Mikhail Mishustin, the Russian prime minister, who was tasked by Vladimir Putin with leading the response to the country’s coronavirus outbreak, has been diagnosed with Covid-19 and will self-isolate.

Mishustin, Russia’s most-high profile Covid-19 patient so far, disclosed the diagnosis during a televised video call with President Putin on Thursday evening. It was not immediately clear how severe Mishustin’s symptoms are, though one news agency reported that he had an elevated temperature of 39 degrees. Putin indicated during the call that Mishustin would be taken to hospital.

Confirmed coronavirus cases in Russia passed 100,000 on Thursday. The first deputy prime minister, Andrei Belousov, would take on Mishustin’s duties in his absence, Putin said.

“Dear Vladimir Vladimirovich, I have just found out that the tests I gave for coronavirus have come back positive … Accordingly, I will go into self-isolation, fulfilling my doctors’ orders. This is necessary to do in order to protect my colleagues,” Mishustin told Putin during the call.

It is unlikely that Mishustin has been in direct contact with Putin in recent weeks. Putin has led semi-regular video calls with members of the government from his residence at Novo-Ogaryovo. He has not been pictured in public recently.

In his remarks, Mishustin urged Russians to take the disease seriously and follow the difficult self-isolation rules that have been imposed by the government. Earlier this week, Putin announced that he would extend the country’s “non-working days” through the May holidays, including the anniversary of the defeat of Nazi Germany.

“Dear Mikhail Vladimirovich, what is happening to you right now can happen to anyone, I’ve always said so. You are someone very active, I want to thank you for the work that has been done until now,” Putin told Mishustin. “When you get to the hospital, I’ll be waiting for your call,” he added.