Transmission Of Acute Respiratory Infections Research Articles

Aerosol generation and risk of transmission of acute respiratory infections: A systematic review

Aerosol generation and risk of transmission of acute respiratory infections: A systematic review

Brushing Teeth and Acute Respiratory Infections in Day Care Facilities: An Ecological Study in Selected Regions of Lower Saxony, Germany (2013-2018)

Dental group prophylaxis in day-care centers with teeth brushing as one of its components is intended to reduce caries incidence and promote dental health. However, various barriers can hinder implementation of this preventive measure. One concern relates to an increased risk of transmission of acute respiratory infections (ARI) in day-care centers. The ZINFEKT study aimed at determining whether and to what extent there are differences in the occurrence of ARI between day-care centers that implement vs. those that do not implement teeth brushing. In an ecological study, 2013-2018 data from the ARI surveillance of the Public Health Agency of Lower Saxony were merged with information from the Dental Services on teeth brushing for n=33 day-care facilities from the urban municipality of Braunschweig, the region of Hannover, and the administrative district of Osnabrück (all Lower Saxony, Germany). Following the concept of patient days from hospital infection surveillance, "ill child weeks" were specified as observational units, defined as weeks for which an ARI had been reported for a registered child. Besides cross-tabulations, relative risks for ill child weeks by teeth brushing and Breslow-Day Tests for interactions with area, size of day-care center, ARI season and time slot with ARI seasons were computed. Overall, the ARI-rate, defined at the proportion of ill child weeks, was 4.6% higher in day-care centers in which teeth brushing took place, vs. centers in which this measure was not implemented (17.9 vs. 13.3%, p<0.0001). In analyses stratified by the geographic and temporal co-variables, the direction of this difference did not change (with one exception: day-care centers with 50 or less registered children) . The assumption that regular teeth brushing is associated with higher ARI rates in day-care centers does seem to have an empirical basis. However, despite the study's limitations (primarily its ecological design and possibly limited representativeness of the day-care centers), the identified difference - due both to its magnitude and possibly improvable hygiene compliance - to our assessment does not speak against brushing teeth as a component of dental group prophylaxis in day-care centers.

Soap versus sanitiser for preventing the transmission of acute respiratory infections in the community: a systematic review with meta-analysis and dose–response analysis

ObjectiveTo compare the effectiveness of hand hygiene using alcohol-based hand sanitiser to soap and water for preventing the transmission of acute respiratory infections (ARIs) and to assess the relationship between...

Practice of Personal Protective Measures and Risk of Acute Respiratory Infections Among Students: A Longitudinal Observational Study

Background: We aimed to investigate whether the implementation of personal protective measures against coronavirus disease 2019 reduced the transmission of influenza-like illnesses.Methods: We did a longitudinal study to examine the association between practicing personal protective measures recommended by the World Health Organization and cases of influenza-like illnesses. We followed a group of international students from 95 countries located in five continents from October 2020 to March 2021. Their frequency of wearing masks, social distancing, washing hands, and avoiding crowds, as well as their reported cases of influenza-like illnesses during the 2020-2021 flu season were examined. We used Kaplan-Meier analysis to compare the occurrence of symptoms of influenza-like illnesses among students who adhered with those who did not adhere to the personal protective measures. We performed a multivariate Cox proportional hazard regression to investigate the association between the frequency of implementing the protective measures and reported cases of influenza-like illnesses.Findings: From October 2020 to March 2021, 139 (18%) students reported symptoms of influenza-like illnesses. The survival analysis showed that students who adhered to the protective measures had a reduced risk of influenza-like illnesses. We found that students who frequently wore facemasks were 33.6% less likely to show symptoms of influenza-like illnesses adjusting for all the other personal protective measures (HR=0.664, 95%CI=0.494-0.893, p=0.006). Similarly, students who frequently disinfected their hands were 17.1% less likely to report symptoms of influenza-like illnesses (HR=0.821, 95%CI=0.793- 0.915, p=0.029). Furthermore, students who exercised social distancing measures were 23.5% less likely to report symptoms of influenza-like illnesses adjusting for the other measures (HR= 0.765, 95%CI=0.610 - 0.960, p=0.020). We found a two-fold increased risk of influenza-like illnesses among students who did not frequently implement all the personal protective measures as compared with those who adhered to the measures ((HR=2.16, 95%CI=1.53-3.05, PInterpretations: Our study shows that personal protective measures against COVID-19 (including wearing facemasks, hand hygiene, and social distancing) prevented the transmission of acute respiratory infections during the 2020-2021 flu season. Our findings suggest that personal protective measures with high feasibility and high acceptability could be implemented during influenza epidemics to reduce transmission, particularly in populations at highest risk of developing severe complications.Funding We did not receive any funding for this research.Declaration of Interest: All authors declare no competing interests.Ethical Approval: Ethical approval for this study was obtained from the Non-Interventional Clinical Research Ethics Committee of Hacettepe University (No. GO 20/885)

