RIR.knit

Influenza-Like Illness

What is Influenza-like Illness?
Influenza-like illness (ILI) is a measure that is used for flu surveillance around the world. It is focused on people’s symptoms and not laboratory-confirmed respiratory viruses. ILI is defined as a doctor’s visit due to any respiratory pathogen that presents with 1) fever (temperature of 100° F or greater), and 2) having a cough and/or sore throat. These data should be evaluated in the context of other surveillance data to obtain a complete and accurate picture of influenza activity.

Current Influenza-like Illness Intensity Level
The gauge to the right (Figure 1) displays this week’s ILI percentage and the current intensity level in Davis County. The intensity level shows how much ILI activity is occurring this week, divided into four categories: low, medium, high, and very high.

Influenza-like Illness Trend Data
The graph below (Figure 2) shows the percent of outpatient healthcare visits in Davis County due to ILI.

Figure 1. Current ILI Intensity Level

Figure 2. Percent of Outpatient Visits due to Influenza−Like Illness (ILI), by Week, Davis County

Tips to use the data chart

There are two buttons in the upper left-hand corner of the graph. These buttons automatically zoom to a specified date on the X axis.

Click the “All Data” button to view all the available data.
Click the “Current Season” button to view the data for the current respiratory illness season (typically either the end of September or early October).

A toolbar appears in the upper right-hand corner of the graph when your mouse is in the graph. You may then click those icons to interact with the graph (zoom in or out, return to the default view, move the graph, etc.).
Hover your mouse over any spot on a specific line in the graph. It will display the disease you’re looking at, the specific data value, and the associated date.
If multiple lines are displayed in the legend on the right-hand side, you can click them to change what you want to see on the graph.

A single click removes that line from the graph.
A double-click makes it the only one on the graph

Nationwide Influenza-like Illness Activity
The image below displays the most recent nationwide influenza-like illness (ILI) map from CDC’s Weekly US Influenza Report. Each state and territory are categorized based on its current ILI activity. There are five activity levels: minimal, low, moderate, high, and very high. This map uses the proportion of outpatient visits to healthcare providers for influenza-like illness to measure the ILI activity level within a state. It does not, however, measure the extent of geographic spread of flu within a state. Therefore, outbreaks occurring in a single city could cause the state to display high activity levels.

Emergency Department

Emergency Department Visits
The amount of people that go to the emergency department (ED) for an illness is one way to figure out how severe the circulating viruses are. These ED data are based on diagnosis discharge codes from syndromic surveillance data from the National Syndromic Surveillance Program (NSSP) at CDC. These data should be interpreted as preliminary and should be used to only identify and monitor trends.

In addition, the numbers and percentages presented here are based on the patient’s address of residence when visiting an ED. For example, if a Davis County resident visits an ED in Salt Lake, the count will be associated with the Davis County numbers.

Current Emergency Department Visit Intensity Levels
The gauges to the right (Figure 3) display this week’s percentage of ED visits due to COVID-19, influenza, and RSV. They also show the current intensity level for each in Davis County. The intensity level shows how many ED visits are occurring this week, divided into four categories: low, medium, high, and very high.

Emergency Department Trend Data
The graph below (Figure 4) shows the percent of ED visits in Davis County that are attributable to COVID-19, influenza, and RSV.

Figure 3. Current ED Intensity Levels

Figure 4. Percent of Emergency Department (ED) Visits due to COVID-19, Influenza, & RSV, by Week, Davis County

Tips to use the data chart

There are two buttons in the upper left-hand corner of the graph. These buttons automatically zoom to a specified date on the X axis.

Click the “All Data” button to view all the available data.
Click the “Current Season” button to view the data for the current respiratory illness season (typically either the end of September or early October).

A toolbar appears in the upper right-hand corner of the graph when your mouse is in the graph. You may then click those icons to interact with the graph (zoom in or out, return to the default view, move the graph, etc.).
Hover your mouse over any spot on a specific line in the graph. It will display the disease you’re looking at, the specific data value, and the associated date.
If multiple lines are displayed in the legend on the right-hand side, you can click them to change what you want to see on the graph.

A single click removes that line from the graph.
A double-click makes it the only one on the graph

Hospitalizations

Hospitalizations
The amount of people that are hospitalized for an illness is one way to figure out how severe the circulating viruses are. Hospitalizations that are associated with COVID-19 or influenza is a reportable condition in Utah. People meet the case definition for a COVID-19 or flu hospitalization if they are hospitalized for any length of time and have a positive laboratory test within a specific time frame.

Current Hospitalization Intensity Levels
The gauges to the right (Figure 5) display this week’s rate of hospitalizations due to COVID-19 and influenza. They also show the current intensity level for each in Davis County. The intensity level shows how many hospitalizations are occurring this week, divided into four categories: low, medium, high, and very high.

Hospitalization Trend Data
The graph below (Figure 6) shows the rate of hospitalizations (per 100,000 people) in Davis County that are attributable to COVID-19 and influenza.

Figure 5. Current
Hospitalization Intensity Levels
Rate per 100,000 people

Figure 6. Weekly Rate of Hospitalizations due to COVID−19 & Influenza, per 100,000 People, Davis County

Tips to use the data chart

There are two buttons in the upper left-hand corner of the graph. These buttons automatically zoom to a specified date on the X axis.

Click the “All Data” button to view all the available data.
Click the “Current Season” button to view the data for the current respiratory illness season (typically either the end of September or early October).

