hispanic/Latino ethnicity (p<0.0001) was negatively associated, and adequate PCV-7 immunization status (p=0.001) appeared to increase the risk of ABS. Girls had more ABS episodes than boys (0.5±0.8 vs 0.3±0.6 episodes/year, respectively, p=0.03). Viruses were detected in 63% during the initial URI visit; rhinovirus detection was positively correlated with ABS risk (p=0.01). Bacterial cultures were positive in 82/83 (99%) available samples obtained at the initial URI visit; polymicrobial (56%), Moraxella catarrhalis (20%) and Streptococcus pneumoniae (10%) were the most common cultures. Presence of pathogenic bacteria overall and presence of M. catarrhalis during URI were positively correlated with the risk for ABS (p=0.04 for both). Conclusion ABS complicates 8% of URI in young children. Girls have more frequent ABS episodes than boys. Presence of rhinovirus and M. catarrhalis during URI are positively correlated with the risk for ABS complication.

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.