The Centers for Disease Control and Prevention (CDC) has detected multiple cases of the new COVID-19 variant NB.1.8.1 , which has been linked to a spike in cases in China. A CDC spokesperson confirmed the findings to Fox News Digital, but said there had been too few cases for the strain to be included in the agency’s COVID Data Tracker. A CDC map showing COVID-19 cases detected through wastewater (sewage) testing indicates that most states are seeing either low or very low levels of the virus. The only state experiencing a high level of viral activity, according to CDC data, is South Dakota. The COVID-19 NB.1.8.1 variant has been linked to a high number of cases in China and Hong Kong .