SEATTLE (AP) — The first known case of the coronavirus variant discovered in South Africa has surfaced in King County, and 19 additional cases of the variant first found in the UK have been identified, according to the Washington State Department of Health.

The variant that emerged in South Africa in December was identified through genomic sequencing at the UW Medicine Virology Laboratory, the Department of Health said Tuesday.

The mutated version of the virus was first found in the United States last month.

The strain first identified in the UK was first found a month ago in Washington state. The additional cases announced Tuesday bring the total number of UK variant cases to 39 in the state, officials said.

Scientists believe both virus strains more easily spread than others.

“Despite the decrease in our case count, we are very concerned about the emergence of these variants and how it will affect future case counts," Acting State Health Officer Scott Lindquist, MD, MPH. said in a news release. "As a community, we need to re-double our efforts to prevent the spread of this virus and its variants by following public health guidance.”