Federal health officials are warning that cases of dengue are rising higher than expected this year in the U.S. amid a record number of global cases of the mosquito-borne disease.

As of Monday, there have been more than 9.7 million dengue cases reported in the Americas, which is twice as many reported in all of 2023, the Centers for Disease Control and Prevention said in a health advisory issued Tuesday.

In the U.S., there have been 2,241 confirmed cases so far, compared to 3,036 during all of 2023. This years total includes 1,498 cases in Puerto Rico, which declared a public health emergency in March, a month thats historically a low-dengue season.