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Epidemic and emerging disease alerts in the Pacific as of 21 October 2025

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Highlights/updates since the last map was sent on PacNet on 14 October 2025:

Dengue

  • American Samoa: On 8 July 2025, American Samoa declared a public health emergency in response to a dengue outbreak, with 264 lab-confirmed cases reported by 12 October. There are eight cases admitted in hospital, and no severe complications or dengue haemorrhagic fever have been observed. Laboratory results by Hawaii State Laboratory confirmed co-circulation of DENV-1 and DENV-2, prompting authorities to urge the public to take mosquito bite precautions, eliminate breeding sites, and support vector control efforts. The red alert for DENV-1 and DENV-2 is maintained. – Source: American Samoa Department of Health Update as of 12th October 2025 accessed on 21 October 2025.

  • Cook Islands: On 22 May 2025, the Cook Islands Ministry of Health declared a dengue outbreak in Rarotonga, with 174 cases reported by 15 October, 164 recovered and 10 still active. Most of the cases belong to the 10-19 age group with no fatalities or severe dengue cases reported. Of 50 serotyped samples, 47 were DENV-1 and 3 were DENV-2, confirming co-circulation. Authorities are conducting clean-up and mass spraying campaigns, urging the public to eliminate mosquito breeding sites, use repellents, wear protective clothing, and seek medical care if symptoms appear. The blue alert for DENV-1 and DENV-2 is maintained. – Source: Cook Islands 2025 Dengue Outbreak Situation Report #56 (15 0ctober 2025) accessed on 21 October 2025.

  • French Polynesia: In EpiWeek 41, 9 new dengue cases (eight confirmed and one probable) were reported. Since November 27, 2023, a total of 2,653 cases has been recorded, including 2,372 confirmed and 281 probable cases. One hospitalisation reported in EpiWeek 41. The positivity rate increased this week as compared to last week. The blue alert for DENV-1 is maintained. – Source: Bulletin de surveillance sanitaire de Polynésie française n°38- 2025 shared withPPHSN Coordinating Body focal point on 21 October 2025.

  • Kiribati: The Ministry of Health and Medical Services confirmed a dengue outbreak on 24 April 2025, after a significant rise in confirmed cases. As of 15 October 2025, the Health Ministry reported a total of 491 confirmed dengue cases and 1,436 suspected dengue cases with 68 hospitalisations, all of which have been discharged, and one confirmed death. There have been no new cases since the last report on 9 October 2025. Dengue cases range in age from 1 month to 95 years, with the most affected group being those aged 3 to 9 years. Among all reported cases, 54% are female and 46% male. The serotypes that are responsible for this current outbreak are Dengue Virus Type 1 (DENV-1) and Dengue Virus Type 2 (DENV-2), tested at VIDRL in Melbourne. The Ministry of Health and Medical Services is actively promoting health awareness on social media through posters, press releases, and videos. It continues to investigate cases, conduct house-to-house inspections in high-risk areas, eliminate mosquito breeding sites, and advise community members to maintain a clean and healthy environment. Based on the sustained decline in case numbers for the past four weeks, the red alert for DENV-1 and DENV-2 has been downgraded to a blue alert. – Source: Dengue Fever Situational Report #24 (15 October 2025) shared with PPHSN Coordinating Body focal point on 15 October 2025.

  • Samoa: As of 12 October 2025, Samoa Ministry of Health has recorded a total of 14,996 clinically diagnosed dengue cases since January, including 61 new confirmed cases and seven dengue-related deaths. Children under 15 years account for 74% of cases, and the circulating serotypes remain predominantly DENV-1 (91%) and DENV-2 (9%). Case numbers increased by 4.5% compared to the previous EpiWeek, with 287 new clinical cases of which 61 are lab**-confirmed. Hospital admissions decreased by 45%, with 18 new admissions, none in ICU. The most affected districts were Aana Alofi 4 (24 cases), Aiga I le Tai and Anoamaa 2 (13 cases respectively) in Upolu. The Ministry of Health continues its whole-of-government response through the Integrated Vector Control Committee, focusing on source reduction, environmental sanitation, and widespread risk communication. The blue alert for DENV-1 and DENV-2 is maintained– Source: Dengue Fever Outbreak Situation Report in Samoa Issue No.26, Epi-week 41: 06th –12th October 2025 accessed on 21 October 2025.

  • Tuvalu: The Tuvalu Department of Health declared a dengue outbreak on 5 June 2025. As of 19 October 2025, 782 suspected cases were tested, with 230 confirmed positive. The dengue cases are widely distributed along Fongafale, one atoll, Amatuku and three outer islands, Nanumaga (9 cases) Nukufetau (14 cases) and Vaitupu (1 case). The outbreak is due to Dengue Virus Type 2 (DENV-2). Currently, 96% of cases have recovered, while 3 remain active. 12 patients (six children and six adults) have been hospitalised since the start of the outbreak, with no current admissions and no deaths reported. Children under 14 years account for 72% of cases ranging in age from 3 months to 68 years. Of the confirmed cases, 136 cases are males and 94 females. In EpiWeek 42 (13 – 19 October), 4 new cases were detected, with 12.9% positivity rate, showing a decrease in the number of cases compared to the previous week. The Department of Health continues to implement control measures, including response team coordination, technical support and assistance from external partners (SPC, PacMOSSI, WHO and DFAT), targeted spraying and ongoing public awareness through talkback shows and community engagement. The red alert for DENV-2 is maintained. – Source: Dengue Fever Outbreak, Situation report #16 (19 October 2025) shared with PPHSN Coordinating Body focal point on 21 October 2025.

