Severe Acute Respiratory Infection Case Definition Research Articles

Establishing severe acute respiratory infection (SARI) surveillance in a sentinel hospital, Ireland, 2021 to 2022.

BackgroundIn 2020, due to the COVID-19 pandemic, the European Centre for Disease Prevention and Control (ECDC) accelerated development of European-level severe acute respiratory infection (SARI) surveillance.AimWe aimed to establish SARI surveillance in one Irish hospital as part of a European network E-SARI-NET.MethodsWe used routine emergency department records to identify cases in one adult acute hospital. The SARI case definition was adapted from the ECDC clinical criteria for a possible COVID-19 case. Clinical data were collected using an online questionnaire. Cases were tested for SARS-CoV-2, influenza and respiratory syncytial virus (RSV), including whole genome sequencing (WGS) on SARS-CoV-2 RNA-positive samples and viral characterisation/sequencing on influenza RNA-positive samples. Descriptive analysis was conducted for SARI cases hospitalised between July 2021 and April 2022.ResultsOverall, we identified 437 SARI cases, the incidence ranged from two to 28 cases per week (0.7-9.2/100,000 hospital catchment population). Of 431 cases tested for SARS-CoV-2 RNA, 226 (52%) were positive. Of 349 (80%) cases tested for influenza and RSV RNA, 15 (4.3%) were positive for influenza and eight (2.3%) for RSV. Using WGS, we identified Delta- and Omicron-dominant periods. The resource-intensive nature of manual clinical data collection, specimen management and laboratory supply shortages for influenza and RSV testing were challenging.ConclusionWe successfully established SARI surveillance as part of E-SARI-NET. Expansion to additional sentinel sites is planned following formal evaluation of the existing system. SARI surveillance requires multidisciplinary collaboration, automated data collection where possible, and dedicated personnel resources, including for specimen management.

Antibiotic use among SARI patients according to the AWaRe classification before and during the COVID-19 pandemic in Bangladesh

Background: Irrational antibiotic use among hospitalized patients can lead to antibiotic resistance. For rational use, the WHO introduced the Access, Watch, and Reserve (AWaRe) classification of antibiotics. We explored antibiotic use according to the AWaRe classification among patients hospitalized with severe acute respiratory infection (SARI) between the prepandemic and COVID-19 pandemic periods in Bangladesh. Methods: From June 2017 to November 2022, we analyzed SARI inpatient data from the hospital-based influenza surveillance platform at 9 tertiary-level hospitals in Bangladesh. We defined June 2017–February 2020 as the prepandemic period and March 2020–November 2022 as the pandemic period. Physicians identified inpatients meeting the WHO SARI case definition and recorded patient demographics, clinical characteristics, and antibiotics received during hospitalization. We used descriptive statistics to summarize the data. Results: We enrolled 20,640 SARI patients (median age, 20 years; IQR, 1.6–50; 63% male); and among them, 18,197 (88%) received antibiotics (26% of those received >1 different course of antibiotics). Compared to the prepandemic period, the proportion of antibiotic use among SARI patients was higher during the pandemic: 93% (9,887 of 10,655) versus 83% (8,310 of 9,985) (P < .001). According to AWaRe classification, Access, Watch, and Reserve groups accounted for 32% (n = 2,623), 86% (n = 7,158), and 0.05% (n = 4), respectively, before the pandemic and 32% (n = 3,194), 90% (n = 8,850), and 0.08% (n = 8), respectively, during the pandemic (Fig.). The most common antibiotic prescribed for children aged <5 years during the prepandemic was ceftriaxone (n = 1,940, 74%), followed by amikacin (n = 325, 13%) and flucloxacillin (n = 300, 12%); similarly, during the pandemic, most common antibiotic prescribed was ceftriaxone (n = 3,097, 79%), followed by amikacin (n = 723, 18%) and flucloxacillin (n = 348, 9%). The most common antibiotic prescribed for patients aged ≥5 years during the prepandemic period was ceftriaxone (n = 3,174, 54%), followed by amoxicillin-clavulanic acid (n = 1,304, 22%) and azithromycin (n = 1,038, 18%). During the pandemic, the most common antibiotic prescribed for patients aged ≥5 years was ceftriaxone (n = 3,793, 64%), followed by amoxicillin-clavulanic acid (n = 1,327, 22%) and clarithromycin (n = 797, 13%). Among children aged <5 years, use of the Watch group of antibiotics during the prepandemic and pandemic periods was similar: 94% (n = 3,688) versus 95% (n = 2,347) (P = .099). However, among patients aged ≥5 years, the use of Watch antibiotics was higher during the pandemic compared to the prepandemic period: 87% (n = 5,163) versus 82% (n = 4,811) (P < .001). Conclusions: Use of antibiotics in the Watch group was predominant among SARI patients both before and during the COVID-19 pandemic, and it increased among SARI patients aged ≥5 years during the pandemic period in Bangladesh. Promoting antibiotic stewardship programs for physicians, including in-service training on antibiotic use, could reduce irrational antibiotic use, which might contribute to mitigating antibiotic resistance in the country.Financial support: This study was funded by the CDC.Disclosures: None

Burden of Influenza-Associated Respiratory Hospitalizations, Vietnam, 2014-2016.

