Severe Influenza Cases Research Articles

Evaluation of HA-D222G/N polymorphism using targeted NGS analysis in A(H1N1)pdm09 influenza virus in Russia in 2018-2019.

Outbreaks of influenza, which is a contagious respiratory disease, occur throughout the world annually, affecting millions of people with many fatal cases. The D222G/N mutations in the hemagglutinin (HA) gene of A(H1N1)pdm09 are associated with severe and fatal human influenza cases. These mutations lead to increased virus replication in the lower respiratory tract (LRT) and may result in life-threatening pneumonia. Targeted NGS analysis revealed the presence of mutations in major and minor variants in 57% of fatal cases, with the proportion of viral variants with mutations varying from 1% to 98% in each individual sample in the epidemic season 2018–2019 in Russia. Co-occurrence of the mutations D222G and D222N was detected in a substantial number of the studied fatal cases (41%). The D222G/N mutations were detected at a low frequency (less than 1%) in the rest of the studied samples from fatal and nonfatal cases of influenza. The presence of HA D222Y/V/A mutations was detected in a few fatal cases. The high rate of occurrence of HA D222G/N mutations in A(H1N1)pdm09 viruses, their increased ability to replicate in the LRT and their association with fatal outcomes points to the importance of monitoring the mutations in circulating A(H1N1)pdm09 viruses for the evaluation of their epidemiological significance and for the consideration of disease prevention and treatment options.

Identification of key candidate biomarkers for severe influenza infection by integrated bioinformatical analysis and initial clinical validation.

One of the key barriers for early identification and intervention of severe influenza cases is a lack of reliable immunologic indicators. In this study, we utilized differentially expressed genes screening incorporating weighted gene co‐expression network analysis in one eligible influenza GEO data set (GSE111368) to identify hub genes associated with clinical severity. A total of 10 genes (PBI, MMP8, TCN1, RETN, OLFM4, ELANE, LTF, LCN2, DEFA4 and HP) were identified. Gene set enrichment analysis (GSEA) for single hub gene revealed that these genes had a close association with antimicrobial response and neutrophils activity. To further evaluate these genes' ability for diagnosis/prognosis of disease developments, we adopted double validation with (a) another new independent data set (GSE101702); and (b) plasma samples collected from hospitalized influenza patients. We found that 10 hub genes presented highly correlation with disease severity. In particular, BPI and MMP8 encoding proteins in plasma achieved higher expression in severe and dead cases, which indicated an adverse disease development and suggested a frustrating prognosis. These findings provide new insight into severe influenza pathogenesis and identify two significant candidate genes that were superior to the conventional clinical indicators. These candidate genes or encoding proteins could be biomarker for clinical diagnosis and therapeutic targets for severe influenza infection.

Low rate of oseltamivir prescription among adults and children with confirmed influenza illness in France during the 2018-19 influenza season.

Oseltamivir shows effectiveness in reducing influenza-related symptoms, morbidity and mortality. Its prescription remains suboptimal. We aim to describe oseltamivir prescription in confirmed cases of influenza and to identify associated factors. A prospective monocentric observational study was conducted between 1 December 2018 and 30 April 2019. All patients with a virologically confirmed influenza diagnosis were included. Factors associated with oseltamivir prescription were studied. Influenza was confirmed in 755 patients (483 children and 272 adults), of which 188 (25.1%) were hospitalized and 86 (11.4%) had signs of severity. Oseltamivir was prescribed for 452 patients (59.9%), more frequently in children than in adults [329/483 (68.1%) versus 123/272 (45.2%), P < 0.001]. Factors associated with oseltamivir prescription were evaluated in 729 patients (246 adults and 483 children). Patients with at least one risk factor for severe influenza received oseltamivir less frequently (50%, 137/274) than those without risk factors (70%, 315/452) (P < 0.001). Pregnant women received oseltamivir in 81% of cases (17/21). Severe influenza cases were treated with oseltamivir in only 45.3% (39/86). The median duration of symptoms was 24 h (IQR 12-48) in treated patients versus 72 h (IQR 48-120) in untreated patients (P < 0.01). Oseltamivir should be administered as early as possible, preferably within 24-48 h after illness onset, for the best benefits. It is, however, very important to promote the use of neuraminidase inhibitor ('NAI') treatment beyond 48 h in some specific patient populations.

