Cause Of Influenza-like Illness Research Articles

Prevalence and Predictors for Respiratory Viral Infections among Liver Disease Patients.

Respiratory viral infections (RVIs) cause significant hospitalizations every year. Also, RVIs caused by either influenza or noninfluenza group of viruses can have adverse outcomes, especially among immunosuppressed patients. Regular and timely supervision is needed for accurate etiological identification, to prevent inappropriate use of antibiotics in patients with nonbacterial etiology. This study aimed to identify the spectrum of RVIs and clinical characteristics among liver disease patients with influenza-like illness (ILI). In this study, medical records of patients with ILI, whose requests for respiratory viral testing came from September 2016 to December 2022 were retrospectively reviewed. Respiratory viruses were identified using FilmArray 2.0 respiratory panel (BioFire Diagnostics, USA). Of the 1,577 liver disease patients with ILI, the overall prevalence of RVI was 28% (n = 449). Infection by noninfluenza viruses (NIVs) was detected in 329 patients (73%), higher than those infected with influenza viruses. In multivariable logistic regression analysis, female gender [odds ratio (OR): 2.5, 95% confidence interval (CI): 1.5-4.2], infection with influenza B (OR: 3.3, 95% CI: 1.09-9.9) and decompensated cirrhosis (OR: 3.9, 95% CI: 1.7-8.5) were independent risk factors for mortality. Regarding seasonality, influenza peaked in monsoons and winters, whereas NIVs circulated throughout the year. Overall, this study adds new knowledge regarding the incidence of RVI and the distribution of respiratory viral etiologies among liver disease patients with ILI. The findings highlight that female gender, decompensated cirrhosis, and influenza B infection are independently associated with poor clinical outcomes. Early etiological identification of viral causes of ILI could aid in an enhanced understanding of the prevalence of ILI and the timely management of the patients. Respiratory viral infections can cause severe illness in individuals with underlying liver disease. Accurate diagnosis and risk stratification is crucial in mitigating the adverse health effects. Samal J, Prabhakar T, Prasad M, et al. Prevalence and Predictors for Respiratory Viral Infections among Liver Disease Patients. Euroasian J Hepato-Gastroenterol 2023;13(2):108-114.

2200. Impact of COVID-19 Pandemic on Influenza-like Illness (ILI) Experience among Healthcare Workers in Military Treatment Facilities

Abstract Background Healthcare workers (HCWs) are at heightened risk of exposure to respiratory pathogens, and occupy an important epidemiologic position in the COVID-19 pandemic. PAIVED, a multicenter, multiservice study assessing influenza vaccine effectiveness in the Department of Defense over four consecutive influenza seasons (2018-22), provides an opportunity to describe influenza like illness (ILI) experience and assess the impact of SARS-CoV-2 in HCWs compared to non-HCWs. Methods PAIVED participants were randomized to receive either egg-based, cell-based, or recombinant-derived influenza vaccine and then surveyed weekly for ILI. At enrollment, participants provided key demographic data including whether they were HCWs with direct patient contact. ILI was defined a priori as 1) having cough or sore throat plus 2) feeling feverish/having chills or having body aches/fatigue. Participants with ILI completed a symptom diary for seven days and submitted a nasal swab for pathogen detection. Study recruitment was conducted from September-January over four consecutive years. Results Of 13188 eligible participants enrolled, 4819 (36%) were HCWs. Overall, HCWs were more likely to be female (43% vs 31%), active duty military (86% vs 69%), and to identify as white (61% vs 56%). HCWs more commonly reported ILI than non-HCWs (25% vs 21%, p< 0.01). Of those experiencing ILI, SARS-CoV-2 was identified in a higher proportion of HCWs than non-HCWs (17% vs 12%, p< 0.01). Influenza was isolated in similar proportion of HCWs and non-HCWs (5% vs 4%). Each group reported similar ILI duration and severity (p< 0.01). Conclusion In a prior analysis of the 2019-20 PAIVED season, HCWs were more likely than non-HCWs to report ILI, have shorter illness duration, and isolate influenza A (H1N1). The propensity for HCWs to report ILI persisted over the four years. While SARS-CoV-2 emerged as a major pathogen in both groups, HCWs were more likely to have it identified as a cause of ILI, suggesting increased risk of symptomatic SARS-CoV-2 in our HCW population. Influenza incidence was lower than that of SARS-COV-2, and did not differ between HCWs and non-HCWs. Mean duration of illness did not differ between groups over four years; this equalization may relate to the higher incidence of SARS-CoV-2 in HCWs. Disclosures Jitendrakumar Modi, MD, GlaxoSmithKline: I am a paid speaker for GSK. I do not speak for their flu brand. 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.

