That report marks the first time the county has reported more than 400 new cases of the novel coronavirus infections in a single day. The county's previous single-day record was 345 new cases, set Saturday.
The county also reported nine coronavirus-related deaths Wednesday. Those nine ranged in age from a man in his 40s to a woman in her 90s. The county medical examiner's office is also investigating the death of a 12-year-old, which may be related to the virus, officials said.
In a statement released Wednesday afternoon, Dallas County Judge Clay Jenkins said the county's rising hospitalization rate is of particular concern. The hospitalization rate has climbed by 40% over the past two weeks.
"If these percentage increases continue, many more people will get sick and die in the coming weeks," Jenkins said.
Jenkins said he was pleased Gov. Greg Abbott agreed to allow counties to enact certain mask requirements. Abbott, who has feuded with local officials over mask requirements, gave his blessing Wednesday to a Bexar County order requiring businesses to require staff and customers to wear masks while they're on the premises.
"Once enacted in Dallas County and in other local jurisdictions, this will save countless lives," Jenkins said. "In the meantime, it's up to all of us to focus on what is safe for ourselves, our family, and our community."