This was said on radio by a spokesman from the logistics industry who spoke about a spike in the duration of sick leave
in his sector. Not an official statistic, or maybe not yet. It was worrying information, since a big part of the economy depends on parcels being sent and delivered. We are used to having to wait longer, because there are so many parcels. Now the next bottleneck remains invisible to most: the lack of people to do the work.
The info from the health authorities here is mainly about number of tests, number of persons infected, persons admitted to IC and deaths from COVID.
Little attention is being paid to those who fall ill and stay at home. Among those, some suffer little or no symptoms, but others become seriously ill and remain ill and tired for a long time. Their illness is called 'mild', not because it is necessarily mild, but because they do not quite meet the threshold for hospitalization.
Re your link I see that your government is studying long time illness and long term effects too
https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects.html
An ongoing flood of pilgrims will be every health authority's nightmare with for instance albergues as hotspots for infection.