Influenza: A Global Health Threat in COVID-19’s Shadows

Where have all the influenza cases gone? At the height of the COVID-19 pandemic, flu cases declined dramatically – thanks in part to the prevalence of handwashing, mask-wearing and social distancing [1]. At the end of the 2020-2021 flu season, the Centers for Disease Control (CDC) reported unprecedented lows across the United States [2]. However, influenza remains a global, yet underestimated, health threat and its burden can vary substantially between seasons.

In a recent webinar, Dr. Ari Frenkel, Co-founder & Chief Scientific Officer at Arkstone Medical Solutions, joined Labroots to discuss influenza, its history and the need for adequate testing. According to Dr. Frenkel, over the past few years managing COVID-19 has taken priority over testing for more common illnesses including other respiratory infections like the flu. “Influenza is one of those pathogens that can present very similar to COVID-19 and can be overlooked if SARS-CoV-2 is the only microbe being tested for,” said Dr. Frenkel.

Watch the webinar

A history of influenza pandemics and epidemics

When COVID-19 first emerged, many people were reminded of past pandemics such as the one caused by the H1N1 influenza virus in 2009. Although the Swine flu sticks out in recent memory, the world has been ravaged by four influenza pandemics and several epidemics over the last century. The Spanish Flu (1918-1919) was the twentieth century’s deadliest pandemic, leading to an estimated 50 million deaths worldwide, while the Swine flu may have resulted in up to 500,000 or more deaths globally. The Asian flu (1957-1958) and Hong Kong flu (1968) both resulted in around 1 million deaths globally [3].

According to Dr. Frenkel, there has been a significant decline in the death toll between each flu pandemic. This is due to the growth of modern medicine, utilization of vaccines and an increased understanding of public health measures. Still, thousands of Americans die from the flu each year [4].

Influenza testing, treating and takeaways

With the emergence of new testing options, diagnosing and reporting flu cases is simple. Diagnostic tests for the flu are either antigen- or molecular-based, offering different degrees of sensitivity and specificity. As Dr. Frenkel explained, sensitivity refers to a test’s ability to identify patients with a disease, while specificity is the ability of a test to identify people without the disease. “The antigen test can rule in a disease but is poor at ruling out the disease. Molecular tests are good for both ruling in the disease and ruling out the disease,” said Dr. Frenkel.

While a conventional singleplex PCR (polymerase chain reaction) test only detects a single microbe, multiplex PCR tests can detect two or more target sequences of DNA or RNA, making it possible to test for multiple pathogens at once. This is especially useful when a patient is displaying respiratory symptoms that can present as the cold, the flu, or COVID-19.

Advancements in technology that allow us to rapidly test for influenza and other microbes at the same time are a powerful defense against future flu waves. With the development of antivirals, supportive treatments like supplemental oxygen and the influenza vaccine, care and prevention have improved as well. Despite these improvements, Dr. Frenkel cautioned there is always the risk of a future influenza pandemic. “It doesn’t take much to realize that influenza is a global threat,” said Dr. Frenkel.

To learn more solutions to prevent, diagnose and treat influenza, watch the free webinar on-demand.

For information on Thermo Fisher Scientific’s multiplex PCR testing solutions, please click here.

Sources: