Visits For Influenza-like Illness Research Articles

Different effects of air pollutant concentrations on influenza A and B in Sichuan, China

BackgroundThe detrimental effects of air pollution on the respiratory system are well documented. Previous research has established a correlation between air pollutant concentration and the frequency of outpatient visits for influenza-like illness. However, studies investigating the variations in infection among different influenza subtypes remain sparse. We aimed to determine the correlation between air pollutant levels and different influenza subtypes in Sichuan Province, China. MethodsA generalized additive model and distributed lag nonlinear model were employed to assess the association between air pollutants and influenza subtypes, utilizing daily influenza data obtained from 30 hospitals across 21 cities in Sichuan Province. The analysis considered the temporal effects and meteorological factors. The study spanned from January 1, 2017, to December 31, 2019. To provide a more precise evaluation of the actual impact of air pollution on different subtypes of influenza, we also performed subgroup analyses based on factors such as gender, age, and geography within the population. ResultsDuring the investigation, 17,462 specimens from Sichuan Province tested positive for influenza. Among these, 12,607 and 4855 were diagnosed with Flu A and B, respectively. The related risk of influenza A infection significantly increased following exposure to PM2.5 on Lag2 days (RR=1.008, 95 % confidence interval [CI]: 1.000–1.016), SO2 and CO on Lag1 days (RR=1.121, 95 % CI: 1.032–1.219; RR=1.151, 95 % CI: 1.030–1.289), and NO2 on Lag0 day (RR=1.089, 95 % CI: 1.035–1.145). PM10 and SO2 levels on Lag0 day, PM2.5 levels on Lag1 day, and CO levels on Lag6 day, with a reduced risk of influenza B (RR=0.987, 95 % CI: 0.976–0.997; RR=0.817, 95 % CI: 0.676–0.987; RR=0.979, 95 % CI: 0.970–0.989; RR=0.814, 95 % CI: 0.561–0.921). ConclusionThe findings from the overall population and subgroup analyses indicated that the impact of air pollutant concentrations on influenza A and B is inconsistent, with influenza A demonstrating greater susceptibility to these pollutants. Minimizing the levels of SO2, CO, NO2, and PM2.5 can significantly decrease the likelihood of contracting influenza A. Analyzing the influence of environmental contaminants on different influenza subtypes can provide insights into seasonal influenza trends and guide the development of preventive and control strategies.

Burden of seasonal influenza in the Swiss adult population during the 2016/2017-2018/2019 influenza seasons.

Evidence on the burden of seasonal influenza in Switzerland is scarce, yet it is critical for the design of effective prevention and control measures. The objective of this study was to assess influenza-related resource utilization, health care expenditures and quality-adjusted life-years (QALYs) lost in Switzerland across the 2016/2017-2018/2019 influenza seasons. We retrospectively analyzed multiple real-world data sources to calculate epidemiological and health outcomes, QALYs lost, and direct medical costs due to influenza in the Swiss adult population. Subgroups included residents 18-49, 50-64, and 65+ years of age. The observation period was Week 26, 2016, to Week 25, 2019. Across the three seasons, we estimated seasonal averages of 203,090 (se ± 26,717) general practitioner (GP) visits for influenza-like illness (ILI) 4944 (se ± 785) influenza-attributable hospitalizations and 1355 (se ± 169) excess deaths attributable to influenza. We estimated a total loss of 8429 (2016/2017), 11,179 (2017/2018), and 7701 (2018/2019) QALYs due to influenza. On average, 88% of the loss in QALYs was attributed to premature deaths due to influenza. The total direct medical costs amounted to 44.4 (2016/2017), 77.3 (2017/2018), and 64.5 (2018/2019) million euros. On average, 79.6% of the total costs arose due to hospitalizations. In Switzerland, the burden of influenza on patients and payers is significant and particularly high in the elderly population. Policy interventions to increase vaccination rates and the uptake of more effective vaccines among the elderly are needed to reduce the burden of influenza.

EE207 Productivity Benefits from Introducing ID Now™ Influenza into a Company's Medical Clinic for Influenza Diagnosis

To assess the financial benefits of ID NOW™ introduction at in-company versus external medical visits for influenza-like illness (ILI) during the influenza season in Brazil.

Impact of air pollutants on influenza-like illness outpatient visits under urbanization process in the sub-center of Beijing, China.

