It is not clearly established if coinfections are more severe than single viral respiratory infections.The aim of the study was to study and to compare simple infections and viral coinfections of respiratory syncytial virus (RSV) in hospitalized children.From September 2005 to August 2013, a prospective study was conducted on children younger than 14 years of age, admitted with respiratory infection to the Pediatric Department of the Severo Ochoa Hospital, in Spain. Specimens of nasopharyngeal aspirate were taken for virological study by using polymerase chain reaction, and clinical data were recorded. Simple RSV infections were selected and compared with double infections of RSV with rhinovirus (RV) or with human bocavirus (HBoV).In this study, 2993 episodes corresponding to 2525 children were analyzed. At least 1 virus was detected in 77% (2312) of the episodes. Single infections (599 RSV, 513 RV, and 81 HBoV) were compared with 120 RSV-RV and 60 RSV-HBoV double infections. The RSV-RV coinfections had fever (63% vs 43%; P < 0.001) and hypoxia (70% vs 43%; P < 0.001) more often than RV infections. Hypoxia was similar between single or dual infections (71%). Bronchiolitis was more frequent in the RSV simple group (P < 0.001). Pediatric intensive care unit admission was more common in RSV simple or RSV-RV groups than in the RV monoinfection (P = 0.042).Hospitalization was longer for both RSV simple group and RSV-HBoV coinfection, lasting about 1 day (4.7 vs 3.8 days; P < 0.001) longer than in simple HBoV infections. There were no differences in PICU admission. RSV single group was of a younger age than the other groups.Coinfections between RSV-RV and RSV-HBoV are frequent. Overall viral coinfections do not present greater severity, but have mixed clinical features.

Monitoring antiretroviral therapy requires that human immunodeficiency virus type 1 (HIV-1) viremia assays are applicable to all distinct variants. This study evaluates the performance of three commercial viral load assays-Versant HIV-1 RNA bDNA v3.0, Cobas AmpliPrep/Cobas TaqMan HIV-1, and NucliSens HIV-1 EasyQ v1.2-in testing 83 plasma specimens from patients carrying HIV-1 non-B subtypes and recombinants previously defined by phylogenetic analysis of the pol gene. All 28 specimens from patients under treatment presented viremia values below the detection limit with the three methods. In the remaining 55 specimens from naive individuals viremia could not be detected in 32.7, 20, and 14.6% using the NucliSens, Versant, or TaqMan tests, respectively, suggesting potential viral load underestimation of some samples by all techniques. Only 32 (58.2%) samples from naive subjects were quantified by the three methods; the NucliSens test provided the highest HIV RNA values (mean, 4.87 log copies/ml), and the Versant test provided the lowest (mean, 4.16 log copies/ml). Viremia differences of greater than 1 log were seen in 8 (14.5%) of 55 specimens, occurring in 10.9, 7.3, and 5.4%, respectively, of the specimens in comparisons of Versant versus NucliSens, Versant versus TaqMan, and TaqMan versus NucliSens. Differences greater than 0.5 log, considered significant for clinicians, occurred in 45.5, 27.3, and 29% when the same assays were compared. Some HIV-1 strains, such as subtype G and CRF02_AG, showed more discrepancies in distinct quantification methods than others. In summary, an adequate design of primers and probes is needed for optimal quantitation of plasma HIV-RNA in non-B subtypes. Our data emphasize the need to use the same method for monitoring patients on therapy and also the convenience of HIV-1 subtyping.