This was known by WHO since April (at least).
Why now?
https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200402-sitrep-73-covid-19.pdf?sfvrsn=5ae25bc7_2#:~:text=An%20asymptomatic%20laboratory%2Dconfirmed,more%20information%20becomes%20available.