Cardiopulmonary resuscitation and risk of transmission of acute respiratory infections to rescuers: a systematic review snapshot

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan City, China, in December 2019. Currently, the zoonotic origin of SARS-CoV-2 is unknown. However, one of the hallmarks in severe cases of coronavirus disease 2019 (COVID-19) is hypoxemic respiratory failure. Management of severe cases involves procedures such as non-invasive ventilation and endotracheal intubation that have the potential to generate respiratory aerosols. During the current coronavirus (COVID-19) pandemic, we need to mitigate any risks related to resuscitation as best we can, even if this is disruptive or at some point proven to be overly cautious. Unless we are presented with new evidence, any maneuver performed during cardiopulmonary resuscitation (CPR) should be considered an aerosol generating procedure. Limited data from the SARS epidemic suggests baseline risk of infection among health care workers may be 10%. Performing endotracheal intubation is associated with a 3-5 times higher risk. If causative, this represents an enormous potential for harm (an absolute risk increase of up 40%). Thus, performing endotracheal intubation during CPR should be treated as a very high-risk procedure and managed with the highest precautions, including donning appropriate full enhanced personal protective equipment before entering the scene, to guard against contact with both airborne and droplet particles. The aim of this systematic review snapshot was to identify and summarize in the form of a clinical synopsis the literature surrounding the potential risk of infection transmission associated with key interventions performed in the context of cardiac arrest. © Journal of Emergency and Critical Care Medicine. All rights reserved.

Transmission of Acute Respiratory Infections in a City: Agent-Based Approach

An incidence curve of acute respiratory infections in Moscow has three picks between September and April and reaches its maximum in January- February. The emergence of new strains of influenza A could account for only one pick a year. The most cases of common cold are caused by ubiquitous low pathogenic viruses. In order to simulate weekly fluctuation of incidence rate of acute respiratory illnesses we developed an agent-based model. It contains 10 millions agents with such attributes as sex, age, social status, levels of specific immune memory and lists of contacts. Each agent can contact with members of its household, colleagues or classmates. Through such contacts susceptible agent can be infected with one of seven circulating respiratory viruses. Viruses differ in their immunologic properties and assume to present influenza A virus, influenza B virus, parainfluenza, adenovirus, coronavirus, rhinovirus and respiratory syncytial virus. The rate of transmission depends on duration of contact, vulnerability of susceptible agent, infectivity of infected agent and air temperature. Proposed network of social interactions proved to be sufficiently detailed as it provided good fitting for observed incidence rate including periods of school holidays and winter public holidays. Additionally, the estimates of basic reproductive rate for the viruses confirm that all these viruses except new strains of influenza A are relatively harmless and unable to cause significant growth of acute respiratory infections morbidity.

