• 1
    Small C-L, Shaler CR, McCormick S et al. Influenza infection leads to increased susceptibility to subsequent bacterial superinfection by impairing NK cell responses in the lung. J Immunol 2010; 184:20482056.
  • 2
    Hament JM, Kimpen JL, Fleer A, Wolfs TF. Respiratory viral infection predisposing for bacterial disease: a concise review. FEMS Immunol Med Microbiol 1999; 26:189195.
  • 3
    Seki M, Kosai K, Yanagihara K et al. Disease severity in patients with simultaneous influenza and bacterial pneumonia. Intern Med 2007; 46:953958.
  • 4
    Brundage JF. Interactions between influenza and bacterial respiratory pathogens: implications for pandemic preparedness. Lancet Infect Dis 2006; 6:303312.
  • 5
    Finelli L, Fiore A, Dhara R et al. Influenza-associated pediatric mortality in the United States: increase of staphylococcus aureus coinfection. Pediatrics 2008; 122:805811.
  • 6
    Beadling C, Slifka MK. How do viral infections predispose patients to bacterial infections? Curr Opin Infect Dis 2004; 17:185191.
  • 7
    McCullers JA. Insights into the interaction between influenza virus and pneumococcus. Clin Microbiol Rev 2006; 19:571582.
  • 8
    Loving CL, Brockmeier SL, Vincent AL, Palmer MV, Sacco RE, Nicholson TL. Influenza virus coinfection with bordetella bronchiseptica enhances bacterial colonization and host responses exacerbating pulmonary lesions. Microb Pathog 2010; 49:237245.
  • 9
    Diavatopoulos DA, Short KR, Price JT et al. Influenza A virus facilitates Streptococcus pneumoniae transmission and disease. FASEB J 2010; 24:17891798.
  • 10
    McCullers JA, McCauley JL, Browell S, Iverson AR, Boyd KL, Normark BH. Influenza enhances susceptibility to natural acquisition of and disease due to Streptococcus pneumoniae in ferrets. J Infect Dis 2010; 202:12871295.
  • 11
    Grabowska K, Högberg L, Penttinen P, Svensson A, Ekdahl K. Occurrence of invasive pneumococcal disease and number of excess cases due to influenza. BMC Infect Dis 2006; 6:58.
  • 12
    Brundage JF, Shanks GD. Deaths from Bacterial Pneumonia during 1918–19 Influenza Pandemic. Emerg Infect Dis 2008; 14:8.
  • 13
    Lee EH, Wu C, Lee EU et al. for the New York City Department of Health and Mental Hygiene 2009 H1N1 Influenza Investigation Team. Fatalities associated with the 2009 H1N1 influenza a virus in New York City. Clin Infect Dis 2010; 50:14981504.
  • 14
    Sachedina N, Donaldson LJ. Paediatric mortality related to pandemic influenza A H1N1 infection in England: an observational population-based study. Vol 376; November 2010;18461852.
  • 15
    Peltola VT, Murti KG, McCullers JA. Influenza virus neuraminidase contributes to secondary bacterial pneumonia. J Infect Dis 2005; 192:249257.
  • 16
    Aebi T, Weisser M, Bucher E, Hirsch HH, Marsch S, Siegemund M. Co-infection of Influenza B and Streptococci causing severe pneumonia and septic shock in healthy women. BMC Infect Dis 2010; 10:308.
  • 17
    Scaber J, Saeed S, Ihekweazu C, Efstratiou A, McCarthy N, O'Moore E. Group A streptococcal infections during the seasonal influenza outbreak 2010/11 in South East England. Euro Surveill 2011; 16(5):pii=19780.
  • 18
    Morens DM, Taubenberger JK, Fauci AS. Predominant role of bacterial pneumonia as a cause of death in pandemic influenza: implications for pandemic influenza preparedness. J Infect Dis 2008; 198:962970.
  • 19
    Oxford JS, Sefton A, Jackson R, Innes W, Daniels RS, Johnson NP. World War I may have allowed the emergence of “Spanish” influenza. Lancet Infect Dis 2002; 2:111114.
  • 20
    Chien YW, Klugman KP, Morens D. Bacterial pathogens and death during the 1918 influenza pandemic. N Engl J Med 2009; 361:25822583.