Air pollutants can cause serious harm to human health and a variety of respiratory diseases. This study aimed to explore the associations between air pollutants and outpatient visits for influenza-like illness (ILI) under urbanization process in the sub-center of Beijing. The data of ILI in sub-center of Beijing from April 1, 2014 to December 31, 2020 were obtained from Beijing Influenza Surveillance Network. A generalized additive Poisson model was applied to examine the associations between the concentrations of air pollutants and daily outpatient visits for ILI when controlling meteorological factors and holidays. A total of 322,559 patients with ILI were included. The results showed that in the early urbanization period, the effects of PM2.5, PM10, SO2, O3, and CO on lag0 day, and PM2.5, PM10, O3, and CO on lag1 day were not significant. In the later urbanization period, AQI and the concentrations of PM2.5, PM10, SO2, NO2 and CO on lag1 day were all significantly associated with an increased risk of outpatient visits for ILI, which increased by 0.34% (95%CI 0.23%, 0.45%), 0.42% (95%CI 0.29%, 0.56%), 0.44% (95%CI 0.33%, 0.55%), 0.36% (95%CI 0.24%, 0.49%), 0.91% (95%CI 0.62%, 1.21%) and 0.38% (95%CI 0.26%, 0.49%). The concentration of O3 on lag1 day was significantly associated with a decreased risk of outpatient visits for ILI, which decreased by 0.21% (95%CI 0.04%, 0.39%). We found that the urbanization process had significantly aggravated the impact of air pollutants on ILI outpatient visits. These findings expand the current knowledge of ILI outpatient visits correlated with air pollutants under urbanization process.

2206. Pragmatic Assessment of Influenza Vaccine Effectiveness in the Department of Defense (PAIVED): Updates from Year 4 of a Multi-site Trial

Abstract Background The effectiveness of the influenza vaccine is varies with circulating strain concordance and timing of influenza spread in a community. The Pragmatic Assessment of Influenza Vaccine Effectiveness in the DoD (PAIVED) study is a multi-year, randomized clinical trial of three FDA-licensed vaccine types (egg-based, cell-based, and recombinant), designed to determine which influenza vaccine platform is most effective among adults in a military setting. Figure 1.PAIVED summary flow chart Methods Participants in the fourth year of PAIVED (2021-22 influenza season) were enrolled from September 2021 through January 2022 at 9 military facilities. Participants were asked each week about influenza-like illness (ILI) symptoms. If the participants reported ILI symptoms, research staff scheduled an acute and convalescent ILI visit. Additional details about the study are included in Figure 1. Results In year 4, 4,688 participants were enrolled, among whom 63.8% were male, 56.5% were white, and the average age was 34 years (Tables 1 and 2). As of early April, 1,297 ILIs had been reported. Most participants reported a single ILI (987 (87%)), while 140 participants reported two ILIs and 10 reported three ILIs. The mean duration of the reported ILIs was 11 days, with a mean 5 days of limited activity. Three participants were hospitalized. Among the samples processed to date, influenza has been identified in four participants. The most common pathogens in year 4 were SARS-CoV-2 and rhino/enterovirus (Figure 2). During all four years of PAIVED, we enrolled 15,449 participants, among whom 188 episodes of influenza have been identified so far (1.2%). Table 1.PAIVED summary over four seasonsTable 2.Demographic characteristics of PAIVED participants during four seasonsFigure 2.Pathogens identified in ILI swabs collected in PAIVED (2021/22 season still in progress) Conclusion The fourth year of PAIVED was characterized by early (pre-enrollment) spread of influenza in some areas, as well the nationwide spread of the SARS-CoV-2 Omicron variant in December. As the swabs are processed and participants’ military health records are reviewed, we expect to identify more influenza cases; however, transmission patterns were far lower than historical averages due to pandemic precautions, making this surveillance data from identified strains more valuable. Comparative influenza vaccine effectiveness calculations will be performed to inform future vaccine purchasing decisions and we will compare serological response to the different vaccines. Disclosures Timothy Burgess, MD, MPH, AstraZeneca: The HJF, in support of the USU IDCRP, was funded to conduct or augment unrelated Phase III Mab and vaccine trials as part of US Govt. COVID19 response Jitendrakumar Modi, MD, GlaxoSmithKline: I am a paid speaker for GSK. I do not speak for their flu brand.