Controversies in airway management of COVID-19 patients: updated information and international expert consensus recommendations

Controversies in airway management of COVID-19 patients: updated information and international expert consensus recommendations

COVID-19: What do we know?

• Evidence regarding the provision of orthodontic care during the COVID-19 pandemic is examined.

Use of a new face shield for patients of the endoscopy unit to avoid aerosol exchange in the COVID-19 era.

Use of a new face shield for patients of the endoscopy unit to avoid aerosol exchange in the COVID-19 era.

Adult cardiac surgery and the COVID-19 pandemic: Aggressive infection mitigation strategies are necessary in the operating room and surgical recovery

The COVID-19 pandemic necessitates aggressive infection mitigation strategies to reduce the risk to patients and healthcare providers. This document is intended to provide a framework for the adult cardiac surgeon to consider in this rapidly changing environment. Preoperative, intraoperative, and postoperative detailed protective measures are outlined. These are guidance recommendations during a pandemic surge to be used for all patients while local COVID-19 disease burden remains elevated.

Improving staff safety during tracheostomy in COVID-19 patients.

Dear Editor,At 29th of February the World Health Organization (WHO) reported 85403 confirmed globally confirmed case of COVID-19 [1]. COVID-19 is dramatically increasing in Italy, the last report from the ministry of health on the 9th of march reported the presence of 9172 confirmed cases and 733 patients in intensive care unit (ICU) [2]. We agree with Chan et al that physicians managing airway procedures are at particularly high risk to contract the COVID-19 infection [3]. We support the authors that claimed for a full protective wearing including N95 respirator, gown, cap, eye protection, and gloves, during aerosol generating procedures (AGP) [3]. However, we’d like to focus the attention on the tracheostomy procedures in COVID-19 patients since otolaryngologists, anesthesiologists and intensive care physicians are at high risk of contracting the infection during tracheostomy [3]. Tracheostomy is required in case of prolonged mechanical ventilation and intensive care unit (ICU) stay [4]. Surgical tracheostomy is an AGP associated with an increased risk severe acute respiratory distress (SARS) infection [5]. Strict adherence to infection control guidelines in SARS is mandatory in performing tracheostomy in ICU or operating room [6].Few years ago, we proposed the double lumen endotracheal tube (DLET) for percutaneous tracheostomy in critically ill patients [7]. DLET was equipped with an upper channel that allows passage of a bronchoscope during the percutaneous tracheostomy and with a lower channel exclusively dedicated to patient ventilation [7]. The lower channel is equipped with a distal cuff positioned just above the carina that may allow a safe mechanical ventilation by keeping stable gas-exchange and limiting the spread of aerosol during the procedure [7]. During the percutaneous procedure, the puncture of the anterior tracheal wall, Seldinger insertion, dilatation, and cannula positioning were all performed with the DLET correctly placed in the trachea. The DLET was removed at the end of the tracheostomy when the cannula is inserted and correctly positioned with the FFB [7].Surgical tracheostomy in COVID-19 patients should be done with a close collaboration between otolaryngologists, preforming the surgical procedure, and anesthesiologists or intensive care physicians managing the general anesthesia and the airway.When a surgical tracheostomy is done under general anesthesia, just before the surgeon makes the tracheal stoma, the endotracheal tube is withdrawn, so that the cuff of the tube is not in the surgical field [8]. But when the surgeon makes the tracheal incision, ventilation is lost and the surgeon has to be quick enough to create the soma and insert the tracheostomy tube in a short time [8]. During this procedure a large spread of aerosol may occur. To avoid the aerosol, we suggest to push down the endotracheal tube beyond the site chosen for the tracheal stoma at the beginning of the procedure. The endotracheal tube should reach the tracheal carina so the cuff is surely distal to the tracheostomy site. By checking the airway pressure and the end-tidal CO2, on the mechanical ventilator we can realize if the endotracheal tube is still in the lower tract of the trachea or in the endobronchial tract. Our previous experience with the DLET demonstrated that the endotracheal tube and the tracheal cannula can be simultaneously inserted inside the trachea [7]. According to this, pushing down the endotracheal tube and cuffed it at the level of the carina may avoid the spread of aerosol and, then, may add an extra security for the medical staff during a procedure at high risk of generating aerosol.ReferencesCoronavirus disease 2019 (COVID-19) Situation Report – 40.https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200229-sitrep-40-covid-19.pdfItalian Minister of Health. COVID-19 Italian cases.http://www.salute.gov.it/portale/nuovocoronavirus/dettaglioContenutiNuovoCoronavirus.jsp?lingua=italianoi19:291-301Tran K, Cimon K, Severn M et al. Aerosol Generating Procedures and Risk of Transmission of Acute Respiratory Infections to Healthcare Workers: A Systematic Review. . PLoS ONE 2012; 7(4): e35797. doi:10.1371/journal.pone.0035797Chun-Wing A, Yin -Chun L, Kit-Ying L. Management of Critically Ill Patients with Severe Acute Respiratory Syndrome (SARS). Int. J. Med. Sci. 2004 1(1): 1-10Vargas M, Servillo G, Tessitore G, Aloj F, Brunetti I, Arditi E, et al. Percutaneous dilatational tracheostomy with a double-lumen endotracheal tube. A Comparison of Feasibility, Gas Exchange, and Airway Pressures. Chest 2015; 147:1267-74Walts PA, Sudish CM, DeCamp MM. Techniques of surgical tracheostomy. Clin Chest Med 24 (2003) 413 – 422

