Travel-associated Dengue Surveillance — United States, 2006–2008

Table 1.  Cases* of imported dengue reported to ArboNET and CDC Dengue Branch (CDCDB), by state, 2006–2008^†

State	Reported to CDCDB			Reported to ArboNET			Total
	Case classification		Travel history	Case classification		Travel history	Case classification
	Probable§	Laboratory-confirmed¶	Travel destinations of laboratory-confirmed dengue (No. of laboratory-positive specimens and serotype, if available)**	Probable§	Laboratory-confirmed¶	Travel destinations for laboratory-confirmed dengue**	Probable§	Laboratory-confirmed¶
Alabama	0	0		6	2	Brazil, Indonesia	6	2
Alaska	1	0		0	0		1	0
Arizona	9	1	Dominican Republic (DENV-1)	13	0		22	1
Arkansas	0	0		0	0		0	0
California	2	0		0	0		2	0
Colorado	1	2	Costa Rica (DENV-1), St. Barthelemy (DENV-2)	0	0		1	2
Connecticut	1	1	Unknown (DENV-1)	0	0		1	1
Delaware	0	0		0	2	India, Tahiti	0	2
District of Columbia	0	0		0	0		0	0
Florida	0	1	St. Lucia (DENV-2)	89	10	Brazil, Costa Rica, Dominican Republic (2), El Salvador, Guatemala and Honduras, Mexico, Puerto Rico (3)	89	11
Georgia	6	4	Costa Rica (DENV-1), Honduras (2, DENV-1), India (DENV-3)	0	12	Dominican Republic, Haiti, Honduras (2), India (2), Mexico, Nicaragua, Nigeria, Puerto Rico, St. Barthelemy (2)	6	16
Hawaii	6	2	Unknown (DENV-1), unknown (DENV-2)	0	0		6	2
Idaho	0	0		0	0		0	0
Illinois	1	0		6	0		7	0
Indiana	0	0		0	0		0	0
Iowa	0	0		12	0		12	0
Kansas	0	0		0	0		0	0
Kentucky	0	0		0	0		0	0
Louisiana	1	0		0	0		1	0
Maine	7	1	Haiti, Turks, and Caicos (DENV-1)	2	0		9	1
Maryland	0	2	Tahiti (2, DENV-1)	0	0		0	2
Massachusetts	13	4	Costa Rica (DENV-1), New Zealand (DENV-1), Puerto Rico (DENV-3), St. Kitt's (DENV-3).	0	0		13	4
Michigan	1	0		0	0		1	0
Minnesota	0	0		44	0		44	0
Mississippi	0	0		0	0		0	0
Missouri	2	0		10	0		12	0
Montana	0	0		0	0		0	0
Nebraska	0	0		0	0		0	0
Nevada	1	0		6	1	Dominican Republic	7	1
New Hampshire	0	0		2	2	Brazil, India	2	2
New Jersey	0	2	Puerto Rico (2, DENV-2)	0	0		0	2
New Mexico	0	0		2	0		2	0
New York	38	4	Dominican Republic (2), (DENV-1, DENV-4), Haiti (DENV-1), St. Martin and Antilles (DENV-3)	158	20	Bangladesh (2), Caribbean (unspecified), Dominican Republic (3), Guatemala (4), Haiti and Zambia, India, Indonesia (2), Mexico, Peru, Puerto Rico (2), unknown (2)	196	24
North Carolina	5	0		4	0		9	0
North Dakota	0	0		0	0		0	0
Ohio	1	2	India (DENV-2), Cambodia (DENV-3)	22	0		23	2
Oklahoma	0	0		3	2	Mexico, St. Barthelemy	3	2
Oregon	1	0		0	0		1	0
Pennsylvania	0	1	Unknown (DENV-3)	13	8	Bangladesh, Honduras, Jamaica, Puerto Rico (3), St. Martin, Thailand	13	9
Rhode Island	0	0		0	0		0	0
South Carolina	0	0		0	1	Puerto Rico	0	1
South Dakota	1	0		2	1	Haiti	3	1
Tennessee	0	0		0	0		0	0
Texas	6	1	Maldives (DENV-2)	22	39	Bangladesh (2), Brazil (2), El Salvador (2), Guatemala, Honduras (2), India (6), Malaysia, Mexico (6), Pakistan, Panama, Paraguay, Philippines, Puerto Rico (5), Singapore (2),Tahiti, Thailand, unknown (2), Venezuela (2)	28	40
Utah	0	0		0	0		0	0
Vermont	0	0		0	0		0	0
Virginia	0	1	St. Barthelemy and St. Thomas (DENV-4)	25	5	Costa Rica, El Salvador, Jamaica, Puerto Rico, St. Thomas	25	6
Washington	0	0		21	7	El Salvador, Honduras, Nicaragua (3), Philippines, Sri Lanka	21	7
West Virginia	0	0		2	0		2	0
Wisconsin	1	0		4	16	Costa Rica (2), Granada, Guatemala and Mexico, Honduras, Laos, Mexico (3), Nicaragua, Nigeria, Puerto Rico (2), St. Lucia, Saudi Arabia, Thailand	5	16
Wyoming	1	1	Ecuador (DENV-4)	0	0		1	1
Total	106	30		468 ††	128 §§		574	158

