HONOLULU - The Hawai‘i Department of Health (DOH) has confirmed a new travel-related case of dengue virus on O?ahu, bringing the total number of dengue cases in the state for 2025 to three. The affected individual in this current case was exposed to the virus while traveling in a region where dengue is common.

DOH teams have been deployed to conduct inspections and implement mosquito control measures in the affected area. The public is encouraged to follow best practices to help prevent local transmission, as outlined below.

Dengue virus is transmitted from an infected person to a mosquito, and then to another person. While Hawai‘i is home to the mosquitoes that can carry dengue, the disease is not endemic (established) in the state, and cases are currently limited to travelers. Several regions worldwide are experiencing higher-than-usual dengue activity.

Dengue outbreaks occur in many parts of the world, including Central and South America, Asia (including the Republic of the Philippines), the Middle East, Africa and several Pacific Islands, such as U.S. territories like American Samoa, the Federated States of Micronesia, the Republic of the Marshall Islands and the Republic of Palau. Many popular tourist destinations in the Caribbean, including Puerto Rico, are also affected.

In 2024, there were 16 travel-related cases of dengue reported in the state of Hawai?i. Cases reported travel to the following countries prior to symptoms onset: Brazil, Argentina, Costa Rica, El Salvador, Guatemala, Mexico, Puerto Rico, Honduras, Indonesia, Thailand, Japan, Philippines and India. All destinations listed are areas where dengue is known to be endemic.

Anyone who plans to travel to or has recently visited an area with dengue risk is vulnerable to infection. The Centers for Disease Control and Prevention (CDC) advises travelers to take standard precautions when visiting such areas. This includes using an Environmental Protection Agency (EPA)-registered insect repellent, wearing long-sleeved shirts and long pants outdoors, and sleeping in air-conditioned rooms, rooms with window screens, or under insecticide-treated bed nets. Some countries are reporting increased dengue cases, so travelers should review up-to-date country-specific travel information for guidance on dengue risk and prevention measures at least four to six weeks before traveling.

Travelers returning from dengue-endemic areas should take precautions to prevent mosquito bites for three weeks. If dengue symptoms develop within two weeks of return, travelers should seek medical evaluation.

Symptoms of dengue can range from mild to severe and include fever, nausea, vomiting, rash and body aches. Symptoms typically last two to seven days, and while severe illness can occur, most people recover within a week. Individuals who have recently traveled and are experiencing these symptoms should contact their health care provider.

In areas with suspected or confirmed dengue cases, DOH personnel from the Vector Control Branch conduct inspections and mosquito-reduction activities. Reducing mosquito populations lowers the risk of dengue transmission to others. In areas without reported dengue cases, eliminating mosquito breeding sites around the home is a helpful preventive measure.

Mosquitoes need only small amounts of standing water to breed. Common breeding sites include buckets, water-catching plants (such as bromeliads), small containers, planters, rain barrels and even cups left outside. Pouring out containers of standing water can significantly reduce the potential for mosquito breeding.

For more information, visit the Disease Outbreak Control Division (DOCD) and Vector Control Branch (VCB) websites.