Influenza-like Illness Events Research Articles

Efficacy of add-on Ayurveda and Yoga intervention in health care workers of tertiary care hospital during COVID-19: Randomized controlled trial

BackgroundThe present study aimed to evaluate the safety and prophylactic efficacy of add-on Comprehensive Ayurveda and mindfulness-based Yoga (CAY) regimen to standard care among HealthCare Workers (HCWs) against COVID-19. Materials and methodsThis prospective single-blind (outcome assessor-blinded) RCT was conducted in tertiary care hospital in Delhi during July 2020–April 2021. HCWs of both sexes were randomized to add-on CAY intervention or control group. The primary outcomes were the incidence of confirmed COVID-19 positive cases and influenza-like illness events (ILI). Secondary outcomes were anxiety (GAD-7), depression (PHQ-9), and quality of life (SF-36) at the end of 12 weeks. ResultsThree hundred fifty-six participants (181 in intervention and 175 in the control group) were randomized. With the modified intention to treat approach, we analyzed 309 participants. The mean age for the intervention and control group was 39.3 ± 10.1 and 36.6 ± 10 years, respectively. Incidence of COVID-19 event was higher in control group compared to CAY group (16 of 164 [9.8%] vs. 11 of 145 [7.6%]; P = 0.50). The incidence of ILI events was also higher in the control group as compared to the CAY group (14 of 164 [8.5%] vs 9 of 145 [6.2%]). The health change domain of the SF-36 questionnaire showed statistically significant improvement in the CAY group as compared to the control group (P < 0.01). ConclusionIncidence of COVID-19 and ILI events was lower in the CAY group compared with the contr ol group, though the difference is not statistically significant.

Risk of stroke and myocardial infarction after influenza-like illness in New York State

BackgroundInfluenza may be associated with increased stroke and myocardial infarction (MI) risk. We hypothesized that risk of stroke and MI after influenza-like illness (ILI) would be higher in patients in New York State. We additionally assessed whether this relationship differed across a series of sociodemographic factors.MethodsA case-crossover analysis of the 2012–2014 New York Statewide Planning and Research Cooperative System (SPARCS) was used to estimate odds of ischemic stroke and MI after ILI. Each patient’s case window (the time period preceding event) was compared to their control windows (same dates from the previous 2 years) in conditional logistic regression models used to estimate odds ratios and 95% confidence intervals (OR, 95% CI). We varied the case windows from 15 to 365 days preceding event as compared to control windows constructed using the same dates from the previous 2 years. Analyses were stratified by sex, race, and urban-rural status based on residential zip code.ResultsA total of 33,742 patients were identified as having ischemic stroke and 53,094 had MI. ILI events in the 15 days prior were associated with a 39% increase in odds of ischemic stroke (95% CI 1.09–1.77), increasing to an almost 70% increase in odds when looking at ILI events over the last year (95% CI 1.56, 1.83). In contrast, the effect of ILI hospitalization on MI was strongest in the 15 days prior (OR = 1.24, 95% CI 1.06–1.44). The risk of ischemic stroke after ILI was higher among individuals living in rural areas in the 90 days prior to stroke and among men in the year prior to event. In contrast, the association between ILI and MI varied only across race with whites having significantly higher ILI associated MI.ConclusionThis study highlights risk period differences for acute cardiovascular events after ILI, indicating possible differences in mechanism behind the risk of stroke after ILI compared to the risk of MI. High risk populations for stroke after ILI include men and people living in rural areas, while whites are at high risk for MI after ILI. Future studies are needed to identify ways to mitigate these risks.

Relative Effectiveness of the Cell-Cultured Quadrivalent Influenza Vaccine Compared to Standard, Egg-derived Quadrivalent Influenza Vaccines in Preventing Influenza-like Illness in 2017-2018.

