The prevalence of the common cold might be on the decline thanks to the emergence of viral megatests.
If you’re experiencing symptoms like a blocked nose and a persistent cough, a visit to an emergency room or urgent care could allow you to pinpoint the exact microbe responsible for your ailment. This is made possible by novel testing methods that can simultaneously screen for a broad spectrum of pathogens – sometimes as many as 18 to 20 viruses and bacteria.
The adoption of these multifaceted tests, also known as multiplex tests, has seen a steady rise in recent years. They proved particularly valuable during the previous autumn and winter seasons, when the US was grappling with multiple simultaneous respiratory infections, including Covid-19, respiratory syncytial virus, and influenza.
While these tests can facilitate swift diagnoses for medical practitioners in high-traffic environments, they are not without their caveats. They can help you identify the exact virus responsible for your illness, but this information might not be of much use given the absence of specific treatments for most viral infections.
Moreover, these tests can potentially exacerbate patients’ stress levels. It’s one thing to be told you have a cold, but it’s a different scenario when diagnosed with an adenovirus or bocavirus – so what does that exactly imply?
Emerging tests, rising concerns
Dr. Sarah Nosal, a primary care physician based in the Bronx, New York, has been increasingly observing this trend in her medical practice.
In a recent instance, a mother visited with her 2-year-old who, despite a cough and a runny nose, was still lively enough to climb into Nosal’s lap during the examination.
Over the weekend, the family had visited an urgent care clinic where the child had been administered a test that screens for 18 viruses simultaneously. The test returned positive for adenovirus, metapneumovirus, and enterovirus.
Nosal recounted how the parents were taken aback and worried, asking “why? Why does my child have so many viruses?”
Nosal explained that research has shown that co-infections are not that uncommon, especially during the colder seasons. For instance, an Australian study involving nearly 2,400 children with respiratory infections found that one in four children with a viral illness were infected with more than one virus. The authors of the study inferred that the presence of multiple viruses simultaneously does not necessarily lead to a more severe illness in a child.
However, the notion of their child having three viruses at once can understandably alarm parents.
While acknowledging the parents’ concerns, Nosal said, “That’s not unusual, but we don’t typically test children. So we don’t always have this information.”
Furthermore, there are no specific treatments available for the viruses that the young patient had tested positive for. Therefore, despite the seemingly intimidating diagnosis, Nosal’s advice would likely remain unchanged: adequate rest, hydration, and comforting care.
The act of testing may not necessarily alter treatment
Given that Covid testing has normalized nasal swabbing, a growing number of patients are keen to identify the exact cause of their symptoms.
“Having the capability to label specific illnesses has certainly changed the landscape,” remarked Dr. Preeti Malani, an infectious disease specialist at the University of Michigan. She believes that the Covid era has significantly shifted this paradigm.
However, multiplex tests aren’t accessible everywhere. Doctors are more likely to request them in environments like emergency departments or urgent care clinics, where speedy diagnoses are critical.
Labcorp and Quest Diagnostics, two of the largest commercial lab testing companies in the US, have confirmed an increase in doctors’ requests for multiplex tests since 2019. Neither company, however, released precise figures.
Malani emphasizes that tests for certain infections, particularly the flu and Covid-19, remain crucial, especially when these viruses are actively circulating in a given area.
“Recognizing a Covid diagnosis is crucial because it influences our treatment approach. There are available treatments, which are often underutilized by those who could potentially benefit from them,” she added.
Although Covid rarely poses a serious threat to children, diagnosing them can help protect more vulnerable family members, like grandparents.
Certain individuals with underlying health conditions that compromise their immune function could potentially benefit from multiplex tests. In such cases, the results might influence doctors’ strategies for managing the illness.
However, studies suggest that the utility of multiplex testing could be limited in other scenarios.
While these tests can screen for both viruses and bacteria, proponents argue that they could help reduce unnecessary treatments like prescribing antibiotics – which target bacteria – for viral infections.
But a recent study from the Children’s Hospital of Colorado contradicted this assertion. Among 931 children who received rapid respiratory panel tests in the emergency department, doctors who were informed of their patients’ test results were just as likely to prescribe antibiotics as those who weren’t. Children whose doctors were aware of their respiratory panel results also experienced longer ER stays and were more likely to be admitted to the hospital.
“In most cases, it won’t alter the course of treatment and, frankly, it might end up being an unnecessary visit,” Malani concluded.