Attachments
Please find an erratum regarding last week epidemic and emerging disease alerts in the Pacific:
Dengue
- Samoa: As of 4 January 2026, Samoa Ministry of Health has recorded a cumulative total of 16,299 clinically diagnosed dengue cases since January 2025, including 4,717 laboratory-confirmed cases, and seven dengue-related deaths. Case numbers increased by 8% compared to the previous EpiWeek, with 40 new clinical cases of which 29 are lab-confirmed. – Source: Dengue-sitrep-issue-no-38 accessed on 27 January 2026.
Highlights/updates since the last map was sent on PacNet on 20 January 2026:
Dengue
- Samoa: As of 11 January 2026, Samoa Ministry of Health has recorded a cumulative total of 16,319 clinically diagnosed dengue cases since January 2025, including 4,732 laboratory-confirmed cases, and seven dengue-related deaths. Children under 15 years account for 74% of the cases, and the circulating serotypes remain predominantly DENV-1 (91%) and DENV-2 (9%). Case numbers decreased by 50% compared to the previous EpiWeek, with 20 new clinical cases of which 15 are lab-confirmed. There are no hospital admissions for this EpiWeek 02 (5 January – 11 January 2026). Although activity has declined, transmission remains ongoing across Upolu and Savaii, and authorities continue community outreach, vector‑control messaging, and public health advisories urging early care‑seeking and mosquito‑bite prevention. The blue alert for DENV-1 and DENV-2 remains in effect. – Source: Dengue-sitrep-issue-no-39 accessed on 27 January 2026.
Influenza
- French Polynesia: In French Polynesia, an influenza outbreak is ongoing, with 448 confirmed cases reported since it began in EpiWeek 47 of 2025, including 447 Influenza A cases. During the current reporting period (EpiWeek 03: 12 January – 18 January 2026), ten new Influenza A cases were identified; eight required hospitalizations, including one admitted to intensive care. Two additional deaths were reported, bringing the cumulative total to twelve. Influenza A(H3N2) remains the predominant subtype, all indicators have decreased compared to the previous week, and as of EpiWeek 03, the decline of the wave is now confirmed. A red alert for Influenza A is changed to blue. – Source: Bulletin de surveillance sanitaire de Polynésie française n°3 - 2026 shared with PPHSN Coordinating Body focal point on 27 January 2026.
- Wallis and Futuna: As of 26 January 2026 in Wallis, influenza‑like illness (ILI) activity has fallen sharply below alert thresholds, with syndromic, and non‑specific indicators all showing a return to baseline. In Futuna, ILI activity remains elevated but decreasing, with some number of consultations indicator still above threshold yet trending downward, and influenza A detections continuing though at lower levels. Overall, both islands show a declining epidemic curve, with Wallis reaching post‑epidemic and Futuna still experiencing ongoing but improving influenza circulation. The red alert for Influenza A is changed to blue. – Source: Personal communication with Wallis and Futuna focal point on 27 January 2026 and Tableau de bord de la surveillance multi source - ADSWF accessed on 27 January 2027.
- Federated States of Micronesia: Yap EpiNet team declared an influenza‑like illness (ILI) outbreak on 8 December 2025 after detecting a surge in outer islands, with 21 new ILI cases reported (between the 16 of January – 23 of January 2026) bringing the cumulative total since 16 November 2025 to 938 cases as of 23 January 2026. The laboratory has confirmed 58 influenza A cases, including two subtyped as A(H3) and 3 respiratory syncytial virus (RSV) infections. The most affected age group is 0-4 years. Although ILI activity has recently declined both on the mainland and in the outer islands, sentinel surveillance continues due to ongoing sporadic new cases. The red alert for Influenza A is changed to blue. – Sources: Yap State Government situational update accessed on 27 January 2026 and State Department of Health Services, Situational Report No. 19 (16 January 2026) shared with PPHSN Coordinating Body focal point on 23 January 2026.
Influenza-like illness
- Republic of Marshall Islands: The Republic of the Marshall Islands (RMI) Communicable Disease Weekly Report for EpiWeek 03 (12–18 January 2026) indicates that influenza-like illness (ILI) activity remains above the national alert threshold. However, case numbers continue to decline gradually from the peak observed in late December 2025, suggesting ongoing but steady transmission rather than a rapidly expanding outbreak. Higher ILI activity continues to be reported mainly from Majuro and several neighbouring Island communities. The aetiology is yet to be determined thus a grey alert for ILI remains in effect. – Source: RMI Communicable Disease Weekly Report for EpiWeek 03 (12 – 18 January 2026) shared with PPHSN Coordinating Body Focal point on 23 January 2026.
