Influenza‐like illness‐related emergency department visits: Christmas and New Year holiday peaks and relationships with laboratory‐confirmed respiratory virus detections, Edmonton, Alberta, 2004–2014

Abstract

BackgroundEmergency department (ED) visit volumes can be especially high during the Christmas–New Year holidays, a period occurring during the influenza season in Canada.MethodsUsing daily data, we examined the relationship between ED visits for the chief complaint “cough” (for Edmonton, Alberta residents) and laboratory detections for influenza A and respiratory syncytial virus (RSV) (for Edmonton and surrounding areas), lagged 0–5 days ahead, for non‐pandemic years (2004–2008 and 2010–2014) using multivariable linear regression adjusting for temporal variables. We defined these cough‐related visits as influenza‐like illness (ILI)‐related ED visits and, for 2004–2014, compared Christmas–New Year holiday (December 24–January 3) and non‐holiday volumes during the influenza season (October–April).ResultsAdjusting for temporal variables, ILI‐related ED visits were significantly associated with laboratory detections for influenza A and RSV. During non‐pandemic years, the highest peak in ILI‐related visit volumes always occurred during the holidays. The median number of holiday ILI‐related visits/day (42.5) was almost twice the non‐holiday median (24) and was even higher in 2012–2013 (80) and 2013–2014 (86). Holiday ILI‐related ED visit volumes/100 000 population ranged from 56.0 (2010–2011) to 117.4 (2012–2013). In contrast, lower visit volumes occurred during the holidays of pandemic‐affected years (2008–2010).ConclusionsDuring non‐pandemic years, ILI‐related ED visit volumes were associated with variations in detections for influenza A and RSV and always peaked during the Christmas–New Year holidays. This predictability should be used to prepare for, and possibly prevent, this increase in healthcare use; however, interventions beyond disease prevention strategies are likely needed.

Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections

“…Lower respiratory tract infections (LRTIs) accounted for greater than 90% of all DALYs, with approximately 35% of cases occurring in children less than 5 years old (13,14). The impact of respiratory infections on human health is reflected in the large number of hospital and emergency room visits for both adults and children (e.g., in the United States, there are 140,000 to 710,000 FLU-related hospital-izations per year), where respiratory viral infection is the most common reason to seek medical care (15,16).…”

“…Antibacterial prescription rates did not vary between groups; however, there was a statistically significant difference between antiviral prescription rates: the FLU-positive group was more likely to be treated with an antiviral agent (80/105 [81%] treated) than were patients in the non-influenza virus pathogen group (6/109 [5.5%]) and the no-pathogen-detected group (2/81 [2.5%]) (P Ͻ 0.001) (254). Respiratory panel use allows for more comprehensive characterization of viruses for general epidemiology/surveillance (15,265) and outbreak investigation. Other, less tangible but important, benefits to respiratory viral panel use may also include improved patient and physician satisfaction with an improved test turnaround time.…”

Incorporating calendar effects to predict influenza seasonality in Milwaukee, Wisconsin

“…All reviewed works primarily evaluated transmission patterns of influenza during extreme mass gatherings [20,21,34]. Otherwise, researchers rarely considered differential effects of holidays at different times of the year, instead combining all holiday weeks under one dichotomous variable [13] or isolating their analyses to a single time of the year [35]. While some works have reviewed differences in incidence risk ratios (IRRs) before, during and after individual school holidays, none have explored holiday categorisation effects on these IRRs or seasonal signatures [2,3,6].…”

Diagnostic accuracy of a rapid RT-PCR assay for point-of-care detection of influenza A/B virus at emergency department admission: A prospective evaluation during the 2017/2018 influenza season

“…[1] The number of emergency department visits for influenza-like illnesses is estimated at around 100 per 100 000 inhabitants. [2] The management of these epidemics is therefore a real medical challenge. Many studies have shown increased emergency department stay lengths, bed use and premature patient departures during influenza epidemics.…”