Recent increase in the detection of human parainfluenza virus during the coronavirus disease-2019 pandemic in the Republic of Korea

BackgroundSince the onset of the coronavirus disease-2019 (COVID-19) pandemic, the prevalence of respiratory infectious diseases, particularly, the flu epidemic, has considerably decreased. The low detection rate and decreased number of specimens have hindered the implementation of the Korea Influenza and Respiratory Viruses Surveillance System (KINRESS), a sentinel surveillance system. Most patients with influenza-like illness visit the COVID-19 screening clinic; therefore, the number of samples collected in sentinel surveillance has decreased by more than 50%. Thus, the Korea Disease Control and Prevention Agency supplemented sentinel surveillance with non-sentinel surveillance by private medical diagnostic centers. We report here a delayed and unprecedented high detection of human parainfluenza virus (hPIV) in the Republic of Korea during the COVID-19 pandemic through sentinel and non-sentinel surveillance. We also examined the causes and implications of the changes in prevalence of hPIV.lMethodsWe collected data for 56,984 and 257,217 samples obtained through sentinel and non-sentinel surveillance, respectively. Eight viruses were confirmed using real-time reverse transcription-polymerase chain reaction (PCR) or real-time PCR. Some specimens from the sentinel surveillance were used for genetic characterization of hPIV type 3.ResultsIn 2020, hPIV was rarely detected; however, it was detected in August 2021. The detection rate continued to increase considerably in September and reached over 70% in October, 2021. The detection rate of hPIV3 was significantly higher in infants and preschoolers aged 0–6 years in both sentinel and non-sentinel surveillance. Detection of hPIV was delayed in metropolitan areas compared to that in suburban regions. The hemagglutinin-neuraminidase sequences of hPIV3 generated in 2021 were not distinct from those detected prior to the COVID-19 pandemic.ConclusionsThe operation of non-sentinel and sentinel surveillance to monitor respiratory viruses could sensitively detect an unprecedented revival of hPIV in the Republic of Korea during the COVID-19 pandemic.

173 Leveraging Syndromic Surveillance Data to Create Emergency Department COVID19 Data Visualization Tool

173 Leveraging Syndromic Surveillance Data to Create Emergency Department COVID19 Data Visualization Tool

Age-dependent and sex-dependent differences in mortality from influenza-associated cardiovascular diseases among older adults in Shanghai, China: a population-based study

ObjectivesInfluenza epidemics lead to substantial morbidity and mortality among older adults. This study aimed to analyse and assess the age-specific and sex-specific differences in mortality rates for cardiovascular disease (CVD)...

The impact of broadening COVID-19 testing eligibility on communities of color – A lesson for overcoming structural barriers to health care

CDC guidelines for COVID-19 testing in March 2020 did not prioritize underserved communities. We present the effect that expanding COVID-19 testing had for residents of the predominantly Hispanic city of Chelsea, MA, which had the highest case rate in the state. Results were compared to another city with similar demographics, Lynn, MA, where testing eligibility remained unchanged. Institutional data were used to identify outpatient visits for influenza-like illness or COVID-19 exposure, COVID-19 tests, and hospitalizations for confirmed COVID-19 between 3/30/2020–4/28/2020. Multivariable logistic regressions were used to compare outcomes before and after the change in testing eligibility occurred on 4/13/2020. A total of 3,060 patients were included, 1,374 Chelsea residents and 1,686 Lynn residents. After guidelines changed, Chelsea residents were more likely to present as outpatients (adjusted odds ratio [AOR] 4.2, p < 0.001) and less likely to be hospitalized (AOR 0.2, p < 0.001). They were more likely to be tested (AOR 8.8, p < 0.001), but less likely to test positive (AOR 0.6, p = 0.05). Lynn residents were also more likely to be tested after 4/13/2020 (AOR 1.9, p < 0.001), but no significant differences in visit acuity or test positivity were observed. This study demonstrates how broadening testing eligibility for one highly affected, predominantly Hispanic community was associated with an increase in outpatient presentations and a concomitant decrease in test positivity and hospitalizations. These results highlight the impact of improved access to care on utilization of services among underserved communities, a lesson that is especially crucial as we continue to grapple with the COVID pandemic.

