Nauru's 2025 dengue outbreak faded by September. The daytime routine still applies.

Are there mosquitoes in Nauru? Yes, including the day-biting Aedes mosquitoes that spread dengue, and Nauru declared a dengue outbreak in 2025 that caused 2 deaths, then faded by mid-September. There is no malaria, so for most visitors, who come for government, aid or contract work, the plan is daytime repellent and a screened room.

The 2025 outbreak and earlier ones

The World Health Organization's Western Pacific office lists Nauru among nine Pacific countries that officially declared dengue outbreaks in 2025, with 2 dengue deaths. Its weekly tracking of dengue-like illness showed Nauru's first reports of the year in late June, a sharp rise in July, a second in August and a decline by early September. In 2026, WHO's chart shows a single report in early January and nothing after, through early October. A quiet chart can also mean late reporting, and it isn't clear whether the outbreak was formally declared over.

Earlier outbreaks are on record. A 2023 study by WHO Western Pacific staff counted 251 cases in 2014, 964 cases and 3 deaths in 2017, and 114 cases in 2018. There is no CDC travel notice, and Nauru isn't on CDC's global dengue list.

The daytime routine

Aedes bite in daylight, with peaks after sunrise and in the late afternoon, around homes and water containers on the coastal ring where most people live. Put repellent on over sunscreen in the morning and again in the late afternoon, and choose a screened or air-conditioned room. Medical care on Nauru is limited, so see a doctor promptly for any fever. Our dengue & Zika routine has the full schedule.

CDC's Zika page lists Nauru as having the mosquito that spreads Zika but no reported cases, and for those places it tells pregnant travelers to "Prevent mosquito bites during and after travel." CDC also lists leptospirosis, so avoid floodwater and muddy fresh water.

When to go

Any month without an active outbreak is a reasonable one, and none had been reported in 2026 through early October. The 2025 outbreak ran from late June to about mid-September, and the wet season runs roughly November to February. Before you fly, check the Pacific epidemic alert maps or Nauru's health department.

Where you're going

Adding Kiribati or the Marshall Islands? Our Kiribati and Marshall Islands briefings cover their recent dengue outbreaks.

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were in Nauru, especially with headache, rash or body aches in the two weeks after you get home. Our after-bites guide covers the warning signs.

Traveler questions