Maternal knowledge and practices regarding childhood acute respiratory infections in Lubumbashi, DRC

Introduction Acute respiratory infections (ARIs) are a public health problem in the Democratic Republic of Congo (DRC) and cover a range of infections, from the common cold to pneumonia. ARIs are the leading cause of death in children under-5, with the majority of deaths occurring in developing countries. Objective To assess the knowledge and home-based practices used by mothers of children under-fives during episodes of ARI. Methods A cross-sectional study was carried out among mothers of children under-five who were selected in Lubumbashi (DRC). A pre-tested questionnaire administered by researchers was used for data collection. Results Of the 582 mothers interviewed, the majority had a good knowledge of the symptoms (87.46%), danger signs of severe ARIs (95.02%) and a good knowledge of the modes of transmission of ARIs (68.73%). Knowledge level was significantly associated with age and education level regarding modes of transmission. Three hundred and sixty-eight (63.23%) mothers indicated that they use traditional remedies: 252 (43.30%) apply palm oil to their children’s noses and as many mothers (n = 252; 43.30%) apply mentholatum ointment to the nose. Almost all of the mothers (n = 579; 99.48%) indicated that they dress the child with several layers of clothes. Oral self-medication was used by 575 mothers (98.80%). Conclusion The mothers’ knowledge of modes of transmission, symptoms and danger signs of ARIs was good in the community studied in Lubumbashi. Knowledge level was associated with age and level of education regarding modes of transmission.

Problems related to acute respiratory infection among under-5 children in Sorong, West Papua: a community diagnosis approach

Acute respiratory infections (ARIs) are the leading cause of morbidity and mortality in children under five years, with a periodic prevalence of 25.9% in West Papua (2013). This study aims to explain the factors associated with ARIs in under-5 children in Sorong District, West Papua. This cross-sectional study was conducted in two districts, where trained medical students interviewed 135 mothers/caregivers by using a structured questionnaire and interviewed cadres and health workers for qualitative observation. About 85.5% of respondents stated that their children had ARIs in the previous two weeks (n=135), much higher than the data from Sorong District Health Office, which only reached 24.63%. Dominant risk factors were large household size, smoking at home, and improper handwashing habits. Only half of the respondents went to a physician in a primary care facility. Nearly half of the respondents had difficulty in accessing the facility. The majority of caregivers used over-the-counter or traditional medicine. Around 70% of respondents in Makbon Subdistrict did nothing to prevent the transmission of ARIs among children. ARIs remains a massive problem in the Sorong district. We need to educate the mothers/caregivers about the rational use of medicine and the prevention of ARIs, and also advocate for better access to clean water, sanitation, and healthcare facilities.