Outbreaks of Human Metapneumovirus in Western Sydney Aged-Care Facilities in 2018.

Human metapneumovirus (hMPV), first described in 2001, is a cause of acute respiratory tract infection in the elderly, with symptoms ranging from mild to severe, including pneumonia, but outbreaks are rarely described. Between 1 July and 31 December 2018, there were three outbreaks of Influenza-like Illness (ILI) where hMPV was the primary pathogen observed, among 64 aged-care facilities (ACFs) in Western Sydney. These outbreaks were investigated by the Western Sydney Local Health District (WSLHD) Public Health Unit (PHU); multiplex polymerase chain reaction (PCR) testing was performed on nasopharyngeal swabs collected by the ACF. hMPV was the main causative pathogen in three outbreaks (27, 28, and 15 symptomatic cases, respectively) in late winter and early spring. Fifty-five residents and 15 staff cases (70 total cases) were identified; hMPV was detected in 12 of 63 specimens submitted. Of the cases in residents, eight were hospitalised (8/63; 15%), including five with confirmed hMPV and a further one epidemiologically linked to a positive case. Six residents died (6/63; 11%) during the hMPV outbreaks; four of these had laboratory-confirmed hMPV, with a further case epidemiologically linked to a hMPV case, with a primary diagnosis of pneumonia/viral pneumonia. The sixth death was not epidemiologically linked, nor did this case exhibit any respiratory symptoms during the outbreak; however, it was reported in line with public health guidelines. A major challenge in 2018 was the incompleteness of testing for, and awareness of, hMPV as a viral cause of ILI by facilities, laboratories, and emergency departments, which generally opted for rapid testing for influenza and RSV only. There is no licensed vaccine or approved treatment for hMPV, so efficient infection control measures are most important.

Different Clinical Presentations of Human Rhinovirus Species Infection in Children and Adults in Mexico.

BackgroundHuman rhinoviruses (HRVs) are a common cause of influenza-like illness, with the ability to infect the upper and lower respiratory tracts. In this study we aim to describe the clinical and molecular features of HRV infection in Mexican children and adults.MethodsWe performed a hospital-based, 4-year multicenter prospective observational cohort study of patients with influenza-like illness. Participants who tested positive for HRV were included. We described demographic, clinical, and laboratory characteristics and the association between HRV types, illness severity, and clinical outcomes.ResultsOf the 5662 subjects recruited, 1473 (26%) had HRV; of those, 988 (67.1%) were adults (≥18 years) and 485 (32.9%) were children. One hundred sixty-seven (11.33%) samples were sequenced; 101 (60.5%) were rhinovirus species A (HRV-A), 22 (13.2%) were rhinovirus species B (HRV-B), and 44 (26.3%) were rhinovirus species C (HRV-C). Among children and adults, 30.5% and 23.5%, respectively, were hospitalized (non–intensive care unit [ICU]). The odds of HRV-C are higher than HRV-A for participants in the ICU (compared to outpatient) and when platelets, lymphocytes, white blood cells, and lactate dehydrogenase are increased. The odds of HRV-C are higher than HRV-A and HRV-B with shortness of breath. The odds of HRV-A are higher than HRV-B, and the odds of HRV-B are higher than HRV-C, when mild symptoms like muscle ache and headache occur.ConclusionsRhinoviruses are a common cause of influenza-like illness. It is necessary to improve the surveillance, testing, and species identification for these viruses to understand different clinical presentations and risk factors associated with worse outcomes. Clinical Trials Registration. NCT01418287.

