Highlights/updates since the last map was sent on PacNet on 15 September 2026:
Dengue
• Marshall Islands: The 8th Outbreak Situation Report on dengue in Majuro and Ebeye, dated 18 September 2026 and covering 15 August to 17 September, records 256 specimens tested (Majuro 241, Ebeye 15) and 98 confirmed positive (Majuro 89, Ebeye 9), with no deaths and six cumulative hospitalisations, all recovered and discharged. The confirmed-case attack rate is 3.8 per 1,000 in Majuro (population 23,158) and 0.9 per 1,000 in Ebeye (population 9,739). The outbreak has extended to a second atoll: Ebeye, on Kwajalein Atoll, recorded its first case on 7 September, case count rose from one confirmed case on 11 September to five on 15 September and nine on 17 September, and accounted for seven of the 16 cases with onset in the past seven days, against nine in Majuro. Serotyping confirms DENV-1 only. Response status remains ACTION, with vector control at confirmed-case households, 16 schools and 16 churches sprayed, community fogging in high-risk areas and town-hall outreach across the seven zones. The red alert for dengue (DENV-1) remains in effect. – Sources: RMI Ministry of Health and Human Services, Outbreak Situation Reports #6, Outbreak Situation Reports #7 and Outbreak Situation Reports #8 accessed on 22 September 2026.
• Samoa: The Dengue Fever Outbreak Situation Report Issue No. 73 for EpiWeek 36 (31 August to 06 September 2026) reports 17 new cases, down 23 percent on the previous week, with no new admissions, no intensive care admissions and no deaths. No case was laboratory confirmed this week, down 100 percent on the previous week. Since 1 January 2025 Samoa has recorded 20,232 clinically diagnosed cases, 5,538 laboratory-confirmed cases and nine dengue-related deaths. Both DENV-1 (52 percent) and DENV-2 (48 percent) circulate, children under 15 years account for 73 percent of cases, and 92 percent of cases are from Upolu. The blue alert for dengue (DENV-1 & DENV-2) remains in effect. – Source: Ministry of Health Samoa, Dengue Fever Outbreak Situation Report Issue No. 73 accessed on 22 September 2026.
• Vanuatu: Situation Report #13, dated 14 September 2026, reports 11 new laboratory-confirmed dengue cases during EpiWeek 37, bringing the cumulative total to 150 confirmed cases. Eight cases are from Efate and three from Santo. The three Santo cases are the first identified outside Efate during this outbreak, indicating extension to a second island. The confirmed cases were reported from the Luganville and East Santo area councils. On Efate, cases have been reported across seven area councils, Erakor accounting for 35 percent. Fourteen dengue-associated hospitalisations have been reported, all recovered and discharged, with no severe dengue and no deaths. DENV-1 remains the only serotype detected. Specimens from Santo and additional samples from Port Vila have been submitted for serotyping and results are pending. The red alert for dengue (DENV-1) remains in effect. – Source: Vanuatu National Surveillance Unit, Dengue Outbreak on Efate and Santo Island, Situation Report #13 shared with the PPHSN Coordinating Body Focal point on 21 September 2026.
Measles and rubella
• Papua New Guinea: The National Department of Health weekly bulletin for EpiWeek 37, published 15 September 2026, reported nine laboratory-confirmed measles cases year to date, up from eight, with a new detection in the National Capital District and the most recent onset on 29 August 2026. Laboratory-confirmed rubella cases rose from 16 to 18 year to date, with the latest onset also on 29 August. Five patients were positive for both measles and rubella. Syndromic surveillance recorded 45 acute fever and rash cases nationally in EpiWeek 37, above the alert threshold, of which 31 were in the National Capital District. Year to date, 333 acute fever and rash cases have been reported and 265 samples submitted. The red alert for measles remains in effect for Papua New Guinea. – Source: Papua New Guinea National Department of Health, Public Health Events Weekly Bulletin, EpiWeek 37, shared with the PPHSN Coordinating Body Focal point on 21 September 2026.