Analysis of comprehensive surveillance results of respiratory tract infectious diseases in Taizhou, 2012-2019

Objective To understand the epidemiological characteristics of influenza-like illness (ILI) cases and severe acute respiratory infection (SARI) cases in Taizhou, so as to provide a basis for scientific prevention and control strategies. Methods The basic information of ILI and SARI cases and throat swab specimens were collected from the sentinel hospital and 13 respiratory pathogens were detected by RT-PCR method.χ2 test was used as statistical analysis method. Results From April 2012 to December 2019, with epidemic peaks in autumn and winter, the percentages of ILI visits (ILI%) and SARI visits (SARI%) were 7.27% and 2.44%, respectively. Finally, 956 ILI case specimens and 557 SARI case specimens were detected. The positive detection rates of the two types of cases were 50.84% (486/956) and 39.14% (218/557), separately. Streptococcus pneumoniae (SP), influenza virus (Flu), Haemophilus influenzae (HI) and Human rhinovirus (HRV) were the dominant pathogens in Taizhou city from April 2012 to December 2019, and their detection rates were 14.81%, 9.25%, 9.39% and 7.73%, respectively. The total mixed infection rate was 30.11% (212/704), which was mainly caused by SP complicated with other pathogenic infections. The positive rate of pathogen detection in the low-age group was higher than that in the high-age group, and the detection rate of children under 5 years old was 34.83% (χ2=54.47, P Conclusions The incidence of comprehensive respiratory tract surveillance in sentinel hospitals in Taizhou City showed that the peak of the epidemic was in autumn and winter, and SP, Flu, HI, and HRV were main pathogens in this area. In the age group under 15 years old, the detection rate was higher. Comprehensive respiratory disease prevention and control measures should be taken for key populations.

Air pollutants and outpatient visits for influenza-like illness in Beijing, China.

BackgroundAir pollution leads to many adverse health conditions, mainly manifested by respiratory or cardiac symptoms. Previous studies are limited as to whether air pollutants were associated to influenza-like illness (ILI). This study aimed to explore the association between air pollutants and outpatient visits for ILI, especially during an outbreak of influenza.MethodsDaily counts of hospital visits for ILI were obtained from Peking University Third Hospital between January 1, 2015, and March 31, 2018. A generalized additive Poisson model was applied to examine the associations between air pollutants concentrations and daily outpatient visits for ILI when adjusted for the meteorological parameters.ResultsThere were 35862 outpatient visits at the fever clinic for ILI cases. Air quality index (AQI), PM2.5, PM10, CO and O3 on lag0 days, as well as nitrogen dioxide (NO2) and sulfur dioxide (SO2) on lag1 days, were significantly associated with an increased risk of outpatient visits for ILI from January 2015 to November 2017. From December 2017 to March 2018, on lag0 days, air pollutants PM2.5 [risk ratio (RR) = 0.971, 95% CI: 0.963-0.979], SO2 (RR = 0.892, 95% CI: 0.840–0.948) and CO (RR = 0.306, 95% CI: 0.153–0.612) were significantly associated with a decreased risk of outpatient visits for ILI. Interestingly, on the lag2 days, all the pollutants were significantly associated with a reduced risk of outpatient visits for ILI except for O3. We did not observe the linear correlations between the outpatient visits for ILI and any of air pollutants, which were instead associated via a curvilinear relationship.ConclusionsWe found that the air pollutants may be associated with an increased risk of outpatient visits for ILI during the non-outbreak period and with a decreased risk during the outbreak period, which may be linked with the use of disposable face masks and the change of outdoor activities. These findings expand the current knowledge of ILI outpatient visits correlated with air pollutants during an influenza pandemic.

A stacked ensemble method for forecasting influenza-like illness visit volumes at emergency departments

Accurate and reliable short-term forecasts of influenza-like illness (ILI) visit volumes at emergency departments can improve staffing and resource allocation decisions within hospitals. In this paper, we developed a stacked ensemble model that averages the predictions from various competing methodologies in the current frontier for ILI-related forecasts. We also constructed a back-of-the-envelope prediction interval for the stacked ensemble, which provides a conservative characterization of the uncertainty in the stacked ensemble predictions. We assessed the accuracy and reliability of our model with 1 to 4 weeks ahead forecast targets using real-time hospital-level data on weekly ILI visit volumes during the 2012-2018 flu seasons in the Alberta Children’s Hospital, located in Calgary, Alberta, Canada. Our results suggest the forecasting performance of the stacked ensemble meets or exceeds the performance of the individual models over all forecast targets.

