Predictors of fatality in pandemic influenza A (H1N1) virus infection among adults

Abstract

BackgroundThe fatality attributed to pandemic influenza A H1N1 was not clear in the literature. We described the predictors for fatality related to pandemic influenza A H1N1 infection among hospitalized adult patients.MethodsThis is a multicenter study performed during the pandemic influenza A H1N1 [A(H1N1)pdm09] outbreak which occurred in 2009 and 2010. Analysis was performed among laboratory confirmed patients. Multivariate analysis was performed for the predictors of fatality.ResultsIn the second wave of the pandemic, 848 adult patients were hospitalized because of suspected influenza, 45 out of 848 (5.3%) died, with 75% of fatalities occurring within the first 2 weeks of hospitalization. Among the 241 laboratory confirmed A(H1N1)pdm09 patients, the case fatality rate was 9%. In a multivariate logistic regression model that was performed for the fatalities within 14 days after admission, early use of neuraminidase inhibitors was found to be protective (Odds ratio: 0.17, confidence interval: 0.03-0.77, p = 0.022), nosocomial infections (OR: 5.7, CI: 1.84-18, p = 0.013), presence of malignant disease (OR: 3.8, CI: 0.66-22.01, p = 0.133) significantly increased the likelihood of fatality.ConclusionsEarly detection of the infection, allowing opportunity for the early use of neuraminidase inhibitors, was found to be important for prevention of fatality. Nosocomial bacterial infections and underlying malignant diseases increased the rate of fatality.

Risk factors for nosocomial infection among hospitalised severe influenza A(H1N1)pdm09 patients

“…However, few studies have focused on nosocomial infection in patients with influenza A(H1N1)pdm09 infection. A small number of studies have reported that the incidence of nosocomial pneumonia in patients hospitalised for influenza was approximately 5.6-7.0% [4][5][6] and was as high as 26-32% in patients requiring mechanical ventilation [7] or admitted to the intensive care unit (ICU) [3]. Once the nosocomial infection occurred, the mortality of critical ill patients with influenza A(H1N1)pdm09 infection could be as high as 50-60% [3,8], even when antibiotics have been widely used.…”

Influenza-Associated Hemophagocytic Syndrome in Adults: Case Report and Review

“…Unfortunately, treatment was never started in many cases because of delayed diagnosis. In the study by Beutel et al [14], the median time from the onset of symptoms to the diagnosis of VAHS was 23 days (interquartile range [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. This could explain, at least in part, the poor prognosis of HPS secondary to influenza A infection.…”

“…Mortality caused by influenza H1N1 infection is between 0.77% and 5.3% [22,23]. In the case of avian influenza and influenza H1N1 associated hemophagocytic syndrome, the mortality is around 50%-89% [1,14,21].…”

An Overview of the 2009 A(H1N1) Pandemic in Europe: Efficiency of the Vaccination and Healthcare Strategies

“…In the literature there are a number of papers devoted to the study of 2009 A(H1N1) pandemic in a single country such as Turkey [ 4 ], Denmark [ 5 ], Canada [ 6 ], Iran [ 7 ], Morocco [ 8 ], and Mexico [ 9 ] or to a comparative study [ 10 – 14 ]. Several others focus on the transmission dynamics of the pandemic, providing estimates of “basic reproduction number,” “incubation period (latent period),” “generation time,” and “serial interval” as below.…”