Czech President Milos Zeman has returned to hospital, hours after he was discharged from the Central Military Hospital (CVH) in Prague.
His new ailment has been diagnosed to be COVID-19 infection, local TV reports.
Earlier in the day, Zeman was discharged after undergoing treatment since 10 October.
The 77-year-old was expected to receive further treatment at his residence in Lany Castle.
But COVID has changed all that.
As president, Zeman has an important role in forming the government after the election.
He is expected to appoint liberal-conservative election winner Petr Fiala of the Civic Democratic Party (ODS) as prime minister soon.
At present, the previous government under multi-billionaire Andrej Babis is running things on a caretaker basis.
Zeman is the first Czech president to be directly elected twice by the people, following a constitutional amendment and has been in place since 2013.
The former Social Democrat maintains close relations with Russia and China.