Distinguishing viruses responsible for influenza-like illness

The many respiratory viruses that cause influenza-like illness (ILI) are reported and tracked as one entity, defined by the CDC as a group of symptoms that include a fever of 100 degrees Fahrenheit, a cough, and/or a sore throat. In the United States alone, ILI impacts 9–49 million people every year. While tracking ILI as a single clinical syndrome is informative in many respects, the underlying viruses differ in parameters and outbreak properties. Most existing models treat either a single respiratory virus or ILI as a whole. However, there is a need for models capable of comparing several individual viruses that cause respiratory illness, including ILI. To address this need, here we present a flexible model and simulations of epidemics for influenza, RSV, rhinovirus, seasonal coronavirus, adenovirus, and SARS/MERS, parameterized by a systematic literature review and accompanied by a global sensitivity analysis. We find that for these biological causes of ILI, their parameter values, timing, prevalence, and proportional contributions differ substantially. These results demonstrate that distinguishing the viruses that cause ILI will be an important aspect of future work on diagnostics, mitigation, modeling, and preparation for future pandemics.

The Epidemiological Pattern and Co-infection of Influenza A and B by Surveillance Network From 2009 to 2014 in Anhui Province, China.

Influenza-like illness (ILI) is one of the most important public health problems globally, causing an enormous disease burden. Influenza infections are the most common cause of ILI. Bacterial and virus co-infection is common yet the data of co-infection with influenza A and B viruses are scarce. To identify the epidemiological patterns of and co-infection of influenza A and B in Anhui province, China, we analyzed the surveillance data of 5 years from 2009 to 2014 collected by the Chinese National influenzas network. The results showed that the weekly ratio of ILI was 3.96 ± 1.9% (95% CI 3.73–4.2%) in outpatients and the highest affected population was children under 5 years old. The epidemic of influenza viruses was highest during 2009–2010. For the other 4 surveillance years, school-aged people (5–14 years) were the most highly affected population. Influenza B and H3N2 viruses were more prevalent than H1N1pdm09 virus after 2010. In addition, a significant co-circulation of influenza A (H1N1pdm09 and H3N2) and influenza B virus was detected with 0.057% PCR positive rate during 2009–2014 in Eastern China, yet isolated only in pediatric patients. Our data reveals school-aged population would be the main vulnerable population and a distinct seasonality for influenza. In addition, the co-infection of influenza A and B were found in Anhui Province, China. Ongoing surveillance is critical to understand the seasonality variation and make evidence-based vaccination recommendations. Information on the epidemiological patterns and co-infections of influenza A and B can help us to implement different strategies for selecting vaccine formulations and monitoring new emerging influenza strains. In addition, the identification of the susceptible population can help us to develop more precise protection measures.

Aggregating forecasts of multiple respiratory pathogens supports more accurate forecasting of influenza-like illness.

Influenza-like illness (ILI) is a commonly measured syndromic signal representative of a range of acute respiratory infections. Reliable forecasts of ILI can support better preparation for patient surges in healthcare systems. Although ILI is an amalgamation of multiple pathogens with variable seasonal phasing and attack rates, most existing process-based forecasting systems treat ILI as a single infectious agent. Here, using ILI records and virologic surveillance data, we show that ILI signal can be disaggregated into distinct viral components. We generate separate predictions for six contributing pathogens (influenza A/H1, A/H3, B, respiratory syncytial virus, and human parainfluenza virus types 1-2 and 3), and develop a method to forecast ILI by aggregating these predictions. The relative contribution of each pathogen to the total ILI signal is estimated using a Markov Chain Monte Carlo (MCMC) method upon forecast aggregation. We find highly variable overall contributions from influenza type A viruses across seasons, but relatively stable contributions for the other pathogens. Using historical data from 1997 to 2014 at US national and regional levels, the proposed forecasting system generates improved predictions of both seasonal and near-term targets relative to a baseline method that simulates ILI as a single pathogen. The hierarchical forecasting system can generate predictions for each viral component, as well as infer and predict their contributions to ILI, which may additionally help physicians determine the etiological causes of ILI in clinical settings.

