The vast and diverse Pacific region is currently under close observation by health authorities as several communicable diseases show increased activity. From mosquito-borne illnesses like dengue to highly contagious respiratory infections such as measles and whooping cough, public health teams are actively monitoring and responding to these alerts. The ongoing efforts underscore the critical importance of robust surveillance systems and community awareness in safeguarding public health across these island nations. ## Dengue Fever: A Persistent Threat Across the Pacific Dengue, a viral infection transmitted by mosquitoes, continues to pose a significant health challenge in the Pacific. Symptoms typically include high fever, severe headache, pain behind the eyes, muscle and joint pains, and a skin rash. In severe cases, it can lead to hemorrhagic fever, which can be life-threatening. Prevention primarily revolves around controlling mosquito populations by eliminating breeding sites, using insect repellents, and wearing protective clothing. **New Caledonia** is currently experiencing ongoing dengue transmission, with over 2,100 cases reported since the beginning of the year. Health officials are urging residents to seek immediate medical attention if they develop symptoms like fever, headache, or muscle and joint pain, and importantly, to avoid aspirin and ibuprofen if dengue is suspected, as these can increase the risk of bleeding. The region remains under a 'blue alert' for dengue, signaling continued vigilance. Further south, **Samoa** has witnessed a notable increase in dengue activity. Recent data shows a near doubling of new cases in a single week, with two different dengue virus types (DENV-1 and DENV-2) circulating simultaneously. Children under 15 years old are disproportionately affected, accounting for the majority of reported cases. Health initiatives in Samoa are focusing on educating the community, implementing vector control measures to reduce mosquito breeding, and encouraging early presentation to healthcare facilities. A 'blue alert' also remains in effect here, emphasizing the need for ongoing community and clinical awareness. Meanwhile, on South-West Efate Island in **Vanuatu**, a dengue outbreak continues, exceeding the typical alert threshold. While cases are concentrated in specific areas like Pango and Erakor, local transmission has been confirmed, with some cases also linked to recent travel, suggesting potential importations from other regions. Health authorities are actively working to identify the specific type of dengue virus circulating. Vanuatu is under a 'red alert' due to the sustained transmission, signifying a high level of concern and response. ## Measles Activity in Australia Measles, a highly contagious viral disease, continues to be a concern in **Australia**, with cases linked to infections brought in from overseas and subsequent spread within local communities. Multiple states, including New South Wales, Victoria, Queensland, and Western Australia, have reported significant numbers of cases this year. Public exposure sites, such as airport terminals and medical centers, have been identified, underscoring the ease with which the virus can spread. Health authorities are strongly advocating for everyone born after 1965 to ensure they have received two doses of a measles-containing vaccine, especially before any international travel. This recommendation is crucial for protecting individuals and preventing further community transmission, as Australia remains under a 'red alert' for measles. Measles is preventable through vaccination, and widespread immunization is key to preventing outbreaks. ## Pertussis (Whooping Cough) Concerns Across the Pacific Pertussis, commonly known as whooping cough, is a serious bacterial infection that affects the respiratory system and is characterized by severe, uncontrolled coughing fits. It is highly contagious and can be particularly dangerous for infants and young children. Vaccination is the most effective way to prevent pertussis and is recommended for all age groups, including pregnant women to protect newborns. **Guam** is reporting ongoing pertussis transmission, with cases identified across various age groups, though adolescents and infants are particularly affected. Public health efforts include widespread vaccination campaigns, like free back-to-school immunization clinics, and promoting early medical consultation for compatible symptoms. A 'red alert' for pertussis indicates the continued need for heightened awareness and preventive actions. **New Zealand** has been grappling with a national pertussis epidemic since late 2024. While recent weekly case numbers have shown some fluctuations, overall activity remains significant. Infants under one year old and children aged 5-9 years continue to have the highest notification rates, and sadly, the epidemic has led to hospitalizations and one reported death. This highlights the vulnerability of young children and the importance of vaccination to mitigate severe outcomes. New Zealand is under a 'blue alert,' indicating a sustained level of concern. Separately, **Palau** has also identified confirmed cases of pertussis. Health officials are actively responding with comprehensive public health measures, including tracing contacts of infected individuals and reviewing their vaccination status, offering both vaccinations and antibiotic treatments as preventive steps. All reported cases are stable and recovering. ## Other Noteworthy Health Alerts Beyond these major concerns, several other health issues are being monitored across the region: ### Imported Arbovirus Cases in New Zealand New Zealand has reported imported cases of both dengue and Zika virus, with both individuals having recently traveled to Indonesia. This serves as a vital reminder for healthcare professionals to take detailed travel histories from patients presenting with relevant symptoms, especially given the global movement of people and the potential for introducing new pathogens. ### Ciguatera Fish Poisoning in Vanuatu **Vanuatu** continues to monitor cases of ciguatera fish poisoning (CFP), an illness caused by eating reef fish contaminated with toxins. While activity has recently been below the alert threshold, a significant number of cases have been reported this year across multiple islands. Cases are often linked to various reef fish species. Health authorities are working to reinforce public health messages to help communities reduce their risk of exposure by being cautious about the types and sources of fish consumed. ### Diphtheria on the Rise in Australia **Australia** is experiencing a substantial increase in diphtheria cases, far exceeding historical averages. The outbreak is primarily concentrated in remote and regional areas, disproportionately affecting Aboriginal and/or Torres Strait Islander communities in the Northern Territory and Western Australia. Both skin (cutaneous) and respiratory forms of the disease are being reported, with hospitalizations and one death attributed to diphtheria. Genomic analysis suggests links between cases across different states, emphasizing the widespread nature of the current activity. Diphtheria is a serious bacterial infection preventable by vaccination, stressing the urgency of immunization efforts in affected communities. ### Highly Pathogenic Avian Influenza (HPAI) H5N1 in Australian Wild Birds **Australia** has confirmed several cases of highly pathogenic avian influenza (HPAI) H5N1 in migratory seabirds across multiple states. These detections in birds arriving from subantarctic regions are being closely monitored, especially given how recent weather patterns may have altered migratory routes. While this event highlights the ongoing risk of H5N1 introduction to the Pacific via wildlife, the public health risk remains low, with no human cases linked to these animal detections reported so far. Surveillance efforts have been intensified along coastal areas to track the situation. ### Influenza-Like Illnesses (ILI) in Solomon Islands The **Solomon Islands** Ministry of Health is closely tracking an increasing trend in influenza-like illnesses (ILI), particularly in certain provinces and the capital, Honiara. While the current trend falls within expected seasonal patterns and does not constitute an outbreak, routine laboratory tests have detected the circulation of Respiratory Syncytial Virus (RSV) alongside seasonal influenza A and B. This highlights the importance of ongoing surveillance to quickly identify any unusual increases or emerging threats. ### Malaria: An Imported Case in French Polynesia An imported case of malaria has been reported in **French Polynesia** in an individual who had recently traveled to West Africa. This serves as a critical reminder for all healthcare professionals, especially in regions where malaria is not endemic, to meticulously document travel histories for patients presenting with fever or other compatible symptoms. This vigilance helps ensure timely diagnosis and treatment, preventing potential onward transmission, though local spread is rare in such imported cases. Overall, these health alerts underscore the dynamic nature of disease patterns in the Pacific. Continued collaboration between regional health organizations and national health ministries, along with strong public awareness and adherence to preventive measures, remains paramount for protecting communities against these diverse health threats.