A toolbar appears in the upper right-hand corner of the graph when your mouse is in the graph. You may then click those icons to interact with the graph (zoom in or out, return to the default view, move the graph, etc.).
Hover your mouse over any spot on a specific line in the graph. It will display the disease you’re looking at, the specific data value, and the associated date.
If multiple lines are displayed in the legend on the right-hand side, you can click them to change what you want to see on the graph.

A single click removes that line from the graph.
A double-click makes it the only one on the graph

Wastewater

What is Wastewater Surveillance?
People who are infected with SARS-CoV-2 (and potentially other pathogens) shed viral RNA (genetic material from the virus) in their waste. This RNA can be detected and measured in samples of community wastewater (untreated biological waste). Wastewater, also called sewage, can come from both residential use (toilets, showers, and sinks) as well as non-household sources like industrial use and rain.

Wastewater surveillance can capture the presence of SARS-CoV-2 shed by people who have COVID-19, even if they don’t have symptoms. It is often an early indicator if COVID-19 cases are increasing or decreasing. However, it is not currently possible to accurately and reliably predict the number of infected individuals in a community based solely on wastewater surveillance data. You can explore more data and information about wastewater surveillance at the Utah Wastewater Surveillance System webpage.

Data
There are three sewer districts in Davis County from which there are four sampling sites. The table on the right (Table 1) shows those four sites, the corresponding cities, and the wastewater data. The “Level” column shows the relative concentration of SARS-CoV-2 viral RNA found in the wastewater. It is categorized into a six-tier system:

Very low
Low
Watch
Elevated
Very elevated
Extremely elevated

The “Trend” column shows if those concentrations are increasing, decreasing, or staying the same (labeled as “No trend”).

Table 1. COVID-19 Wastewater Surveillance, Davis County, as of May 21, 2026


Site	Level	Trend
North Davis Layton, Clearfield, Syracuse, West Point area	Very Low	No trend ⇆
Central Davis Kaysville, Farmington, Fruit Heights area	Very Low	No trend ⇆
South Davis - North Bountiful, Centerville, Woods Cross, West Bountiful area	Very Low	No trend ⇆
South Davis - South North Salt Lake area	Very Low	No trend ⇆

School Absenteeism

What is Absenteeism?
Absenteeism refers to excused or unexcused absences from elementary or secondary (middle/high) school. Frequent school absences are associated with lifelong negative academic, social, and health effects. It is a complex issue with many different, yet interrelated causes.

School Absenteeism Trend Data
The graph below (Figure 7) shows the weekly percent of elementary school absenteeism in Davis School District. Data for overall absences and absences specifically due to illness are shown. Here, illness is self-reported by parent or guardian. It includes respiratory, rash, gastrointestinal, and other/unknown illnesses. For comparison, the respective dashed lines show the average over the past 5 school years.

Figure 7. Percentage of Elementary School Absenteeism (Overall Absence and Absence Due to Illness), by Week, Davis School District, 2025-2026 School Year

Tips to use the data chart

There are two buttons in the upper left-hand corner of the graph. These buttons automatically zoom to a specified date on the X axis.

Click the “All Data” button to view all the available data.
Click the “Current Season” button to view the data for the current respiratory illness season (typically either the end of September or early October).

A toolbar appears in the upper right-hand corner of the graph when your mouse is in the graph. You may then click those icons to interact with the graph (zoom in or out, return to the default view, move the graph, etc.).
Hover your mouse over any spot on a specific line in the graph. It will display the disease you’re looking at, the specific data value, and the associated date.
If multiple lines are displayed in the legend on the right-hand side, you can click them to change what you want to see on the graph.

A single click removes that line from the graph.
A double-click makes it the only one on the graph

Resources & Notes

Utah Department of Health and Human Services (UDHHS)

Statewide Respiratory Disease Surveillance: Data and trends for COVID-19, influenza, and RSV in Utah. Updated on Wednesdays during respiratory season, October 1st - April 30th.

Utah Wastewater Surveillance System: People who are infected with SARS-CoV-2 (and potentially other pathogens) shed viral RNA (genetic material from the virus) in their feces. This RNA can be detected and measured in samples of community wastewater. Wastewater, also called sewage, can come from both residential use (toilets, showers, and sinks) as well as non-household sources like industrial use and rain.

Centers for Disease Control and Prevention (CDC)

Weekly Flu Report: A weekly influenza surveillance report prepared by the Influenza Division. Updated on Fridays.

Respiratory Illnesses: Respiratory viruses are viruses that cause illnesses in the respiratory system. These illnesses share similar symptoms, risk factors, and prevention strategies.

Core Prevention Strategies
Each year, respiratory viruses are responsible for millions of illnesses and thousands of hospitalizations and deaths in the United States. The good news is there are actions you can take to help protect yourself and others from health risks caused by respiratory viruses.

Stay up to date with recommended immunizations. Talk to your doctor or trusted healthcare provider about what may be recommended for you and your family.

Practice good hygiene like washing your hands regularly and cleaning commonly touched surfaces.
If you are sick, stay home and stay away from others.
Seek health care promptly for treatment if you have risk factors for severe illness; treatment may help lower your risk of severe illness.

Intensity Levels
Intensity levels used in this dashboard are based on Intensity Thresholds (IT) generated from the Moving Epidemic Method (MEM). Percentiles are used to determine the categories. Values below the IT50 threshold are shown in green in the gauges, and are considered low severity. Indicators between IT50 and IT90 (yellow) are considered moderate severity, indicators between IT90 and IT98 (red) are considered high severity, and indicators above IT98 are considered very high severity (purple). This methodology was published by CDC researchers in the American Journal of Epidemiology in October 2017.