The Centers for Disease Control and Prevention (CDC) has warned Americans against traveling to another tropical destination by adding the island nation of Mauritius to its highest risk category for travel on Monday.

The move from Level 3 “high risk” to the Level 4 “very high risk” category comes as COVID cases in the location have recently spiked. COVID cases surged nearly 180% in the last week, according to data from the World Health Organization.

This is the only destination that was added to the Level 4 category on Monday, which now includes about 125 nations, including Canada, Mexico, most of Europe, and the Caribbean.

A Level 4 location is deemed by the CDC as having more than 500 COVID cases per 100,000 residents reported in the past 28 days.

The CDC advises Americans to avoid travel to a Level 4 destination regardless of vaccination status, saying that “Even if you are up to date with your COVID-19 vaccines, you may still be at risk for getting and spreading COVID-19.”

Last week, Hong Kong, New Zealand and Thailand were added to the Level 4 “very high risk” category.

The list of Level 4 nations still tops any other travel category that has been compiled by the CDC, but some destinations are dropping off the “very high" warning list as their COVID situations improved last week.

Making moves from Level 4 to the Level 3 “high risk" category due to declining COVID cases were nine locations in the Caribbean and Atlantic – Cuba, the Bahamas, the British Virgin Islands, the Dominican Republic, Jamaica, Saint Kitts and Nevis, Saint Vincent and the Grenadines, Sint Maarten, and Turks and Caicos Islands.

A Level 3 location has between 100 and 500 cases of the virus per 100,000 residents reported in the past 28 days, the CDC said.

The Level 2 “moderate” risk category also saw updates with four new entries that include Gabon, Kyrgyzstan, Zambia, and most notably cruise ship travel. The three destinations were previously listed in the Level 3 category and have since seen an improvement in their COVID situations, while cruise ship travel was also previously listed as Level 3.

The CDC deems a Level 2 destination as having between 50 and 99 COVID cases per 100,000 residents in the past 28 days.

Several changes were also made by the CDC to the Level 1 “low risk" category, where a location would need to have fewer than 50 cases of the virus per 100,000 residents over the past 28 days. A total of 11 places moved to Level 1 on Monday, including Angola, Burkina Faso, Comoros, Djibouti, Equatorial Guinea, Liberia, Mali, Mauritania, Saba, São Tomé and Príncipe, and Senegal.

No new updates were made to the CDC’s “unknown” risk category where reliable information is not available on a location’s COVID situation. However, the CDC does warn against traveling to destinations in the “unknown” category because the COVID risk is simply unknown in these areas.

The pandemic has caused a sharp drop in the number of tourists visiting Mexico's Caribbean coast
The pandemic has caused a sharp drop in the number of tourists visiting Mexico's Caribbean coast AFP / ELIZABETH RUIZ