Transmission of respiratory and gastrointestinal infections in German households with children attending child care.

Transmission of acute respiratory infections (ARI) and acute gastroenteritis (AGE) often occurs in households. The aim of this study was to assess which proportion of ARI and AGE is introduced and transmitted by children in German households with children attending child care. We recruited families with children aged 0-6 years in Braunschweig (Germany), for a 4 months prospective cohort study in the winter period 2014/2015. Every household member was included in a health diary and used nasal swabs for pathogen identification in case of ARI. We defined a transmission if two persons had overlapping periods with symptoms and used additional definitions for sensitivity analyses. In total, 77 households participated with 282 persons. We observed 277 transmission events for ARI and 23 for AGE. In most cases, the first infected person in a household was a child (ARI: 63%, AGE: 53%), and the risk of within-household transmission was two times higher when the index case was a child. In 26 ARI-transmission events, pathogens were detected for both cases; hereof in 35% (95% confidence interval (17-56%)) the pathogens were different. Thus, symptomatic infections in household members, apparently linked in time, were in 2/3 associated with the same pathogens.

Effectiveness of N95 respirators versus surgical masks in protecting health care workers from acute respiratory infection: a systematic review and meta-analysis.

Conflicting recommendations exist related to which facial protection should be used by health care workers to prevent transmission of acute respiratory infections, including pandemic influenza. We performed a systematic review of both clinical and surrogate exposure data comparing N95 respirators and surgical masks for the prevention of transmissible acute respiratory infections. We searched various electronic databases and the grey literature for relevant studies published from January 1990 to December 2014. Randomized controlled trials (RCTs), cohort studies and case-control studies that included data on health care workers wearing N95 respirators and surgical masks to prevent acute respiratory infections were included in the meta-analysis. Surrogate exposure studies comparing N95 respirators and surgical masks using manikins or adult volunteers under simulated conditions were summarized separately. Outcomes from clinical studies were laboratory-confirmed respiratory infection, influenza-like illness and workplace absenteeism. Outcomes from surrogate exposure studies were filter penetration, face-seal leakage and total inward leakage. We identified 6 clinical studies (3 RCTs, 1 cohort study and 2 case-control studies) and 23 surrogate exposure studies. In the meta-analysis of the clinical studies, we found no significant difference between N95 respirators and surgical masks in associated risk of (a) laboratory-confirmed respiratory infection (RCTs: odds ratio [OR] 0.89, 95% confidence interval [CI] 0.64-1.24; cohort study: OR 0.43, 95% CI 0.03-6.41; case-control studies: OR 0.91, 95% CI 0.25-3.36); (b) influenza-like illness (RCTs: OR 0.51, 95% CI 0.19-1.41); or (c) reported workplace absenteeism (RCT: OR 0.92, 95% CI 0.57-1.50). In the surrogate exposure studies, N95 respirators were associated with less filter penetration, less face-seal leakage and less total inward leakage under laboratory experimental conditions, compared with surgical masks. Although N95 respirators appeared to have a protective advantage over surgical masks in laboratory settings, our meta-analysis showed that there were insufficient data to determine definitively whether N95 respirators are superior to surgical masks in protecting health care workers against transmissible acute respiratory infections in clinical settings.

Public perceptions of non-pharmaceutical interventions for reducing transmission of respiratory infection: systematic review and synthesis of qualitative studies.