Nutraceutical Targeting of Inflammation-Modulating microRNAs in Severe Forms of COVID-19: A Novel Approach to Prevent the Cytokine Storm.

The coronavirus disease 2019 (COVID-19) pandemic has become the number one health problem worldwide. As of August 2020, it has affected more than 18 million humans and caused over 700,000 deaths worldwide. COVID-19 is an infectious disease that can lead to severe acute respiratory syndrome. Under certain circumstances, the viral infection leads to excessive and uncontrolled inflammatory response, which is associated with the massive release of inflammatory cytokines in pulmonary alveolar structures. This phenomenon has been referred to as the “cytokine storm,” and it is closely linked to lung injury, acute respiratory syndrome and mortality. Unfortunately, there is currently no vaccine available to prevent the infection, and no effective treatment is available to reduce the mortality associated with the severe form of the disease. The cytokine storm associate with COVID-19 shows similarities with those observed in other pathologies such as sepsis, acute respiratory distress syndrome, acute lung injury and other viral infection including severe cases of influenza. However, the specific mechanisms that cause and modulate the cytokine storm in the different conditions remain to be determined. micro-RNAs are important regulators of gene expression, including key inflammatory cytokines involved in the massive recruitment of immune cells to the lungs such as IL1β, IL6, and TNFα. In recent years, it has been shown that nutraceutical agents can modulate the expression of miRs involved in the regulation of cytokines in various inflammatory diseases. Here we review the potential role of inflammatory-regulating-miRs in the cytokine storm associated with COVID-19, and propose that nutraceutical agents may represent a supportive therapeutic approach to modulate dysregulated miRs in this condition, providing benefits in severe respiratory diseases.

Cytokine response level in patients with influenza A (H1N1) in pregnant women and the incidence of newborn pathology

Background: The physiological course of pregnancy is largely determined by immunological processes, the violation of which in the perinatal period can cause various congenital pathologies. The course of influenza during pregnancy largely depends on the level of physiological adjustment of the immune response. It is known that in severe cases of influenza A (H1N1), excessive production of a number of pro-inflammatory cytokines, the cytokine storm, is observed, with the development of endothelial necrosis.&#x0D; Aim: To determine the nature of the cytokine response to influenza A (H1N1) against the background of pregnancy and to clarify its relationship with the development of intrauterine neonatal pathology.&#x0D; Materials and methods: A total of 94 pregnant women were treated at the special clinical infectious diseases hospital of the Ministry of Health of the Krasnodar Region for influenza A (H1N1) during the epidemic recovery from December 2015 to February 2016. The diagnosis of influenza is confirmed by the isolation of RNA of influenza A (H1N1) virus by PCR in a nasopharyngeal scraping. Influenza occurred in the first trimester in 20 (21.3%), in the second trimester in 36 (38.3%) and in the third trimester in 38 (40.4%) women. The outcomes of pregnancy were traced, and a retrospective analysis of 91 neonatal observation cards in the maternity hospital was conducted. The comparison groups were as follows: 25 women with physiological pregnancy, 16 pregnant women with chronic placental insufficiency and intrauterine infection, and a control group of 20 healthy, non-pregnant women of reproductive age. The levels of IL-2, IL-4, IL-10, IFN-, and IFN- cytokines in blood serum were studied using the enzyme immunoassay with Vector-Best reagent kits (Novosibirsk) at a sensitivity of 1 pg/ml. The study of cytokine status was conducted at the height of the flu on the first day of admission to the hospital.&#x0D; Results: In pregnant women with influenza compared with physiological pregnancy, there are considerable decreases in the levels of IL-4 and IL-10, whereas IFN- and IFN- do not change significantly but have a wide range of indicators. Against the background of altered immunoreactivity in pregnancy, the immunosuppressive effects of the influenza virus, in blocking the production of type I interferons, exert a more pronounced negative effect. In pregnant women with influenza and those with chronic placental insufficiency combined with intrauterine infection, unidirectional changes in the levels of IL-4 and IL-10 against physiological pregnancy were detected. The level of IFN- in chronic placental insufficiency combined with intrauterine infection was significantly higher than the figures reported by other groups. The level of IFN- in chronic fetoplacental insufficiency and intrauterine infection was reduced. A significant increase in the IFN-/IL4 coefficient was associated with the development of intrauterine infection of the fetus. The level of IFN- was maximally reduced in women with influenza in the first trimester of pregnancy, whose newborns subsequently had developmental defects in the cardiovascular system. A decrease in the level of IFN- may reflect the onset of failure of the compensatory mechanisms of immunological regulation of pregnancy.&#x0D; Conclusion: Determination of the level of interleukins in the acute period of influenza in pregnant women makes it possible to assess the threat of development of the pathology of newborns. The determination of the levels of IL-4, IFN-, and IFN- is of diagnostic value. A high risk of intrauterine infection can be predicted with an increase in the IFN-/IL-4 coefficient. Prognostically unfavorable for the development of newborn malformations is a decrease in the level of IFN- in the development of influenza in women who are in early gestation.

