Different features of influenza A H1N1pdm09 virus infection among adults in 2009/10 and 2010/11 (original) (raw)
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Hospitalized pandemic influenza A (H1N1) patients in a university hospital
Central European Journal of Medicine, 2011
The purpose of this study was to describe the demographic and clinical features of hospitalized patients with the pandemic H1N1 influenza A virus infection in a tertiary care hospital in Central Anatolia, Turkey. The patients, all over 16 years of age and hospitalized for influenza-like symptoms between 1 November 2009 and 31 December 2009, were retrospectively identified from the records of the Infectious Diseases Department. Eighty patients whose diagnoses were confirmed by real-time PCR were included in this study. The median age of the patients was 27 years; 41 of them were male. Thirty-seven of the patients had a radiologically proven pneumonia. Eighteen of 37 (48.6%) patients with pneumonia had an underlying co-morbid medical condition, and 14 required intensive care unit admission. Patients with pneumonia had higher levels of C-reactive protein. All patients but one received oseltamivir treatment. Six patients with pneumonia received only antiviral therapy, while 31 of the pa...
Clinical Microbiology and Infection, 2012
Although the influenza A (H1N1) 2009 virus is expected to circulate as a seasonal virus for some years after the pandemic period, its behaviour cannot be predicted. We analysed a prospective cohort study of hospitalized adults with influenza A (H1N1) 2009 pneumonia at 14 teaching hospitals in Spain to compare the epidemiology, clinical features and outcomes of influenza A (H1N1) 2009 pneumonia between the pandemic period and the first post-pandemic influenza season. A total of 348 patients were included: 234 during the pandemic period and 114 during the first post-pandemic influenza season. Patients during the post-pandemic period were older and more likely to have chronic obstructive pulmonary disease, chronic kidney disease and cancer than the others. Septic shock, altered mental status and respiratory failure on arrival at hospital were significantly more common during the post-pandemic period. Time from illness onset to receipt of antiviral therapy was also longer during this period. Early antiviral therapy was less frequently administered to patients during the post-pandemic period (22.9% versus 10.9%; p 0.009). In addition, length of stay was longer, and need for mechanical ventilation and intensive-care unit admission were significantly higher during the post-pandemic period. In-hospital mortality (5.1% versus 21.2%; p <0.001) was also greater during this period. In conclusion, significant epidemiological changes and an increased severity of influenza A (H1N1) 2009 pneumonia were found in the first post-pandemic influenza season. Physicians should consider influenza A (H1N1) 2009 when selecting microbiological testing and treatment in patients with pneumonia in the upcoming influenza season.
Influenza and Other Respiratory Viruses, 2012
A few months into the 2009 influenza pandemic, nine European countries implemented case-based surveillance of hospitalised severe influenza infections. In the present study, we assess the association between patient characteristics, in particular underlying conditions, and the severity level of influenza A(H1N1)pdm09 infection during the 2010-2011 season. Patient age, the presence of underlying conditions, pneumonia, acute respiratory distress syndrome (ARDS) and the need for ventilation were significantly associated with the severity of influenza A(H1N1)pdm09 infection. Despite limitations essentially because of the heterogeneity of the data reported, this study provides insight into severe influenza cases.
Risk factors for severe influenza a virus infections in post-2009 pandemic period
Srpski arhiv za celokupno lekarstvo, 2016
Introduction. Literature data concerning risk factors for severe influenza in post-2009 pandemic period, from low- and middle-income Central and Eastern European countries are very limited. Objective. The aim of this study was to investigate the risk factors for severe A(H1N1)pdm09 and A(H3N2) influenza during the post-2009 pandemic period. Methods. During four consecutive seasons of 2010/2011-2013/2014, nasopharyngeal or nasal and pharyngeal swab samples from 153 patients with mild and 147 patients with severe influenza were tested using real-time reverse transcription polymerase chain reaction (real-time RT PCR) assays. Results. The study indicated three statistically significant risk factors of influenza severity, including presence of chronic underlying illness/condition [odds ratio (OR) of 15.2, 95% confidence interval (CI) of 1.8-125.4, p = 0.001), age ?15 years (OR 9.2, 95% CI 3.5-24.1, p < 0.001), and delay in medical care of more than two days after the symptoms onset (O...
Outcomes of influenza A(H1N1)pdm09 virus infection: results from two international cohort studies
PloS one, 2014
Data from prospectively planned cohort studies on risk of major clinical outcomes and prognostic factors for patients with influenza A(H1N1)pdm09 virus are limited. In 2009, in order to assess outcomes and evaluate risk factors for progression of illness, two cohort studies were initiated: FLU 002 in outpatients and FLU 003 in hospitalized patients. Between October 2009 and December 2012, adults with influenza-like illness (ILI) were enrolled; outpatients were followed for 14 days and inpatients for 60 days. Disease progression was defined as hospitalization and/or death for outpatients, and hospitalization for >28 days, transfer to intensive care unit (ICU) if enrolled from general ward, and/or death for inpatients. Infection was confirmed by RT-PCR. 590 FLU 002 and 392 FLU 003 patients with influenza A (H1N1)pdm09 were enrolled from 81 sites in 17 countries at 2 days (IQR 1-3) and 6 days (IQR 4-10) following ILI onset, respectively. Disease progression was experienced by 29 (1 ...