Pertussis
• Vanuatu: Situation Report 4 on the pertussis outbreak in Penama Province, dated 14 September 2026, reported 307 new clinically diagnosed cases during EpiWeek 37, bringing the cumulative total on Ambae Island to 584 cases, of which 580 are clinically diagnosed and four laboratory confirmed. The outbreak more than doubled in one week. Two cases required hospitalisation and both have been discharged. No deaths have been reported. Individuals aged 15 years and over account for 53 percent of cases, followed by children aged 5 to 9 years, while infants under two years account for 5 percent. Vaccination status is unknown for 88 percent of cases. One laboratory-confirmed case from North Ambae had recent travel history to Santo Island and remains under investigation. The red alert for pertussis remains in effect for Vanuatu. – Source: Vanuatu National Surveillance Unit, Pertussis Outbreak in Penama Province, Situation Report 4, shared with the PPHSN Coordinating Body Focal point on 21 September 2026.
Respiratory diseases
• New Zealand: For the week ending 13 September 2026, the weekly all-cause hospitalisation rate for severe acute respiratory infection in the Auckland region decreased for a second consecutive week and is now in the medium activity band, down from very high, although it remains higher than at this time in previous years. The influenza-positive severe acute respiratory infection rate also decreased and is now in the high band. Influenza remained the most commonly detected virus, with test positivity among SARI patients at 51.9 percent, while positivity among sentinel general practice samples fell sharply from 38.5 to 14.0 percent. Both A/H1 and A/H3 are circulating, with A/H3 predominant. Pacific peoples continue to experience the highest cumulative rates of influenza-, RSV- and SARS-CoV-2-positive hospitalisation and the highest rates of influenza- and RSV-positive intensive care admission of any ethnic group. The red alert for influenza A remains in effect for New Zealand. – Source: New Zealand acute respiratory illness dashboard, week ending 13 September 2026, PHF Science accessed on 21 September 2026.
Rotavirus
• Federated States of Micronesia: Situation Report #14 on the diarrhoeal outbreak in Yap State, dated 20 September 2026, reported five new cases between 18 and 20 September and a cumulative total of 220 clinically diagnosed cases since the outbreak was detected on 31 August, up from 200 on 16 September. The increase includes 14 earlier paediatric cases from Satawal, added in Situation Report #13 (17 September) after delayed data became available. One child was admitted during the period and is the only patient currently hospitalised; there have been 11 admissions since the outbreak began, nine of them children, and ten discharges. No death has been reported. The two new cases tested were both positive for rotavirus with Escherichia coli co-infection, and laboratory detections since August now total 26 rotavirus, 44 E. coli, 9 Giardia lamblia and 1 Salmonella, often as co-infections. The Yap State Communicable Disease Report for EpiWeek 37 showed 34 diarrhoeal cases against a peak of 90 in EpiWeek 35, still above the alert threshold of seven for a fourth consecutive week, with 82 percent of cases paediatric. Of 15 cases tested by gastrointestinal panel that week, ten were positive, most frequently for rotavirus A. Health authorities urge parents to keep rotavirus vaccination on schedule and have advised more frequent testing of water supplies. Additional cases from Elato remain under verification. The grey alert for diarrhoea is changed to a red alert for Rotavirus for the Federated States of Micronesia (Yap State). – Sources: Yap State Diarrhoeal Outbreak Situation Reports #13 and #14, shared with the PPHSN Coordinating Body Focal point on 22 September 2026, and Yap State Communicable Disease Report, EpiWeek 37, shared on 18 September 2026.
• Vanuatu: Situation Report No. 4 on the rotavirus outbreak in Tanna Island, Tafea Province, report dated 16 September 2026, recorded 320 acute watery diarrhoea cases between 7 and 13 September (EpiWeek 37) from 11 health facilities, bringing the cumulative total to 819 cases, of which three are laboratory confirmed and 816 clinically diagnosed. The outbreak alert threshold of 34 cases per week was exceeded in EpiWeek 33 and case numbers have risen every week since, EpiWeek 37 being the highest so far. Children under five account for most cases and 86 percent are under two years of age. Thirty-nine cases have been hospitalised since EpiWeek 33, 36 have been discharged and two remain in hospital. One death was reported in EpiWeek 35, in a one-year-old child with severe dehydration and underlying malnutrition. Among cases with known vaccination status, 20 percent had received one dose of rotavirus vaccine and 10 percent had completed the schedule, while status was unknown for 64 percent. Water quality testing detected Escherichia coli contamination, indicating possible faecal contamination of water sources. The red alert for rotavirus remains in effect for Vanuatu. – Source: Rotavirus Outbreak in Tanna Island, Tafea Province, Situation Report No. 4, shared with the PPHSN Coordinating Body Focal point on 17 September 2026.
