Staying One Step Ahead of Viral Infection
Genomic markers predict viral infection up to three days before symptoms appear
Even before COVID-19 took over the world, researchers from Duke Health were investigating biomarkers to identify presymptomatic respiratory viruses and help control their spread (1) – a focus they did not realize would become so crucial so quickly. After all, acute viral infections are the most common reason for primary care visits in high-income countries. And, after COVID-19, viral outbreaks will continue to threaten public health worldwide. Despite this need, we face logistical barriers to detecting infection early, such as availability of tools and the need for a priori knowledge of the pathogen in question.
Over five years, the Duke Health team recruited and monitored 1,465 students for symptoms of respiratory infection. 264 index cases were identified, with RT-PCR confirming presence of viral infection in 57 percent of cases and detecting nine different viruses in total. Close contacts of confirmed cases were monitored for symptoms and viral shedding; a blood-based 36-gene RT-PCR assay measured transcriptomic responses.
The assay accurately predicted infection up to three days before peak illness, when symptoms were minimal or absent and before viral shedding was detectable. The assay was 99 percent accurate for predicting illness from influenza, 95 percent accurate for adenovirus, and 93 percent accurate for the cold-causing coronavirus strain.
“We can use the body’s natural immune response signals to detect a viral infection with a high degree of accuracy, even at a time when people have been exposed to the pathogen but don’t yet feel sick,” said Micah McClain, lead author of the study (2).
Transcriptional biomarkers could be used to inform outbreak management across a range of viral causes and stages of disease. Now, the team is looking at the effectiveness of these markers in detecting SARS-CoV-2. “Our data show that these biomarkers of viral infection are present and detectable before clinical disease develops and thus could form the basis of novel approaches to early identification and management of emerging viral outbreaks and pandemics,” said McClain.
- MT McClain et al., Lancet Infect Dis, [Online ahead of print] (2020). PMID: 32979932.
- Duke Health (2020). Available at: bit.ly/3iZPlSt.
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