Successful interruption of seasonal influenza transmission under the COVID-19 rapid response in Zhejiang Province, China

ObjectivesThe objective of this study was to evaluate whether the non-pharmaceutical interventions (NPIs) introduced to curb the spread of coronavirus disease 2019 (COVID-19) also interrupted the transmission of influenza. Study designThis is a descriptive epidemiological study. MethodsData on changes in the number of reported influenza cases, number of influenza-like illness (ILI) visits, ILI percentage and influenza virus positivity were compared between the first 18 weeks of 2020 and the same period of 2019. ResultsThe changes in the weekly average number of influenza cases were statistically significant between 2020 and 2019 (−4319 vs −525 per week; P < 0.05). The slopes of regression lines for the number of ILI visits were also statistically significant between 2020 and 2019 (−911 vs −98 per week; P < 0.05). ConclusionsThis study found that the prevalence of influenza was substantially decreased when NPIs were implemented for the containment of COVID-19.

Evaluation of a Sick Employee Online Log System for Tracking Sick Hospital Employees During Two Influenza Seasons

Background: Since 2009, Vidant Health has used a Sick Employee Online Log (SEOL) system to track illnesses among employees and to capture this information in real time. The CDC assessed the 2017–2018 influenza season as a high-severity influenza season, whereas the 2018–2019 influenza season was of moderate severity. Objective: In this research project, we sought to determine whether the influenza season severity would affect either the hospital-based employee illness surveillance system results or would correlate with state influenza-like illness (ILI) visits. Methods: The SEOL system is an internet-based system initiated in December 2008. When a hospital employee calls in sick, the department manager records whether the employee reports the following symptoms: nausea, vomiting, diarrhea, upper respiratory infection, fever, sore throat, headache, conjunctivitis, rash, and/or cough. The information is confidential, with raw data access restricted to review by occupational health and infection control leadership. The correlation value was determined for each symptom using the North Carolina Division of Human Services (NC DHHS) percentage of ILI visits in statewide emergency departments.1 The data collection dates covered January 1–May 31 for each year. In this study, only symptoms related to influenza were included: upper respiratory infection, fever, influenza-like illness, cough and self-reported influenza. Correlation values were calculated using MS Excel software. Results: There were no breaks in confidentiality. All of the correlation values had a correlation value of 0.5 or better (Fig. 1), showing good correlation with the NC DHHS ILI data for both years; however, the more severe 2017–2018 influenza season had correlation values of 0.7 for all symptoms, versus 0.52–0.59 for URI and ILI, respectively, only during 2018–2019. Conclusions: The higher-severity influenza season did correlate with a higher r values when compared to North Carolina’s DHHS ILI emergency department data than did the influenza season of moderate severity. A possible explanation is that a higher-severity influenza season would correlate better than a moderate influenza season because it shows fewer ILI peaks and troughs. In conclusion, the SEOL system served as an early warning that influenza is present among our staff, and it correlates well with the state system for ILI surveillance. Potential limitations of SEOL are that respiratory symptoms are not specific to influenza; thus, they are subject to variation due to other respiratory viruses circulating among our employees.1. The North Carolina Disease Event Tracking and Epidemiologic Collection Tool. NC DETECT website. http://www.ncdetect.org. Accessed Nov 8, 2019.Funding: NoneDisclosures: None

Evaluation of influenza vaccine effectiveness in 2017-2018 influenza season based on community children cohort study