Quantifying the direct secondary health care cost of seasonal influenza in England

BackgroundThe winter pressure often experienced by NHS hospitals in England is considerably contributed to by severe cases of seasonal influenza resulting in hospitalisation. The prevention planning and commissioning of the influenza vaccination programme in the UK does not always involve those who control the hospital budget. The objective of this study was to describe the direct medical costs of secondary care influenza-related hospital admissions across different age groups in England during two consecutive influenza seasons.MethodsThe number of hospital admissions, length of stay, and associated costs were quantified as well as determining the primary costs of influenza-related hospitalisations. Data were extracted from the Hospital Episode Statistics (HES) database between September 2017 to March 2018 and September 2018 to March 2019 in order to incorporate the annual influenza seasons. The use of international classification of disease (ICD)-10 codes were used to identify relevant influenza hospitalisations. Healthcare Resource Group (HRG) codes were used to determine the costs of influenza-related hospitalisations.ResultsDuring the 2017/18 and 2018/19 seasons there were 46,215 and 39,670 influenza-related hospital admissions respectively. This resulted in a hospital cost of £128,153,810 and £99,565,310 across both seasons. Results showed that those in the 65+ year group were associated with the highest hospitalisation costs and proportion of in-hospital deaths. In both influenza seasons, the HRG code WJ06 (Sepsis without Interventions) was found to be associated with the longest average length of stay and cost per admission, whereas PD14 (Paediatric Lower Respiratory Tract Disorders without Acute Bronchiolitis) had the shortest length of stay.ConclusionThis study has shown that influenza-related hospital admissions had a considerable impact on the secondary healthcare system during the 2017/18 and 2018/19 influenza seasons, before taking into account its impact on primary health care.

Severe cases of seasonal influenza and detection of seasonal A(H1N2) in Russia in 2018-2019.

Data obtained from monitoring cases of severe influenza, cases of vaccinated individuals, and unique cases were used to describe influenza viruses that circulated in Russia in the 2018-2019 epidemic season. A high proportion of the mutations D222G/N in A(H1N1)pdm09 HA was detected in fatal cases. Viruses of the B/Victoria lineage with deletions in HA were detected in Russia, and a reassortant seasonal influenza A(H1N2) virus was identified. A C-terminal truncation in the NS1 protein was detected in a substantial proportion of A(H3N2) viruses.

Efectividad de la vacuna de la gripe para prevenir casos graves. Temporada 2018/2019

ObjectiveTo know the effectiveness of the 2018/2019 flu vaccine for the prevention of severe cases of flu in a tertiary hospital. MethodCase-control study. We included all patients hospitalized with influenza confirmed by laboratory during 2018/2019 season. Those who met the criteria of severe case of influenza (pneumonia, multiorgan failure, septic shock, ICU admission or death) were considered as cases. Non severe cases of influenza were included in the control group. We calculated the effectiveness of the raw and adjusted vaccine (to prevent severe cases of influenza) and its 95% confidence interval using formula VE=(1−odds ratio)×100. ResultsEffectiveness of flu vaccine adjusted by age group and comorbidities was 60.7% (20.5-80.5). In the analysis adjusted and restricted to each sex, age group and presence of comorbidities, the influenza vaccine had a positive effect in all groups and categories, with effectiveness in the age group 65 years or more being 55.0% (2.6-79.2). ConclusionsFlu vaccination reduced the severity of influenza in hospitalized patients. These findings should be taken into account to improve vaccination strategies and achieve better vaccination coverage in the high-risk population in order not only to decrease flu cases, but also their severity.