Influenza A(H1N1)pdm09 and postpandemic influenza in Lithuania
Open Medicine, 2016
The objective of this study is to describe the clinical and epidemiological characteristics of patients hospitalized in Lithuania who are infected with influenza A(H1N1)pdm09 and to compare pandemic A(H1N1) pdm09 infection with postpandemic.In total, 146 subjects hospitalized with influenza A(H1N1) pdm09 were identified from 2009–2011. There were 53 during the initial pandemic wave in the summer of 2009, 69 during the peak pandemic period, and 24 during the “postpandemic” period that we included in this study. There were 22 subjects who died after laboratory confirmation of influenza A(H1N1)pdm09.No deaths were documented during the first wave. Subjects presenting during the peak of pandemic influenza had a greater incidence of fever (100% vs 77.4%; p<0.001), dry cough (95.7% vs 82.7%; p=0.01), and vomiting (26.1% vs 1.9%, p<0.001) as compared with patients infected during the first wave. The rate of bacterial pneumonia was 18.8% (13/69) during the peak pandemic period and 12....
Background: Descriptive analyses of influenza A (H1N1) 2009 were conducted on the pandemic (H1N1) 2009 influenza cases in Uppsala County. Uppsala County, situated close to the Stockholm urban area, has approximately 330 000 inhabitants. The pandemic influenza became a notifiable disease on May 2009 under the Swedish Communicable Disease Act, which implies that suspected influenza cases must be laboratory-verified and reported to the county medical officer and to the Swedish Institute for Infectious Disease Control. Methods: The analyses were performed using the patients' unique identification code via an electronic database system (eCRF) complemented by the patients' records. Results: In all, 456 confirmed influenza cases were reported from June 2009 to the end of December 2009. The main outbreak was restricted to 5 weeks in the autumn of 2009 when 82% of the cases were reported. Thirty-five percent of the patients had underlying medical risk conditions. No difference in symptoms was found between patients with underlying medical conditions and patients without risk. However, 64% of the patients with underlying medical conditions received antiviral therapy compared with 24% for the other patients. Patients with medical conditions received the vaccination in the beginning of the epidemic, whereas patients without risk received the vaccination at a later time. Forty-nine patients admitted vaccination, and of these, 46 received the vaccination 1week or less before onset of illness. The study showed that the epidemiological and clinical picture did not differ from seasonal influenza and that younger age groups were more affected than older age groups (i.e., older persons had some protection, probably through earlier contact with similar virus strains). Conclusions: The pandemic-based information from national and international authorities was crafted in the shadow of the threat from H5N1 avian influenza and was not in proportion to mainly mild-to-moderate illness caused by the 2009 H1N1 pandemic. Keywords: Pandemic influenza, A (H1N1) 2009, notified cases, vaccine coverage
2015
Background: Pandemic H1N1 influenza virus is a cause of a wide spread out break of febrile respiratory infection in Turkey and worldwide. We describe the characteristics of patients who were hospitalized with H1N1/A influenza in Dicle University, Diyarbakir, Turkey from October 2009 to mid-November 2009. Methods: We collected data of 36 patients who were hospitalized for at least 3 days for influenza-like illness and who were positive for the H1N1/A virus using by real-time reverse-transcriptase-polymerase-chain-reaction assay. Results: Of the 36 patients we studied, 17% were admitted to an intensive care unit and 8% died. Seventeen percent of the patients were children under the age of 18 years, but never were 45 years of age or older. Eighty percent of the patients had at least one underlying medical condition; these conditions included asthma, chronic obstructive pulmonary disease; diabetes; lung, heart, and neurologic diseases; and pregnancy. All of the patients who underwent chest radiography on admission, 28 (78%) had findings consistent with pneumonia. Three (8%) of the patient were died. The median age of patients who died (29.6 years) was not significantly higher than that of the non-fatal cases (26.5 years, p > 0.05). Of the 36 patients for whom data were available regarding the use of antiviral drugs, such therapy was initiated in 26 patients (72%) at a median of 3 days after the onset of illness. Conclusions: During of the 45 daily period, H1N1/A influenza caused severe illness requiring hospitalization, including pneumonia and death. Nearly three quarters of the patients had one or more underlying medical conditions. One severe illnesses were reported among person with pregnancy. Patients seemed to benefit from antiviral therapy. Data suggest that the use of antiviral drugs was beneficial in hospitalized patients, especially when such therapy was initiated early.