SANTA CLARA COUNTY, Calif. (KRON) — Another case of the South African COVID-19 variant was detected in the South Bay, officials announced Wednesday.

A second case of the B.1.351, also known as the South African variant, has been detected in Santa Clara County.

The case is believed to be a result of community transmission and is not travel related.

“Considering the national trends, we have been operating under the assumption that these variants were circulating at some level in our communities,” Dr. Sara Cody, Health Officer and Director of Public Health for the County of Santa Clara, said. “This latest case confirms that we do have community transmission, and reminds us to not let down our guard in the middle of this pandemic.”

One travel-related case of the variant was detected in the county earlier this year.

Another case of the variant was confirmed in Alameda County in February, bringing the total number of South African variants in the Bay Area to three.

Another variant of concern, B.1.1.7 which was first identified in the United Kingdom, has been found in 15 cases in Santa Clara County.

Health officials caution that the true level of community spread tied to these variants is unknown.