# 5697
Last summer, the CDC issued a Health Advisory via their HAN (Health Alert Network) in order to inform health care providers of the possibility of seeing Dengue Fever in returning visitors from areas where the virus is being seen.
This is an official
CDC HEALTH ADVISORY
Distributed via Health Alert Network
Sunday, July 25, 2010, 22:35 EDT (10:35 PM EDT)
CDCHAN-00315-2010-07-25-ADV-N
Summary
Dengue virus transmission has been increasing to epidemic levels in many parts of the tropics and subtropics. Travelers to these areas are at risk of acquiring dengue virus and developing dengue fever (DF) or the severe form of the disease, dengue hemorrhagic fever (DHF).
The return of locally acquired dengue fever to Florida in 2009 - after an absence of 6 decades - was no doubt due to repeated introductions of the virus by travelers coming from countries where the virus is endemic.
You can find the CDC MMWR report on the reemergence of Dengue in Key West HERE.
In Travel-Associated Dengue Surveillance --- United States, 2006—2008, also published last summer, the MMWR came out with a new report on Travel Associated Dengue in the United States.
This surveillance pre-dates the Key West outbreak, and as the study reports, `Clinically recognized cases of travel-associated dengue likely underestimate the risk for importation because many dengue infections are asymptomatic or mildly symptomatic’.
Worldwide, the explosive growth of Dengue – when combined with our highly mobile society – provides ample opportunities for this mosquito borne virus to travel to new regions.
Dengue’s success is well illustrated by the following graph from the World Health Organization.
What this graph doesn’t indicate is another doubling of dengue cases has taken place over the past 5 years.
All of which serves as prelude to Friday’s MMWR release, which looked at the incidence of Dengue fever in travelers returning from Haiti last fall. You can read the entire report at the link below.
Dengue Virus Infections Among Travelers Returning from Haiti --- Georgia and Nebraska, October 2010
Weekly
July 15, 2011 / 60(27);914-917
The gist, however, is that of 28 travelers who had recently returned from spending 7-11 days in Haiti, 7 (25%) showed laboratory evidence of recent DENV infection.
As the report explains:
All 28 travelers were asked to participate in a survey using a 53-item questionnaire to collect information regarding demographics, medical and travel history, pretravel preparations and knowledge, mosquito-avoidance practices while in Haiti, and illnesses during and after travel. Twenty-five (89%) travelers participated: 21 by telephone or in-person interviews, two by proxy, and two by self-administration.
Based on this questionnaire, 90% had a pre-travel health care appointment and 57% researched travel advice on the Internet. 95% reported having pre-travel knowledge about infectious diseases in Haiti, and 48% stated they were aware of the dangers of Dengue.
Despite these opportunities for awareness, only 24% reported using mosquito repellent several times a day.
Moreover, no statistically significant association was found between acquiring a dengue infection and pre-travel knowledge or mosquito-avoidance practices.
The editorial note concludes by saying:
All travelers to Haiti should seek pretravel health counseling, preferably 4--6 weeks before travel, receive information about risks for DENV infection, and employ recommended mosquito-avoidance practices.
Clinicians evaluating travelers with febrile illness who recently have returned from Haiti or other DENV-endemic areas are encouraged to consider dengue in their differential diagnosis, submit specimens for laboratory testing, and report cases of dengue expeditiously to local or state health departments
Whether you are tramping through the tropics where Dengue is endemic, or simply strolling through your neighborhood when mosquitoes are active, this advice from the Florida health department remains worth heeding.
