During the past two flu seasons, the feared twindemic, a simultaneous surge in COVID-19 and flu cases, never materialized [1]. This year, the concern is not just a twindemic, but a tripledemic. Respiratory syncytial virus (RSV) infections are surging, sending many children to the hospital and straining the healthcare system [2]. The flu season has only just begun, but the Centers for Disease Control and Prevention (CDC) estimate that there have already been more than 53,000 flu-related hospitalizations in the United States [3]. At the same time, COVID-19 continues to be a threat worldwide.
With so many viruses circulating, some experts believe a robust testing strategy is our best defense. At two recent events, presenters from Thermo Fisher Scientific explored the current state of respiratory infections globally, the need for testing, and potential advantages of multiplex PCR.
The Global Burden of Respiratory Pathogens
Acute respiratory infections, commonly caused by viruses including RSV, rhinovirus, influenza, coronavirus, and adenovirus, are one of the leading causes of death globally [4]. However, at the height of the pandemic, coronavirus and COVID-19 took center stage. During her presentation at the 2022 Annual Conference of the European Society for Clinical Virology (ESCV), Dr. Jelena Feenstra, PhD, Senior Manager of Global Scientific Communications at Thermo Fisher Scientific, shared data demonstrating the impact the global pandemic shutdown had on two common viruses – flu and RSV. Although they are now surging, there was very little flu and RSV activity in 2021. “When the COVID-19 pandemic started, that had a major impact on the circulation of other respiratory viruses because a lot of measures [had] been put in place to protect the public health,” said Dr. Feenstra.
With masking, social distancing and other measures relaxed, as well as decreased population immunity, we are now seeing higher activity of other viral respiratory infections.
Watch the ESCV presentations here
Defining When Testing is Needed
Respiratory infections, when caused by viral pathogens, are commonly classified by respiratory syndrome. For example, a coughing or feverish patient may be diagnosed with the croup or an influenza-like illness. Other common respiratory syndromes include the common cold, bronchiolitis, or pneumonia. However, these classifications don’t offer a full picture of disease spread. “Viruses can actually cause each of these or many of these respiratory syndromes,” said Dr. Feenstra. Your common cold could be from a rhinovirus, but several other viruses could also be the culprit, including RSV. Due to overlapping symptoms between viruses, testing is needed to know for certain what pathogen is causing disease. Although not required in all situations, testing for respiratory disease is needed when it could impact care and treatment decisions, infection control, patient cohorting, or epidemiological surveillance.
In a separate virtual presentation, Thermo Fisher Scientific numbered key reasons on why to test for multiple respiratory viruses simultaneously. One of importance to laboratory managers is that multiplex testing combines targets for each virus into a single test that makes distinguishing these infections much easier. Consequently, this enables physicians to choose the appropriate treatments and protocols for their patients with the speed and accuracy that they deserve.
Watch “Prepare your lab for flu season with multiplex PCR”
Advantages of Multiplex PCR Testing
Due to their similar symptoms, the CDC now recommends that clinicians test for both SARS-CoV-2 and influenza when the viruses are co-circulating [5]. To prepare for future outbreaks beyond COVID-19, support for multiplex PCR testing is growing. In 2021 the Academy of Medical Sciences, one of the four UK National Academies, published its support, stating: “Given overlapping symptoms, routine multi-pathogen testing for SARS-CoV-2, influenza (and possibly other respiratory infections) is important for surveillance, treatment decisions (such as timely use of antivirals for influenza), minimizing isolation times, and avoiding and reducing rates of transmission.” [6]
Multiplex PCR offers many advantages that may help navigate current or future disease outbreaks where multiple pathogens are in circulation at once. Both presentations mentioned above detail the benefits of this technology, highlighting its ability to provide high sensitivity and specificity, fast turnaround times, high throughput, and the ability to detect co-infections from just one patient sample.
Laboratories in the clinical diagnostics industry are tasked with selecting panels that include the respiratory viruses with the highest clinical relevance, especially those in hospital and primary care facilities, such as Influenza, RSV, Adenovirus, Rhinovirus, Enterovirus, Human Metapneumovirus, and Parainfluenza. [7]
Watch the recording of Dr. Feenstra’s presentation from ESCV 2022 on-demand to learn more about diagnosing viral infections using multiplex PCR.
For more on multiplex PCR and how this technology can prepare labs for the current flu season as well as future respiratory viral outbreaks, watch this free webinar on-demand.
To learn more about molecular testing for respiratory pathogens, please visit: https://www.thermofisher.com/respiratory
Sources:
- JAMA | The Dreaded “Twindemic” of Influenza and COVID-19 Has Not Yet Materialized—Might This Be the Year?
- Yale Medicine | ‘Tripledemic:’ What Happens When Flu, RSV, and COVID-19 Cases Collide?
- Centers for Disease Control and Prevention | Weekly U.S. Influenza Surveillance Report
- FIFARMA | Acute respiratory infections (ARI): among the leading causes of death in the world
- Centers for Disease Control and Prevention | Testing Guidance for Clinicians When SARS-CoV-2 and Influenza Viruses are Co-circulating
- Academy of Medical Sciences | COVID-19: Looking Ahead to Winter 2021-22 and Beyond
- Horemheb-Rubio, G. (2022, June 11). Respiratory viruses dynamics and interactions: ten years of surveillance in central Europe – BMC Public Health. BioMed Central. https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-022-13555-5