Epidemiology of viral respiratory tract infections in a prospective cohort of infants and toddlers attending daycare

Department of Pediatrics, Madigan Army Medical Center, BLDG 9040 Fitzsimmons Drive, Tacoma, WA 98431, United States.
Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology (Impact Factor: 3.02). 09/2010; 49(1):16-20. DOI: 10.1016/j.jcv.2010.06.013
Source: PubMed


The epidemiology of respiratory tract infections (RTIs) in a daycare cohort has not been explored using molecular techniques.
(1) Determine the overall incidence of RTIs in a daycare cohort using real-time reverse transcriptase polymerase chain reaction (RT-PCR). (2) Determine the relative incidence and impact of specific respiratory viruses, and characterize and compare clinical features associated with these pathogens.
In this prospective cohort study conducted from February 2006 to April 2008, nasal swabs were obtained from symptomatic children ages 0-30 months enrolled in fulltime daycare. RT-PCR was performed to detect respiratory syncytial virus (RSV), human metapneumovirus (MPV), influenza (Flu) viruses A and B, parainfluenza (PIV), adenovirus (AdV), human coronaviruses (CoV) and rhinovirus (RhV). Symptom diaries were completed for each illness.
We followed 119 children (mean age 10 months; range 2-24 months) for 115 child years. The mean annual incidence of RTI per child was 4.2 the first year and 1.2 the second year of the study. At least 1 virus was identified in 67% RTIs. Co-infections were common (27% RTIs), with RhV, CoV, and AdV the most common co-pathogens. PIV was identified in 12% of RTIs with a high incidence of PIV4. The viruses with the greatest impact on our population were RSV, RhV and AdV.
Using molecular techniques, viruses were identified in approximately twice as many RTIs as previously reported in a daycare cohort. Infections with newly identified viruses, such as HMPV and CoV subtypes were less frequent and severe than infections with RSV, AdV and RhV.

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    • "The mean annual incidence of respiratory tract infections in the United States was reported to be 4.2 and 1.2 for the first and the second years of a child's life, respectively. Furthermore, 27% of respiratory tract infections resulted from coinfection with two or more viruses, including rhinovirus, human coronavirus, and adenovirus [4]. Since the year 2000, many new respiratory viruses have been identified including H5N1 avian influenza, SARS-coronavirus, human coronavirus NL63, human coronavirus HKU1, human metapneumovirus, human bocavirus, and human rhinovirus type C [5, 6]. "
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    ABSTRACT: A total of 84 nasopharyngeal swab specimens were collected from 84 patients. Viral nucleic acid was extracted by three automated extraction systems: QIAcube (Qiagen, Germany), EZ1 Advanced XL (Qiagen), and MICROLAB Nimbus IVD (Hamilton, USA). Fourteen RNA viruses and two DNA viruses were detected using the Anyplex II RV16 Detection kit (Seegene, Republic of Korea). The EZ1 Advanced XL system demonstrated the best analytical sensitivity for all the three viral strains. The nucleic acids extracted by EZ1 Advanced XL showed higher positive rates for virus detection than the others. Meanwhile, the MICROLAB Nimbus IVD system was comprised of fully automated steps from nucleic extraction to PCR setup function that could reduce human errors. For the nucleic acids recovered from nasopharyngeal swab specimens, the QIAcube system showed the fewest false negative results and the best concordance rate, and it may be more suitable for detecting various viruses including RNA and DNA virus strains. Each system showed different sensitivity and specificity for detection of certain viral pathogens and demonstrated different characteristics such as turnaround time and sample capacity. Therefore, these factors should be considered when new nucleic acid extraction systems are introduced to the laboratory.
    BioMed Research International 04/2014; 2014:430650. DOI:10.1155/2014/430650 · 2.71 Impact Factor
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    • "Attending childcare or kindergarten was previously reported as a risk factor for GI and respiratory symptoms.5,17–20 Our results support those findings but additionally suggest that childcare/kindergarten attendance increases the risks of these health outcomes by approximately 60%. "
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    ABSTRACT: Background Although gastrointestinal (GI), respiratory, and dermal symptoms are common, few studies have conducted concurrent and comparative prospective analyses of risk factors for these 3 morbidity outcomes. Methods We used data from a community-based randomized controlled trial among 277 South Australian families to analyze GI (diarrhea, vomiting), respiratory (sore throat, runny nose, cough) and dermal (rash, generalized itch, dermal infection) symptoms. Results Log-binomial regression analysis revealed similar risks of GI (adjusted risk ratio [RR], 1.65; 95% CI, 1.05–2.58) and respiratory (RR, 1.68; 95% CI, 1.31–2.15) symptoms among childcare/kindergarten attendees. Swimming in public pools/spas in the current or previous week was associated with all 3 symptom complexes, conferring similar risk for each (RR for GI: 1.33; 95% CI, 0.99–1.77; respiratory: 1.20; 95% CI, 1.04–1.38; dermal: 1.41; 95% CI, 1.08–1.85). Pet ownership was not associated with symptoms. Household clustering of GI and respiratory symptoms was common, and clustering of respiratory symptoms correlated with number of individuals per household. Conclusions This simultaneous examination of risk factors for 3 health outcomes yielded new comparative data that are useful for developing prevention strategies.
    Journal of Epidemiology 11/2013; 24(1). DOI:10.2188/jea.JE20130082 · 3.02 Impact Factor
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    • "Coinfections were common, occurring in 20.4% of RTIs, with some pathogens, such as RhV and MPV, being commonly identified as coinfections while others, such as AdV and RSV were mostly detected as single infections. Similar rates (between 11.1% and 39.6%) were found in other PCR based studies [10,11,13,14]. Sensitive RT-PCR assays make it possible to identify a large spectrum of viral agents, but an identified virus may be concerned with persistence of a virus after a recently afflicted RTI. "
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    ABSTRACT: Background The purpose of this study was to determine the incidence and seasonal distribution of viral etiological agents and to compare their clinical manifestations and disease severity, including single and co infections. Methods Multiplex reverse-transcription PCR was performed for the detection of viruses in nasopharyngeal aspirat. Disease severity was grouped using a categorization index as very mild/mild, and moderate/severe. Clinical and laboratory characteristics of hospitalized children with viral respiratory tract infection were analyzed. Results Viral pathogens were detected in 103/155 (66.5%) of patients. In order of frequency, identified pathogens were respiratory syncytial virus (32.0%), adenovirus (26.2%), parainfluenza viruses type 1–4 (19.4%), rhinovirus (18.4%), influenza A and B (12.6%), human metapneumovirus (12.6%), coronavirus (2.9%), and bocavirus (0.9%). Coinfections were present in 21 samples. Most of the children had very mild (38.8%) and mild disease (37.9%). Severity of illness was not worse with coinfections. The most common discharge diagnoses were "URTI" with or without LRTI/asthma (n=58). Most viruses exhibited strong seasonal patterns. Leukocytosis (22.2%) and neutrophilia (36.6%) were most commonly detected in patients with adenovirus and rhinovirus (p<0.05). Monocytosis was the most remarkable finding in the patients (n=48, 53.3%), especially in patients with adenovirus (p<0.05). Conclusions RSV and RhV were associated with higher severity of illness in hospitalized children. RSV found to account for half of LRTI hospitalizations. In AdV and FluA and B infections, fever lasted longer than in other viruses. Coinfections were detected in 21 of the patients. The presence of coinfections was not associated with increased disease severity.
    Italian Journal of Pediatrics 03/2013; 39(1):22. DOI:10.1186/1824-7288-39-22 · 1.52 Impact Factor
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