Last week saw the highest number of Perth and Kinross pupil absences due to a COVID-related illness of the entire school year.
On January 18 there were 285 pupils absent due to a COVID-related illness.
Perth and Kinross Council said 500 pupils were infected with the virus between January 12 and 18.
However all Perth and Kinross schools remain open with the Scottish Government saying keeping schools safely open and minimising disruption is a "priority".
The latest Scottish Government statistics show 808 pupils and 108 members of staff were absent from Perth and Kinross schools for COVID-related reasons on January 18.
COVID-related absences include self-isolating or being off as a precaution due to fear of infection as well as an actual COVID-related illness. In the case of a member of staff they may also be shielding, quarantining or looking after someone with COVID.
January 18 saw the highest number of pupil absences due to a COVID-related illness this entire 2021/22 school year.
A Scottish Government graph shows on January 18 285 pupils were absent because of a COVID-related illness, 476 were self-isolating and 47 were kept off "as a precautionary measure contrary to public health guidance".
The number of pupil absences due to a COVID-related illness has been rising since January 10 when there were 194 pupils absent with a COVID-related sickness.
A Perth and Kinross Council spokesperson said: "There were over 500 confirmed cases amongst pupils last week but this represents less than five per cent of the total school roll."
A spokesperson confirmed "last week" referred to January 12 to January 18 inclusive.
They added: "All schools remain open and continue to have a high standard of mitigations in place to protect pupils and staff and maintain continuity of learning.
"However, the virulence of Omicron means we are seeing a fairly high number of infections amongst pupils, and a lower number among staff.
"Schools and ELC provision will continue to follow and promote the relevant mitigations around physical distancing, hand and respiratory hygiene, use of face coverings by all school/ELC staff and by pupils in secondary schools, and testing and vaccination for everyone who is eligible."
Previously an entire class was asked to isolate as a precaution when there was a positive case recorded.
Now when parents/carers are asked to register a child's positive COVID case with Test and Trace they are asked not to list children/teachers in their class as they are deemed "low-risk" contacts.
And when pupils/staff are identified as a close contact they can choose to return to school provided they are fully vaccinated (three doses) at least 14 days before they saw the close contact or are under 18 years and four months. The latest guidance states instead of self-isolating provided they have no symptoms they can take daily Lateral Flow Device tests for seven days or the duration of the self-isolation period - whichever is sooner. If the test is positive they must isolate.
A spokesperson for the Scottish Government told the Local Democracy Reporting Service: "Our priority is to keep schools safely open and to minimise further disruption to education.
“Safety guidance for schools was strengthened in light of Omicron and based upon clinical and public health advice. Alongside local authorities and other partners, we will continue to monitor the data closely."
COVID-related pupil absences in Perth and Kinross peaked in the 2021/22 session prior to Christmas on December 22 but the majority were due to pupils being kept home "as a precautionary measure contrary to public health guidance". On December 22 there were 3613 COVID-related absences: 2553 were kept home as a precaution, 898 were self-isolating and 162 had a COVID-related illness.