BackgroundInfluenza antigens may undergo adaptive mutations during egg-based vaccine production. In the 2017–2018 influenza season, quadrivalent, inactivated cell-derived influenza vaccine (ccIIV4) vaccine was produced using A(H3N2) seed virus propagated exclusively in cell culture, thus lacking egg adaptive changes. This United States study estimated relative vaccine effectiveness (rVE) of ccIIV4 vs egg-derived quadrivalent vaccines (egg-derived IIV4) for that season.MethodsVaccination, outcome, and covariate data were ascertained retrospectively from a electronic medical record (EMR) dataset and analyzed. The study cohort included patients ≥ 4 years of age. rVE was estimated against influenza-like illness (ILI) using diagnostic International Classification of Diseases, Ninth or Tenth Revision codes. The adjusted odds ratios used to derive rVE estimates were estimated from multivariable logistic regression models adjusted for age, sex, race/ethnicity, geographic region, and health status.ResultsOverall, 92 187 individuals had a primary care EMR record of ccIIV4 and 1 261 675 had a record of egg-derived IIV4. In the ccIIV4 group, 1705 narrowly defined ILI events occurred, and 25 645 occurred in the standard egg-derived IIV4 group. Crude rVE was 9.2% (95% confidence interval [CI], 4.6%–13.6%). When adjusted for age, sex, health status, comorbidities, and geographic region, the estimated rVE changed to 36.2% (95% CI, 26.1%–44.9%).ConclusionsccIIV4, derived from A(H3N2) seed virus propagated exclusively in cell culture, was more effective than egg-derived IIV4 in preventing ILI during the 2017–2018 influenza season. This result suggests that cell-derived influenza vaccines may have greater effectiveness than standard egg-derived vaccines.

Evidence for Cross-species Influenza A Virus Transmission within Swine Farms, China

BackgroundOur understanding of the risk factors for swine influenza A virus transmission between humans and pigs is sparse.MethodsBeginning in 2015, we used a One Health approach and serial sampling to prospectively study 299 swine workers and 100 controls, their 9000 pigs, and six pig farm environments in China for influenza A viruses (IAVs) using molecular, culture, and immunological techniques. Study subjects were closely monitored for influenza-like illness (ILI) events.ResultsUpon enrollment, swine workers had higher serum neutralizing antibody titers against swine H1N1 and higher nasal wash total IgA and specific IgA titers against swine H1N1 and H3N2 viruses. Over a period of 12 months, IAVs were detected by qRT-PCR in 52 (12%) of 432 environmental swabs, 275 (7.6%) of 3600 pig oral secretion, 25 (5.8%) of 432 water, 24 (5.5%) of 432 aerosol, and 20 (4.6%) of 432 fecal-slurry specimens. Five (15.6%) of 32 subjects with ILI events had nasopharyngeal swab specimens that were positive for IAV and 17 (53%) demonstrated 4-fold rises in neutralization titers against a swine virus. Reassorted Eurasian avian-like swine H1N1, pdm09(H1N1)-like virus, and swine-like H3N2 viruses were identified in pig farms. The H1N1 viruses were nearly genetically identical with the human H1N1 viruses isolated from the subjects with ILI.ConclusionThere was considerable evidence of A(H1N1)pdm09-like, swine H1N1 and swine H3N2 viruses reassorting and circulating within the pig farms and crossing species. These data suggest that stronger surveillance for novel influenza virus emergence within swine farms is imperative.Disclosures All authors: No reported disclosures.

Evidence for Cross-species Influenza A Virus Transmission Within Swine Farms, China: A One Health, Prospective Cohort Study.

Our understanding of influenza A virus transmission between humans and pigs is limited. Beginning in 2015, we used a One Health approach and serial sampling to prospectively study 299 swine workers and 100 controls, their 9000 pigs, and 6 pig farm environments in China for influenza A viruses (IAVs) using molecular, culture, and immunological techniques. Study participants were closely monitored for influenza-like illness (ILI) events. Upon enrollment, swine workers had higher serum neutralizing antibody titers against swine H1N1 and higher nasal wash total immunoglobulin A (IgA) and specific IgA titers against swine H1N1 and H3N2 viruses. Over a period of 12 months, IAVs were detected by quantitative reverse-transcription polymerase chain reaction in 46 of 396 (11.6%) environmental swabs, 235 of 3300 (7.1%) pig oral secretion, 23 of 396 (5.8%) water, 20 of 396 (5.1%) aerosol, and 19 of 396 (4.8%) fecal-slurry specimens. Five of 32 (15.6%) participants with ILI events had nasopharyngeal swab specimens that were positive for IAV, and 17 (53.1%) demonstrated 4-fold rises in neutralization titers against a swine virus. Reassorted Eurasian avian-lineage H1N1, A(H1N1)pdm09-like, and swine-lineage H3N2 viruses were identified in pig farms. The A(H1N1)pdm09-like H1N1 viruses identified in swine were nearly genetically identical to the human H1N1 viruses isolated from the participants with ILI. There was considerable evidence of A(H1N1)pdm09-like, swine-lineage H1N1, and swine-lineage H3N2 viruses circulating, likely reassorting, and likely crossing species within the pig farms. These data suggest that stronger surveillance for novel influenza virus emergence within swine farms is imperative.