Is C-reactive protein associated with influenza A or B in primary care patients with influenza-like illness? A cross-sectional study

Objective Identifying influenza A or B as cause of influenza-like illness (ILI) is a challenge due to non-specific symptoms. An accurate, cheap and easy to use biomarker might enhance targeting influenza-specific management in primary care. The aim of this study was to investigate if C-reactive protein (CRP) is associated with influenza A or B, confirmed with PCR testing, in patients presenting with ILI. Design Cross-sectional study. Setting Primary care in Lithuania, Norway and Sweden. Subjects A total of 277 patients at least 1 year of age consulting primary care with ILI during seasonal influenza epidemics. Main outcome measures Capillary blood CRP analysed as a point-of-care test and detection of influenza A or B on nasopharyngeal swabs in adults, and nasal and pharyngeal swabs in children using PCR. Results The prevalence of positive tests for influenza A among patients was 44% (121/277) and the prevalence of influenza B was 21% (58/277). Patients with influenza A infection could not be identified based on CRP concentration. However, increasing CRP concentration in steps of 10 mg/L was associated with a significantly lower risk for influenza B with an adjusted odds ratio of 0.42 (0.25–0.70; p<.001). Signs of more severe symptoms like shortness of breath, sweats or chills and dizziness were associated with higher CRP. Conclusions There was no association between CRP and influenza A. Increased concentration of CRP was associated with a lower risk for having influenza B, a finding that lacks clinical usefulness. Hence, CRP testing should be avoided in ILI, unless bacterial pneumonia is suspected. Key points Identifying influenza A or B as cause of influenza-like illness (ILI) is a challenge due to non-specific symptoms. There was no association between concentration of CRP and influenza A. Increased concentration of CRP was associated with a lower risk for having influenza B, a finding that lacks clinical usefulness. A consequence is that CRP testing should be avoided in ILI, unless bacterial pneumonia or similar is suspected.

Underweight, overweight, and obesity as independent risk factors for hospitalization in adults and children from influenza and other respiratory viruses.

BackgroundThe relationship between obesity and risk of complications described during the 2009 influenza pandemic is poorly defined for seasonal influenza and other viral causes of influenza‐like illness (ILI).MethodsAn observational cohort of hospitalized and outpatient participants with ILI was conducted in six hospitals in Mexico. Nasopharyngeal swabs were tested for influenza and other common respiratory pathogens.ResultsA total of 4778 participants were enrolled in this study and had complete data. A total of 2053 (43.0%) had severe ILI. Seven hundred and seventy‐eight (16.3%) were positive for influenza, 2636 (55.2%) were positive for other viral respiratory pathogens, and 1364 (28.5%) had no respiratory virus isolated. Adults with influenza were more likely to be hospitalized if they were underweight (OR: 5.20), obese (OR: 3.18), or morbidly obese (OR: 18.40) compared to normal‐weight adults. Obese adults with H1N1 had a sixfold increase in odds of hospitalization over H3N2 and B (obese OR: 8.96 vs 1.35, morbidly obese OR: 35.13 vs 5.58, respectively) compared to normal‐weight adults. In adults with coronavirus, metapneumovirus, parainfluenza, and rhinovirus, participants that were underweight (OR: 4.07) and morbidly obese (OR: 2.78) were more likely to be hospitalized as compared to normal‐weight adults. All‐cause influenza‐like illness had a similar but less pronounced association between underweight or morbidly obesity and hospitalization.ConclusionsThere is an increased risk of being hospitalized in adult participants that are underweight or morbidly obese, regardless of their viral pathogen status. Having influenza, however, significantly increases the odds of hospitalization in those who are underweight or morbidly obese.

