Respiratory virus data
About wastewater data
Monitoring the concentration of the COVID, Flu and RSV found in samples from wastewater treatment facilities serving Santa Clara County residents tell us how much infection is spreading within a community.
Wastewater data is available sooner than case results, which is why it is called an “early signal” for understanding if infections are increasing or decreasing or if new diseases are showing up.
This graph shows the concentrations of COVID, Flu A, Flu B, and RSV in wastewater. Higher concentration indicates more spread of the disease in the community. The graph also provides information on how high current concentrations are compared to past periods.
Please note: In the Wastewater Disease Comparison display, scales for the different diseases on the y-axis are not necessarily equivalent.
The “high, medium, and low” concentration levels describe concentration values compared to thresholds that are generated based on the COVID, Flu, or RSV wastewater concentration values from the past 365 days. For more information, see below.
The current concentration are shown as levels (High, Medium, and Low) that are based on looking back at all data from the last 365 days across all 4 sites within Santa Clara County, weighted by the population size of each sewershed. The range of values included in the bottom third of all data points are represented by the low level, the range values included in the middle third of data points are represented by the medium level, and the range of values included in the top third of data points are represented as the high level. The "High", "Medium" and "Low" lines in the graph denote the values at the 33rd and 66th percentiles.
For COVID, the daily change in concentration compares the current 7-day average COVID concentration at each sewershed to the prior day’s 7-day average. The Dashboard displays the average of daily change from the past 7 days.
For Flu and RSV, the daily change in concentration compares the current 5-day average flu or RSV concentration at each sewershed to the prior day’s 5-day average. The Dashboard displays the average of daily change from the past 5 days.
Wastewater samples are collected at four wastewater treatment facilities that collectively serve 98% of Santa Clara County’s total population. Each wastewater treatment facility collects wastewater from a defined geographic area, called a “sewershed.”.
San Jose: San Jose - Santa Clara Regional Wastewater Facility
- San Jose-Santa Clara Regional Wastewater Facility serves people in the cities of San Jose, Santa Clara and Milpitas; Cupertino Sanitary District (City of Cupertino and nearby unincorporated areas); West Valley Sanitation District (Cities of Campbell, Los Gatos, Monte Sereno, and Saratoga); County Sanitation District No. 2-3 (unincorporated area); and Burbank Sanitary District (unincorporated area).
Palo Alto: Palo Alto Regional Water Quality Control Plant
- Palo Alto Regional Water Quality Control Plant serves people in Los Altos, Los Altos Hills, Mountain View, Palo Alto, Stanford University, and the East Palo Alto Sanitary District. Note: A portion of wastewater received at the Palo Alto Regional Water Quality Control Plant comes from San Mateo County.
Sunnyvale: Donald M. Somers Water Pollution Control Plant
- Donald M. Somers Water Pollution Control Plant serves people in the city of Sunnyvale; Rancho Rinconada portion of Cupertino; and Moffett Federal Airfield.
Gilroy: South County Regional Wastewater Authority
- South County Regional Wastewater Authority serves people in the cities of Gilroy and Morgan Hill.
Protocol for Sample Collection and Testing: Samples for testing consist of “settled solids” from wastewater entering each treatment plant. Samples are collected seven days a week from the wastewater treatment plants and are transported daily to a commercial lab for analysis. Laboratory staff process the samples to quantify SARS-CoV-2 (the virus that causes COVID), Flu A, Flu B, and RSV concentration in the wastewater. These procedures use methods to concentrate solids and extract RNA and detect viral RNA.
Interpretation of Plots: Data reflected in the table below show the results for Influenza A, and the concentrations are “normalized” by the concentration of a plant virus that is harmless to humans but is shed in stool. This plant virus is the pepper mild mottle virus, or PMMoV. Normalizing by PMMoV adjusts for changes in the amount of feces in the sample and the efficiency of the procedures from day to day.
Wastewater typically contains waste from a variety of sources, such as from your shower or a commercial process. These types of waste do not have stool so they dilute the sample. Therefore, we adjust this sample to the known amount of feces in the wastewater to get an accurate result.
The COVID wastewater curves are the 7-day trimmed average of the sample results. This is done by using seven consecutive samples, eliminating the maximum and minimum among the seven samples, and then taking the mean. The smoothing is right aligned.
The Flu and RSV wastewater curves displayed are the 5-day trimmed average of the sample results. This is done by using samples from each day with the previous four days, eliminating the maximum and minimum among the five samples, and then taking the mean. The smoothing is right aligned.
Safer air in, viruses out
If you own a business or work for a business, air flow is an important part of keeping employees and customers healthy. Airborne viruses spread more easily indoors. Businesses can take three simple steps to make the indoors safer for everyone, especially when wastewater is showing high levels of virus in Santa Clara County.