  • 21
    Frost WH. The epidemiology of influenza. JAMA 1919; 73:313318.
  • 22
    Frost WH. Statistics of influenza morbidity with special reference to certain factors in case incidence and case-fatality. Public Health Rep. 1920; 35:584597. [cited 2008 May 30]. Available from
  • 23
    Britten RH. The incidence of epidemic influenza, 1918–19. Public Health Rep 1932; 47:303339. [cited 2008 May 30]. Available from
  • 24
    Petersdorf RG, Fusco JJ, Harter DH, Albrink WS. Pulmonary infections complicating Asian influenza. Arch Intern Med 1959; 103:262272.
  • 25
    Hers JFP, Masurel N, Mulder J. Bacteriology and histopathology of the respiratory tract and lungs in fatal Asian influenza. Lancet 1958; 2:11411143.
  • 26
    Robertson L, Caley JP, Moore J. Importance of staphylococcus aureus in pneumonia in the 1957 epidemic of influenza A. Lancet 1958; 2:233236.
  • 27
    Schwarzmann SW, Adler JL, Sullivan RJ, Marine WM. Bacterial pneumonia during the Hong Kong influenza epidemic of 1968–1969. Arch Intern Med 1971; 127:10371041.
  • 28
    Roden AT. 1969 National experience with Hong Kong influenza in the United Kingdom, 1968–69. Bull World Health Organ 1969; 41:375380.
  • 29
    Tillett HE, Smith JW, Gooch CD. Excess deaths attributable to influenza in England and Wales: age at death and certified cause. Int J Epidemiol 1983; 12:344352.
  • 30
    Sharrar RG. National influenza experience in the USA, 1968–69. Bull World Health Organ 1969; 41:361366.
  • 31
    Centers for Disease Control and Prevention (CDC). Bacterial coinfections in lung tissue specimens from fatal cases of 2009 pandemic influenza A (H1N1) — United States, May–August 2009. MMWR Morb Mortal Wkly Rep 2009; 58:10711074.
  • 32
    Nguyen-Van-Tam JS, Openshaw PJ, Hashim A et al. Risk factors for hospitalisation and poor outcome with pandemic A/H1N1 influenza: United Kingdom first wave (May-September 2009). Thorax 2010; 65:645651.
  • 33
    Lucas S. Predictive clinicopathological features derived from systematic autopsy examination of patients who died with A/H1N1 influenza infection in the UK 2009–10 pandemic. Health Technol Assess 2010; 14:83114.
  • 34
    Palacios G, Hornig M, Cisterna D et al. Streptococcus pneumoniae coinfection is correlated with the severity of h1n1 pandemic influenza. PLoS ONE 4:e8540.
  • 35
    Weinberger DM, Simonson L, Jordan R, Steiner C, Miller M, Viboud C. Impact of the 2009 influenza pandemic on pneumococcal pneumonia hospitalizations in the United States. J Infect Dis 2012; 205:458465.
  • 36
    Martín-Loeches I, Sanchez-Corral A, Diaz E et al. H1N1 SEMICYUC Working Group. Community-acquired respiratory coinfection in critically ill patients with pandemic 2009 influenza A(H1N1) virus. Chest 2011; 139:555562.
  • 37
    Shieh WJ, Blau DM, Denison AM et al. 2009 pandemic Influenza a (H1H1) pathology and pathogenesis of 100 fatal cases in the United States. Am J Pathol 2010; 177:166175.
  • 38
    Cox CM, Blanton L, Dhara R, Brammer L, Finelli L. 2009 pandemic Influenza A (H1N1). Deaths among children-United States, 2009–2010. Clin Infect Dis 2011:52: (Suppl 1) S69S74.
  • 39
    Cuquemelle E, Soulis F, Villers D et al. Can procalcitonin help identify associated bacterial infection in patients with severe influenza pneumonia? A multicentre study. Intensive Care Med 2011; 37:796800.
  • 40
    Kuster SP, Tuite AR, Kwong JC, McGeer A, the Toronto Invasive Bacterial Diseases Network, Fisman D. Evaluation of coseasonality of influenza and invasive pneumococcal disease: results from prospective surveillance. PLoS Med 2011; 8:e1001042.
  • 41
    Mazick A, Gergonne B, Wuillaume F et al. Higher all-cause mortality in children during autumn 2009 compared with the three previous years: pooled results from eight European countries. Euro Surveill 2010; 15(5):pii=19480.
