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Flu

Recent Findings from the IDCRP Acute Respiratory Infections Research Area:

Chen WJ, Arnold JC, Fairchok MP, et al. Epidemiologic, clinical, and virologic characteristics of human rhinovirus infection among otherwise healthy children and adults: Rhinovirus among adults and children. Journal of Clinical Virology. 2015;64(3):74-82.

Background: Human rhinovirus (HRV) is a major cause of influenza-like illness (ILI) in adults and children. Differences in disease severity by HRV species have been described among hospitalized patients withunderlying illness. Less is known about the clinical and virologic characteristics of HRV infection among other wise healthy populations, particularly adults. Objectives: to characterize molecular epidemiology of HRV and association between HRV species and clinical presentation and viral shedding. Study design: observational, prospective, facility-based study of ILI was conducted from February 2010 to April 2012. Collection of nasopharyngeal specimens, patient symptoms, and clinical information occurred on days 0, 3, 7, and 28. Patients recorded symptom severity daily for the first 7 days of illness in asymptom diary. HRV was identified by RT-PCR and genotyped for species determination. Cases who were co-infected with other viral respiratory pathogens were excluded from the analysis. We evaluated the associations between HRV species, clinical severity, and patterns of viral shedding. Results: eighty-four HRV cases were identified and their isolates genotyped. Of these, 62 (74%) were>18 years. Fifty-four were HRV-A, 11 HRV-B, and 19HRV-C. HRV-C infection was more common among children than adults (59% vs. 10%, P < 0.001). Among adults, HRV-A was associated with higher severity of upper respiratory symptoms compared to HRV-B (P = 0.02), but no such association was found in children. In addition, adults shed HRV-A significantly longer than HRV-C (P trend = 0.01). Conclusions: among otherwise healthy adults with HRV infection, we observed species-specific differences in respiratory symptom severity and duration of viral shedding.

 

Fairchok MP, Chen WJ, Arnold JC, et al. Neuraminidase inhibitor therapy in a military population. Journal of Clinical Virology. 2015;67:17-22.

Background: Although neuraminidase inhibitors (NI) are the mainstay of treatment for influenza infection, prescribing practice for these agents is not well described. Additionally, benefit is contested. Objectives We examined provider prescriptions of NI during the 2009 pandemic and post-pandemic periods. We also evaluated the effectiveness of NI in reducing severity of influenza infection. Study design Data on NI prescription and severity of influenza infection were compiled in healthy pediatric and adult beneficiaries enrolled in a prospective study of influenza like illness conducted at five military medical centers over five years. Subjects underwent nasal swabs to determine viral etiology of their infection. Demographic, medication and severity data were collected. Subjects with positive influenza were included. Results Two hundred sixty three subjects were influenza positive [38% [H1N1] pdm09, 38.4% H3N2, and 20.5% B); 23.9% were treated with NI. NI were initiated within 48 h in 63% of treated subjects. Although NI use increased over the five years of the study, early use declined. Most measures for severity of illness were not significantly reduced with NI; adults treated within 48 h had only a modest reduction in duration and severity of some of their symptoms. Conclusions NI use in our population is increasing, but early use is not. NI use resulted in no reduction in complications of illness. Resolution of symptoms and reduction in severity of some symptoms were slightly better in adults who were treated early. These modest benefits do not support routine treatment with NI in otherwise healthy individuals with influenza.