Viral causes of Influenza Like Illness in Uganda, 2008 to 2017.

Introduction: Respiratory pathogens continue to present an ever increasing threat to public health (1,2). Influenza, Respiratory syncytial virus, human metapneumovirus and other respiratory viruses are major etiological agents for influenza like illnesses (ILI) (3-5). Establishment of viral causes of ILI is critical for prevention and mitigation strategies to disease threats. Makerere University Walter Reed Project (MUWRP) together with the Ugandan Ministry of Health and partners undertook surveillance to determine viral causes of influenza-like illness in Uganda.Methods: From 2008, MUWRP established hospital-based sentinel sites for surveillance activities. A total of five hospital-based sites were established, where patients aged 6 months or older presenting with ILI were enrolled. Consents were obtained as required, and a throat and/ or nasopharyngeal swab collected. Samples were screened by PCR for viral causes.Results: From October 2008 to March 2017 a total of 9,472 participants were enrolled in the study from five hospital-based surveillance sentinel sites. Majority of participants were children under 5 years n= 8,169 (86.2%). 615 (6.5%) samples tested positive for influenza A, while 385 (4.1%) tested positive for influenza B viruses and 10 (0.1%) were co-infections between influenza A and B. Of the 2,062 influenza negative samples, results indicated positivity for the following organisms; adenoviruses (9.4%), respiratory syncytial B (7.3%), parainfluenza-3 (4.5%), parainfluenza-1 (4.3%), respiratory syncytial A (3.5%), human bocavirus (1.7%), human metapneumovirus (1.7%), human coronavirus (1.5%), parainfluenza-4 (1.4%) and parainfluenza-2 (0.9%) by PCR.Conclusions: Influenza viruses account for about 11% of the causes of influenza like illness, with influenza A being the dominant type. Among the other viral causes of ILI, adenoviruses were the most dominant. Detection of other viral causes of ILI is an indication of the public health threats posed by respiratory pathogens.

Self-Swabbing for Virological Confirmation of Influenza-Like Illness Among an Internet-Based Cohort in the UK During the 2014-2015 Flu Season: Pilot Study.

BackgroundRoutine influenza surveillance, based on laboratory confirmation of viral infection, often fails to estimate the true burden of influenza-like illness (ILI) in the community because those with ILI often manage their own symptoms without visiting a health professional. Internet-based surveillance can complement this traditional surveillance by measuring symptoms and health behavior of a population with minimal time delay. Flusurvey, the UK’s largest crowd-sourced platform for surveillance of influenza, collects routine data on more than 6000 voluntary participants and offers real-time estimates of ILI circulation. However, one criticism of this method of surveillance is that it is only able to assess ILI, rather than virologically confirmed influenza.ObjectiveWe designed a pilot study to see if it was feasible to ask individuals from the Flusurvey platform to perform a self-swabbing task and to assess whether they were able to collect samples with a suitable viral content to detect an influenza virus in the laboratory.MethodsVirological swabbing kits were sent to pilot study participants, who then monitored their ILI symptoms over the influenza season (2014-2015) through the Flusurvey platform. If they reported ILI, they were asked to undertake self-swabbing and return the swabs to a Public Health England laboratory for multiplex respiratory virus polymerase chain reaction testing.ResultsA total of 700 swab kits were distributed at the start of the study; from these, 66 participants met the definition for ILI and were asked to return samples. In all, 51 samples were received in the laboratory, 18 of which tested positive for a viral cause of ILI (35%).ConclusionsThis demonstrated proof of concept that it is possible to apply self-swabbing for virological laboratory testing to an online cohort study. This pilot does not have significant numbers to validate whether Flusurvey surveillance accurately reflects influenza infection in the community, but highlights that the methodology is feasible. Self-swabbing could be expanded to larger online surveillance activities, such as during the initial stages of a pandemic, to understand community transmission or to better assess interseasonal activity.

