key: cord-0953854-bjyn1py4 authors: Camargo, Clarice; Guatura, Sandra Baltazar; Bellei, Nancy title: Respiratory viral coinfection among hospitalized patients with H1N1 2009 during the first pandemic wave in Brazil date: 2012-04-30 journal: The Brazilian Journal of Infectious Diseases DOI: 10.1016/s1413-8670(12)70302-1 sha: 72f7e36f7ce5258d62dfe872cd4b06719b6409ea doc_id: 953854 cord_uid: bjyn1py4 Abstract Influenza A coinfections with other respiratory viruses were investigated in 25.8% (41/159) of the samples from patients hospitalized in 2009 at our University Hospital. Out of the 41 influenza A cases, nine cases (21.9%) were coinfected with other viruses, with a similar frequency among children and adults (p=0.47), and seasonal influenza cases were more prevalent than H1N1 2009 influenza virus. Adenovirus was the most frequently detected (4/9) among coinfected cases. Coinfection was not associated with higher morbidity or mortality (p=0.75). Pandemic H1N1 2009 influenza virus had disseminated globally after being identified in Mexico and the United States in April. The H1N1 2009 morbidity and mortality were particularly severe in Brazil during the first pandemic wave. H1N1 2009 has been associated with a higher severity rate among some risk groups and young adults than seasonal influenza. 1 The frequency of viral coinfections with seasonal or pandemic Infuenza A and clinical correlation is not well known. The purpose of this study was to investigate coinfection of confirmed influenza A and other respiratory virus in samples collected from hospitalized patients during the first pandemic wave in a Brazilian Sentinel Hospital. We [2] [3] [4] [5] [6] [7] [8] Demographic, clinical, laboratory and radiologic data were obtained from medical records. Nosocomial acquisition of the H1N1 2009 was defined as an onset of illness after more than 72 hours of hospital admission. Descriptive statistics consisted of the characterization of the studied individuals and the assessment of coinfection through calculation of the respective median value and range. Chi-squared test was used in univariate analysis comparing categorical variables, with a significance level of p < 0.05. Non-conditional logistic regression analysis was used to identify independent associations between coinfection and groups of individuals. All reported p-values are two-tailed. The dependent variable was coinfection with influenza A, and the independent variables were presence of symptomatology and groups of individuals. The results were presented as odds ratios (OR) with t h e r e s p e c t i v e 9 5 % c o n f i d e n c e i n t e r v a l ( C I ) a n d p-value. All data were entered into and analyzed using the Statistical Package for Social Sciences (SPSS) version 11.0 (SPSS Inc. -Chicago, IL, USA). Out of the 159 samples collected from hospitalized patients ( In this study, from August 19 to November 31, 2009, we analyzed viral coinfections cases among hospitalized patients with confirmed influenza A. We found that coinfection with other respiratory pathogens was common (21.9%). This high rate is in accordance with other studies, where dual and multiple infections varied from 5% to 20% of all viral lower respiratory tract infection (LRTI). [10] [11] Coinfections were more common among children (majority ≤ 1 year of age) than adults, and were detected most often associated with IAV than H1N1 2009. Other studies also report high rates of multiple infections in young children, mostly in children aged less than 12 months, 12 and hospitalized children with acute respiratory tract infection. [13] [14] Among respiratory viruses tested in this study, AdV was the most commonly coinfecting virus with influenza A. Some studies reported high rates of coinfections with AdV. Tiveljung-Lindell et al. 15 observed dual infection with AdV in 16.2%, and Calvo et al. 16 found coinfection in 78.6% of AdV infections. We did not observe distinct clinical characteristics of cases infected by H1N1 2009, IAV, neither there were differences between single and coinfected cases, although the number of coinfections was small. Our findings do not allow the conclusion of greater severity of coinfected cases. Papadopoulos et al. 17 reported that coinfections were associated with increased disease severity, but other studies do not support this observation. In the majority of studies, coinfections do not show clinical differences compared to single infection neither in hospitalized 18 nor in outpatient children. 10 Establishing the relevance of coinfections is difficult. Some interpretations include concomitant infections, sequential infections, or long term, post-infection viruses. 19 The development of quantitative PCR, as well as its correlation with the clinical characteristics, may become a useful tool to clarify the role of coinfections. These data confirm that other respiratory viruses cocirculate with influenza and suggest the need for further analysis regarding the impact of coinfections on these patients' outcome. Writing committee of the WHO consultation on clinical aspects of pandemic (H1N1) 2009 influenza, et al. Clinical aspects of pandemic 2009 influenza A (H1N1) virus infection Reverse transcription polymerase chain reaction and direct immunofluorescence assay in comparison with virus isolation for detection of influenza A and B Influenza detection and subtyping by reverse transcriptase polymerase chain reaction-restriction fragment length polymorphism for laboratory surveillance in Brazil Phylogenetic analysis of rhinovirus isolates collected during successive epidemic seasons Human metapneumovirus infections in young and elderly adults Molecular typing of human adenoviruses by PCR and sequencing of a partial region of the hexon gene Pancoronavirus RT-PCR Assay for Detection of All Known Coronaviruses CDC protocol of real time RT-PCR for influenza A (H1N1). WHO. Available at Respiratory virus infections among hospitalized patients with suspected influenza A H1N1 2009 virus during the first pandemic wave in Brazil Frequency of detection of picornaviruses and seven others respiratory pathogens in infants Multiple simultaneous viral infections in infants with acute respiratory tract infections in Spain Viruses in communityacquired pneumonia in children aged less than 3 years old: High rate of viral coinfection Risk factors for hospitalization due to respiratory syncytial virus infection among infants in the Basque Country Frequent detection of viral coinfection in children hospitalized with acute respiratory tract infection using a real-time polymerase chain reaction Development and implementation of a molecular diagnostic platform for daily rapid detection of 15 respiratory viruses Detection of new respiratory viruses in hospitalized infants with bronchiolitis: a three-year prospective study Association of rhinovirus infection with increased disease severity in acute bronchiolitis Co-infections virales lors des bronchiolites du nourrisson immunocompetent:etude prospective epidemiologique Human bocavirus and acute wheezing in children We acknowledge Dr. Eurico Arruda (FMRP-USP) for providing the HRV 39 isolate. The authors acknowledge the financial support of the Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP Project number: 07/01166-9), and of the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). All authors declare to have no conflict of interest.