Prof Kurt Krause, the former inaugural director of the University of Otago's Webster Centre for Infectious Diseases, said Covid-19 affected multiple systems throughout the body.
‘‘The ACE2 receptor, which the virus uses to break into human cells, can be found on a wide range of human cell surfaces, including respiratory, gastrointestinal, arterial, kidney and even in the brain,’’ he said.
The widespread nature of these receptors was behind ‘‘the unusual symptoms we are reading about’’.
Many Covid-19 symptoms, including fever and headaches, were common to other virus infections, but the loss of smell was a distinctive indicator, in some cases, of Covid-19 and loss of taste could also occur.
Prof Krause was also ‘‘cautiously optimistic’’ that the United States antiviral drug remdesivir — which a recent study showed to cut the death rate and speed up recovery among Covid-19 patients — could help improve the overall treatment outlook, combined, potentially, with a cocktail of other antiviral drugs.
The drug was not the complete answer but provided ‘‘a bit of light’’.
Prof Krause is among a group of researchers investigating antiviral drugs and vaccine development to counter Covid-19.