  • 42
    Gupta RK, George R, Nguyen-Van-Tam JS. Bacterial pneumonia and pandemic influenza planning. Emerg Infect Dis 2008; 14:11871192.
  • 43
    Peacey M, Hall RJ, Sonnberg S et al. Pandemic (H1N1) 2009 and seasonal influenza A (H1N1) Co-infection, New Zealand, 2009. Emerg Infect Dis 2010; 16:16181620.
  • 44
    Esper F. Rate and Influence of Respiratory Virus Coinfection on Pandemic (H1N1) Influenza Disease. Infectious Diseases Society of America 48th annual meeting, Vancouver. Oral abstract session, 23 October 2010.
  • 45
    HPA-Influenza. HPA - Health Protection Agency Homepage - Protecting People, Preventing Harm, Preparing for Threats. Web. 19 July 2011.
  • 46
    Maxwell ES, Ward TG, Van Metre TEjr. The relation of influenza virus and bacteria in the etiology of pneumonia. J Clin Invest 1949; 28:307318.
  • 47
    Cartwright KAV, Jones DM, Smith AJ, Stuart JM, Kaczmarski EB, Palmer SR. Influenza A and meningococcal disease. Lancet 1991; 338:554557.
  • 48
    Reilly S. Influenza A and meningococcal disease. Lancet 1991; 338:11431144.
  • 49
    Pether JVS. Bacterial meningitis after influenza. Lancet 1982; i:804.
  • 50
    Jansen AGSC, Sanders EAM, Van der Ende A, Van Loon AM, Hoes AW, Hak E. Invasive pneumococcal and meningococcal disease: association with influenza virus and respiratory syncytial virus activity? Epidemiol Infect 2008; 136:14481454.
  • 51
    Simonson L, Taylor RJ, Young-Xu Y, Haber M, May L, Klugman KP. Impact of pneumococcal conjugate vaccination of infants on pneumonia and influenza hospitalization and mortality in all age groups in the United States. mBio 2011; 2(1):e00309e00310.
  • 52
    Madhi SA, Klugman KP and the Vaccine Trialist Group. A role for Streptococcus pneumoniae in virus-associated pneumonia. Nat Med August 2004; 10(8):811813.
  • 53
    Bhat N, Wright JG, Broder KR et al. Influenza special investigations team influenza-associated deaths among children in the United States, 2003–2004. N Engl J Med 2005; 353:25562567.
  • 54
    Hageman JC, Uyeki TM, Francis JS et al. Severe community-acquired pneumonia due to staphylococcus aureus, 2003–04 influenza season. Emerg Infect Dis 2006; 12:894899.
  • 55
    Centers for Disease Control and Prevention (CDC). Severe methicillin-resistant staphylococcus aureus community-acquired pneumonia associated with influenza–Louisiana and Georgia, December 2006-January 2007. MMWR Morb Mortal Wkly Rep 2007; 56:325329.
  • 56
    Kallen AJ, Brunkard J, Moore Z et al. Staphylococcus aureus community-acquired pneumonia during the 2006 to 2007 influenza season. Ann Emerg Med 2009; 53:358365.
  • 57
    Peng D, Zhao D, Liu J et al. Multipathogen infections in hospitalized children with acute respiratory infections. Virol J 2009; 6:155.
  • 58
    Takao S, Hara M, Kakuta O et al. Eleven cases of co-infection with influenza type A and type B suspected by use of a rapid diagnostic kit and confirmed by RT-PCR and virus isolation. Kansenshogaku Zasshi 2005; 79:877886.
  • 59
    Sasaki A, Suzuki H, Saito R et al. Prevalence of human metapneumovirus and influenza virus infections among Japanese children during two successive winters. Pediatr Infect Dis J 2005; 24:905908.
  • 60
    Laguna-Torres VA, Go′mez J, Aguilar PV et al. The peru influenza working group changes in the viral distribution pattern after the appearance of the novel influenza A H1N1 (pH1N1) virus in influenza-like illness patients in Peru. PLoS ONE 2010; 5:e11719.
  • 61
    Archer B, Cohen C, Naidoo D et al. Interim report on pandemic H1N1 influenza virus infection in South Africa, April to October 2009: epidemiology and factors associated with fatal cases. Euro Surveill 2009; 14(42):pii=19369.