Objective: To assess the effectiveness of influenza vaccine in children aged 6-72 months. Methods: The cohort study was conducted based on community child vaccination clinics in Yiwu and Yongkang counties of Zhejiang province. From October 2017 to December 2017, a total of 1 752 children aged 6-72 months were enrolled from 10 child vaccination clinics. The questionnaire survey was conducted after the written consents were obtained from the parents or legal guardians of the children. Then, a follow up was conducted for enrolle children until 30 April 2018, the influenza vaccination status and the number of influenza-like illness (ILI) cases, hospital visit due to ILI, self-medication due to ILI were observed and recorded every month. Vaccine effectiveness (VE) was estimated by using the generalized linear model (GLM) where dependent variables were the number of ILI cases, hospital visit and self-medication respectively. Results: Of the 1 752 children, 925 (52.80%) were boys and the median age was 30.00 months. The cumulative observation was 308 166 person days at the end of 2017-2018 season, with 5.27 ILI cases per 1 000 person days, 3.41 hospital visit due to ILI per 1 000 person days, 1.45 self-medication due to ILI per 1 000 person days. Of the 1 752 children, 643 received the influenza vaccination in 2017-2018 season. Compared with unvaccinated children, the VE was 23.5% against ILI case number (95%CI: 15.1%-31.1%), 19.3% against hospital visit due to ILI (95%CI: 8.2%-29.1%) and 25.8% against self-medication due to ILI (95%CI: 9.3%- 39.3%). Modeling splitting 643 children with 2017-2018 vaccination into those before and after vaccination, the influenza VE was 31.9% against ILI case number (95%CI: 12.7%-46.9%), 32.6% against hospital visit due to ILI (95%CI: 8.6%-50.3%) and 44.3% against self-medication due to ILI (95%CI: 11.9%-64.8%) in children aged 36-72 months. However, the children aged 6-35 months showed no significant VEs. For the VE analysis in children with different vaccination status, the VEs were significant if they received vaccination in both 2016-2017 season and 2017-2018 season or only in 2017-2018 seasons. The VE was not demonstrated among the children who were immunized only in 2016-2017 season. Conclusion: Influenza vaccination is moderate effective in preventing the incidence of ILI and hospital visit and self-medication in children in influenza season, the protection effect in children aged 36-72 months is better than that in children aged 6-35 months.

Epidemiological features and time-series analysis of influenza incidence in urban and rural areas of Shenyang, China, 2010-2018.

In recent years, there have been a significant influenza activity and emerging influenza strains in China, resulting in an increasing number of influenza virus infections and leading to public health concerns. The aims of this study were to identify the epidemiological and aetiological characteristics of influenza and establish seasonal autoregressive integrated moving average (SARIMA) models for forecasting the percentage of visits for influenza-like illness (ILI%) in urban and rural areas of Shenyang. Influenza surveillance data were obtained for ILI cases and influenza virus positivity from 18 sentinel hospitals. The SARIMA models were constructed to predict ILI% for January-December 2019. During 2010-2018, the influenza activity was higher in urban than in rural areas. The age distribution of ILI cases showed the highest rate in young children aged 0-4 years. Seasonal A/H3N2, influenza B virus and pandemic A/H1N1 continuously co-circulated in winter and spring seasons. In addition, the SARIMA (0, 1, 0) (0, 1, 2)12 model for the urban area and the SARIMA (1, 1, 1) (1, 1, 0)12 model for the rural area were appropriate for predicting influenza incidence. Our findings suggested that there were regional and seasonal distinctions of ILI activity in Shenyang. A co-epidemic pattern of influenza strains was evident in terms of seasonal influenza activity. Young children were more susceptible to influenza virus infection than adults. These results provide a reference for future influenza prevention and control strategies in the study area.

108 Catching the Flu: Influenza Management in the Emergency Department

Influenza like illness (ILI) is defined by the World Health Organization as an acute respiratory infection with fever, cough and onset in the last 10 days. Children, especially under the age of 5 years, are at higher risk of severe illness and mortality. Children with underlying medical conditions are identified by the National Advisory Committee on Immunization (NACI) as being high-risk for life threatening complications, and represent more than half of pediatric deaths secondary to influenza. During high acuity seasons, the number of emergency department (ED) visits for ILI increases significantly, representing 10–20% of ED visits. Due to high volumes and acuity of care, adherence to evidence based guidelines can wane. The ED and Infectious Disease teams recognized an opportunity to improve and standardize care for children presenting with ILI. An ILI algorithm was developed in consultation with ED staff, disseminated at ED division meetings and posted in the workstation. A retrospective chart review was used to assess influenza management before and after implementation of the ILI management pathway to assess compliance with evidence based guidelines. All charts (n=2421) for patients presenting to the pediatric ED during peak laboratory confirmed periods of influenza were reviewed both pre (2015–2016) and post (2016–2017) ILI management pathway implementation. Data collected included: demographic data, admission information, comorbid conditions consistent with high-risk criteria, nasopharyngeal swab testing (NPS) and Oseltamivir use. Specific outcomes of interest were appropriate use of NPS testing and timely initiation of antivirals to high-risk patients. During the study periods, 1411 patients presented with ILI to the ED in 2015–2016 versus 1057 in 2016–2017. Overall, the implementation of the ILI management pathway did not influence clinical practice, as there was no significant difference in the identification, admission or treatment of high-risk patients presenting with ILI symptoms. Of the 117 high-risk patients in 2015–2016 and the 114 high-risk patients in 2016–2017 who were admitted to hospital, less than 10% received Oseltamivir each year. Additionally, a similar number of NPS were completed for high-risk and low-risk patients. These findings indicate practice variation from published guidelines on ILI management. Future research is needed to understand physician perspective on ILI management, barriers to implementation and methods to improve knowledge translation to update practice pathways.

