NHS Highland's director of public health Dr Tim Allison described the outbreak as 'a significant situation'.
But, despite the increase in cases, Argyll and Bute has kept its level one Covid status.
The latest Public Health Scotland figures showed that 142 cases of Covid were identified across Argyll and Bute from June 13 to June 19.
Hotspots include Oban, Helensburgh and Dunoon and, alongside a number of commercial firms, Oban's Atlantis Leisure Centre and Dunoon Grammar School were closed for a spell amid a small number of positive test results and staff pressures due to isolation rules.
Schools around Argyll report isolated cases and have issued letters to parents assuring them that all precautions continue to be taken.
NHS Highland advises people in Argyll to minimise contact with others to limit further spread, and to use PCR testing to try and contain the outbreaks.
Typical symptoms of Covid are a new, continuous cough; a high temperature or fever; and a loss of or change in normal taste or smell.
Other symptoms can include headache, sore muscles and joints, tiredness, sore throat, cold-like symptoms and diarrhoea and vomiting. Anyone that becomes unwell should isolate immediately and seek a PCR test.
Dr Allison said: 'This is a significant situation and we expect the case numbers to rise further.
'Please continue to follow all guidance from NHS Highland's contact tracing team.
'If you have been identified as a close contact, please self-isolate and get a PCR test.
'If you are identified as a close contact and your test is negative you must continue to isolate for 10 days as advised.'
First Minister Nicola Sturgeon announced on Tuesday that the easing of lockdown would be delayed by three weeks, with all current levels across Scotland remaining in force until July 19 to allow more people to be vaccinated.
Minor changes from Monday (June 28) include live entertainment being allowed at weddings but no dancing.
People accompanying the couple down the aisle will no longer need to wear face masks and those working at weddings will no longer count towards the total number of people attending.
For funerals, people from more than one household will be allowed to carry a coffin.
The government will not be advising an immediate return to full office working on August 9 and Ms Sturgeon suggested home-working should be more feasible post-Covid than it was before.
The government will continue to keep the need for travel restrictions under review and it is likely some targeted restrictions will still be needed after August 9.
The government is also working on plans for the return of schools, colleges and universities.
The first minister said: 'The virus is still with us. But the vaccines are protecting more of us.'
She added that all priority groups one to nine will be fully vaccinated by the end of next week and, by July 18, all adults will have had their first dose.
Second doses for all adults should be completed by September 12.
There could be booster jabs in the autumn and potential vaccinations for 12- to 17-year-olds.
Yes! I would like to be sent emails from West Coast Today
I understand that my personal information will not be shared with any third parties, and will only be used to provide me with useful targeted articles as indicated.
I'm also aware that I can un-subscribe at any point either from each email notification or on My Account screen.