Influenza burden estimates are essential to informing prevention and control policies. To complement recent influenza vaccine production capacity in Vietnam, we used acute respiratory infection (ARI) hospitalization data, severe acute respiratory infection (SARI) surveillance data, and provincial population data from 4 provinces representing Vietnam’s major regions during 2014–2016 to calculate provincial and national influenza-associated ARI and SARI hospitalization rates. We determined the proportion of ARI admissions meeting the World Health Organization SARI case definition through medical record review. The mean influenza-associated hospitalization rates per 100,000 population were 218 (95% uncertainty interval [UI] 197–238) for ARI and 134 (95% UI 119–149) for SARI. Influenza-associated SARI hospitalization rates per 100,000 population were highest among children <5 years of age (1,123; 95% UI 946–1,301) and adults >65 years of age (207; 95% UI 186–227), underscoring the need for prevention and control measures, such as vaccination, in these at-risk populations.

Comparison of common acute respiratory infection case definitions for identification of hospitalized influenza cases at a population-based surveillance site in Egypt.

BackgroundMultiple case definitions are used to identify hospitalized patients with community-acquired acute respiratory infections (ARI). We evaluated several commonly used hospitalized ARI case definitions to identify influenza cases.MethodsThe study included all patients from a population-based surveillance site in Damanhour, Egypt hospitalized for a broad set of criteria consistent with community acquired ARIs. Naso- and oropharyngeal (NP/OP) swabs were tested for influenza using RT-PCR. Sensitivity, specificity and PPV for influenza identification was compared between the 2014 WHO Severe Acute Respiratory Infection (SARI) definition (fever ≥38°C and cough with onset within 10 days), the 2011 WHO SARI definition (fever ≥38°C and cough with onset within 7 days), the 2006 PAHO SARI definition, the International Emerging Infections Program (IEIP) pneumonia case definition, and the International Management of Childhood Illness (IMCI) case definitions for moderate and severe pneumonia.ResultsFrom June 2009-December 2012, 5768 NP/OP swabs were obtained from 6113 hospitalized ARI patients; 799 (13.9%) were influenza positive. The 2014 WHO SARI case definition captured the greatest number of ARI patients, influenza positive patients and ARI deaths compared to the other case definitions examined. Sensitivity for influenza detection was highest for the 2014 WHO SARI definition with 88.6%, compared to the 2011 WHO SARI (78.2%) the 2006 PAHO SARI (15.8%) the IEIP pneumonia (61.0%) and the IMCI moderate and severe pneumonia (33.8% and 38.9%) case definitions (IMCI applies to <5 only).ConclusionsOur results support use of the 2014 WHO SARI definition for identifying influenza positive hospitalized SARI cases as it captures the highest proportion of ARI deaths and influenza positive cases. Routine use of this case definition for hospital-based surveillance will provide a solid, globally comparable foundation on which to build needed response efforts for novel pandemic viruses.

Severe Acute Respiratory Infections (SARI) surveillance in over-65-years-old patients: the experience of a University hospital (seasons 2017-2018 and 2018-2019).

Influenza is a relevant public health problem, also due to the risk of complications. The most effective measure to prevent influenza is vaccination; therefore, at present, there is consensus among European countries, regarding the need for routine seasonal influenza vaccination of elderly and individuals at increased risk of severe influenza. At the same time, influenza surveillance is necessary to understand the viruses circulating and effectiveness of vaccination strategies. The present study reports the results of two seasons influenza surveillance (2017/2018 and 2018/2019) conduced in an University Hospital in Rome among hospitalized patients aged ≥65 years. A prospective cohort study. The study consisted of systematic daily screening of all admissions among patients aged ≥65 years meeting a syndromic SARI case definition during two consecutive influenza seasons: 2017/2018 and 2018/2019. Characteristics of patients and their risk factors were collected by a standardized questionnaire and nose-pharyngeal swabs were performed to each patient. Influenza vaccine effectiveness (IVE), rates of vaccinated subjects and case fatality rate were also evaluated. Influenza was laboratory confirmed in 11 (9.9%) of the 111 and 11 (9.6%) of the 115 enrolled patients in seasons 2017/18 and 2018/19, respectively. Adjusted IVE against all influenza type, calculated for each season, was 88.5% (95% CI: 38.9 to 97.8) and 61.7% (95% CI: -59.9 to 90.9) for 2017/2018 and 2018/2019 seasons, respectively. Our analysis shows a Case Fatality Rate of 2.7% and 4.3% for the 2017/18 and 2018/19 seasons, respectively. The surveillance of SARI conduced in one hospital in Rome confirmed that influenza is an important cause of hospital admissions. Routine monitoring of infectious diseases and related aetiology associated with SARI, also at the local-level, is useful for targeting the right preventive measures.

