Highly frequent infections with human rhinovirus in healthy young children: A longitudinal cohort study
ABSTRACT Human rhinoviruses (HRVs) are an important cause of respiratory tract infections.
We questioned whether the high prevalence rates of HRVs found in epidemiological studies is due to long-term individual continuity or a result of frequent infections with different HRV subtypes.
In a 6-month winter period 18 healthy controls, aged 0-7 years, were at least sampled every two weeks for HRV-PCR, irrespective of respiratory symptoms. All HRV positive samples were genotyped to determine HRV diversity.
In total 272 samples were collected. HRV was found in 101/272 (37%) samples. Genotyping revealed 27 different HRV subtypes. A median of 3.0 different HRV subtypes was found per child. Re-infections and continuity with identical HRV sequences were observed. The number of HRVs were higher in the youngest age group (p=0.01) and they had more different HRV subtypes (p=0.05) compared to oldest age group.
We found a high HRV exposition with a considerable diverse population of HRV subtypes in young children. These results have major implications for future research into the pathogenic role of HRV in respiratory diseases. Characterisation of subtypes will be necessary to discriminate between prolonged continuity and re-infections in patients with respiratory diseases.
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ABSTRACT: Background: Infants, toddlers, and children of primary-school age without any special risk factors generally have three to ten febrile respiratory infections per year. Most such infections are of viral origin and self-limiting, but viral infection is often hard to distinguish from bacterial infection. The use of a multiplex polymerase chain reaction (PCR) to detect viruses in respiratory secretions is potentially beneficial, as it might help physicians avoid giving antibiotics unnecessarily. Methods: This article is based on a selective review of the literature and on the findings of the authors' own investigations. Results: Multiplex PCR is a highly sensitive, highly specific test for the detection of viral nucleic acids in respiratory secretions. If PCR reveals the presence of RNA derived from respiratory syncytial virus, human metapneumovirus, parainfluenza virus, or influenza virus, then an acute infection caused by the corresponding pathogen is probably present, and further treatment can be given accordingly. On the other hand, the nucleic acids of adeno-, boca-, rhino-or coronaviruses can be found in relatively trivial infections as well as in asymptomatic persons, probably reflecting either a prior infection or a current subclinical one. For children in particular, upper respiratory infections are so common in the winter months that acute and prior infections with these pathogens cannot be distinguished by multiplex PCR. The use of multiplex PCR in children has not been shown to shorten hospital stays or to lessen antibiotic consumption or overall cost. Conclusion: The detectability of viral nucleic acids is an important contribution to the diagnostic assessment of children with severe respiratory infection. For these highly sensitive diagnostic tests to be used optimally, primary viral infections must be distinguished from bacterial superinfections.Deutsches Ärzteblatt International 09/2014; 111(38):639-45. DOI:10.3238/arztebl.2014.0639 · 3.61 Impact Factor
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ABSTRACT: Enteroviruses (EVs) often infect humans, presenting as endemic or epidemic infections. In this study, the diversity of infecting EVs was studied among 146 children and 137 adults in a small community in Cameroon. The participants provided 2,458 fecal samples during 1-year monthly collection; 10 or more samples were obtained from 55%. Partial 5′UTR-VP4 region could be sequenced in 393/547 PCR positive samples obtained from 119 children and 85 adults. EV-RNA was detected in at least one sample from 235 participants (83%) during the study period. A total of 121 different strains were identified, 66 infected only children, 29 only adults, and 26 infected both children and adults. There were children with up to five episodes with different strains, and adults with up to four such episodes. Infants aged <5 years were significantly more often EV infected compared to older participants. Infections with species EV-C constituted two third of all cases, and overall EV infections were more common during the rainy season. Species EV-B more often infected children than adults. Most strains were detected only for certain months of the year; however five strains were observed during the time spans of 5–10 months. Two strains were excreted up to eight months in three children and one adult. In 11 of the 128 families with paired samples the child and the adult were infected simultaneously by the same strain, indicating common source of infection. The study revealed a surprising complexity of EV ecosystem in a single community. J. Med. Virol. © 2014 Wiley Periodicals, Inc.Journal of Medical Virology 03/2014; DOI:10.1002/jmv.23926 · 2.22 Impact Factor
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ABSTRACT: There is evidence that respiratory viruses play a key role in the development and exacerbation of obstructive respiratory diseases in children. This review attempts to juxtapose the separate profiles and prototypes of pathogenenetic mechanisms represented by the two most common amongst such viruses: respiratory syncytial virus (RSV) and human rhinovirus (HRV). RSV represents the most common agent of severe airway disease in infants and young children, and is predominant in winter months. Large epidemiological studies have revealed an unequivocal relationship between RSV infection and subsequent wheezing into childhood, thought to be related to long-term changes in neuroimmune control of the airways rather than allergic sensitisation. HRV is a highly diverse group of viruses that affect subjects of all ages, is ubiquitous and occurs year-round. In contrast to RSV, infections with HRV cause minimal cytotoxicity but induce a rapid production of cytokines and chemokines with amplification of the inflammatory response. The susceptibility to HRV-induced bronchiolitis and subsequent wheezing appears to be linked to individual predisposition since it is often associated with a family or personal history of asthma/atopy. Thus, RSV probably serves as an "inducer" rather than a "trigger". Conversely, HRVs seem to serve as a "trigger" rather than an "inducer" in predisposed individuals.European Respiratory Journal 10/2014; DOI:10.1183/09031936.00062714 · 7.13 Impact Factor