Care for diabetes with COVID-19: Advice from China.

Care for diabetes with COVID-19: Advice from China.

Influenza Virus Z-RNAs Induce ZBP1-Mediated Necroptosis

Influenza A virus (IAV) is a lytic RNA virus that triggers receptor-interacting serine/threonine-protein kinase 3 (RIPK3)-mediated pathways of apoptosis and mixed lineage kinase domain-like pseudokinase (MLKL)-dependent necroptosis in infected cells. ZBP1 initiates RIPK3-driven cell death by sensing IAV RNA and activating RIPK3. Here, we show that replicating IAV generates Z-RNAs, which activate ZBP1 in the nucleus of infected cells. ZBP1 then initiates RIPK3-mediated MLKL activation in the nucleus, resulting in nuclear envelope disruption, leakage of DNA into the cytosol, and eventual necroptosis. Cell death induced by nuclear MLKL was a potent activator of neutrophils, a cell type known to drive inflammatory pathology in virulent IAV disease. Consequently, MLKL-deficient mice manifest reduced nuclear disruption of lung epithelia, decreased neutrophil recruitment into infected lungs, and increased survival following a lethal dose of IAV. These results implicate Z-RNA as a new pathogen-associated molecular pattern and describe a ZBP1-initiated nucleus-to-plasma membrane "inside-out" death pathway with potentially pathogenic consequences in severe cases of influenza.

Characteristics of hospitalizations with an influenza diagnosis, France, 2012-2013 to 2016-2017 influenza seasons.

BackgroundEstimating the global burden of influenza hospitalizations is required to allocate resources and assess interventions that aim to prevent severe influenza. In France, the current routine influenza surveillance system does not fully measure the burden of severe influenza cases. The objective was to describe the characteristics and severity of influenza hospitalizations by age‐group and by season between 2012 and 2017.MethodsAll hospitalizations with a diagnosis of influenza in metropolitan France between July 2012 and June 2017 were extracted from the French national hospital discharge database (PMSI). For each season, the total number of influenza hospitalizations, admissions to intensive care units (ICU), proportion of deaths, lengths of stay, and distribution in diagnosis‐related groups were described by age‐group.ResultsOver the five seasons, 91 255 hospitalizations with a diagnosis of influenza were identified. The average influenza hospitalization rate varied from 13/100 000 in 2013‐2014 to 46/100 000 in 2016‐2017. A high rate was observed in elderlies during the 2014‐2015 and 2016‐2017 seasons, dominated by A(H3N2) virus. The youngest were impacted in 2015‐2016, dominated by B/Victoria virus. The proportion of influenza hospitalizations with ICU admission was 10%, and was higher in age‐group 40‐79 years. The proportion of deaths and length of stay increased with age.ConclusionsThe description of influenza hospitalizations recorded in the PMSI give key information on the burden of severe influenza in France. Analyses of these data annually is valuable in order to document the severity of influenza hospitalizations by age‐group and according to the circulating influenza viruses.

Hospital-acquired influenza infections detected by a surveillance system over six seasons, from 2010/2011 to 2015/2016

BackgroundIn addition to outbreaks of nosocomial influenza, sporadic nosocomial influenza infections also occur but are generally not reported in the literature.This study aimed to determine the epidemiologic characteristics of cases of nosocomial influenza compared with the remaining severe cases of severe influenza in acute hospitals in Catalonia (Spain) which were identified by surveillance.MethodsAn observational case-case epidemiological study was carried out in patients aged ≥18 years from Catalan 12 hospitals between 2010 and 2016. For each laboratory-confirmed influenza case (nosocomial or not) we collected demographic, virological and clinical characteristics. We defined patients with nosocomial influenza as those admitted to a hospital for a reason other than acute respiratory infection in whom ILI symptoms developed ≥48 h after admission and influenza virus infection was confirmed using RT-PCR. Mixed-effects regression was used to estimate the crude and adjusted OR.ResultsOne thousand seven hundred twenty-two hospitalized patients with severe laboratory-confirmed influenza virus infection were included: 96 (5.6%) were classified as nosocomial influenza and more frequently had > 14 days of hospital stay (42.7% vs. 27.7%, P < .001) and higher mortality (18.8% vs. 12.6%, P < .02). The variables associated with nosocomial influenza cases in acute-care hospital settings were chronic renal disease (aOR 2.44 95% CI 1.44–4.15) and immunodeficiency (aOR 1.79 95% CI 1.04–3.06).ConclusionsNosocomial infections are a recurring problem associated with high rates of chronic diseases and death. These findings underline the need for adherence to infection control guidelines.