Capturing respiratory syncytial virus season in Belgium using the influenza severe acute respiratory infection surveillance network, season 2018/19.

BackgroundRespiratory syncytial virus (RSV) is a common cause of severe respiratory illness in young children (< 5 years old) and older adults (≥ 65 years old) leading the World Health Organization (WHO) to recommend the implementation of a dedicated surveillance in countries.AimWe tested the capacity of the severe acute respiratory infection (SARI) hospital network to contribute to RSV surveillance in Belgium.MethodsDuring the 2018/19 influenza season, we started the SARI surveillance for influenza in Belgium in week 40, earlier than in the past, to follow RSV activity, which usually precedes influenza virus circulation. While the WHO SARI case definition for influenza normally used by the SARI hospital network was employed, flexibility over the fever criterion was allowed, so patients without fever but meeting the other case definition criteria could be included in the surveillance.ResultsBetween weeks 40 2018 and 2 2019, we received 508 samples from SARI patients. We found an overall RSV detection rate of 62.4% (317/508), with rates varying depending on the age group: 77.6% in children aged < 5 years (253/326) and 34.4% in adults aged ≥ 65 years (44/128). Over 90% of the RSV-positive samples also positive for another tested respiratory virus (80/85) were from children aged < 5 years. Differences were also noted between age groups for symptoms, comorbidities and complications.ConclusionWith only marginal modifications in the case definition and the period of surveillance, the Belgian SARI network would be able to substantially contribute to RSV surveillance and burden evaluation in children and older adults, the two groups of particular interest for WHO.

Evaluating the diagnostic accuracy of the WHO Severe Acute Respiratory Infection (SARI) criteria in Middle Eastern children under two years over three respiratory seasons.

The World Health Organization created the Severe Acute Respiratory Infection (SARI) criteria in 2011 to monitor influenza (flu)-related hospitalization. Many studies have since used the SARI case definition as inclusion criteria for surveillance studies. We sought to determine the sensitivity, specificity, positive predictive value, and negative predictive value of the SARI criteria for detecting ten different respiratory viruses in a Middle Eastern pediatric cohort. The data for this study comes from a prospective acute respiratory surveillance study of hospitalized children <2 years in Amman, Jordan from March 16, 2010 to March 31, 2013. Participants were recruited if they had a fever and/or respiratory symptoms. Nasal and throat swabs were obtained and tested by real-time RT-PCR for eleven viruses. Subjects meeting SARI criteria were determined post-hoc. Sensitivity, specificity, positive predictive value, and negative predictive value of the SARI case definition for detecting ten different viruses were calculated and results were stratified by age. Of the 3,175 patients enrolled, 3,164 were eligible for this study, with a median age of 3.5 months, 60.4% male, and 82% virus-positive (44% RSV and 3.8% flu). The sensitivity and specificity of the SARI criteria for detecting virus-positive patients were 44% and 77.9%, respectively. Sensitivity of SARI criteria for any virus was lowest in children <3 months at 22.4%. Removing fever as a criterion improved the sensitivity by 65.3% for detecting RSV in children <3 months; whereas when cough was removed, the sensitivity improved by 45.5% for detecting flu in same age group. The SARI criteria have poor sensitivity for detecting RSV, flu, and other respiratory viruses-particularly in children <3 months. Researchers and policy makers should use caution if using the criteria to estimate burden of disease in children.

