Aus der Studie https://www.medrxiv.org/content/10.1101/2021.05.06.21256289v1.full.pdf

“people with a higher concentration of viral genetic material (positive cases with low Ct
values; below 25) are more likely to be infectious in a household than those with lower
concentrations (positive cases with high Ct values; above 25). …….high Ct values cluster
with negative cases – indicating transmission has not been observed." [8] "