Differences among Severe Cases of Sars-CoV-2, Influenza, and Other Respiratory Viral Infections in Pediatric Patients: Symptoms, Outcomes and Preexisting Comorbidities

OBJECTIVES:Previous studies focusing on pediatric patients hospitalized with severe coronavirus disease 2019 (COVID-19) have been limited to small case series. We aimed to evaluate the characteristics of a large population of pediatric patients with severe COVID-19 and compare them with patients with severe cases of influenza and other respiratory viruses (ORV).METHODS:We performed a cross-sectional study of Brazilian data from the National Epidemiological Surveillance Information System, gathered from January 1st to July 14th, 2020. The sample included 4,784 patients (2,570 with confirmed COVID-19, 659 with influenza, 1,555 with ORV). Outcome measures included clinical features, preexisting comorbidities, pediatric intensive care unit admissions, need for ventilatory support, and death.RESULTS:Compared with the influenza and ORV groups, the COVID-19 group had a higher proportion of newborns and adolescents, as well as lower frequencies of fever, cough, dyspnea, respiratory distress, and desaturation. Although use of invasive ventilatory support was similar among groups, death rate was highest for COVID-19 (15.2% vs. 4.5% vs. 3.2%, p<0.001), with death risk more than three times the other groups (adjusted OR=3.7 [95% CI 2.5-5.6]). The presence of two or more comorbidities further increased this risk (OR=4.8 [95% CI 3.5-6.6]). Preexisting comorbidities were reported in 986 patients with severe COVID-19 (38%). Mortality rate among COVID-19 patients was significantly higher for almost all comorbidities reported.CONCLUSION:Severe COVID-19 had a higher mortality rate than other viral respiratory illnesses, despite the lower frequency of fever, cough, dyspnea, respiratory distress, and desaturation. Death risk was strongly associated with preexisting comorbidities.

Humoral immunity to influenza and severe influenza cases in Russia in 2018-2019

Humoral immunity to influenza and severe influenza cases in Russia in 2018-2019

The 2017\u20132018 influenza season in Bucharest, Romania: epidemiology and characteristics of hospital admissions for influenza-like illness

BackgroundSeasonal influenza causes a considerable burden to healthcare services every year. To better measure the impact of severe influenza cases in Romania, we analyzed active surveillance data collected during the 2017–2018 season from patients admitted for influenza-like illness (ILI) at a tertiary care hospital in Bucharest.MethodsPatients admitted for acute ILI were included if they were resident in the Bucharest-Ilfov region, had been hospitalized for at least 24 h, and had onset of symptoms within 7 days before admission. Patient demographics, healthcare use, vaccination status, and outcome data were collected by questionnaire or by searching clinical records. Respiratory swabs were also obtained from each patient to confirm influenza A (A/H1 and A/H3 subtypes) or influenza B (Yamagata and Victoria lineages) infection by real-time reverse-transcription polymerase chain reaction assay.ResultsThe study included 502 patients, many (45.2%) of whom were aged < 5 years. Overall, 108 patients (21.5%) had one or more comorbidities. Seventeen adults aged 18–64 years (3.4%) had been vaccinated against influenza. Patients were hospitalized for a median of 5 days and most (90.4%) were prescribed antiviral treatment. More than one-half of the patients (n = 259, 51.6%) were positive for influenza. Most influenza cases were caused by B viruses (172/259, 66.4%), which were mostly of the B/Yamagata lineage (85 of 94 characterized, 90.4%). Most of the subtyped A viruses were A/H1 (59/74, 79.7%). A/H1 viruses were frequently detected in influenza-positive admissions throughout the 2017–2018 season, whereas the predominant B/Yamagata viruses were detected around the middle of the season, with a peak in cases at week 7 of 2018. Eleven patients were admitted to an intensive care unit; of these, one patient with confirmed B/Yamagata infection died.ConclusionsThese results show that seasonal influenza results in considerable hospitalization in Bucharest-Ilfov, Romania and suggest vaccine coverage should be extended, especially to the youngest age groups. The data from this study should help inform and optimize national influenza healthcare policies.