BackgroundNon-pharmaceutical public health interventions may provide simple, low-cost, effective ways of minimising the transmission and impact of acute respiratory infections in pandemic and non-pandemic contexts. Understanding what influences the uptake of non-pharmaceutical interventions such as hand and respiratory hygiene, mask wearing and social distancing could help to inform the development of effective public health advice messages. The aim of this synthesis was to explore public perceptions of non-pharmaceutical interventions that aim to reduce the transmission of acute respiratory infections.MethodsFive online databases (MEDLINE, PsycINFO, CINAHL, EMBASE and Web of Science) were systematically searched. Reference lists of articles were also examined. We selected papers that used a qualitative research design to explore perceptions and beliefs about non-pharmaceutical interventions to reduce transmission of acute respiratory infections. We excluded papers that only explored how health professionals or children viewed non-pharmaceutical respiratory infection control. Three authors performed data extraction and assessment of study quality. Thematic analysis and components of meta-ethnography were adopted to synthesise findings.ResultsSeventeen articles from 16 studies in 9 countries were identified and reviewed. Seven key themes were identified: perceived benefits of non-pharmaceutical interventions, perceived disadvantages of non-pharmaceutical interventions, personal and cultural beliefs about infection transmission, diagnostic uncertainty in emerging respiratory infections, perceived vulnerability to infection, anxiety about emerging respiratory infections and communications about emerging respiratory infections. The synthesis showed that some aspects of non-pharmaceutical respiratory infection control (particularly hand and respiratory hygiene) were viewed as familiar and socially responsible actions to take. There was ambivalence about adopting isolation and personal distancing behaviours in some contexts due to their perceived adverse impact and potential to attract social stigma. Common perceived barriers included beliefs about infection transmission, personal vulnerability to respiratory infection and concerns about self-diagnosis in emerging respiratory infections.ConclusionsPeople actively evaluate non-pharmaceutical interventions in terms of their perceived necessity, efficacy, acceptability, and feasibility. To enhance uptake, it will be necessary to address key barriers, such as beliefs about infection transmission, rejection of personal risk of infection and concern about the potential costs and stigma associated with some interventions.

Aerosol Generating Procedures and Risk of Transmission of Acute Respiratory Infections to Healthcare Workers: A Systematic Review

Aerosol generating procedures (AGPs) may expose health care workers (HCWs) to pathogens causing acute respiratory infections (ARIs), but the risk of transmission of ARIs from AGPs is not fully known. We sought to determine the clinical evidence for the risk of transmission of ARIs to HCWs caring for patients undergoing AGPs compared with the risk of transmission to HCWs caring for patients not undergoing AGPs. We searched PubMed, EMBASE, MEDLINE, CINAHL, the Cochrane Library, University of York CRD databases, EuroScan, LILACS, Indian Medlars, Index Medicus for SE Asia, international health technology agencies and the Internet in all languages for articles from 01/01/1990 to 22/10/2010. Independent reviewers screened abstracts using pre-defined criteria, obtained full-text articles, selected relevant studies, and abstracted data. Disagreements were resolved by consensus. The outcome of interest was risk of ARI transmission. The quality of evidence was rated using the GRADE system. We identified 5 case-control and 5 retrospective cohort studies which evaluated transmission of SARS to HCWs. Procedures reported to present an increased risk of transmission included [n; pooled OR(95%CI)] tracheal intubation [n = 4 cohort; 6.6 (2.3, 18.9), and n = 4 case-control; 6.6 (4.1, 10.6)], non-invasive ventilation [n = 2 cohort; OR 3.1(1.4, 6.8)], tracheotomy [n = 1 case-control; 4.2 (1.5, 11.5)] and manual ventilation before intubation [n = 1 cohort; OR 2.8 (1.3, 6.4)]. Other intubation associated procedures, endotracheal aspiration, suction of body fluids, bronchoscopy, nebulizer treatment, administration of O2, high flow O2, manipulation of O2 mask or BiPAP mask, defibrillation, chest compressions, insertion of nasogastric tube, and collection of sputum were not significant. Our findings suggest that some procedures potentially capable of generating aerosols have been associated with increased risk of SARS transmission to HCWs or were a risk factor for transmission, with the most consistent association across multiple studies identified with tracheal intubation.