Hospital-based Influenza Morbidity and Mortality (HIMM) Surveillance for A/H7N9 Influenza Virus Infection in Returning Travelers.

Since 2013, the Hospital-based Influenza Morbidity and Mortality (HIMM) surveillance system began a H7N9 influenza surveillance scheme for returning travelers in addition to pre-existing emergency room (ER)-based influenza-like illness (ILI) surveillance and severe acute respiratory infection (SARI) surveillance. Although limited to eastern China, avian A/H7N9 influenza virus is considered to have the highest pandemic potential among currently circulating influenza viruses. During the study period between October 1st, 2013 and April 30th, 2016, 11 cases presented with ILI within seven days of travel return. These patients visited China, Hong Kong, or neighboring Southeast Asian countries, but none of them visited a livestock market. Seasonal influenza virus (54.5%, 6 among 11) was the most common cause of ILI among returning travelers, and avian A/H7N9 influenza virus was not detected during the study period.

Automated influenza case detection for public health surveillance and clinical diagnosis using dynamic influenza prevalence method.

To assess the performance of a Bayesian case detector (BCD) for influenza surveillance and clinical diagnosis. BCD uses a Bayesian network classifier to compute the posterior probability of a patient having influenza based on 31 findings from narrative clinical notes. To assess the potential for disease surveillance, we calculated area under the receiver operating characteristic curve (AUC) to indicate BCD's ability to differentiate between influenza and non-influenza encounters in emergency department settings. To assess the potential for clinical diagnosis, we measured AUC for diagnosing influenza cases among encounters having influenza-like illnesses. We also evaluated the performance of BCD using dynamically estimated influenza prevalence, and measured sensitivity, specificity and positive predictive value. For influenza surveillance, BCD differentiated between influenza and non-influenza encounters well with an AUC of 0.90 and 0.97 with dynamic influenza prevalence (P < 0.0001). For clinical diagnosis, the addition of dynamic influenza prevalence to BCD significantly improved AUC from 0.63 to 0.85 to distinguish influenza from other causes of influenza-like illness. BCD can serve as an influenza surveillance and a differential diagnosis tool via our dynamic prevalence approach. It enhances the communication between public health and clinical practice.

Porcine Hemagglutinating Encephalomyelitis Virus and Respiratory Disease in Exhibition Swine, Michigan, USA, 2015.

Acute outbreaks of respiratory disease in swine at agricultural fairs in Michigan, USA, in 2015 raised concern for potential human exposure to influenza A virus. Testing ruled out influenza A virus and identified porcine hemagglutinating encephalomyelitis virus as the cause of influenza-like illness in the affected swine.

Contribution of non- influenza respiratory viruses in causation of Influenza like Illness (ILI) during influenza epidemic: A laboratory based study

IntroductionAccording to CDC USA February 2016 document for outpatient illness surveillance, Influenza like illness (ILI) is defined as fever (temperature of 100°F [37.8°C] or greater) and a cough and/or a sore throat without a known cause other than influenza. Most of the laboratories do not test for other known causes of ILI, especially in situation like epidemics. ObjectiveIn the present study we detected Influenza and other respiratory viruses in the cases presenting as ILI during a flu epidemic in North India from January to April 2015. Materials and methodsTotal 200 cases, 50 from each month, that were negative for all types of influenza viruses, were randomly selected and tested by Multiplex Real- Time PCR for detection of other respiratory viruses; rhinovirus, adenovirus, Respiratory Syncitial virus (RSV), Human Boca virus (hBoV), Para Influenza viruses 1,2,3, and 4 (PIV 1, PIV 2, PIV 3, PIV 4), measles virus and human Meta Pneumo virus (hMPV). ResultsA total of 28/200 cases (14%) showed presence of other respiratory viruses. Rhinovirus was most commonly detected, (17/200; 8.5%) followed by adenovirus (7/200, 3.5%), RSV (5/200, 2.5%), hBoV (2/200, 1%), and PIV-3 (2/200, 1%). PIV 1, 2, 4, measles and hMPV were not detected in any of the samples. ConclusionEven during an epidemic other respiratory viruses contribute substantially to ILI

