At a glance: Democratic presidential primary results and state delegate counts

A poll deputy uses her cellphone as she wears gloves as a preventive measure against the outbreak of coronavirus disease (COVID-19) during the Democratic presidential primary election in Miami, Florida, U.S. March 17, 2020. REUTERS/Maria Alejandra Cardona

WASHINGTON (Reuters) - Former Vice President Joe Biden extended his lead in the delegate race for the Democratic presidential nomination on Tuesday, sweeping the day's contests with wins in Arizona, Florida and Illinois as the country grappled with the coronavirus.

There were 441 delegates at stake in the three states. A string of earlier victories had put Biden ahead of U.S. Senator Bernie Sanders in the race to amass the minimum 1,991 delegates needed to secure the nomination and challenge Republican President Donald Trump in the Nov. 3 election.