The Hawaii Department of Health (DOH) has confirmed two separate travel-related cases of Zika and dengue virus on Oʻahu. The individuals involved were exposed to the viruses while traveling in areas where Zika or dengue is known to circulate. These cases are not related to each other or to any previous cases reported in Hawaii.
This marks the first confirmed case of Zika on Oʻahu in 2026. The last travel-related Zika case in Hawaii was reported in 2025. Between 2015 and 2019, when Zika was circulating globally, Hawaii saw more frequent travel-associated cases, with a peak of 25 cases in 2017. No locally acquired cases have been documented in the state.
Based on the onset date of symptoms, the new dengue case will be recorded as the fifteenth case for Hawaii in 2025.
In response, DOH teams have been deployed to affected areas for outreach, inspections, and mosquito control measures. Because both viruses are transmitted by mosquitoes that exist locally, controlling mosquito populations is considered critical for preventing further spread. The department will continue monitoring mosquito numbers and take additional actions as needed. Residents are also encouraged to eliminate mosquito breeding sites around their homes as a preventive measure.
While mosquitoes capable of transmitting these diseases are present in Hawaii, there is no evidence that either virus is established locally; all identified cases have been among travelers.
Zika virus symptoms are generally mild and may include fever, rash, headache, joint pain, red eyes, and muscle pain. Most infections do not result in symptoms. Hospitalization and death from Zika are uncommon but serious complications can occur rarely. Infection during pregnancy can cause birth defects and pregnancy complications such as miscarriage or preterm birth.
Travelers should check current risk information before departure and take precautions against mosquito bites during trips and for three weeks after returning home. Recommended steps include using EPA-registered insect repellent, wearing protective clothing, staying indoors with screens or under bed nets treated with insecticide, and avoiding standing water near living spaces.
Anyone experiencing symptoms within two weeks after visiting an area at risk for Zika should consult a healthcare provider and inform them about possible exposure. Testing is not routinely recommended for asymptomatic travelers.
Zika can also be sexually transmitted even if the infected person does not show symptoms at the time. The Centers for Disease Control and Prevention (CDC) recommends men use condoms or abstain from sex for at least three months after travel to a risk area; women should do so for at least two months.
Dengue remains a year-round risk in many tropical regions worldwide. Some countries—including Samoa, the Philippines, Vietnam, Colombia, Cuba, Nicaragua—as well as Puerto Rico and American Samoa—are reporting increased dengue activity or outbreaks this year. Travelers should review country-specific information before departure and seek medical evaluation if they develop symptoms after travel such as fever, nausea, vomiting, rash or body aches.
Healthcare providers who suspect Zika or dengue infection are advised to call the Disease Reporting Line at 808-586-4586.
Residents across Hawaii are urged to wear long sleeves and pants or use approved repellents—especially at dusk and dawn—to reduce mosquito bites. Mosquitoes need very little standing water to breed; residents should regularly check their surroundings following rain events and drain any containers holding water.
For more information about disease prevention efforts led by DOH—including its Disease Outbreak Control Division—visit their official website: https://health.hawaii.gov/. The department operates statewide programs focused on disease prevention and health promotion across multiple islands through offices like its main headquarters at Kinau Hale on Punchbowl Street in Honolulu (https://health.hawaii.gov/). DOH also provides public health preparedness services through its Office of Public Health Preparedness (https://health.hawaii.gov/).
“The Centers for Disease Control and Prevention (CDC) advises travelers to check current Zika risk information before departure. Travelers should take precautions to avoid mosquito bites during their trips, and for three weeks after returning. This includes using Environmental Protection Agency (EPA)-registered insect repellent, wearing protective clothing and staying in air-conditioned or screened rooms or under insecticide-treated bed nets. Travelers returning from an area with risk of Zika should take steps to prevent mosquito bites for three weeks after their return.”
“Anyone experiencing symptoms within two weeks after visiting an area with risk of Zika should consult a healthcare provider and inform them of possible exposure in a Zika-affected area. Testing is not routinely recommended for travelers who do not have symptoms.”
“Zika can also be transmitted through sex from a person who has Zika to their partners, even if the infected person does not have symptoms at the time. The virus has been found in semen, vaginal fluids, saliva, urine and breast milk. The CDC recommends that after travel to an area with risk of Zika, men use condoms or abstain from sex for at least three months. For women, use condoms or abstain for at least two months.”
“Healthcare providers and individuals who suspect Zika or dengue infection are advised to call the Disease Reporting Line at 808-586-4586.”
“Finally, no matter where you live, if the area is prone to mosquitoes, wear long sleeves and long pants and or use approved EPA-registered repellents especially at dusk and dawn to reduce your chances of mosquito bites. The mosquitoes that can carry and transmit Zika or dengue require very little standing water to multiply If you notice an unusually high number of mosquitoes it’s likely there’s a new container of standing water in the area around you Particularly after the recent weeks of rainy weather it’s important to look around your homes gardens drain any recycling trash tire container tarp bucket flowerpot plant other container which may be holding water.”