Clinical characteristics and outcome of respiratory syncytial virus infection among adults hospitalized with influenza-like illness in France

ObjectivesThe aim of this study was to analyse characteristics and outcome of respiratory syncytial virus (RSV) infection in adults hospitalized with influenza-like illness (ILI). MethodsPatients hospitalized with ILI were included in this prospective, multicentre study carried out in six French hospitals during three consecutive influenza seasons (2012–2015). RSV and other respiratory viruses were detected by multiplex PCR in nasopharyngeal swabs. Risk factors for RSV infection were identified by backward stepwise logistic regression analysis. ResultsA total of 1452 patients hospitalized with ILI were included, of whom 59% (861/1452) were >65 years and 83% (1211/1452) had underlying chronic illnesses. RSV was detected in 4% (59/1452), and influenza virus in 39% (566/1452). Risk factors for RSV infection were cancer (adjusted OR 2.1, 95% CI 1.1–4.1, p 0.04), and immunosuppressive treatment (adjusted OR 2.0, 95% CI 1.1–3.8, p 0.03). Patients with RSV had a median length of stay of 9 days (6–25), and 57% of them (30/53) had complications, including pneumonia (23/53, 44%) and respiratory failure (15/53, 28%). Fifteen per cent (8/53) were admitted to an intensive care unit, and the in-hospital mortality rate was 8% (4/53). Pneumonia was more likely to occur in patients with RSV than in patients with RSV-negative ILI (44% (23/53) versus 26% (362/1393), p 0.006) or with influenza virus infection (44% versus 28% (157/560), p 0.02). ConclusionRSV is an infrequent cause of ILI during periods of influenza virus circulation but can cause severe complications in hospitalized adults. Risk factors for RSV detection in adults hospitalized with ILI include cancer and immunosuppressive treatment. Specific immunization and antiviral therapy might benefit patients at risk.

Acute Effects of Air Pollution on Influenza-like Illness in Nanjing, China

Influenza-like illness causes substantial morbidity and mortality. Air pollution has already been linked to many health issues, and increasing evidence in recent years supports an association between air pollution and respiratory infections. It is a pioneer study in China to quantify the effects of air pollution on influenza-like illness. This study used wavelet coherence analysis and generalized additive models to explore the potential association between air pollution (including particulate matter with aerodynamic diameter ≦2.5 μm (PM2.5), particulate matter with aerodynamic diameter ≦10 μm (PM10) and nitrogen dioxide (NO2) and influenza-like illness (a total of 59860 cases) in Nanjing, China from January 1, 2013 to December 31, 2013. The average concentrations of PM2.5, PM10 and NO2 were 77.37 μg/m3, 135.20 μg/m3 and 55.80 μg/m3. An interquartile range increase in PM2.5 concentration was associated with a 2.99% (95% confidence interval (CI): 1.64%, 4.36%) increase in daily influenza-like cases on the same day, while the corresponding increase in NO2 was associated with a 3.77% (95% CI: 2.01%, 5.56%) increase in daily cases. People aged 0-4 were proved to be significantly susceptible to PM10 and NO2; 5-14 ages were significantly susceptible to PM2.5 and PM10; and 15-24 ages were significantly susceptible to all the analyzed air pollutants. Air pollution effects tended to be null or negative for patients aged over 25, which might be due to the small number of influenza-like cases in this age group. This study can be useful for understanding the adverse health effects of air pollution and the cause of influenza-like illness.

Acute effects of air pollution on influenza-like illness in Nanjing, China: A population-based study.