  • 62
    Tan CK, Kao CL, Shih JY et al. Coinfection with Mycobacterium tuberculosis and pandemic H1N1 influenza A virus in a patient with lung cancer. J Microbiol Immunol Infect 2011; 44:316318.
  • 63
    Ormsby CE, De la Rosa-Zamboni D, Vazquez-Pérez J et al. Severe 2009 pandemic influenza A (H1N1) infection and increased mortality in patients with late and advanced HIV disease. AIDS 2011; 4:435439.
  • 64
    Hopkins BS, Johnson KE, Ksiazek JM, Sun G, Greinwald JH, Rutter M. H1N1 influenza A presenting as bacterial tracheitis. Otolaryngol Head Neck Surg 2010; 142:612614.
  • 65
    Rizzo C, Caporali MG, Rota MC. Pandemic influenza and pneumonia due to legionella pneumophila: a frequently underestimated coinfection. Clin Infect Dis 2010; 51:115.
  • 66
    Obando I, Valderrabanos ES, Millan JA, Neth OW. Necrotising pneumonia due to influenza A (H1N1) and community-acquired methicillin-resistant Staphylococcus aureus clone USA 300: successful management of the first documented paediatric case. (Case report)Arch Dis Child 2010; 95:305306.
  • 67
    Rodriguez EL, Tomashek KM, Gregory CJ et al. Co-infection with dengue virus and pandemic (H1N1) 2009 Virus. Emerg Infect Dis 2010; 16:882884.
  • 68
    Kahar-Bador M, Nathan AM, Soo MH et al. Fatal influenza A (H3N2) and Campylobacter jejuni coinfection. Singapore Med J 2009; 50:e112.
  • 69
    Scott JAG, English M. What are the implications for childhood pneumonia of successfully introducing Hib and pneumococcal vaccines in developing Countries? PLoS Med 2008; 5:e86.
  • 70
    Tramontana AR, George B, Hurt AC et al. Oseltamivir resistance in adult oncology and hematology patients infected with pandemic (H1N1) 2009 virus, Australia. Emerg Infect Dis 2010; 16:10681075.
  • 71
    Payungporn S, Poomipak W, Makkoch J, Rianthavorn P, Theamboonlers A, Poovorawan Y. Detection of oseltamivir sensitive/resistant strains of pandemic influenza A virus (H1N1) from patients admitted to hospitals in Thailand. J Virol Methods 2011; 177:133139.
  • 72
    Cinti SK, Barnosky AR, Gay SE et al. Bacterial pneumonias during an influenza pandemic: how will we allocate antibiotics? Biosecur Bioterror 2009; 7:311316.
  • 73
    Huber VC, Peltola V, Iverson AR, McCullers JA. Contribution of vaccine-induced immunity toward either the ha or the na component of influenza viruses limits secondary bacterial complications. J Virol 2010; 84:41054108.
  • 74
    Vila-Corcoles A, Ochoa-Gondar O, Guzmán JA, Rodriguez-Blanco T, Salsench E, Fuentes CM. EPIVAC study group. Effectiveness of the 23-valent polysaccharide pneumococcal vaccine against invasive pneumococcal disease in people 60 years or older. BMC Infect Dis 2010; 10:73.
  • 75
    Hedlund J, Christenson B, Lundbergh P, Ortqvist A. Effects of a large-scale intervention with influenza and 23-valent pneumococcal vaccines in elderly people: a 1-year follow-up. Vaccine 2003; 21:39063911.
  • 76
    Tessmer A, Welte T, Schmidt-Ott R et al. Influenza vaccination is associated with reduced severity of community-acquired pneumonia. Eur Respir J 2011; 38:147153.
  • 77
    Kumar A. Early versus late oseltamivir treatment in severely ill patients with 2009 pandemic influenza A (H1N1): speed is life. J Antimicrob Chemother 2011; 66:959963.
  • 78
    Rubin JL, McGarry LJ, Klugman KP, Strutton DR, Gilmore KE, Weinstein MC. Public health and economic impact of vaccination with 7-valent pneumococcal vaccine (PCV7) in the context of the annual influenza epidemic and a severe influenza pandemic. BMC Infect Dis 2010; 10:14.