Coronavirus variants first found in the UK and South Africa have been detected in Washington D.C., the district's health director LaQuandra Nesbitt said Thursday.
The UK variant, known as B.1.1.7, was found in three people and the South Africa variant, B.1.351, in one person, she said during a news conference.
"Every positive test is not sequenced to be detected for variants only a sampling of cases are sequenced for variants," said Nesbitt. "Not every one of those positive cases is sequenced either by the DC Public Health lab or sent to the CDC for sequencing."
"They are sampling a number of cases and so we've had some of the cases that have been sampled for sequencing come back as positive for this variant," she said.
She was notified of the new strains by the Centers for Disease Control and Prevention (CDC) late Wednesday.
At least 35 US states have confirmed the more transmissible variants, according to the CDC.
There are at least 930 cases of the UK variant and nine of the South African variant.