Epidemiology Of Influenza-like Illness Research Articles

Epidemiology of Influenza-like Illness and Respiratory Viral Etiology in Adult Patients in Taiyuan City, Shanxi Province, China between 2018 and 2019.

To determine the epidemiological status of influenza and understand the distribution of common respiratory viruses in adult patients with influenza-like illness (ILI) cases in Taiyuan City, Shanxi Province, China, epidemiological data between 2018 and 2019 were retrieved from the China Influenza Surveillance Information System, and two sentinel ILI surveillance hospitals were selected for sample collection. All specimens were screened for influenza virus (IFV) and the other 14 common respiratory viruses using real-time polymerase chain reaction. The results of the 2-year ILI surveillance showed that 26,205 (1.37%) of the 1,907,869 outpatients and emergency patients presented with ILI, with an average annual incidence of 297.75 per 100,000 individuals, and ILI cases were predominant in children <15 years (21,348 patients, 81.47%). Of the 2713 specimens collected from adult patients with ILI, the overall detection rate of respiratory viruses was 20.13%, with IFV being the most frequently detected (11.79%) and at a relatively lower rate than other respiratory viruses. Further subtype analysis indicated an alternating or mixed prevalence of H1N1 (2009), H3N2, Victoria, and Yamagata subtypes. This study provides a baseline epidemiological characterization of ILI and highlights the need for a nationwide detection and surveillance system for multiple respiratory pathogens.

677. Compliance and Performance Characteristics of Subject Collected Versus Health-care Worker Collected Nasal Swabs for Respiratory Viral Surveillance

Abstract Background Self-collection of mid-nasal swabs (SCNS) at home is a convenient alternative to health-care worker-collected nasal swabs (HCWC) for determining the pathogen-specific epidemiology of influenza-like illness (ILI). We evaluated the compliance and performance characteristics of SCNS vs. HCWC for respiratory pathogens during 2019-2020 flu season. Methods Adult Military Health System (MHS) beneficiaries were enrolled in an influenza vaccine effectiveness trial (PAIVED). Following vaccination, subjects were instructed on SCNS and completion of a symptom diary and were contacted weekly to ascertain ILI symptoms (fever, sore throat, and/or cough). In the event of an ILI, subjects completed the symptom diary and SCNS and were scheduled a clinic visit for HCWC. Swabs were tested with the Luminex NxTAG® Respiratory Pathogen Panel. We evaluated compliance with swab collection, positive percent agreement (PPA) of SCNS using PCR detection from either HCWC or SCNS as the reference standard, and agreement between paired swabs using the Cohen Kappa coefficient (Κ). Results 1808 ILI were reported by 972 participants enrolled during the study period. Compliance with HCWC was higher than SCNS (58% [1042] vs. 42% [766]; p&amp;lt; 0.001). SCNS were associated with a shorter interval from symptom onset (median: 4 days [IQR:2-6 days] vs. clinic collect: 7 days [IQR:4-9 days]; p &amp;lt; 0.001). 663 paired swabs were available for 609 participants (Table 1). The overall detection rate was higher in SCNS (36%) than HCWC (26%; p&amp;lt; 0.001) (Figure 1). The overall PPA was 85.7% and a PPA of approximately 80% of greater was observed for influenza, rhino/enterovirus, parainfluenza and respiratory syncytial virus. Agreement between paired swabs was poor due to the lower detection rates in HCWC. Table 1. Demographics and swab collection data for 609 participants who provided 663 paired swabs Figure 1. Detection by pathogen in 663 paired swabs Conclusion SCNS were associated with higher detection rates compared to HCWC, likely due to the shorter interval between symptom onset and swab collection. Strategies to improve compliance with SCNS and minimize the interval between symptom onset and swab collection are needed to optimize detection of respiratory pathogens in this MHS cohort. Disclosures Ryan C. Maves, MD, EMD Serono (Advisor or Review Panel member)Heron Therapeutics (Advisor or Review Panel member) Jitu Modi, MD, GSK (Speaker's Bureau)

Epidemiology of viral respiratory infections in Australian working-age adults (20-64 years): 2010-2013.