Severe cases of seasonal influenza in Russia in 2017-2018

Aim. Evaluation of herd immunity prior to the 2017-2018 influenza season, and characterization of influenza viruses isolated from severe or fatal influenza cases and from influenza cases in people vaccinated in the fall of 2017. Materials and methods. Evaluation of herd immunity in hemagglutination inhibition assay. Isolation of influenza viruses. Antigenic and genetic analysis. Results. Prior to epidemic season 33-47% of blood sera samples collected on the territory of Russia showed presence of protective antibody titers against vaccine strains of influenza A, 24-30% of samples — against B/Victoria. During 2017-2018 epidemic season 87 influenza A and B viruses were isolated. A(H1N1)pdm09 strains belonged to clade 6B.1, B/Yamagata strains to clade 3, and B/Victoria strains to clade 1A; they were antigenically similar to corresponding vaccine strains. A(H3N2) viruses belonged to clade 3C.2a and were difficult to characterize antigenically. One strain of influenza virus А(H1N1pdm09) was resistant to oseltamivir and had H275Y amino acid substitution in neuraminidase. All other isolates were susceptible to neuraminidase inhibitors. Conclusion. Influenza vaccination with vaccine effective against current circulating strains and treatment with neuraminidase inhibitor drugs at first manifestation of clinical signs of influenza disease are effective means of population protection against influenza.

Severe cases of seasonal influenza in Russia in 2017-2018.

The 2017–2018 influenza epidemic season in Russia was characterized by a relatively low morbidity and mortality. We evaluated herd immunity prior to the 2017–2018 influenza season in hemagglutination inhibition assay, and performed characterization of influenza viruses isolated from severe or fatal influenza cases and from influenza cases in people vaccinated in the fall of 2017. During the 2017–2018 epidemic season, 87 influenza A and B viruses were isolated and viruses of the 75 influenza cases, including selected viral isolates and viruses analyzed directly from the original clinical material, were genetically characterized. The analyzed A(H1N1)pdm09 viruses belonged to clade 6B.1, B/Yamagata-like viruses belonged to clade 3, and B/Victoria-like viruses belonged to clade 1A and they were antigenically similar to the corresponding vaccine strains. A(H3N2) viruses belonged to clade 3C.2a and were difficult to characterize antigenically and the analysis indicated antigenic differences from the corresponding egg-grown vaccine strain. The next generation sequencing revealed the presence of D222/G/N polymorphism in the hemagglutinin gene in 32% of the analyzed A(H1N1)pdm09 lethal cases. This study demonstrated the importance of monitoring D222G/N polymorphism, including detection of minor viral variants with the mutations, in the hemagglutinin gene of A(H1N1)pdm09 for epidemiological surveillance. One strain of influenza virus A(H1N1)pdm09 was resistant to oseltamivir and had the H275Y amino acid substitution in the NA protein. All other isolates were susceptible to NA inhibitors. Prior to the 2017–2018 epidemic season, 67.4 million people were vaccinated, which accounted for 46.6% of the country's population. Just before the epidemic season 33–47% and 24–30% of blood sera samples collected within the territory of Russia showed the presence of protective antibody titers against vaccine strains of influenza A and influenza B/Victoria-like, respectively. Mass vaccination of the population had evidently reduced the severity of the flu epidemic during the 2017–2018 influenza epidemic season in Russia.

Epidemiology of severe cases of influenza and other acute respiratory infections in the Eastern Mediterranean Region, July 2016 to June 2018

BackgroundInfluenza surveillance systems in the Eastern Mediterranean Region have been strengthened in the past few years and 16 of the 19 countries in the Region with functional influenza surveillance systems report their influenza data to the EMFLU Network. This study aimed to investigate the epidemiology of circulating influenza viruses, causing SARI, and reported to the EMFLU during July 2016 to June 2018. MethodsData included in this study were collected by 15 countries of the Region from 110 SARI sentinel surveillance sites over two influenza seasons. ResultsA total of 40,917 cases of SARI were included in the study. Most cases [20,551 (50.2%)] were less than 5years of age. Influenza virus was detected in 3995 patients, 2849 (11.8%) were influenza A and 1146 (4.8%) were influenza B. Influenza A(H1N1)pdm09 was the predominant circulating subtype with 1666 cases (58.5%). Other than influenza, respiratory syncytial virus was the most common respiratory infection circulating, with 277 cases (35.9%). ConclusionInfluenza viruses cause a high number of severe respiratory infections in EMR. It is crucial for the countries to continue improving their influenza surveillance capacity in order detect any unusual influenza activity or new strain that may cause a pandemic.

