4.0 The Challenge of Differential Diagnosis

The primary clinical challenge this season is distinguishing COVID-19 caused by new Omicron sub-variants from other common respiratory viruses, such as influenza, based on symptomatology alone. With the notable exception of the uniquely severe pharyngitis associated with the Nimbus variant, there are no significant or consistent symptom changes compared to previous waves that would allow for definitive clinical differentiation. The presentation is overwhelmingly that of a non-specific URTI. This significant clinical overlap renders diagnosis based on symptomatology unreliable and mandates laboratory confirmation to ensure diagnostic certainty.