'Many critically ill patients with 2009 pandemic influenza A (H1N1) (2009 H1N1) infection were noted to be obese, but whether obesity, rather than its associated co-morbidities, is an independent risk factor for severe infection is unknown. Using public health surveillance data, we analyzed demographic and clinical characteristics of California residents hospitalized with 2009 H1N1 infection to assess whether obesity (body mass index [BMI] >= 30) and extreme obesity (BMI >= 40) were an independent risk factor for death among case patients >= 20 years old,' researchers in the United States report (see also Influenza Vaccines).
'During the period 20 April-11 August 2009, 534 adult case patients with 2009 H1N1 infection for whom BMI information was available were observed. Two hundred twenty-eight patients (43%) were >= 50 years of age, and 378 (72%) had influenza-related high-risk conditions recognized by the Advisory Committee on Immunization Practices as risk factors for severe influenza. Two hundred and seventy-four (51%) had BMI >= 30, which is 2.2 times the prevalence of obesity among California adults (23%) and 1.5 times the prevalence among the general population of the United States (33%). Of the 92 case patients who died (17%), 56 (61%) had BMI >= 30 and 28 (30%) had BMI >= 40. In multivariate analysis, BMI >= 40 (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.4-5.9) and BMI >= 45 (OR, 4.2; 95% CI, 1.9-9.4), age >= 50 years (OR, 2.1; 95% CI, 1.2-3.7), miscellaneous immunosuppressive conditions (OR, 3.9; 95% CI, 1.6-9.5), and asthma (OR, 0.5; 95% CI, 0.3-0.9) were associated with death. Half of Californians >= 20 years of age hospitalized with 2009 H1N1 infection were obese. Extreme obesity was associated with increased odds of death,' wrote J.K. Louie and colleagues.
The researchers concluded: 'Obese adults with 2009 H1N1 infection should be treated promptly and considered in prioritization of vaccine and antiviral medications during shortages.'
Louie and colleagues published their study in Clinical Infectious Diseases (A Novel Risk Factor for a Novel Virus: Obesity and 2009 Pandemic Influenza A (H1N1). Clinical Infectious Diseases, 2011;52(3):301-312).
For additional information, contact J.K. Louie, California Dept. of Public Health, Division Communicable Diseases Control, 850 Marina Bay Pkwy, Richmond, CA 94804, USA.
Publisher contact information for the journal Clinical Infectious Diseases is: University Chicago Press, 1427 E 60th St., Chicago, IL 60637-2954, USA.
Keywords: City:Richmond, State:CA, Country:United States, Bariatrics, Biological Products, Diet and Nutrition, Epidemiology, H1N1 Subtype Influenza A Virus, H1N1 Virus, Infectious Diseases, Influenza A virus, Influenza Vaccines, Nutrition Disorders, Obesity, Orthomyxoviridae, Overnutrition, Pandemics, RNA Viruses, Swine Flu, Swine Influenza, Vertebrate Viruses, Viral Vaccines, Virology
This article was prepared by Vaccine Weekly editors from staff and other reports. Copyright 2011, Vaccine Weekly via NewsRx.com.
