(Bloomberg) -- The omicron sub-variant, BA.2, may be boosting transmission in some areas in South Africa’s most populous province, Gauteng, the National Institute for Communicable diseases said.

The NICD, which based its assessment on wastewater surveys, said it is concerned about parts of Tshwane, the municipal area that covers the capital, Pretoria, and Ekurhuleni, an industrial area east of Johannesburg.

The incidence of coronavirus particles continues “to remain at high levels, and may be increasing, suggesting continued community transmission,” the NICD said in a report on Friday. “These data are thought to support the emergence of a new omicron sub-variant.”

South Africa announced the discovery of the omicron variant in November and was the first country to be hit by a wave driven by it. While BA.2 appears to be more transmissible, there’s no indication it causes more severe disease.

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