Epidemiology and molecular characterization of Respiratory Syncytial Virus in Argentina 2017

Background: Human respiratory syncytial virus (RSV) is one of the most frequent cause of respiratory infections, and the main cause of severe cases of bronchiolitis and pneumonia in infants and young children. Viral strains have been separated into two major subtypes (RSV-A and RSV-B), and nucleotide sequence analysis has led to the identification of 11 RSV-A and 23 RSV-B genotypes. Multiple genotypes can co-circulate during successive epidemic seasons, but a new genotype (or one spreading from another country) may replace previously dominant strains. Methods & Materials: The main aim of this study was to investigate the genetic diversity and patterns of the co-circulating genotypes of RSV-A and RSV-B strains in Argentina, and the possible associations between individual RSV genotypes and case definitions. Results: The National Reference Laboratory of Influenza and Other Respiratory Viruses (NRLIRV) received clinical samples of hospitalized children less than 5 years old and elderly, according to different case definitions during the acute phase of the illness: severe acute respiratory infection (SARI) with or without fever, influenza like illness with or without fever and acute respiratory infection. Between epidemiological weeks (EW) 1 and 43, 520 clinical samples were received from different provinces of the country: Chaco, Tucuman, La Rioja and Buenos Aires city collected from January to October 2017, in order to perform subtyping by real time RT-PCR and genotyping by G gene sequencing (969 nt). RSV was detected in 238 samples (55.5%) of the total diagnosed. Initially, RSV circulated in Chaco (EW 1) followed by Tucuman (EW 5-8). Ninety percentage (124/138) and 10% (14/138) of the subtyped samples belonged to A and B, respectively. All group A strains sequenced (10) were closely related to the genetic group ON1 with the 72-nt duplication (originated in Canada). Conclusion: A co-circulation of RSV A and B groups was detected, being group A the predominant and most of these viruses were collected from pediatric and adult patients with SARI case definition with and without fever. Continued genotyping and molecular epidemiological surveillance of RSV are essential to further understanding RSV evolution and transmission in communities and healthcare settings.

Influenza Sentinel Surveillance System in Surb Astvatsamayr Medical Center, 2013-15

ObjectiveThe goal of this study was to identify gaps in the severe acute respiratory infection sentinel surveillance system at Surb Astvatsamayr Medical Center.IntroductionInfluenza is a priority in Armenia. There are two influenza surveillance systems in Armenia: population and sentinel. The medical center (MC) has been included in sentinel surveillance since 2012. In 2015 a study was undertaken to identify gaps in severe acute respiratory infection (SARI) sentinel surveillance system in Surb Astvatsamayr MC.MethodsMedical records and reporting forms of SARI cases were generated for individuals meeting the case definition and analyzed for age groups, risk factors, sentinel surveillance detection methods, laboratory conformation, number of days hospitalized and reporting.ResultsIn 2014, 3016 patients were admitted in the hospital with ARI, of whom 2982 were younger than 18 years. During the 2014-2015 influenza season (week 40, 2014-week 20, 2015), 77 swabs have been taken in total, of which five were influenza positive (4 B and 1 AH1N1). Also in the 2013-2014 influenza season, five samples tested positive (all influenza A). Sixty-one (48%) patients with respiratory disease met the WHO SARI case definition (2011), 84 (66%) of all reviewed patients would have met the SARI case definition. The numbers for the ICU (25 records reviewed) do not reflect the actual percentage of patients admitted with respiratory symptoms. The 33 additional cases taken from the sampling logbook were mainly hospitalized in the ICU. Influenza tests were performed on 34 patients (mainly ICU), five were positive for influenza (four B--all adults—and one AH1N1), and four tested positives for other respiratory pathogens (two RSV, one RV, one BV). All influenza positives had fever or a history of fever and 80% met the WHO SARI case definition (2011). Non-sampled cases generally have fewer reported symptoms, but still 44% of cases fits the WHO SARI case definition (2011).ConclusionsThe percentages of patients meeting the WHO SARI 2011 case definition and the WHO SARI 2014 definition shows that mainly caused by the absence of shortness of breath in the SARI 2014 definition 52% (2011) vs 66% (2014) in Surb Asvatsamayr. A large number of children from Neonatal and Children’s departments fulfil the SARI case definition and could potentially be swabbed in addition to ICU patients. There are gaps in WHO SARI case definitions. The sentinel surveillance system should be improved.