Influenza-like illness causes substantial morbidity and mortality. Air pollution has already been linked to many health issues, and increasing evidence in recent years supports an association between air pollution and respiratory infections. It is a pioneer study in China to quantify the effects of air pollution on influenza-like illness. This study used wavelet coherence analysis and generalized additive models to explore the potential association between air pollution (including particulate matter with aerodynamic diameter ≦2.5 μm (PM2.5), particulate matter with aerodynamic diameter ≦10 μm (PM10) and nitrogen dioxide (NO2)) and influenza-like illness (a total of 59860 cases) in Nanjing, China from January 1, 2013 to December 31, 2013. The average concentrations of PM2.5, PM10 and NO2 were 77.37 μg/m(3), 135.20 μg/m(3) and 55.80 μg/m(3). An interquartile range increase in PM2.5 concentration was associated with a 2.99% (95% confidence interval (CI): 1.64%, 4.36%) increase in daily influenza-like cases on the same day, while the corresponding increase in NO2 was associated with a 3.77% (95% CI: 2.01%, 5.56%) increase in daily cases. People aged 0-4 were proved to be significantly susceptible to PM10 and NO2; 5-14 ages were significantly susceptible to PM2.5 and PM10; and 15-24 ages were significantly susceptible to all the analyzed air pollutants. Air pollution effects tended to be null or negative for patients aged over 25, which might be due to the small number of influenza-like cases in this age group. This study can be useful for understanding the adverse health effects of air pollution and the cause of influenza-like illness.

Prevalence of Human metapneumovirus infection among patients with influenza-like illness: Report from a Tertiary Care Centre, Southern India

Background:Human metapneumovirus (HMPV), discovered in the 21st century, has emerged as an important cause of influenza-like illness in children and adults causing mild upper respiratory tract infection to severe bronchiolitis and community-associated pneumonia. The aim of this study was to determine the prevalence of HMPV in the Union Territory of Puducherry, India, as part of National Influenza Surveillance Programme. Materials and Methods: From November 2011 to December 2013, a total of 447 nasopharyngeal samples were collected from patients with acute respiratory infections and tested for HMPV RNA by real-time polymerase chain reaction. Results: HMPV was identified in 23/447 (5%) samples with 11/23 in the age group of 14–30 years. Most of the HMPV infections were mild with no fatalities. Two patients were co-infected with the respiratory syncytial virus and one with influenza B virus. The seasonal distribution showed increasing HMPV infection cases in rainy months except for a peak in summer of 2012. Phylogenetic analysis based on the sequences of the nucleoprotein gene of one HMPV strain showed a high degree of sequence identity with Indian strains obtained during 2006 and 2011. Conclusion: This study shows that HMPV infection is more common in adults than in children. Sequence homology suggests the circulation of closely related HMPV strains within the country.

Antigenic Drift of A/H3N2/Virus and Circulation of Influenza-Like Viruses During the 2014/2015 Influenza Season in Poland.

Morbidity rates of influenza could be greatly reduced due to vaccination. However, the virus is able to evolve through genetic mutations, which is why vaccines with updated composition are necessary every season. Their effectiveness depends on whether there is a good antigenic match between circulating viruses and vaccine strains. In Poland, the 2014/2015 influenza epidemic started in week 5 (January/February) of 2015 and continued until week 17 (April) of 2015. The influenza activity was moderate with the highest incidence of influence-like illness at week 10/2015 (March). During that season, antigenic drift of influenza virus A/H3N2/ occurred causing higher rates of A/H3N2/ infections. Among the 2416 tested specimens, 22.6 % of influenza cases were positive for A/H3N2/, while A/H1N1/pdm09 constituted 14.6 % cases. Influenza A viruses were detected in co-circulation with influenza B viruses; the latter amounted to 34.1 % of all influenza detections. Other detected causes of influenza-like illness consisted of respiratory syncytial virus (RSV), being predominant, and, sporadically, human coronavirus, parainfluenza 1–3, rhinovirus, and adenovirus. Despite low vaccine effectiveness of solely one component, A/H3N2/, the vaccine could mitigate or shorten the length of influenza infection and reduce the number of severe outcomes and mortality. Thus, vaccination against influenza remains the most effective way to prevent illness and possibly fatal outcomes.