Rationale: Human rhinoviruses (HRV) are the leading cause of upper respiratory infections and have been postulated to trigger asthma exacerbations. However, whether HRV are detected during crises because upper respiratory infections often accompany asthma attacks, or because they specifically elicit exacerbations, is unclear. Moreover, although several hypotheses have been advanced to explain virus-induced exacerbations, their mechanism remains unclear. Objectives: To determine the role of HRV in pediatric asthma exacerbations and the mechanisms mediating wheezing. Methods: We prospectively studied 409 children with asthma presenting with upper respiratory infection in the presence or absence of wheezing. Candidate viral and immune mediators of illness were compared among children with asthma with different degrees of severity of acute asthma. Measurements and Main Results: HRV infections specifically associated with asthma exacerbations, even after adjusting for relevant demographic and clinical variables defined a priori (odds ratio, 1.90; 95% confidence interval, 1.21-2.99; P ¼ 0.005). No difference in virus titers, HRV species, and inflammatory or allergic molecules was observed between wheezing and nonwheezing children infected with HRV. Type III IFN-l 1 levels were higher in wheezing children infected with HRV compared with nonwheezing (P , 0.001) and increased with worsening symptoms (P , 0.001). Moreover, after adjusting for IFN-l 1 , children with asthma infected with HRV were no longer more likely to wheeze than those who were HRV-negative (odds ratio, 1.18; 95% confidence interval, 0.57-2.46; P ¼ 0.66). Conclusions: Our findings suggest that HRV infections in children with asthma are specifically associated with acute wheezing, and that type III IFN-l 1 responses mediate exacerbations caused by HRV. Modulation of IFN-l 1 should be studied as a therapeutic target for exacerbations caused by HRV.Keywords: asthma; interferon-l; rhinovirus; children; asthma exacerbation Asthma exacerbations are the main cause of hospitalization in children, and occur in association with respiratory viral infections (1, 2). Human rhinoviruses (HRV) are frequently isolated in the upper airways of children during respiratory infections and during asthma attacks, and have been postulated to trigger these crises (3, 4). However, whether HRV are detected during asthma crises because they are the most frequent cause of upper respiratory infections (URI; which accompany asthma attacks), or because they can specifically elicit asthma exacerbations is unclear. To our knowledge, no pediatric study has compared the viral etiology of URI in patients with asthma with and without wheezing to investigate the specific association between HRV URI and asthma attacks.Several hypotheses have been advanced to explain the mechanisms that trigger asthma crises during respiratory infections (4-7). Focused mainly on HRV-associated episodes, two nonexclusive theories attribute asthma attacks to direct viral injury and immune-mediated exacerbations ...

Background Human rhinoviruses (HRVs) cause common colds, and the recently discovered HRV-C is increasingly associated with lower respiratory illness among populations such as children and asthmatic patients. Objective To determine how HRV-C is associated with respiratory illness and to evaluate changes in prevalence and species over 2 decades. Methods A prospective study of children younger than 5 years was performed at the Vanderbilt Vaccine Clinic over a 21-year period. Nasal-wash specimens from children presenting with upper or lower respiratory illness at acute care visits were tested for HRV and HRV-positives genotyped. Demographic and clinical features were compared between children with or without HRV, and with different HRV species. Results HRV was detected in 190 of 527 (36%) specimens from a population of 2009 children from 1982 through 2003. Of these, 36% were HRV-C. Age (P = .039) and month of illness (P <.001) were associated with HRV infection and HRV species. HRV-C was significantly associated with lower respiratory illness, compared with HRV-A (P = .014). HRV-A and HRV-C prevalence fluctuated throughout the 21-year period; HRV-C was more prevalent during winter (P = .058). Conclusions HRV-C is not a new virus but has been significantly associated with childhood lower respiratory illness in this population for several decades. Temporal changes in virus prevalence occur, and season may predict virus species. Our findings have implications for diagnostic, preventive, and treatment strategies due to the variation in disease season and severity based on species of HRV infection.

Background Rhinovirus is linked to asthma exacerbations and chronic obstructive pulmonary disease exacerbations in adults. The severity and rates of rhinovirus acute respiratory illnesses (ARI) in adults are uncertain. Objectives We determined rhinovirus-associated ARI rates in adults presenting for care in multiple settings and identified factors associated with rhinovirus detection. Methods This prospective, population-based cohort enrolled Tennessee residents ≥18 years old in the emergency department (ED), outpatient clinics, or hospitalized for ARI December 2008-May 2010. Nasal/throat swabs were collected and tested for rhinovirus and other viruses by RT-PCR. Rates of ED visits and hospitalizations were calculated and rhinovirus-positive and -negative patients were compared. Results Among 2351 enrollees, rhinovirus was detected in 247 (11%). There were 7 rhinovirus-associated ED visits and 3 hospitalizations per 1000 adults annually. Patients with rhinovirus, compared to virus-negative ARI, were more likely to present with wheezing (odds ratio [OR] 1.7, 95% confidence interval [CI] 1.23-2.35, p<0.001), to be a current smoker (OR 2.31, CI 1.68-3.19) or live with a smoker (OR 1.72, CI 1.10-2.67), have a history of chronic respiratory disease (OR 1.61, CI 1.17-2.22), and were less likely to be hospitalized versus seen in the outpatient setting (OR 0.58, CI 0.41-0.83). Conclusion Rhinovirus is associated with a substantial number of ED visits and hospitalizations for ARI in adults. There may be modifiable factors that can reduce the likelihood of presenting with rhinovirus-associated ARI.

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Paragonimiasis is a parasitic infection caused by trematodes of the genus Paragonimus transmitted by eating raw or undercooked crawfish or crabs. The parasite has a tendency to cause pneumonia and to disseminate elsewhere in the body. We are reporting a case in a young male with North American Paragonomiasis highlighting the importance of imaging features.