Influenza‐associated severe acute respiratory infections in 2 sentinel sites in Lebanon—September 2015 to August 2016

BackgroundGiven the sparse information on the burden of influenza in Lebanon, the Ministry of Public Health established a sentinel surveillance for severe acute respiratory infections (SARI) to identify the attribution of influenza to reported cases. We aim to highlight the proportion of influenza‐associated SARI from September 1st, 2015 to August 31st, 2016 in 2 Lebanese hospitals.MethodsThe study was conducted in 2 sentinel sites located in Beirut suburbs and southern province of Lebanon. WHO's 2011 standardized SARI case definition was used. Data from September 1, 2015 to August 31, 2016 were reviewed, and all‐cause hospital admission numbers were obtained. Nasopharyngeal swabs were collected and tested by RT‐PCR. Descriptive and bivariate analyses were conducted using STATA 13.ResultsThe 2 sentinel sites reported 746 SARI cases during the studied time frame: 467 from the southern province site and 279 from the Beirut suburbs site. SARI reports peaked between January and March 2016. All, except 4, cases were sampled, and a co‐dominance of influenza B (43%) and influenza A (H1N1) (41%) was evident. A high proportion of cases was reported in children <2 years 274 (37%). The proportional contribution of influenza‐associated SARI to all‐cause hospital admissions was high in children <2 years in the south (4.5% [95% CI: 3.1‐6.5]) and in children <5 years in Beirut (0.7% [95% CI: 0.6‐0.8]).ConclusionThis is the first study to highlight the proportion of influenza‐associated SARI in 2 hospitals in Lebanon. The findings will be beneficial for supporting respiratory prevention and immunization program policies.

Mortality estimates among adult patients with severe acute respiratory infections from two sentinel hospitals in southern Arizona, United States, 2010\u20132014

BackgroundFrom October 2010 through February 2016, Arizona conducted surveillance for severe acute respiratory infections (SARI) among adults hospitalized in the Arizona-Mexico border region. There are few accurate mortality estimates in SARI patients, particularly in adults ≥ 65 years old.The purpose of this study was to generate mortality estimates among SARI patients that include deaths occurring shortly after hospital discharge and identify risk factors for mortality.MethodsPatients admitted to two sentinel hospitals between 2010 and 2014 who met the SARI case definition were enrolled. Demographic data were used to link SARI patients to Arizona death certificates. Mortality within 30 days after the date of admission was calculated and risk factors were identified using logistic regression models.ResultsAmong 258 SARI patients, 47% were females, 51% were white, non-Hispanic and 39% were Hispanic. The median age was 63 years (range, 19 to 97 years) and 80% had one or more pre-existing health condition; 9% died in hospital. Mortality increased to 12% (30/258, 30% increase) when electronic vital records and a 30-day post-hospitalization time frame were used. Being age ≥ 65 years (OR = 4.0; 95% CI: 1.6–9.9) and having an intensive care unit admission (OR = 7.4; 95% CI: 3.0–17.9) were independently associated with mortality.ConclusionThe use of electronic vital records increased SARI-associated mortality estimates by 30%. These findings may help guide prevention and treatment measures, particularly in high-risk persons in this highly fluid border population.

Sentinel surveillance for influenza in Oman, January 2008-June 2013

Background: Acute respiratory infections, including influenza, comprise a leading cause of morbidity and mortality globally. Influenza surveillance provides important information to inform policy on influenza control and vaccination. While the epidemiology of influenza has been well characterized in western countries, few data exist on influenza epidemiology in the Eastern Mediterranean Region. We describe the epidemiology of influenza virus in Oman. Methods: Using syndromic case definitions and protocols, patients from four regional hospitals in Oman were enrolled in a descriptive prospective study to characterize the burden of severe acute respiratory infections (SARI) and influenza. Patients meeting the SARI case definition provided demographic information as well as oropharyngeal and nasopharyngeal swabs. Specimens were tested for influenza A and influenza B. Influenza A viruses were subtyped using RT-PCR. Results: From January 2008 through June 2013, a total of 5,147 cases were enrolled and tested for influenza. Influenza strains were detected in 8% of cases for whom samples were available. Annual incidence rates ranged from 0.5 to 15.4 cases of influenza-associated SARI per 100,000 population. The median age of influenza patients was 6 years with children 0–2 years accounting for 34% of all influenza-associated hospitalizations. By contrast, the median age of non-influenza SARI cases was 1 year, with children 0–2 years comprising 59% of SARI. Compared to non-influenza SARI cases, a greater proportion of influenza cases had pre-existing chronic conditions and underwent ventilation during hospitalization. Conclusions: Influenza virus is associated with a substantial proportion of SARI in Oman. Influenza in Oman approximately follows northern hemisphere seasonality, with major peaks in October to December and a lesser peak around April. The burden of influenza was greatest in children and the elderly. Future efforts should examine the burden of influenza in other potential risk groups such as pregnant women to inform interventions including targeted vaccination.

