National Emergency Department Visits for COVID-19, Influenza, and Respiratory Syncytial Virus

Charts and data provided by CDC, updates Wednesday by 8am. For the past year, using a rolling 52-week period.

This site provides a combined view of emergency department visit data for multiple respiratory conditions as tracked by the National Syndromic Surveillance Program (NSSP). NSSP is a collaboration among CDC, federal partners, state and local health departments, and academic and private sector partners to collect, analyze, and share electronic data received from multiple health care settings. Data are monitored for a subset of emergency departments across the United States. Additional data and features are forthcoming.

Weekly Emergency Department Visits by Age Group

CDC data visualization screenshot taken on archive date

Resp_ED_Count_Weekly_National.csv

Note, to view a specific respiratory illness, select it within the legend.

*The “Combined” category is created by adding emergency department patient visits with diagnosed COVID-19 to those visits with diagnosed influenza and those visits with diagnosed Respiratory Syncytial Virus (RSV) for the given week.

For more detailed information on these data please see the Companion Guide: NSSP Emergency Department Data on Respiratory Illness.

Weekly Emergency Department Visits by Age Group and Respiratory Illness, as a Percent of All Emergency Department Visits

Resp_ED_Count_Weekly_National.csv

Note, to view a specific age group, select it within the legend.

Findings for each respiratory virus type are presented individually and combined for all three as a percent of total emergency department visits. Additional information available at the Companion Guide: NSSP Emergency Department Data on Respiratory Illness.

For more detailed information on these data please see the Companion Guide: NSSP Emergency Department Data on Respiratory Illness.

Weekly Emergency Department Visits by Viral Respiratory Illness Type and State, as a Percent of All Emergency Department Visits

Resp_ED_Count_Weekly_National.csv

Findings for each respiratory virus type are presented individually and combined for all three as a percent of total emergency department visits. Additional information, including on participating states and jurisdictions, available at the Companion Guide: NSSP Emergency Department Data on Respiratory Illness.

Additional resources

Introduction

The National Syndromic Surveillance Program (NSSP) is a collaboration among CDC, local and state health departments, with private sector partners. Together, these partners collect, share, and analyze automated electronic healthcare data in near-real time.

The national data include emergency departments in all 50 states, the District of Columbia, and Guam. Coverage map: https://www.cdc.gov/nssp/participation-coverage-map.html

Inclusion

Diagnostic codes and clinical terms were used to create definitions for diagnosed COVID-19, influenza, and RSV. Jurisdiction-level data are not shown for Missouri because the proportion of records with a discharge diagnosis is low. Jurisdiction-level data are not shown for New Hampshire, South Dakota, and Washington to ensure data use and other sharing agreements are appropriately addressed prior to public release. Guam is not shown due to small counts.

Emergency department visits were assigned to the Morbidity and Mortality Weekly Report (MMWR) week they occurred; MMWR weeks begin on Sunday and end on the following Saturday. MMWR week #1 of an MMWR year is the first week of the year that has at least four days in the calendar year.

Considerations for Interpretation of Data

Variability in testing practices for different viruses and in different age groups may lead to under-ascertainment of respiratory infections in electronic healthcare data, including emergency department visits. Patients who are less likely to be tested are less likely to be included. These data are based on electronic diagnostic codes transmitted automatically in near real-time, and hospital practices for assigning these codes can vary. These data are dynamic and update as codes are added and changed.

The weekly percent of emergency department visits with COVID-19 diagnosis on this site are not designed to match the percentages shown on the CDC COVID Data Tracker. Metrics will differ across websites due to factors such as updates on different days of the week or different calculations, such as presentation of a 7-day moving average on daily data rather than weekly totals. Data will also differ from state websites due to different update schedules, calculations, or definitions. These data are not a random sample and are not intended to capture data from every hospital. While these data are not designed to be randomly sampled or comprehensive, they provide a useful overall indicator of trends in emergency department use.

How Percent of Visits is Calculated

For data that are presented as a percentage, each respiratory illness is presented as a percent of all emergency department visits by age group. For example, the COVID-19 data show emergency department visits for children ages 5-11 with diagnosed COVID-19 as a fraction of all emergency department visits for children ages 5-11.

Definitions

The following discharge diagnoses (DD) and clinical terms are included: International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), and Systematized Nomenclature of Medicine – Clinical Terms (SNOMED CT). Please note that conditions can be defined in different ways in electronic healthcare data, and some jurisdictions may use different definitions. Short codes listed capture all codes underneath (J09 captures J09.X1-J09.X9).

COVID-19

Definition name in the NSSP Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE) system: CDC COVID-Specific DD v1

Definition name in the NSSP Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE) system: CDC COVID-Specific DD v1
Code Type	Codes	Code Description
Inclusions
ICD-10-CM	J12.82	Pneumonia due to coronavirus disease 2019
ICD-10-CM	U07.1	COVID-19
SNOMED CT	840539006	Disease caused by severe acute respiratory syndrome coronavirus 2
	840544004	Suspected disease caused by severe acute respiratory coronavirus 2
	840533007	Severe acute respiratory syndrome coronavirus 2

Influenza

Definition name in the NSSP ESSENCE system: CDC Influenza DD v1

Definition name in the NSSP ESSENCE system: CDC Influenza DD v1
Code Type	Codes	Code Description
Inclusions
ICD-10-CM	J09	Influenza due to certain identified influenza viruses
	J10	Influenza due to other identified influenza viruses
	J11	Influenza due to unidentified influenza virus
ICD-9-CM	487.0	Influenza with pneumonia
	487.1	Influenza with other respiratory manifestations
	487.8	Influenza with other manifestations
	488.01	Influenza due to identified avian influenza virus with pneumonia
	488.09	Influenza due to identified avian influenza virus with other manifestations
	488.11	Influenza due to identified 2009 H1N1 influenza virus with pneumonia
	488.19	Influenza due to identified 2009 H1N1 influenza virus with other manifestations
	488.81	Influenza due to identified novel influenza A virus with pneumonia
	488.89	Influenza due to identified novel influenza A virus with other manifestations
SNOMED CT	442696006	Influenza caused by influenza A virus subtype H1N1
	442438000	Influenza caused by Influenza A virus
	6142004	Influenza
	195878008	Pneumonia and influenza

RSV

Definition name in the NSSP ESSENCE system: CDC Respiratory Syncytial Virus DD v1

Definition name in the NSSP ESSENCE system: CDC Respiratory Syncytial Virus DD v1
Code Type	Codes	Code Description
Inclusions
ICD-10-CM	B97.4	Respiratory syncytial virus (RSV) as the cause of diseases classified elsewhere
	J12.1	Respiratory syncytial virus pneumonia
	J20.5	Acute bronchitis due to respiratory syncytial virus
	J21.0	Acute bronchiolitis due to respiratory syncytial virus
ICD-9-CM	466.11	Acute bronchiolitis due to respiratory syncytial virus
	480.1	Pneumonia due to respiratory syncytial virus
	079.6	Respiratory syncytial virus
SNOMED CT	55735004	Respiratory syncytial virus infection
	408684006	Healthcare associated respiratory syncytial virus disease
	195881003	Pneumonia caused by respiratory syncytial virus
	10625551000119103	Bronchopneumonia caused by respiratory syncytial virus
	57089007	Respiratory syncytial virus bronchiolitis
	195739001	Acute bronchiolitis caused by respiratory syncytial virus
	79479005	Respiratory syncytial virus bronchitis
	195727009	Acute respiratory syncytial virus bronchitis
	72204002	Respiratory syncytial virus laryngotracheobronchitis
	31309002	Respiratory syncytial virus pharyngitis

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