Travel-linked dengue cases in US peaked in 2019: Report

About 20 percent of the 7,528 confirmed or probable travel-associated U.S. dengue cases reported during 2010 to 2021 occurred in 2019, according to research published in the July 28 issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.

Joshua M. Wong, M.D., from the CDC in Atlanta, and colleagues compared the number and characteristics of travel-associated dengue cases reported to national surveillance in the United States in 2019 with cases reported during 2010 to 2018 and 2020 to 2021.

The researchers found that 7,528 confirmed or probable travel-associated dengue cases were reported during 2010 to 2021. Of these, 20 percent occurred in 2019, representing an increase of 168 percent compared with the annual average of 550 cases in 2010 to 2018 and 2020 to 2021 and a 61 percent increase compared with 913 cases reported in 2016, which was the second highest year on record.

In 2021, the lowest number of cases was reported (205 cases), when travel patterns were altered due to the COVID-19 pandemic. The number of cases as a fraction of air traffic volume to international destinations outside North America or Europe was highest in 2019 compared with other years during 2010 to 2021 (41.9 versus 21.0 cases per million trips).

"Effective and scalable public health measures to prevent dengue will be needed to reduce risk among residents of and travelers to areas where dengue is endemic," the authors write.