Q: What is the public health impact of RSV & influenza virus?
Respiratory syncytial virus (RSV) is a common virus that usually causes mild to moderate illness in children and adults. However, infants, young children, and older adults are at increased risk for severe disease. RSV infections are the leading cause of hospitalization among infants, causing 58,000 hospitalizations and 2.1 million outpatient visits of children five and under annually (American Lung Association). Adults over 65 years, adults with chronic lung or heart disease, and adults with compromised immune systems are at greater risk of severe illness. Each year, 60,000-120,000 older adults are hospitalized with RSV, and 6,000-10,000 die from their infections (CDC).
In 2023, the Food and Drug Administration approved two RSV vaccines for adults 60 and over. Following the FDA approval, the Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization and Practices (ACIP) recommended RSV vaccination for adults 60 and older, in consultation with their primary care provider. These vaccines are expected to become available in Fall 2023.
Influenza virus is a common respiratory virus that causes the flu, which can result in mild to severe illness. While anyone can get the flu, certain groups are at increased risk of serious complications. Adults 65 years and older, people with certain chronic medical conditions, pregnant people, and children under 5 are at greater risk of severe illness.
Seasonal flu causes tremendous disease burden in the US each year. According to a 2018 CDC study, an average of 8% of the US population get sick with the flu annually (3-11% range). During the 2022-2023 season, the CDC estimated that the flu resulted in 12-26 million medical visits, 300,000-650,000 hospitalizations, and 19,000-58,000 deaths. Between 2010 through 2020, the CDC estimated that the flu resulted in 9 million - 41 million illness annually.
Several types of influenza vaccines are available, and yearly vaccination is recommended for everyone six months of age and older. While antiviral medications can be used to treat the flu, prevention through vaccination is most effective.
Q: How does Biobot wastewater monitoring for RSV & influenza work?
RSV and influenza virus are respiratory viruses that are shed in stool by infected individuals. They enter the wastewater system and can then be detected and quantified via wastewater analysis. Biobot's partner lab uses highly sensitive ddPCR (Droplet Digital polymerase chain reaction) methods to identify genetic material from RSV and influenza virus in wastewater samples.
Q: What is the “respiratory panel”? Will RSV & influenza be available as separate analyses?
Biobot’s respiratory panel includes influenza virus A and B, RSV, and SARS-CoV-2. These three respiratory viruses have circulated simultaneously, and together are responsible for tremendous annual disease burden and financial toll in the US and globally. Biobot has developed a panel that groups these respiratory viruses together, yet distinguishes between them and uses individual assays to separately monitor each virus. The panel includes distinct reporting and interpretation of effective concentrations in wastewater for each.
Q: Is the monitoring for RSV and influenza different from COVID-19?
Yes – there are separate polymerase chain reaction (PCR) assays for RSV, influenza virus, and SARS-CoV-2. We test for SARS-CoV-2, RSV, influenza virus using ddPCR (Droplet Digital PCR).
Q: Doesn’t the CDC provide data through FluView?
Yes, the CDC provides weekly influenza virus surveillance data via FluView. However, this does not include data on RSV. FluView consolidates data from public health and clinical laboratories throughout the U.S. in order to provide critical information on prevalence, virus types in circulation, ages of people affected, geographic trends, susceptibility to antivirals, hospitalization and mortality rates, and more.
Importantly, FluView’s data is based on clinical testing, hospitalization, and deaths, which limits it from capturing data on asymptomatic, misdiagnosed, or undiagnosed cases. With a variety of data streams and structures that must be aligned, there are often multi-week time lags between positive tests and report publication. Additionally, not all states are required to report individual flu illnesses or deaths, and many state-specific Weekly Flu Reports are only published during the fall and winter flu season, resulting in an inconsistent picture of flu burden across the U.S.
Wastewater monitoring has the potential to improve upon the current surveillance system and provide insights that can be leveraged for public health action. Wastewater testing can capture viral shedding from asymptomatic or undiagnosed cases, and identify the presence of influenza virus even before people have developed symptoms, potentially serving as an early warning system for the specific geographic area covered by testing. Results from wastewater testing can also become available as fast as 24 hours after sample collection, allowing for almost real time surveillance. Finally, many state-specific Weekly Flu Reports are only published during flu season, whereas wastewater monitoring can be leveraged year-round.