Distinction between rhinovirus-induced acute asthma and asthma-augmented influenza infection

Background: Rhinovirus (RV) is an established trigger of asthma attacks, whereas such a link is less consistent for influenza virus (IFV). Objective: In the context of precision medicine, we hypothesized that IFV infection may cause a condition essentially different from RV, and we investigated this by evaluating clinical characteristics of RV/IFV-positive and -negative children with respiratory symptoms and/or fever. Methods: One thousand two hundred and seven children, 6 months to 13 years old, hospitalized for flu-like illness were recruited in this cross-sectional study. Collected information included demographics, medical history, symptoms/physical findings/diagnosis at presentation and treatment. Nasal secretions were PCR-tested for IFV/RV. Associations were evaluated with adjusted logistic regression models. Results: Rhinovirus positivity was associated with an asthma-like presentation, including increased wheeze/effort of breathing/diagnosis of acute asthma, and decreased fever/vomiting. Conversely, IFV+ children presented with less wheeze/effort of breathing/diagnosis of acute asthma, while they were more frequently febrile. In those with previous asthma history, both viruses induced wheeze; however, IFV was uniquely associated with a more generalised and severe presentation including fever, rales, intercostal muscle retractions and lymphadenopathy. These symptoms were not seen in RV+ asthmatics, who had fewer systemic signs and more cough. Conclusions and Clinical relevance: In children with respiratory symptoms and/or fever, RV but not IFV is associated with wheeze and an asthma-like presentation. In those with an asthma history, IFV causes more generalised and severe disease that may be better described as “asthma-augmented influenza” rather than an “asthma attack.” Differences in the acute conditions caused by these viruses should be considered in the design of epidemiological studies. © 2018 John Wiley & Sons Lt

Performance of rapid influenza testing in hospitalized children

International audienceInfluenza infection is associated with high hospitalization rates among young children. Rapid diagnosis of influenza infection is particularly useful in order to prevent nosocomial infection and allows for the timely initiation of antiviral treatment. We evaluated the performance of a rapid influenza test in hospitalized children during the influenza season. All children (aged 6 months to 14 years) hospitalized with fever and/or respiratory symptoms, admitted during the 2005 influenza season, participated in the study. A multiplex reverse transcriptase polymerase chain reaction (RT-PCR), able to identify IFV-A H1N1, H3N2, and IFV-B subtypes, was performed on nasopharyngeal aspirates. The nasal swab was tested with a lateral-flow immunoassay (QuickVue Influenza Test). The performance of the rapid test was compared with the results of PCR. Influenza infection was diagnosed by PCR in 41/217 (19%) patients. Infection with influenza A virus (H3N2) was diagnosed in all cases. The performance of the QuickVue Influenza Test was estimated as follows: sensitivity 67.5%, specificity 96%, positive predictive value 79%, and negative predictive value 93%. The sensitivity of the test was higher in infants aged 6-12 months, in those with short duration of symptoms, and in the peak phase of the epidemic. The QuickVue Influenza Test is useful and reasonably accurate to detect influenza infection in hospitalized children during the influenza season. Infection with influenza virus is unlikely if the test is negative. A positive result suggests that infection is probable if influenza virus circulates in the community

Impact of influenza infection on children's hospital admissions during two seasons in Athens, Greece

A prospective epidemiologic surveillance of hospitalizations associated with influenza was conducted in order to calculate population-based hospitalization rates. Eligible children were 6 months to 13 years of age and were admitted to one of the two large children’s hospitals in the Athens area during two influenza seasons. Nasopharyngeal aspirates were tested for influenza by a polymerase reaction assay. Influenza accounted for 9.9-11.8% of all admissions during the influenza season and the overall annual rate of hospitalizations was 13.6-16.8 cases per 10,000 children being highest for children under 5 years of age (26-31.2/10,000 children). Febrile seizures and acute otitis media were the two most common complications associated with influenza and antibiotics were administered to 61% of flu positive patients. Influenza is associated with high hospitalization rates among young children and these may be substantially reduced with the introduction of routine immunization. (C) 2010 Published by Elsevier Ltd

Bsx, a Novel Hypothalamic Factor Linking Feeding with Locomotor Activity, Is Regulated by Energy Availability

We recently reported that the hypothalamic homeobox domain transcription factor Bsx plays an essential role in the central nervous system control of spontaneous physical activity and the generation of hyperphagic responses. Moreover, we found Bsx to be a master regulator for the hypothalamic expression of key orexigenic neuropeptide Y and agouti gene-related protein. We now hypothesized that Bsx, which is expressed in the dorsomedial and arcuate nucleus (ARC) of the hypothalamus, is regulated by afferent signals in response to peripheral energy balance. Bsx expression was analyzed using in situ hybridization in fed vs. fasted (24 h) and ghrelin vs. leptin-treated rats, as well as in mice deficient for leptin or the ghrelin signaling. Ghrelin administration increased, whereas ghrelin receptor antagonist decreased ARC Bsx expression. Leptin injection attenuated the fasting-induced increase in ARC Bsx levels but had no effect in fed rats. Dorsomedial hypothalamic nucleus Bsx expression was unaffected by pharmacological modifications of leptin or ghrelin signaling. Obese leptin-deficient (ob/ob) mice, but not obese melanocortin 4 receptor-knockout mice, showed higher expression of Bsx, consistent with dependency from afferent leptin rather than increased adiposity per se. Interestingly, exposure to a high-fat diet triggered Bsx expression, consistent with the concept that decreased leptin signaling due to a high-fat diet induced leptin resistance. Our data indicate that ARC Bsx expression is specifically regulated by afferent energy balance signals, including input from leptin and ghrelin. Future studies will be necessary to test if Bsx may be involved in the pathogenesis of leptin resistance