Poop Don’t Lie!
You are contributing to wastewater data just by flushing the toilet. Wondering how poop ends up being scientific data? Follow the feces. Find out how poop helps Public Health understand disease trends and makes decisions to protect your health.
Brandon in the Lab
Every wondered what goes on in a Public Health lab? Watch how Public Health detects possible infectious disease outbreaks, tests blood for lead, and much more. Tour the lab with Brandon Bonin, Director of the Public Health Laboratory, as he takes you behind the scenes and explains their important work.
Update frequency
This data is updated each weekday, Monday through Friday, reflecting data with a 2 to 4 day delay. Please note: Update frequency is dependent on data availability from data source. Most recent data are preliminary and subject to change.
Source
About emergency department visit data
When people experience symptoms that are concerning or difficult to manage at home, they may visit an emergency department for further testing and treatment. Monitoring these trends can tell us if more people in the community are getting sick from respiratory viruses.
This graph demonstrates the weekly percentage of emergency department visits that result in a diagnosis of COVID, Flu and RSV.
Update frequency: This data is updated every Monday. Please note: Update frequency is dependent on data availability from data source. Most recent data are preliminary and subject to change.
Source: ESSENCE (Electronic Surveillance System for the Early Notification of Community-Based Epidemics)
Emergency Departments reflected in this data source include all hospitals located in Santa Clara County: Good Samaritan Hospital, Kaiser Permanente Santa Clara Medical Center, Kaiser Permanente San Jose Medical Center, O’Connor Hospital, Regional Medical Center of San Jose, St. Louise Regional Hospital, Stanford Medical Center, and Valley Medical Center.
About hospitalizations data
People who are sick with severe symptoms are often hospitalized for further testing, monitoring, and treatment. Monitoring trends in hospitalization can show the severity of illness that is being caused by respiratory viruses in the community. It can also provide information about hospital capacity.
This graph demonstrates the weekly number of hospitalizations that result in a diagnosis of COVID, Flu and RSV.
Update frequency: This data is updated every Monday. Please note: Update frequency is dependent on data availability from data source. Most recent data are preliminary and subject to change.
Source: ESSENCE (Electronic Surveillance System for the Early Notification of Community-Based Epidemics)
Emergency Departments reflected in this data source include all hospitals located in Santa Clara County including: Good Samaritan Hospital, Kaiser Permanente Santa Clara Medical Center, Kaiser Permanente San Jose Medical Center, O’Connor Hospital, Regional Medical Center of San Jose, St. Louise Regional Hospital, Stanford Medical Center, and Valley Medical Center.
About vaccination data
Getting vaccinated can significantly reduce the likelihood of getting infected with a respiratory virus, experiencing severe symptoms, or spreading illness within the community. Monitoring trends in vaccination can give us information on how much community protection there is against respiratory viruses and what populations may require more support.
This graph demonstrates the demographics of individuals who have received the current COVID, Flu and RSV vaccinations. It also shows the current percent of the eligible population in Santa Clara County that has received the most recent COVID, Flu and RSV vaccinations.
Please note: on September 9, 2024, the Public Health Department paused vaccination data updates on the Respiratory Virus Dashboard. The dashboard will be updated with COVID, flu and RSV vaccination data for the 2024-2025 respiratory virus season once the information becomes available.
Visit these links to find more information about who is eligible for vaccination and where you can go.
Update frequency: This data is updated every Monday. Please note: Update frequency is dependent on data availability from data source. Most recent data are preliminary and subject to change.
Source:
- California Department of Public Health, California Immunization Registry
- State of California, Department of Finance, E-2. California County Population Estimates and Components of Change by Year — July 1, 2020-2023, December 2023
- State of California Department of Finance, State and County Population Projections by Race/Ethnicity and Age, 2010 - 2060, Sacramento, California, July 2021
About COVID death data
While COVID deaths have declined significantly since the start of the COVID pandemic, it is still important to monitor who is dying from COVID. This information helps the Public Health Department determine appropriate actions to better prevent the spread of COVID and protect community health.
This graph shows the number of COVID-related deaths that occurred each week. It also demonstrates the demographics of individuals who have died with COVID.
Not all RSV and Flu-related deaths are required by the state to be reported to public health departments, and therefore are not reflected in this dashboard.
Update frequency: This data is updated every Monday. Please note: Update frequency is dependent on data availability from data source. Most recent data are preliminary and subject to change.
Source:
- California Reportable Disease Information Exchange
- National Center for Health Statistics (NCHS) National Vital Statistics System (NVSS)
- U.S. Census Bureau, 2015-2019 American Community Survey, 5-Year Estimates
Comparison of COVID cases and wastewater concentration