Clinical Analysis of Influenza A (H1N1) Viral Pneumonia Complicated with Bacterial Infection


Purpose: We investigated the efficacy of potent or combined antibiotics in patients suffering bacterial infections secondary to H1N1 by retrospectively analyzing their bacterial pathogen spectrum and clinical characteristics. Methods: Multi-center retrospective analysis was performed using clinical data of H1N1 patients from 27 hospitals in Hebei Province, China, from November 1 to December 31, 2009. Results: Of 480 H1N1-infected patients enrolled from an inpatient clinic, 91 were positive for bacterial culture. Bacteria were detected in sputum culture at 7.00 ± 8.87 days post-admission. Compared with the negative group, the patients in the positive sputum culture group had a higher mean age and prevalence of basic diseases, higher APECHEII (Acute Physiology and Chronic Health Evaluation II) score within 24 hours of admission, longer hospital stays, and higher mortality. In total, 189 bacterial strains were isolated, with the majority of samples testing positive for Acinetobacter baumanii (47), Streptococcus viridians (26), or Pseudomonas aeruginosa (19). S. viridians was the major cause of infection within 3 days of admission, while A. baumanii infection was more prevalent from 4 days post-admission; there was a significant difference in the constituent ratio between the two pathogens (p < 0.001). Compared with patients administered common antibiotics, the potent antibiotics group showed no significant difference in hospitalization time, time until bacterial detection, mortality, or detection ratio of resistant strains (p > 0.05). Conclusions: Complicated bacterial infection in H1N1 patients increases hospitalization time and mortality. Gram-negative bacilli and multi-resistant strains are the main sources of infection. Early administration of potent or combined antibiotics, even during the period of rapid onset, may not be suitable in H1N1-infected patients, particularly previously healthy young patients.

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X. Yan, H. Xu, F. Qu, Y. Liu and X. Zhang, "Clinical Analysis of Influenza A (H1N1) Viral Pneumonia Complicated with Bacterial Infection," Chinese Medicine, Vol. 4 No. 1, 2013, pp. 15-18. doi: 10.4236/cm.2013.41003.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] The Ministry of Health of People’s Republic of China, “Diagnosis and Therapy Strategy of Influenza A (H1N1) of the Ministry of Healthy of People’s Republic of China (Version 3),” 2009.
[2] R. J. Leggiadro, “Bacterial Coinfections in Lung Tissue Specimens from Fatal Cases of 2009 Pandemic Influenza A (H1N1)—United States, May-August 2009,” Morbidity and Mortality Weekly Report, Vol. 58, No. 38, 2009, pp. 1071-1074.
[3] H. S. Kim, J. H. Kim, S. Y. Shin, Y. A. Kang, H. G. Lee, J. S. Kim, J. K. Lee and B. Cho, “Fatal Cases of 2009 Pandemic Influenza A (H1N1) in Korea,” Journal of Korean Medical Science, Vol. 26, No. 1, 2011, pp. 22-27. doi:10.3346/jkms.2011.26.1.22
[4] J. K. Louie, M. Acosta, K. Winter, C. Jean, S. Gavali, R. Schechter, D. Vugia, K. Harriman, B. Matyas, C. A. Glaser, et al., “Factors Associated with Death or Hospitalization Due to Pandemic 2009 Influenza A (H1N1) Infection in California,” Journal of the American Medical Association, Vol. 302, No. 17, 2009, pp. 1896-1902. doi:10.1001/jama.2009.1583
[5] B.-W. Dai, W. Tan, L.-F. Sun, et al., “Clinical Analysis of 75 Severe and Critical Patients with Novel Influenza A (H1N1),” Chinese Journal of Practical Internal Medicine, Vol. 30, No. 1, 2010, pp. 6-9.
[6] T. Teke, R. Coskun, M. Sungur, et al., “2009 H1N1 Influenza and Experience in Three Critical Care Units,” International Journal of Medical Sciences, Vol. 8, No. 3, 2011, pp. 270-277. doi:10.7150/ijms.8.270
[7] J. A. McCullers and K. C. Bartmess, “Role of Neuraminidase in Lethal Synergism between Influenza Virus and Streptococcus pneumoniae,” The Journal of Infectious Diseases, Vol. 187, No. 6, 2003, pp. 1000-1009. doi:10.1086/368163
[8] J. A. McCullers, “Insights into the Interaction between Influenza Virus and Pneumococcus,” Clinical Microbiology Reviews, Vol. 19, No. 3, 2006, pp. 571-582. doi:10.1128/CMR.00058-05
[9] N.-S. Zhong, C. Wang, G.-F. Wang, et al., “Guidance of Diagnosis and Therapy of Influenza,” Journal of Community Medicine, Vol. 9, No. 5, 2011, pp. 66-74.

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