Travelers bringing dengue to the U.S.

The U.S. Centers for Disease Control and Prevention reported Thursday that the number of dengue fever in U.S. travelers returning home has risen drastically in the past few years.

Between 2006 and 2008, reports, CDC surveillance teams identified an average of 244 confirmed dengue fever cases that were believed to be travel-related. Only 33.5 cases were reported between 1990 and 2005, according to the CDC’s June 18 Morbidity and Mortality Weekly Report.

CDC officials attribute some of the rise to the addition in 2003 of a new surveillance system, ArboNET, that replaced an older model. CDC officials also noted, however, that the rise also reflects, “substantial increases in dengue incidence throughout subtropical and tropical areas of the world, including the Americas.”

Approximately 574 probable and 158 confirmed dengue cases were identified from 2006 through 2008, for a total of 732 cases, according to CDC estimates. Of those, 596 cases were reported through the ArboNET system and 136 through the older Dengue Branch system. Of the 732 reported cases, 318 patients were hospitalized and one died, the report says.

The CDC also estimated that 649 of the 732 patients reported a history of travel, with specific travel information collected from 613 patients. Of those, 43 percent had traveled to the Caribbean; 34 percent to Mexico, Central America,or South America; 21 percent to Asia and the Pacific; and two percent to Africa, according to the report.

CCD officials also concluded that their numbers could possibly be under reported, as they are based on passive systems, according to the report.