Measles
- Australia: In New South Wales (NSW), NSW Health issued alerts on 21 January and 25 January 2026 after confirming two new measles cases in Sydney one locally acquired and one imported from Southeast Asia (four cases in the last week) bringing the total to 13 cases since 1 December 2025. With increasing risk linked to returning travellers, the public is urged to monitor for symptoms and ensure they are fully vaccinated. In Queensland, as of 19 January 2026, four measles cases have been reported since 12 January 2026: one overseas‑acquired case with onset in December 2025 and three locally acquired cases epidemiologically linked to the imported case. In 2025, Australia recorded 181 cases, and already in 2026, 16 cases have been reported across New South Wales (7), Queensland (6), Victoria (2), and Western Australia (1). The red alert for measles in Australia remains in effect. – Sources: Measles alert for Sydney - 21 Januay 2026, Measles alert for Sydney - 25 January, Notifiable conditions reports: Summary information | Queensland Health and National Communicable Diseases Surveillance Dashboard accessed on 27 January 2026.
Pertussis/Whooping cough
- New Zealand: As of the week ending on 16 January 2026, weekly pertussis cases in New Zealand increased to 71 cases as compared to 51 in previous week ending on 9 January, bringing the total reported cases since the beginning of 2026 to 129. According to the latest report from the New Zealand Institute for Public Health and Forensic Science (PHF Science), 3,861 confirmed, probable and suspect cases have been notified since the start of the national epidemic on 19 October 2024. Of these, 341 cases (9.2%) have required hospitalisation with one reported death. Out of the 323 cases in infants under 1 year, 164 (51.3%) have been hospitalised. The blue alert for pertussis remains in effect. – Sources: Pertussis dashboard and Pertussis report 13 December–9 January 2026 accessed on 27 January 2026.
- Vanuatu: The Vanuatu Ministry of Health continues to monitor the pertussis outbreak, with two new cases reported in EpiWeek 04, bringing the cumulative total to 760 cases since the outbreak was declared on 18 August 2025, including 732 clinically diagnosed and 28 laboratory‑confirmed cases. No deaths or hospitalisations were recorded this week, and overall pertussis activity is steadily declining, with weekly case numbers having dropped notably since EW01. However, transmission remains above the alert threshold, indicating ongoing spread. The most affected age groups continue to be children aged 2–5 years and individuals over 5 years, while infants under three months represent only a small proportion of total cases. To date, the outbreak has resulted in three infant deaths. Geographically, the majority of cases have been reported from Efate (54%) followed by Tanna (37%). The red alert for pertussis is changed to blue*. – Sources: Vanuatu Pertussis Outbreak: Situation Report 11 (26 January 2026) shared on PacNet on 27 January 2026.*
Other Information:
Dengue
- Chuuk: As of January 12, 2026, seven out of 36 individuals screened (18.9%) tested positive for dengue, including one patient hospitalized who had begun to show warning signs. No dengue‑related deaths were reported, and positive cases ranged from 6 to 51 years old, with five cases (71.4%) coming from Satowan Island. Four samples from confirmed cases have been collected and stored for overseas serotyping, screening included both symptomatic individuals and asymptomatic close contacts. Source: CHUUK DENGUE SITREP01 accessed from Yap State Communicable Disease report Week 3 shared with PPHSN Coordinating Body Focal point on 22 January 2026.
- New Zealand: In New Zealand (NZ), for surveillance week 03 of 2026 (17–23 January), 40 confirmed cases, four probable cases, and six cases under investigation of imported dengue were reported, with 86% of confirmed imported cases linked to travel to the Cook Islands. The Institute of Public Health and Forensic Science (PHF Science) noted that this represents the highest weekly number of confirmed and probable dengue notifications reported to EpiSurv since the national notifiable disease surveillance system began in 1997; the previous record was 30 cases in week 2 of 2018. Given the known serological cross‑reactivity between dengue and other flaviviruses, some reported dengue cases may ultimately be reclassified as other flavivirus infections as epidemiological and laboratory investigations continue. Source: NZ Arbovirus Notifications by Country (03: 17/01/2026–23/01/2026) shared with PPHSN Coordinating Body Focal point on 26 January 2026.
Pertussis/Whooping cough
- Guam: The Guam Department of Public Health and Social Services (DPHSS) has confirmed two new laboratory‑confirmed pertussis cases, bringing the total for 2026 to three. Epidemiologic investigations and contact tracing are underway, and residents are encouraged to check the Guam communicable disease dashboard for real‑time updates on respiratory illnesses. Health officials emphasize that vaccination (DTaP/Tdap) remains the most effective protection, especially for infants and high‑risk individuals who are vulnerable to severe complication. Source: Press Release Public Health Alert: DPHSS Confirms Two New Cases of B Pertussis in Guam shared on PacNet on 23 January 2026.
Typhoid fever
- Tonga: Two confirmed cases of typhoid fever were identified in Hofoa, Tongatapu, Tonga, involving adult males from the same household. Diagnoses were confirmed by blood culture on 21 and 22 January 2026. Both patients experienced symptoms for approximately two weeks before hospitalization and are currently in stable condition at Vaiola Hospital. Investigation and contact tracing are ongoing, and stool samples have been collected from household contacts who remain asymptomatic and under surveillance. Source: Typhoid Fever Under Investigation - Ministry of Health Tonga | Facebook accessed on 27 January 2025 and Weekly Communicable Diseases Syndromic Surveillance Epidemiological Week 3 shared with PPHSN Coordinating Body Focal point on 26 January 2026.