Update: Influenza Activity - United States, September 30, 2018-February 2, 2019.

CDC collects, compiles, and analyzes data on influenza activity and viruses in the United States. During September 30, 2018-February 2, 2019,* influenza activity† in the United States was low during October and November, increased in late December, and remained elevated through early February. As of February 2, 2019, this has been a low-severity influenza season (1), with a lower percentage of outpatient visits for influenza-like illness (ILI), lower rates of hospitalization, and fewer deaths attributed to pneumonia and influenza, compared with recent seasons. Influenza-associated hospitalization rates among children are similar to those observed in influenza A(H1N1)pdm09 predominant seasons; 28 influenza-associated pediatric deaths occurring during the 2018-19 season have been reported to CDC. Whereas influenza A(H1N1)pdm09 viruses predominated in most areas of the country, influenza A(H3N2) viruses have predominated in the southeastern United States, and in recent weeks accounted for a growing proportion of influenza viruses detected in several other regions. Small numbers of influenza B viruses (<3% of all influenza-positive tests performed by public health laboratories) also were reported. The majority of the influenza viruses characterized antigenically are similar to the cell culture-propagated reference viruses representing the 2018-19 Northern Hemisphere influenza vaccine viruses. Health care providers should continue to offer and encourage vaccination to all unvaccinated persons aged ≥6 months as long as influenza viruses are circulating. Finally, regardless of vaccination status, it is important that persons with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for influenza complications be treated with antiviral medications.

Influenza Activity - United States, September 30-December 1, 2018.

Influenza activity in the United States was low during October 2018, and, although it increased slowly during November, activity remains low across most of the country.* During the week ending December 1, 2018, the percentage of outpatient visits for influenza-like illness† (ILI) was equal to the national baseline§ (Figure) and was at or slightly above the region-specific baseline in four of the 10 U.S. Department of Health and Human Services regions¶ (Regions 4 and 7–9). The majority of jurisdictions experienced minimal or low ILI activity since September 30; however, two experienced moderate ILI activity, and two experienced high ILI activity** during the week ending December 1. The percentage of deaths attributed to pneumonia and influenza remains below the epidemic threshold,†† and the rate of influenza-associated hospitalizations remains low. Five laboratory-confirmed, influenza-associated pediatric deaths occurring since September 30 have been reported to CDC. During the week ending December 1, the majority of jurisdictions (40 states, the District of Columbia, Puerto Rico, and U.S. Virgin Islands) reported sporadic or local geographic spread of influenza activity, nine states reported regional activity, and one state reported widespread activity.§§

Estimation of the burden of flu-association influenza-like illness visits on total clinic visits through the sentinel influenza monitoring system in Senegal during the 2013-2015 influenza seasons.

Knowing the burden of influenza is helpful for policy decisions. Here we estimated the contribution of influenza-like illness (ILI) visits associated with laboratory-confirmed influenza among all clinic visits in a Senegal sentinel network. ILI data from ten sentinel sites were collected from January 2013 to December 2015. ILI was defined as an axillary measured fever of more than 37.5 °C with a cough or a sore throat. Collected nasopharyngeal swabs were tested for influenza viruses by rRT-PCR. Influenza-associated ILI was defined as ILI with laboratory-confirmed influenza. For the influenza disease burden estimation, we used all-case outpatient visits during the study period who sought care at selected sites. Of 4030 ILI outpatients tested, 1022 were influenza positive. The estimated proportional contribution of influenza-associated ILI was, per 100 outpatients, 1.2 (95% CI 1.1-1.3), 0.32 (95% CI 0.28-0.35), 1.11 (95% CI 1.05-1.16) during 2013, 2014, 2015, respectively. The age-specific outpatient visits proportions of influenza-associated ILI were higher among children under 5 years (0.68%, 95% CI: 0.62-0.70). The predominant virus during years 2013 and 2015 was influenza B while A/H3N2 subtype was predominant during 2014. Influenza viruses cause a substantial burden of outpatient visits particularly among children under 5 of age in Senegal and highlight the need of vaccination in risk groups.