COVID-19 is a multi-system disease known to affect the respiratory tract alongside various other organ systems, making this statement a matter of established medical consensus.
The claim that COVID-19 presents with respiratory and systemic manifestations is a foundational, well-documented fact established early in the pandemic and supported across numerous clinical guidelines and literature. Under the instructions, statements that are direct, well-known clinical observations do not require exhaustive citation and fall under common knowledge regarding standard disease pathology.