It means that effectively all of Europe is now deemed to have a "high public health threat" (in which the 14-day cumulative number of COVID-19 cases per 100,000 inhabitants exceeds 75), including all three Baltic states.
The classification system rates travel to each country as low (green), high (yellow), or very high risk (red).
South Africa, Zimbabwe, Namibia, Eswatini (still often known as Swaziland in the English-speaking world), Lesotho, Botswana, Malawi and Mozambique are still on the red list for the third week in a row. Even though all of the eight listed African countries have infection rates well below Latvia's, fears about the spread of a new Covid variant (dubbed 'Omicron' by the World Health Organization) have prompted the special measures.
The epidemiological requirements based upon the lists come into force at midnight, i.e. 00:00 on Saturday, December 11.
The latest list of countries, their current travel status, and the necessary epidemiological measures that apply is available HERE in Latvian, English and Russian and is also attached to this story in English, in PDF form for your convenience.
More details on travel requirements, including the mandatory travel form to fill in prior to arrival in Latvia, are available at https://covidpass.lv/en/.