Severe acute respiratory infections associated with influenza and non-influenza viruses - Yemen, 2011-2014

Background: In 2010, influenza surveillance started in Yemen after H1N1 influenza outbreak. Ministry of Health (MoH) established two sentinel sites for Severe Acute Respiratory Infection (SARI) at the two main public hospitals in Sana’a and Aden with the support of NAMRU3, where SARI samples tested for influenza and non-influenza viruses by the Real-Time-PCR assay. The aim is to describe the SARI severity as indicated by admission to intensive care unit (ICU) and fatality as well as associated influenza and non-influenza viruses among hospitalized patients of the two sentinel sites in order to provide recommendations for improving influenza surveillance Methods & Materials: Data of hospitalized patients of the two sites who meet WHO SARI case definition during 2011 to 2014 was obtained from MoH. Data was cleaned and analyzed using SPSS program where P value < 0.05 was the cut point for significance Results: 1,665 met SARI cases definition during 2011 to 2014, of which 64% from Aden, two thirds were below the age of two years, 48% were males, 24% has chronic diseases and 33% was admitted to the ICU. Overall fatality rate was 10% which significantly higher among patients from Aden than Sana’a (14% vs. 3%, P <0.001). 1299 (78%) samples were tested where influenza viruses were confirmed in 67 (5%); of which 41 (61%) was type A and 27 (39%) was type B. Non-influenza viruses were detected in 39% (509) of samples including 246 (48%) Respiratory Syncytial Virus and 99 (19%) was Adenovirus. The influenza viruses was significantly higher in Sana’a than Aden (63% vs 37% P value < 0.01) while the Non-influenza virus was significantly higher in Aden than Sana’a (54% vs. 46%, P value < 0.01). The case fatality rate among non-influenza was 11% compared to 6% among influenza cases but the difference was not statistically significant. Conclusion: Our findings showed that most SARI cases was of non-influenza type with high mortality that necessitate prompt diagnosis and treatment of suspected cases. Expanding SARI surveillance to include more public and private hospitals in different governorates is recommended to give more comprehensive picture. Further studies to better understand the geographical differences are needed

Surveillance for severe acute respiratory infections in Southern Arizona, 2010–2014

BackgroundThe Binational Border Infectious Disease Surveillance program began surveillance for severe acute respiratory infections (SARI) on the US–Mexico border in 2009. Here, we describe patients in Southern Arizona.MethodsPatients admitted to five acute care hospitals that met the SARI case definition (temperature ≥37·8°C or reported fever or chills with history of cough, sore throat, or shortness of breath in a hospitalized person) were enrolled. Staff completed a standard form and collected a nasopharyngeal swab which was tested for selected respiratory viruses by reverse transcription polymerase chain reaction.ResultsFrom October 2010–September 2014, we enrolled 332 SARI patients. Fifty‐two percent were male and 48% were white non‐Hispanic. The median age was 63 years (47% ≥65 years and 5·2% <5 years). During hospitalization, 51 of 230 (22%) patients required intubation, 120 of 297 (40%) were admitted to intensive care unit, and 28 of 278 (10%) died. Influenza vaccination was 56%. Of 309 cases tested, 49 (16%) were positive for influenza viruses, 25 (8·1%) for human metapneumovirus, 20 (6·5%) for parainfluenza viruses, 16 (5·2%) for coronavirus, 11 (3·6%) for respiratory syncytial virus, 10 (3·2%) for rhinovirus, 4 (1·3%) for rhinovirus/enterovirus, 3 (1·0%) for enteroviruses, and 3 (1·0%) for adenovirus. Among the 49 influenza‐positive specimens, 76% were influenza A (19 H3N2, 17 H1N1pdm09, and 1 not subtyped), and 24% were influenza B.ConclusionInfluenza viruses were a frequent cause of SARI in hospitalized patients in Southern Arizona. Monitoring respiratory illness in border populations will help better understand the etiologies. Improving influenza vaccination coverage may help prevent some SARI cases.

Clinical characteristics of adult influenza inpatients in ten provinces in China and analysis of severe risk factors