Association of polymorphisms in inflammatory cytokines encoding genes with severe cases of influenza A/H1N1 and B in an Iranian population

BackgroundThe increased levels of blood cytokines is the main immunopathological process that were attributed to severe clinical outcomes in cases of influenza A, influenza B and people with influenza-like illness (ILI). Functional genetic polymorphisms caused by single nucleotide polymorphisms (SNPs) in inflammatory cytokines genes can influence their functions either qualitatively or quantitatively, which is associated with the possibility of severe influenza infections. The aim of the present case-control study was to investigate the association of polymorphisms in inflammatory cytokines genes with influenza patients and ILI group in an Iranian population.MethodsTotal number of 30 influenza B, 50 influenza A (H1N1) and 96 ILI inpatient individuals were confirmed by Real-time RT-PCR and HI assays. The genotype determination was assessed for defined SNPs in IL-1β, IL-17, IL-10 and IL-28 genes.ResultsThe frequencies of the IL-1β rs16944 (P = 0.007) and IL-17 rs2275913 (P = 0.006) genotypes were associated with severe influenza disease, while the frequencies of IL-10 rs1800872 and IL-28 rs8099917 were not associated with the disease (P > 0.05). Also, the absence of A allele in IL-17 rs2275913 SNP increased the risk of influenza A (H1N1) infection (P = 0.008).ConclusionsThis study demonstrated that influenza A- (H1N1) and B-infected patients and also ILI controls have different profiles of immune parameters, and individuals carrying the specific cytokine-derived polymorphisms may show different immune responses towards severe outcome.

Influenza epidemiology and influenza vaccine effectiveness during the 2015\u20132016 season: results from the Global Influenza Hospital Surveillance Network

BackgroundThe Global Influenza Hospital Surveillance Network is an international platform whose primary objective is to study severe cases of influenza requiring hospitalization.MethodsDuring the 2015–2016 influenza season, 11 sites in the Global Influenza Hospital Surveillance Network in nine countries (Russian Federation, Czech Republic, Turkey, France, China, Spain, Mexico, India, and Brazil) participated in a prospective, active-surveillance, hospital-based epidemiological study. Influenza infection was confirmed by reverse transcription-polymerase chain reaction. Influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza was estimated using a test-negative approach.Results9882 patients with laboratory results were included of which 2415 (24.4%) were positive for influenza, including 1415 (14.3%) for A(H1N1)pdm09, 235 (2.4%) for A(H3N2), 180 (1.8%) for A not subtyped, 45 (0.5%) for B/Yamagata-lineage, 532 (5.4%) for B/Victoria-lineage, and 33 (0.3%) for B not subtyped. Of included admissions, 39% were < 5 years of age and 67% had no underlying conditions. The odds of being admitted with influenza were higher among pregnant than non-pregnant women (odds ratio, 2.82 [95% confidence interval (CI), 1.90 to 4.19]). Adjusted IVE against influenza-related hospitalization was 16.3% (95% CI, 0.4 to 29.7). Among patients targeted for influenza vaccination, adjusted IVE against hospital admission with influenza was 16.2% (95% CI, − 3.6 to 32.2) overall, 23.0% (95% CI, − 3.3 to 42.6) against A(H1N1)pdm09, and − 25.6% (95% CI, − 86.3 to 15.4) against B/Victoria lineage.ConclusionsThe 2015–2016 influenza season was dominated by A(H1N1)pdm09 and B/Victoria-lineage. Hospitalization with influenza often occurred in healthy and young individuals, and pregnant women were at increased risk of influenza-related hospitalization. Influenza vaccines provided low to moderate protection against hospitalization with influenza and no protection against the predominant circulating B lineage, highlighting the need for more effective and broader influenza vaccines.