Measles

  • Australia: Queensland Health has reported an ongoing measles outbreak in Cairns, with 12 confirmed cases identified since 1 September 2025. As of 17 October, 135 measles cases have been reported across New South Wales (NSW), Queensland, Victoria and Western Australia (WA), the highest since 2019 largely due to international travel. Western Australia (WA) identified 50 cases of measles in 2025 of which 11 are reported from the current Pilbara community outbreak. Meanwhile, Queensland Health has issued urgent alerts following confirmed measle cases in South East Queensland, particularly in the Sunshine Coast and Gold Coast regions including a local school in Mudgeeraba. Individuals who visited the listed exposure sites during the specified dates and times are advised to monitor for symptoms for up to three weeks from the exposure date, seek medical advice if symptoms develop and to check their vaccination status is up to date. The red alert for measles in Queensland is maintained – Sources: National Communicable Diseases Surveillance Dashboard,Measles alert,Urgent health alert and Cases of measles on the rise accessed on 21 October 2025.

Pertussis/Whooping cough

  • New Zealand: As of the week ending on 10 October, weekly pertussis cases in New Zealand increased to 44 from 21 in the week ending on 3 October, bringing the total reported cases since the beginning of 2025 to 2,106. According to the latest report from the New Zealand Institute for Public Health and Forensic Science (PHF Science), 3,101 confirmed, probable and suspect cases have been notified since the start of the national epidemic on 19 October 2024. Of these, 281 cases (9.5%) have required hospitalisation with one reported death. 132 (51.2%) out of the 261 cases in infants under 1 year have been hospitalised. The blue alert is maintained. – Sources: Pertussis dashboard and Pertussis Report 23 August–19 September 2025 accessed on 21 October 2025.

Other Information:

Diarrhea

  • Federated States of Micronesia: An outbreak of diarrhea occurred on Satawal Island, in Yap, with initial cases reported by the local dispensary staff a week before a funeral held on 12 October 2025. In Epiweek 41 (October 6–12), 15 cases were documented, and investigations revealed that most affected individuals had travelled from Yap, Chuuk, and Pohnpei to attend the funeral. As of 19 October 2025, two new diarrheal cases were reported in Satawal, including a health assistant experiencing abdominal pain and fatigue, and a one-year-old child under monitoring, bringing the total number of patients currently being monitored to three. Age group most affected is the 19-59years (53%) followed by 12-18 years (23%). Out of 34 total cases, 31 have recovered, with symptoms commonly including diarrhea, abdominal pain, nausea, headache, fever, and vomiting. Satawal is facing shortages of medication and IV fluids, administering IV only to severely dehydrated patients, while nearby islands report minimal or no new cases. – Source: Diarrheal Outbreak Satawal Island Situational Report No. 3 (19 October 2025) shared with PPHSN Coordinating Body focal point on 19 October 2025.

Influenza

  • Australia: Western Australia has recorded over 30,000 influenza cases in 2025, marking its worst and longest flu season since records began in 2001. Experts attribute the severity to low vaccination rates, particularly among younger adults, which are below the national average. The surge in flu cases has also been linked to record-breaking ambulance ramping hours, straining the state's healthcare system. – Source: WA's flu season exceeds 30,000 cases accessed on 19 October 2025.

  • Palau: As of 15 October 2025, the Palau Ministry of Health and Human Services (MHHS) reported a significant increase in flu-like illnesses between 29 September and 12 October, with 56 influenza-like Illness (ILI) recorded, including 25 lab-confirmed cases of Influenza A. In the following week, as of 19 October, an additional 68 ILI cases were reported, of which 57 were confirmed as Influenza A. This brings the total number of confirmed Influenza A cases to 82 over the two-week period. - Source: MHHS Reports Increase in Influenza Cases in the Community and MHHS Syndromic Surveillance shared with PPHSN Coordinating Body focal point on accessed on 20 October 2025.

Measles

  • Canada: In Canada, for EpiWeek 41 (5 – 11 October 2025) there has been 30 new measles confirmed cases bringing the total to 5,090 cases (4,729 confirmed, 361 probable) making it the country with the highest number of reported cases in the Region of the Americas, with persistent transmission in provinces like Alberta, British Columbia and Manitoba. – Source: Government of Canada Measles and rubella weekly monitoring report accessed on 21 October 2025.

  • New Zealand: In New Zealand (NZ), since the last PacNet update on 14 October, 1 new measles cases have been reported in Auckland, unrelated to recent cases in Northland and Queenstown. All cases are travel-related, highlighting the critical need for travellers to ensure their MMR vaccinations are up to date before international travel. Residents are urged to monitor for symptoms and to call their healthcare provider if unwell and check their immunisation status. – Sources: New Zealand Health: New measles case in Auckland,New measles case confirmed in Queenstown and Radio New Zealand: Two new measles cases reported in Northland, total in region rises to 12 accessed on 21 October 2025.

  • United States: In the United States, the CDC reported a total of 1,596 measles cases across 42 U.S. jurisdictions, as of 14 October with 86% of these cases linked to forty-four outbreaks. The majority of cases are among unvaccinated individuals (92%), and 12% of the cases have resulted in hospitalization. There have been three confirmed deaths. The 42 jurisdictions that have reported measles cases are as follows, Alabama, Alaska, Arizona, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York City, New York State, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming. – Source: CDC Measles Cases and Outbreaks Update as 15 October 2025, accessed on 21 October 2025.

Mpox

  • Australia: In Victoria Australia, there has been a reported rise in mpox cases with 10 infections since mid-September nine of which were locally acquired in metropolitan Melbourne. The outbreak primarily affects gay, bisexual, and other men who have sex with men (GBMSM), though anyone in close contact with an infected person is at risk. Health authorities are urging increased testing, vaccination and adherence to preventive measures, especially among high-risk groups. – Source: Local transmission of mpox in metropolitan Melbourne accessed on 21 October 2025.

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