To identity the clinical characteristics and severe case risk factors for the adult inpatient cases confirmed of influenza monitored by the sentinel surveillance system for severe acute respiratory infection (SARI) inpatient cases in ten provinces in China. Epidemiology and clinical information surveys were conducted for adult cases (≥ 15 year old) consistent with SARI case definition, who were monitored by SARI sentinel hospitals in ten cities in China from December 2009 to June 2014, with their respiratory tract specimens collected for influenza RNA detection. Adult SARI cases were classified into influenza inpatient group and outpatient group by the detection outcomes, analyzing their demographic information, clinical and epidemiology characteristics respectively, in addition to risk factors for severe inpatient cases. 3 071 adult SARI cases were recruited from ten hospitals, including 240 (7.8%) cases of laboratory-confirmed influenza, most of them being A (H1N1) pdm2009 and A (H3N2) sub-types. Age M of the included influenza cases was 63 year old, 47.1% of them being ≥ 65 seniors. 144 (60.0%) cases of the influenza inpatients suffered from at least one chronic underlying condition, and the proportion of emphysema (7.9%) was higher than non-influenza inpatient cases (3.8%), being statistically significant (χ(2) = 3.963, P = 0.047). 19.4% of the women of childbearing age infected of influenza were in pregnancy, and only 1.1% of the 240 influenza cases had been vaccinated against influenza. The proportion of sore throat and dyspnea found among influenza inpatients was higher than inpatients without influenza. 17.4% of the influenza cases were accepted into ICU for treatment, with no statistical significance with non-influenza inpatient cases (P = 0.160). 23.1% of the influenza inpatients received an antiviral drug therapy, a figure higher than the non-influenza inpatient cases (4.8%) (P < 0.001). 41.5% of the inpatients developed complications, with the proportion of viral pneumonia significantly higher than the non-influenza inpatient cases (P < 0.001). Asthma (RR = 15.200, 95% CI: 1.157-199.633), immunosuppressive diseases (RR = 5.250, 95% CI: 1.255-21.960), pregnancy (RR = 21.000, 95% CI: 1.734-254.275), time interval from onset to admission less 7 days (RR = 1.673, 95% CI: 1.071-2.614) were identified as risk factors of severely-ill influenza cases. It was found that adult influenza inpatients were mostly ≥ 65 year old seniors. The influenza vaccination rate among the influenza cases was very low, and antivirus drugs were used less than necessary. In this regard, influenza vaccination was recommended for high risk groups of pregnant women, seniors and chronic disease patients on annual basis, while influenza inpatients were advised to use antiviral drugs as early as possible.

Estimation of hospitalization rate of laboratory confirmed influenza cases in Jingzhou city, Hubei province, 2010-2012

To estimate the hospitalization rate of severe acute respiratory infection (SARI) cases attributable to influenza in Jingzhou city, Hubei province from 2010 to 2012. SARI surveillance was conducted at four hospitals in Jingzhou city, Hubei province from 2010 to 2012. Inpatients meeting the SARI case definition and with informed consent were enrolled to collect their demographic information, clinical features, treatment, and disease outcomes, with their respiratory tract specimens collected for PCR test of influenza virus. From April, 2010 to September, 2012, 19 679 SARI cases enrolled were residents of Jingzhou, and nasopharyngeal swab was collected from 18 412 (93.6%) cases of them to test influenza virus and 13.3% were positive for influenza. During the three consecutive 2010-2012 flu seasons, laboratory-confirmed influenza was associated with 102 per 100 000, 132 per 100 000 and 244 per 100 000, respectively. As for the hospitalization rate attributable to specific type/subtype of influenza virus, 48 per 100 000, 30 per 100 000 and 24 per 100 000 were attributable to A (H3N2), A (H1N1) pdm2009, and influenza B, respectively in 2010-2011 season; 42 per 100 000 [A (H3N2)] and 90 per 100 000 (influenza B) in 2011-2012 season; 90 per 100 000 [A (H3N2)] and one per 100 000 [influenza B] from April, 2010 to September, 2012. SARI hospitalization caused by influenza A or B occurred both mainly among children younger than five years old, with the peak in children aged 0.5 year old. Influenza could cause a substantial number of hospitalizations and different viral type/subtype result in different hospitalizations over influenza seasons in Jingzhou city, Hubei province. Children less than five years old should be prioritized for influenza vaccination in China.

Surveillance for severe acute respiratory infections (SARI) in hospitals in the WHO European region - an exploratory analysis of risk factors for a severe outcome in influenza-positive SARI cases.