Influenza-like Illness Incidence Is Not Reduced by Influenza Vaccination in a Cohort of Older Adults, Despite Effectively Reducing Laboratory-Confirmed Influenza Virus Infections.

Data on the relative contribution of influenza virus and other respiratory pathogens to respiratory infections in community-dwelling older adults (≥60 years) are needed. A prospective observational cohort study was performed in the Netherlands during 2 winters. Nasopharyngeal and oropharyngeal swabs were collected during influenza-like illness (ILI) episodes and from controls. Viruses and bacteria were identified by multiplex ligation-dependent probe amplification assay and conventional bacterial culture. The ILI incidence in the consecutive seasons was 7.2% and 11.6%, and influenza virus caused 18.9% and 34.2% of ILI episodes. Potential pathogen were detected in 80% of the ILI events with influenza virus, coronaviruses, rhinoviruses, human metapneumovirus, respiratory syncytial virus, parainfluenza viruses, and Haemophilus influenzae being the most common. Influenza vaccination reduced influenza virus infection by 73% (95% confidence interval [CI], 26%-90%) and 51% (95% CI, 7%-74%) in ILI patients. However, ILI incidence was similar between vaccinated (7.6% and 10.8%) and nonvaccinated (4.2% and 11.4%) participants in 2011-2012 and 2012-2013, respectively (P > .05). Influenza virus is a frequent pathogen in older adults with ILI. Vaccination reduces the number of influenza virus infections but not the overall number of ILI episodes: other pathogens fill the gap. We suggest the existence of a pool of individuals with high susceptibility to respiratory infections. NTR3386.

Abstract T P163: Influenza-Like Illness is Associated With Risk of Ischemic Stroke: A Case-Crossover Analysis

Background: Acute triggers of ischemic stroke (IS) remain poorly characterized. Emerging evidence suggests infections may promote short-term pro-inflammatory, pro-coagulant states that precipitate stroke. Objective: We hypothesized that exposure to influenza-like illness (ILI) is associated with increased risk of IS, as time intervals between events decrease. Methods: HCUP/AHRQ administrative claims from all nonfederal hospitals in California (2009) were queried for IS, using a published ICD-9-CM surveillance algorithm, identifying 41,148 unique individuals. A patient identifier was used to link IS patients across hospitalizations with a validated algorithm for ILI using inpatient and emergency department records. For each IS case, ILI events within 15, 30, and 90-day risk periods preceding IS in 2009, were compared to the same time periods one and two calendar years prior (i.e., 2007 and 2008). A 4-day buffer period was used to ensure ILI preceded IS. Conditional logistic regression models, matched on individuals, were used to calculate odds ratios and 95% confidence intervals (OR, 95%CI) for given risk period, after adjusting for monthly prevalence and mean age of ILI hospitalizations. Effects stratified by age are also explored. Results: Median (IQR) age of cases was 74 (62-83) years; 52.4% were female. There were more ILI during the 90-days preceding strokes in 2009 (n=439) than in the same stroke-free calendar period one year prior (n=303) and two years prior (n=81). ILI was associated with IS with decreasing magnitude of effect using windows of 15-days (adjusted OR 6.5, 95%CI, 2.2-19.7), 30-days (adjusted OR=3.7, 95%CI 1.7-8.3), and 90-days (adjusted OR=3.3, 95%CI, 1.9-5.8). The risk associated with ILI was higher among younger patients. Using the 30-day window, the association between ILI and IS was strongest among those 45-to-65-years (n=27,545, adjusted OR=2.53, 95%CI, 0.95-6.8). Conclusion: Influenza-like illness may contribute to a heightened risk of ischemic stroke during short term periods post-infection, especially among younger patients. Presentation with influenza represents an opportunity for targeted prevention of stroke.