Acute respiratory infections cause significant morbidity and mortality accounting for 5.8 million deaths worldwide. In Australia, influenza-like illness (ILI), defined as cough, fever and fatigue is a common presentation in general practice and results in reduced productivity and lost working days. Little is known about the epidemiology of ILI in working-age adults. Using data from the ASPREN influenza surveillance network in Australia (2010-2013) we found that working-age adults made up 45.2% of all ILI notifications with 55% of samples positive for at least one respiratory virus. Viruses most commonly detected in our study included influenza A (20.6%), rhinovirus (18.6%), influenza B (6.2%), human meta-pneumovirus (3.4%), respiratory syncytial virus (3.1%), para-influenza virus (2.6%) and adenovirus (1.3%). We also demonstrated that influenza A is the predominant virus that increases ILI (by 1.2% per month for every positive influenza A case) in working-age adults during autumn-winter months while other viruses are active throughout the year. Understanding the epidemiology of viral respiratory infections through a year will help clinicians make informed decisions about testing, antibiotic and antiviral prescribing and when the beginning of the 'flu season' can be more confidently predicted.

Epidemiology and etiology of influenza-like-illness in households in Vietnam; it’s not all about the kids!

BackgroundHousehold studies provide opportunities to understand influenza-like-illness (ILI) transmission, but data from (sub)tropical developing countries are scarce. ObjectiveTo determine the viral etiology and epidemiology of ILI in households. Study designILI was detected by active case finding amongst a cohort of 263 northern Vietnam households between 2008 and 2013. Health workers collected nose and throat swabs for virus detection by multiplex real-time RT-PCR. ResultsILI was detected at least once in 219 (23.7%) of 945 household members. 271 (62.3%) of 435 nose/throat swabs were positive for at least one of the 15 viruses tested. Six viruses predominated amongst positive swabs: Rhinovirus (28%), Influenza virus (17%), Coronavirus (8%), Enterovirus (5%), Respiratory syncytial virus (3%), Metapneumovirus virus (2.5%) and Parainfluenza virus 3 (1.8%). There was no clear seasonality, but 78% of episodes occurred in Winter/Spring for Influenza compared to 32% for Rhinovirus. Participants, on average, suffered 0.49 ILI, and 0.29 virus-positive ILI episodes, with no significant effects of gender, age, or household size. In contrast to US and Australian community studies, the frequency of ILI decreased as the number of household members aged below 5 years increased (p=0.006). ConclusionThe findings indicate the need for tailored ILI control strategies, and for better understanding of how local childcare practices and seasonality may influence transmission and the role of children.

Viral etiology of medically attended influenza-like illnesses in children less than five years old in Suzhou, China, 2011-2014.

Limited information is available on the non‐influenza etiology and epidemiology of influenza‐like illness (ILI) in China. From April 2011 to March 2014, we collected oropharyngeal swabs from children less than 5 years of age with symptoms of ILI who presented to the outpatient departments of Suzhou University Affiliated Children's Hospital (SCH). We used reverse transcription polymerase chain reaction (rt‐PCR) or PCR to detect 11 respiratory viruses. Among 3,662 enrolled ILI patients, 1,292 (35.3%) tested positive for at least one virus. Influenza virus (16.9%) was detected most frequently (influenza A 7.4%, influenza B 9.5%), followed by respiratory syncytial virus (RSV) (5.6%), parainfluenza virus (PIV) types 1–4 (4.8%), human bocavirus (HBoV) (3.8%), human metapneumovirus (HMPV) (3.5%), and adenovirus (ADV) (3.0%). Co‐infections were identified in 108 (2.9%) patients. Influenza virus predominantly circulated in January–March and June–July. The 2013–2014 winter peaks of RSV and influenza overlapped. Compared with other virus positive cases, influenza positive cases were more likely to present with febrile seizure, and RSV positive cases were more likely to present with cough and wheezing, and were most frequently diagnosed with pneumonia. These data provide a better understanding of the viral etiology of ILI among children less than 5 years of age in Suzhou, China. Influenza is not only the most frequently identified pathogen but it is also the only vaccine preventable illness among the 11 pathogens tested. Such findings suggest the potential value of exploring value of influenza vaccination among this influenza vaccination target group. J. Med. Virol. 88:1334–1340, 2016 . © 2016 Wiley Periodicals, Inc.