* Includes probable and laboratory-confirmed cases.
^† CDCDB received a total of 529 specimens. The 596 total cases reported to ArboNET are the sum of probable (468) and confirmed (128) cases.
^§ Probable is defined as a single immunoglobulin M (IgM)-positive specimen in late acute phase or convalescent phase of illness.
^¶ Laboratory-confirmed results were positive by polymerase chain reaction (PCR) or viral isolation.
** If not specified otherwise, the number of cases from each country is one. Unknown indicates that no location-specific travel history was provided. Does not include travel destinations of persons with probable cases.
^†† Of the 518 probable cases reported to ArboNET, 50 probable cases also were reported to CDCDB. These 50 probable cases were subtracted from the ArboNET total and included in the CDCDB total, resulting in 468 probable cases.
^§§ Of 135 laboratory-confirmed cases reported to ArboNET, seven laboratory-confirmed cases also were reported to CDCDB. These seven cases were subtracted from the ArboNET total and included in the CDCDB total, resulting in 128 laboratory-confirmed cases.

Table 2.  Characteristics of laboratory-confirmed cases of dengue among U.S. travelers — combined ArboNET and CDC Dengue Branch (CDCDB),* 2006–2008

Characteristic	Cases
	No.	(%)†
Total	732	(100)
Sex
Female	350	(48)
Male	375	(51)
Unknown	7	(1)
Age group (yrs)
≤20	118	(16)
21–40	256	(35)
41–60	243	(33)
>60	95	(13)
Unknown	20	(3)
Clinical syndrome
Dengue fever	32	(4)
Dengue fever with hemorrhage	34	(5)
Dengue hemorrhagic fever/Dengue shock syndrome	99	(14)
Other clinical	36	(5)
Uncomplicated fever	429	(59)
Unknown	102	(14)
Outcome
Hospitalized	318	(43)
Died	1	(<1)

* Cases were reported via ArboNET or to CDCDB; 57 cases were detected in both systems.
^† Might not add to 100% because of rounding.

Authors and Disclosures

R Luce, DVM, A Rivera, MS, H Mohammed, PhD, KM Tomashek, MD, Dengue Br and J Lehman

Arboviral Diseases Br, Div of Vector-Borne Infectious Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, CDC.

Sidebar

What is Already known on this Topic?

Dengue infections commonly occur among U.S. residents returning from travel to endemic areas and are more prevalent than malaria among returning travelers from the Caribbean, South America, South Central Asia, and Southeast Asia.

What is Added by this Report?

During 2006–2008, an average of 244 confirmed and probable travel-associated dengue cases annually were identified by two CDC-maintained passive surveillance systems, substantially more than the 33.5 cases (range: 13–77 cases) identified annually during 1990–2005.

What are the Implications for Public Health Practice?

Health-care providers should consider dengue in the differential diagnosis of patients with a history of travel to endemic areas within 14 days of fever onset.