Almost all US dengue arrives on a plane, except in Hawaii

**Dengue is carried by Aedes mosquitoes and is a common cause of acute
febrile illness in travellers returning from the tropics.** In the United
States, that is nearly the whole story.

**5,387 cases were reported from US states during 2010–2017. 93% were
travel-associated.**

The other 7%

Hawaii accounts for two-thirds of locally acquired cases, and more than
twice Florida and Texas combined — a tropical archipelago with established
Aedes populations and a constant flow of visitors from dengue-endemic
regions.

Florida and Texas are the continental pattern: warm, with the mosquito
present, and local transmission that appears and is contained.

New York's single case is the one worth pausing on. It is not a typo and
not a trend; it is the reminder that a competent mosquito and an infected
traveller occasionally meet somewhere nobody is watching.

What it asks of two audiences

Travellers to the tropics are told to prevent bites — the advice is
specific because dengue's mosquito bites during the day, when other advice
about dusk does not apply:

• Use insect repellents
• Wear long-sleeved shirts and long trousers
• Take actions to keep mosquitoes out of the place you are staying

Clinicians are asked to **remain vigilant for suspected dengue and report
it to local health authorities.** Reporting is what makes the 7% visible at
all: a travel-associated case treated and never reported is a missed chance to
know whether the next case nearby was local.

Source: Centers for Disease Control and Prevention, MMWR.