Background.Recently, epidemiological and clinical data have revealed important changes with regard to clinical adenovirus infection, including alterations in antigenic presentation, geographical distribution, and virulence of the virus.Methods. In an effort to better understand the epidemiology of clinical adenovirus infection in the United States, we adopted a new molecular adenovirus typing technique to study clinical adenovirus isolates collected from 22 medical facilities over a 25-month period during [2004][2005][2006]. A hexon gene sequence typing method was used to characterize 2237 clinical adenovirus-positive specimens, comparing their sequences with those of the 51 currently recognized prototype human adenovirus strains. In a blinded comparison, this method performed well and was much faster than the classic serologic typing method.Results. Among civilians, the most prevalent adenovirus types were types 3 (prevalence, 34.6%), 2 (24.3%), 1 (17.7%), and 5 (5.3%). Among military trainees, the most prevalent types were types 4 (prevalence, 92.8%), 3 (2.6%), and 21 (2.4%).Conclusions. For both populations, we observed a statistically significant increasing trend of adenovirus type 21 detection over time. Among adenovirus isolates recovered from specimens from civilians, 50% were associated with hospitalization, 19.6% with a chronic disease condition, 11% with a bone marrow or solid organ transplantation, 7.4% with intensive care unit stay, and 4.2% with a cancer diagnosis. Multivariable risk factor modeling for adenovirus disease severity found that age !7 years (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4-7.4), chronic disease (OR, 3.6; 95% CI, 2.6-5.1), recent transplantation (OR, 2.7; 95% CI, 1.3-5.2), and adenovirus type 5 (OR, 2.7; 95% CI, 1.5-4.7) or type 21 infection (OR, 7.6; 95% CI, 2.6-22.3) increased the risk of severe disease.

Background The clinical impact of polymicrobial respiratory infections remains uncertain. Previous reports are contradictory regarding an association with severe disease. Methods Three hundred and forty-six specimens from children with acute respiratory illness identified at the University of Iowa Hospitals and Clinics Clinical Microbiology Laboratory (CML) were evaluated by DFA, and/or viral culture by CML and later by molecular study for the presence of influenza, parainfluenza (HPIV), respiratory syncytial virus (HRSV), adenovirus (HAdV), human metapneumovirus (HMPV), rhinovirus (HRV), and human bocavirus (HBoV). Demographic and clinical data were abstracted from medical records. Results Multiple viruses were detected in 46 (21.7%) of 212 virus-positive specimens with the most frequent virus-virus combinations being HRV-HRSV (n=12), HRV-HBoV (n=6), and HRV-HPIV 3 (n=4). Risk factors for coinfection included: male gender (OR 1.70, 95% CI 0.83–3.46), 6 mos-1 yr age (OR 2.15, 95% CI 0.75–6.19), and history of immunosuppression (OR 2.05, 95% CI 0.99–4.23). Children with viral coinfections were less likely than children with single virus infections to be admitted to an intensive care unit (OR 0.32, 95% CI 1.12–9.17), however, this may be explained by undetected viral-bacterial coinfections. Conclusions HRV, HRSV, HBoV and polymicrobial infections were prevalent in this study. While the cross-sectional design could not easily examine polymicrobial infection and disease severity, prospective, population-based research regarding the clinical impact of such infections is warranted.

Background-Epidemiological data suggest that clinical outcomes of human adenovirus (HAdV) infection may be influenced by virus serotype, coinfection with multiple strains, or infection with novel intermediate strains. In this report, we propose a clinical algorithm for detecting HAdV coinfection and intermediate strains.

We retrospectively studied 420 pharyngeal swab specimens collected from Peruvian and Argentinean patients with influenzalike illness in 2002 and 2003 for evidence of human metapneumovirus (HMPV). Twelve specimens (2.3%) were positive by multiple assays. Six specimens yielded HMPV isolates. Four of the 6 isolates were of the uncommon B1 genotype.