Other Information:
One Health – High pathogenicity avian influenza
• Australia: The national H5 bird flu dashboard recorded 583 confirmed positive events in wildlife as at 18 September 2026, against 521 on 11 September: South Australia 303, Victoria 184, Tasmania 43, New South Wales 40, Western Australia 10, Queensland 2 and Other Territories 1. New South Wales reported three further events on 21 September in terns at Long Jetty and Nowra, and a silver gull at Merimbula, bringing the state count to 55, state and national figures can differ with reporting timing. Since 12 August reporting is based on events rather than individual detections, and authorities no longer test every species in known transmission areas, so event counts increasingly understate spread. There has been no detection in commercial poultry or captive birds and no human case in Australia. H5 has not been reported from any Pacific Island country or territory to date. – Sources: Bird flu (avian influenza) – DAFF and New South Wales Department of Primary Industries and Regional Development media release of 21 September 2026, accessed on 22 September 2026.
HIV
• Fiji: Fiji formally declared HIV a national emergency on 15 September 2026, following Cabinet endorsement and the establishment of a Cabinet subcommittee. In 2025 Fiji recorded 2,016 new HIV diagnoses, sixteen times the number recorded in 2019. An estimated one in every 60 adults is now living with HIV, against one in 167 five years ago, and two in every 100 pregnant women are living with HIV. Fifty-nine babies were born with HIV in 2025 and 18 died before their first birthday. Only 39 percent of people living with HIV know their status and 22 percent are on treatment. The drivers identified are low condom use and intravenous methamphetamine use. WHO has committed to expanding access to pre-exposure prophylaxis, needle exchange programmes and free treatment, and has called for stronger regional cooperation. – Sources: Government of FijiUNAIDS to support Fiji as it declares HIV a national crisis and puts in new measures to strengthen the response | UNAIDS and World Health Organization statements on the declaration of a national HIV emergency accessed on 22 September 2026.
Respiratory diseases
• Fiji: The Ministry of Health and Medical Services issued Public Advisory #39 on 18 September 2026 reporting 1,780 new influenza-like illness cases in the first week of September, a 75 percent increase on the previous week. Children under five account for 30 percent of all flu-like cases nationwide and the circulating strain is influenza A(H1pdm09). The advisory cites FluTracking Fiji, where reports of cough and fever rose from 10.2 to 16.4 percent in a week. No deaths or hospitalisation figures are given. – Source: Fiji Ministry of Health and Medical Services Public Advisory #39 accessed on 22 September 2026.
• New Caledonia: The Directorate of Health and Social Affairs issued an influenza vigilance bulletin on 17 September 2026. After several months of low circulation, influenza has been resurging since EpiWeek 33, with eight new laboratory-confirmed cases in EpiWeek 37 bringing the 2026 total to 62 cases, 14 of them since EpiWeek 33. Subtyping of the recent cases evidenced seven A/H1N1, two B/Victoria and five influenza A still being subtyped, with A/H1N1pdm09 predominant, and laboratory positivity reached 32 percent in EpiWeek 37. The resurgence is earlier than in 2024 and 2025, when circulation intensified only from EpiWeeks 45 to 50. The share of consultations for acute respiratory infection in the sentinel network reached 8.5 percent in EpiWeek 36 and stood around 7 percent in EpiWeek 37. Emergency department activity rose from 1,433 presentations in EpiWeek 36 to 1,621 in EpiWeek 37, of which 69 were for acute respiratory infection and 24 required admission. – Source: New Caledonia Directorate of Health and Social Affairs, VIGILANCE DASS bulletin on influenza, shared with the PPHSN Coordinating Body Focal point on 18 September 2026.