BackgroundThe 2009 H1N1 pandemic highlighted the need to routinely monitor severe influenza, which lead to the establishment of sentinel hospital-based surveillance of severe acute respiratory infections (SARI) in several countries in Europe. The objective of this study is to describe characteristics of SARI patients and to explore risk factors for a severe outcome in influenza-positive SARI patients.MethodsData on hospitalised patients meeting a syndromic SARI case definition between 2009 and 2012 from nine countries in Eastern Europe (Albania, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Romania, Russian Federation and Ukraine) were included in this study. An exploratory analysis was performed to assess the association between risk factors and a severe (ICU, fatal) outcome in influenza-positive SARI patients using a multivariate logistic regression analysis.ResultsNine countries reported a total of 13,275 SARI patients. The majority of SARI patients reported in these countries were young children. A total of 12,673 SARI cases (95%) were tested for influenza virus and 3377 (27%) were laboratory confirmed. The majority of tested SARI cases were from Georgia, the Russian Federation and Ukraine and the least were from Kyrgyzstan. The proportion positive varied by country, season and age group, with a tendency to a higher proportion positive in the 15+ yrs age group in six of the countries. ICU admission and fatal outcome were most often recorded for influenza-positive SARI cases aged >15 yrs. An exploratory analysis using pooled data from influenza-positive SARI cases in three countries showed that age > 15 yrs, having lung, heart, kidney or liver disease, and being pregnant were independently associated with a fatal outcome.ConclusionsCountries in Eastern Europe have been able to collect data through routine monitoring of severe influenza and results on risk factors for a severe outcome in influenza-positive SARI cases have identified several risk groups. This is especially relevant in the light of an overall low vaccination uptake and antiviral use in Eastern Europe, since information on risk factors will help in targeting and prioritising vulnerable populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0722-x) contains supplementary material, which is available to authorized users.

Implementing hospital-based surveillance for severe acute respiratory infections caused by influenza and other respiratory pathogens in New Zealand.

Recent experience with pandemic influenza A(H1N1)pdm09 highlighted the importance of global surveillance for severe respiratory disease to support pandemic preparedness and seasonal influenza control. Improved surveillance in the southern hemisphere is needed to provide critical data on influenza epidemiology, disease burden, circulating strains and effectiveness of influenza prevention and control measures. Hospital-based surveillance for severe acute respiratory infection (SARI) cases was established in New Zealand on 30 April 2012. The aims were to measure incidence, prevalence, risk factors, clinical spectrum and outcomes for SARI and associated influenza and other respiratory pathogen cases as well as to understand influenza contribution to patients not meeting SARI case definition. All inpatients with suspected respiratory infections who were admitted overnight to the study hospitals were screened daily. If a patient met the World Health Organization's SARI case definition, a respiratory specimen was tested for influenza and other respiratory pathogens. A case report form captured demographics, history of presenting illness, co-morbidities, disease course and outcome and risk factors. These data were supplemented from electronic clinical records and other linked data sources. Hospital-based SARI surveillance has been implemented and is fully functioning in New Zealand. Active, prospective, continuous, hospital-based SARI surveillance is useful in supporting pandemic preparedness for emerging influenza A(H7N9) virus infections and seasonal influenza prevention and control.

Lessons from a one-year hospital-based surveillance of acute respiratory infections in Berlin- comparing case definitions to monitor influenza

BackgroundSurveillance of severe acute respiratory infections (SARI) in sentinel hospitals is recommended to estimate the burden of severe influenza-cases. Therefore, we monitored patients admitted with respiratory infections (RI) in 9 Berlin hospitals from 7.12.2009 to 12.12.2010 according to different case definitions (CD) and determined the proportion of cases with influenza A(H1N1)pdm09 (pH1N1). We compared the sensitivity and specificity of CD for capturing pandemic pH1N1 cases.MethodsWe established an RI-surveillance restricted to adults aged ≤ 65 years within the framework of a pH1N1 vaccine effectiveness study, which required active identification of RI-cases. The hospital information-system was screened daily for newly admitted RI-patients. Nasopharyngeal swabs from consenting patients were tested by PCR for influenza-virus subtypes. Four clinical CD were compared in terms of capturing pH1N1-positives among hospitalized RI-patients by applying sensitivity and specificity analyses. The broadest case definition (CD1) was used for inclusion of RI-cases; the narrowest case definition (CD4) was identical to the SARI case definition recommended by ECDC/WHO.ResultsOver the study period, we identified 1,025 RI-cases, of which 283 (28%) met the ECDC/WHO SARI case definition. The percentage of SARI-cases among internal medicine admissions decreased from 3.2% (calendar-week 50-2009) to 0.2% (week 25-2010). Of 354 patients tested by PCR, 20 (6%) were pH1N1-positive. Two case definitions narrower than CD1 but -in contrast to SARI- not requiring shortness of breath yielded the largest areas under the Receiver-Operator-Curve. Heterogeneity of proportions of patients admitted with RI between hospitals was significant.ConclusionsComprehensive surveillance of RI cases was feasible in a network of community hospitals. In most settings, several hospitals should be included to ensure representativeness. Although misclassification resulting from failure to obtain symptoms in the hospital information-system cannot be ruled out, a high proportion of hospitalized PCR-positive pH1N1-patients (45%) did not fulfil the SARI case-definition that included shortness of breath or difficulty breathing. Thus, to assess influenza-related disease burden in hospitals, broader, alternative case definitions should be considered.