Comparison of the Effectiveness of Trivalent Inactivated Influenza Vaccine and Live, Attenuated Influenza Vaccine in Preventing Influenza-Like Illness Among US Military Service Members, 2006-2009

Influenza is a significant cause of morbidity, and vaccination is the preferred preventive strategy. Data regarding the preferred influenza vaccine type among adults are limited. The effectiveness of 2 currently available influenza vaccines LAIV and TIV in preventing influenza-like illness (ILI) was compared among US military members (aged 18-49 years) during 3 consecutive influenza seasons (2006-2009). ILI, influenza, and pneumonia events post-vaccination were compared between vaccine types using Cox proportional hazard models adjusted for sociodemographic factors, occupation, and geographic area. A total of 41 670 vaccination events were evaluated, including 28 929 during 2 "well-matched" seasons (2006-2007 and 2008-2009: LAIV n = 22 734, TIV n = 6195) and 12 741 during a suboptimally matched season due to mild antigenic drift (2007-2008: LAIV n = 9447, TIV n = 3294). ILI crude incidence rates for LAIV and TIV were 139 and 127 cases per 1000 person-seasons for the well-matched seasons, respectively, and 150 and 165 cases per 1000 person-seasons for the suboptimally matched season, respectively. In the multivariable models, there were no differences in ILI events by vaccine type (well-matched seasons: hazard ratio [HR], 0.97; 95% confidence interval [CI], .90-1.06; suboptimally matched season: HR, 1.00; 95% CI, .90-1.11). There were also no differences in influenza and/or pneumonia events by vaccine group. Between 2006 and 2009, TIV and LAIV had similar effectiveness in preventing ILI and influenza/pneumonia events among healthy adults.

Automated data extraction from general practice records in an Australian setting: Trends in influenza-like illness in sentinel general practices and emergency departments

BackgroundInfluenza intelligence in New South Wales (NSW), Australia is derived mainly from emergency department (ED) presentations and hospital and intensive care admissions, which represent only a portion of influenza-like illness (ILI) in the population. A substantial amount of the remaining data lies hidden in general practice (GP) records. Previous attempts in Australia to gather ILI data from GPs have given them extra work. We explored the possibility of applying automated data extraction from GP records in sentinel surveillance in an Australian setting.The two research questions asked in designing the study were: Can syndromic ILI data be extracted automatically from routine GP data? How do ILI trends in sentinel general practice compare with ILI trends in EDs?MethodsWe adapted a software program already capable of automated data extraction to identify records of patients with ILI in routine electronic GP records in two of the most commonly used commercial programs. This tool was applied in sentinel sites to gather retrospective data for May-October 2007-2009 and in real-time for the same interval in 2010. The data were compared with that provided by the Public Health Real-time Emergency Department Surveillance System (PHREDSS) and with ED data for the same periods.ResultsThe GP surveillance tool identified seasonal trends in ILI both retrospectively and in near real-time. The curve of seasonal ILI was more responsive and less volatile than that of PHREDSS on a local area level. The number of weekly ILI presentations ranged from 8 to 128 at GP sites and from 0 to 18 in EDs in non-pandemic years.ConclusionAutomated data extraction from routine GP records offers a means to gather data without introducing any additional work for the practitioner. Adding this method to current surveillance programs will enhance their ability to monitor ILI and to detect early warning signals of new ILI events.

Influenza Vaccination in Healthy Working Adults in Russia

All age groups are affected by influenza infection, resulting in significant medical and economic burden. Influenza infection of healthy working adults can have a marked effect on companies due to lost work days and reduced productivity. Studies in corporate settings have shown that vaccination programmes reduce this burden, although there is a lack of data in Eastern European countries. To determine the effectiveness of influenza vaccination in healthy working adults in Russia and the economic benefits of such a programme from an employer's perspective. In a prospective, non-randomized, non-placebo-controlled, observational study, healthy vaccinated and unvaccinated adults employed at the Russian Railways Public Corporation were followed for 8 months during the 2005-6 influenza season using questionnaires. A first questionnaire was administered at inclusion to collect general employee information; a second questionnaire was administered to collect data on post-vaccination adverse events; and monthly questionnaires were used to gather data on influenza-like illness (ILI). Effectiveness calculations and cost analyses were performed to evaluate the impact of the influenza vaccination programme on employee productivity and costs for the employer. The study vaccine used was the trivalent, inactivated, split vaccine Vaxigrip® (sanofi pasteur, France). A total of 1331 employees volunteered for the study: 701 were vaccinated and 630 were not. The vaccine effectiveness was 70.4% against ILI events and 80.8% against sick leave days. Assuming that employees working with ILI symptoms had a reduced level of productivity (30-70% of normal), cost savings per vaccinated employee ranged from &U20AC;2.13 to &U20AC;5.43. This study showed that an influenza vaccination programme significantly reduced ILI episodes and absenteeism, and may provide a positive return on investment for the employer.