Children, parents and Respiratory Syncytial Virus in Palermo, Italy: prevention is primary

A study was conducted to describe the characteristics of the Respiratory Syncytial Virus (RSV) infection cases occurring in the season 2006-7 in Palermo, Italy, and to evaluate the parents' knowledge and behaviours concerning prevention and control of acute respiratory infections (ARIs). All children aged between 0 and 2 years, admitted for a lower respiratory tract infection (LRTI) between October 2006 and May 2007, were enrolled in the study. Data were collected about demographic and household characteristics. Furthermore, their parents were asked to compile a structured questionnaire on transmission, prevention and management of ARIs in children. A total of 198 children with a diagnosis of LRTI were enrolled. Ninety-eight (62.0%) of 157 were positive for RSV. Parents were generally aware of transmission of ARIs through sneezing and/or coughing, but less through contaminated objects or hands. Nationality, age and education level of parents and also the age of the patients proved to be associated with some self-reported knowledge and behaviours. Only 24 (12.3%) of the 195 respondents had received advice from GPs or paediatricians about good hygiene practices. It seems essential to implement public health interventions promoting behavioural changes aimed at the primary prevention of ARIs at the community level.

Airborne Transmission via HVAC of Acute Respiratory Infections in Military Facilities? Review of a Basic Training Cohort Study

There is great interest in preventing the spread of acute respiratory infections (ARI) in military housing and in other facilities with multiple occupants such as hospitals. There has been some research on the mode of transmission of ARIs in these types of occupancies, with several studies focusing on direct and indirect contact. This study, based on several barracks at the largest basic training facility for the Army in the United States, investigates the role of airborne transmission via heating, ventilating and air conditioning (HVAC) systems as compared to a combination of airborne, indirect contact and direct contact transmission in a room. The results indicate that there is a significant increase in the number of cases which might be attributable to airborne transmission via HVAC systems in several situations, both for ARIs that required hospitalization, and those which did not.

Pediatric Population Size Is Associated With Geographic Patterns of Acute Respiratory Infections Among Adults

We measure the association between proportion of children and specific pediatric age groups in a local population with the timing and rate of adult emergency department (ED) utilization for influenza and other acute respiratory infections. We performed an ecologic study on a time-series of adult patients presenting to Massachusetts EDs and residing in the greater Boston area from October 1, 2001, to September 30, 2005. Patients presenting with acute respiratory infection, used as a marker for influenza, were aggregated by home address ZIP code. We measured geographic patterns of timing and rate of adult respiratory infection-related ED utilization. We performed correlation analysis of rates and peaks identified in this analysis with pediatric population data from the US census (including specific pediatric age groups) by Poisson regression. One hundred fifty seven thousand five hundred forty two adult respiratory infection-related ED visits (30 visits per 1,000 adults per year) were analyzed. Visits were distributed across 55 of ZIP codes, in which proportions of children (aged 0 to 18 years) ranged from 2.7% to 34.9% in these communities. Proportion of children in a ZIP code was directly associated with timing of seasonal onset of acute respiratory infections among adults (univariate Poisson regression rate ratio [RR] 0.985; 95% confidence interval [CI] 0.977 to 0.993). The proportion of children also explained the patterns of adult acute respiratory infection-related ED utilization rates (RR 1.035; 95% CI 1.024 to 1.047). Three- to 4-year-olds were found to be the most significant predictors of adult illness rate (RR 1.380; 95% CI 1.238 to 1.539) and timing of onset (RR 0.881; 95% CI 0.816 to 0.952). We demonstrate a positive correlation between the timing and rate of ED utilization by adults and the proportion of children in the population. These findings add to a growing body of evidence supporting a critical role played by children in community-wide transmission of acute respiratory infections.