Streptococcus Pneumoniae coinfection is correlated with the severity of H1N1 pandemic Influenza

Fil: Palacios, Gustavo. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Hornig, Mady. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Cisterna, Daniel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Savji, Nazir. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Bussetti, Ana Valeria. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Kapoor, Vishal. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Hui, Jeffrey. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Tokarz, Rafal. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Briese, Thomas. Columbia University. Center for Infection and Immunity; Estados Unidos.Fil: Baumeister, Elsa. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Lipkin, W. Ian. Columbia University. Center for Infection and Immunity; Estados Unidos.Background Initial reports in May 2009 of the novel influenza strain H1N1pdm estimated a case fatality rate (CFR) of 0.6%, similar to that of seasonal influenza. In July 2009, however, Argentina reported 3056 cases with 137 deaths, representing a CFR of 4.5%. Potential explanations for increased CFR included virus reassortment or genetic drift, or infection of a more vulnerable population. Virus genomic sequencing of 26 Argentinian samples representing both severe and mild disease indicated no evidence of reassortment, mutations associated with resistance to antiviral drugs, or genetic drift that might contribute to virulence. Furthermore, no evidence was found for increased frequency of risk factors for H1N1pdm disease. Methods/Principal Findings We examined nasopharyngeal swab samples (NPS) from 199 cases of H1N1pdm infection from Argentina with MassTag PCR, testing for 33 additional microbial agents. The study population consisted of 199 H1N1pdm-infected subjects sampled between 23 June and 4 July 2009. Thirty-nine had severe disease defined as death (n = 20) or hospitalization (n = 19); 160 had mild disease. At least one additional agent of potential pathogenic importance was identified in 152 samples (76%), including Streptococcus pneumoniae (n = 62); Haemophilus influenzae (n = 104); human respiratory syncytial virus A (n = 11) and B (n = 1); human rhinovirus A (n = 1) and B (n = 4); human coronaviruses 229E (n = 1) and OC43 (n = 2); Klebsiella pneumoniae (n = 2); Acinetobacter baumannii (n = 2); Serratia marcescens (n = 1); and Staphylococcus aureus (n = 35) and methicillin-resistant S. aureus (MRSA, n = 6). The presence of S. pneumoniae was strongly correlated with severe disease. S. pneumoniae was present in 56.4% of severe cases versus 25% of mild cases; more than one-third of H1N1pdm NPS with S. pneumoniae were from subjects with severe disease (22 of 62 S. pneumoniae-positive NPS, p = 0.0004). In subjects 6 to 55 years of age, the adjusted odds ratio (OR) of severe disease in the presence of S. pneumoniae was 125.5 (95% confidence interval [CI], 16.95, 928.72; p<0.0001). Conclusions/Significance The association of S. pneumoniae with morbidity and mortality is established in the current and previous influenza pandemics. However, this study is the first to demonstrate the prognostic significance of non-invasive antemortem diagnosis of S. pneumoniae infection and may provide insights into clinical management

Streptococcus pneumoniae Coinfection Is Correlated with the Severity of H1N1 Pandemic Influenza

Initial reports in May 2009 of the novel influenza strain H1N1pdm estimated a case fatality rate (CFR) of 0.6%, similar to that of seasonal influenza. In July 2009, however, Argentina reported 3056 cases with 137 deaths, representing a CFR of 4.5%. Potential explanations for increased CFR included virus reassortment or genetic drift, or infection of a more vulnerable population. Virus genomic sequencing of 26 Argentinian samples representing both severe and mild disease indicated no evidence of reassortment, mutations associated with resistance to antiviral drugs, or genetic drift that might contribute to virulence. Furthermore, no evidence was found for increased frequency of risk factors for H1N1pdm disease.We examined nasopharyngeal swab samples (NPS) from 199 cases of H1N1pdm infection from Argentina with MassTag PCR, testing for 33 additional microbial agents. The study population consisted of 199 H1N1pdm-infected subjects sampled between 23 June and 4 July 2009. Thirty-nine had severe disease defined as death (n = 20) or hospitalization (n = 19); 160 had mild disease. At least one additional agent of potential pathogenic importance was identified in 152 samples (76%), including Streptococcus pneumoniae (n = 62); Haemophilus influenzae (n = 104); human respiratory syncytial virus A (n = 11) and B (n = 1); human rhinovirus A (n = 1) and B (n = 4); human coronaviruses 229E (n = 1) and OC43 (n = 2); Klebsiella pneumoniae (n = 2); Acinetobacter baumannii (n = 2); Serratia marcescens (n = 1); and Staphylococcus aureus (n = 35) and methicillin-resistant S. aureus (MRSA, n = 6). The presence of S. pneumoniae was strongly correlated with severe disease. S. pneumoniae was present in 56.4% of severe cases versus 25% of mild cases; more than one-third of H1N1pdm NPS with S. pneumoniae were from subjects with severe disease (22 of 62 S. pneumoniae-positive NPS, p = 0.0004). In subjects 6 to 55 years of age, the adjusted odds ratio (OR) of severe disease in the presence of S. pneumoniae was 125.5 (95% confidence interval [CI], 16.95, 928.72; p<0.0001).The association of S. pneumoniae with morbidity and mortality is established in the current and previous influenza pandemics. However, this study is the first to demonstrate the prognostic significance of non-invasive antemortem diagnosis of S. pneumoniae infection and may provide insights into clinical management

Coinfection patterns in severe and mild H1N1pdm influenza.

*<p><i>p</i> = 0.0004; ** <i>p</i><0.0001; *** <i>p</i> = 0.0008; ^¶<i>p</i> = 0.0085; ^¶¶<i>p</i> = 0.0017.</p>‡<p>No evidence of other bacterial respiratory pathogens in any subjects, including: <i>C. pneumoniae</i>; <i>L. pneumophila</i>; <i>M. pneumoniae</i>; <i>M. tuberculosis</i>; <i>N. meningitides</i>; <i>C. albicans</i>; <i>Enterobacter spp</i>; <i>Enterococcus spp</i>.; <i>Pseudomonas spp</i>.; <i>S. pyogenes</i>.</p>‡‡<p>No evidence of other viral respiratory pathogens in any subjects, including: strains of FLUAV other than H1N1pdm, FLUBV, HPIV 1-4, HMPV, HEV, HAdV. The <i>A. baumannii</i>-positive case was also positive for <i>S. aureus</i>.</p