Russia has confirmed its coronavirus-related death, a 79-year-old woman with pre-existing health conditions, Moscow’s coronavirus response headquarters said Thursday.

Russia has registered 147 cases of coronavirus but has reported no other deaths.

The unnamed 79-year-old woman was first hospitalized last week and was later moved to an isolated room in an infectious diseases hospital after testing positive for coronavirus, Moscow’s coronavirus headquarters said on its Telegram channel.

Elderly people are among the most at-risk groups for the virus, which can cause a severe respiratory illness.

Doctors initially believed she died from pneumonia, but pathologists later determined her cause of death to be a blood clot.

“The elderly patient had a number of chronic diseases, including type 2 diabetes, artery disease and hypertension. The patient was given comprehensive intensive care,” said Svetlana Krasnova, the head physician at Moscow’s Infectious Diseases Hospital No. 2.

It’s unclear how the woman became infected with coronavirus.

The Moskovsky Komsomolets newspaper reported that the woman had been a professor at the Gubkin Oil and Gas University and that she had been giving lectures up until the day she was hospitalized. The university denied this report, however.

Moscow’s coronavirus headquarters said that it has established the patient’s circle of contacts and placed them under medical supervision. None of the patient’s close contacts are showing symptoms of coronavirus infection, it added.