The vast and diverse Pacific region, along with neighboring Australia and New Zealand, is currently facing several ongoing health challenges, with alerts issued for dengue fever, measles, and pertussis (whooping cough). These alerts underscore the constant need for communities to remain vigilant and for public health efforts to intensify across these nations. Understanding the nature of these diseases, their prevention, and the collective efforts to control them is key to safeguarding public health. ## Dengue Fever: A Persistent Threat in the Tropics Dengue fever, a mosquito-borne illness, continues to be a significant concern across many Pacific islands. This viral infection, spread by Aedes mosquitoes, can cause severe flu-like symptoms, and in some cases, can progress to a more serious form known as severe dengue, which can be life-threatening. The alerts from New Caledonia and Samoa highlight the persistent nature of this disease. In New Caledonia, dengue transmission remains active, with over 2,000 cases reported since the start of 2026. While the capital region of Greater Nouméa has seen comparatively lower spread, partly attributed to an innovative Wolbachia program that helps control mosquito populations, activity persists in other areas. Children and adolescents, particularly in school environments, are experiencing the highest rates of infection. This emphasizes the importance of community-wide efforts to eliminate mosquito breeding sites – any place that can hold standing water, such as old tires, flowerpots, or uncleaned gutters. Samoa is also grappling with ongoing dengue transmission, reporting hundreds of new cases weekly. Both DENV-1 and DENV-2 serotypes are circulating, with the majority of cases concentrated on the island of Upolu. Alarmingly, children under 15 years old represent the largest group affected. Since early 2025, Samoa has reported nearly 20,000 clinically diagnosed cases, with nine related deaths. Public health efforts are focused on educating the community, controlling mosquito populations, and encouraging early medical attention for anyone experiencing symptoms. Elsewhere, New Zealand has noted imported dengue cases, often linked to travel in affected regions like Samoa, while Vanuatu is monitoring a slight increase in cases, though still below outbreak thresholds. These observations underscore how travel can quickly spread infectious diseases across borders, making regional and international cooperation vital. Preventing dengue primarily involves controlling the Aedes mosquito. This means regularly cleaning and emptying water containers, using insect repellent, wearing protective clothing, and installing screens on windows and doors. Seeking medical help promptly for fever, severe headaches, joint and muscle pain, or rash is crucial for early diagnosis and management. ## Measles: The Importance of Immunisation Measles, a highly contagious viral disease, poses another serious health threat, especially in areas with lower vaccination rates. Known for its characteristic rash, fever, and cough, measles can lead to severe complications like pneumonia, encephalitis, and even death, particularly in young children and immunocompromised individuals. Australia is currently experiencing ongoing measles activity, with cases often traced back to international travel that then lead to local spread. New South Wales and Victoria have reported the highest numbers, predominantly among individuals who are unvaccinated or whose vaccination status is unknown. Public health authorities are urgently advising people to ensure they have received both doses of the measles-containing vaccine, especially before any overseas travel. Measles spreads easily through the air when an infected person coughs or sneezes, making high vaccination coverage essential for community protection, also known as 'herd immunity'. The broader context from the Americas further illustrates the global resurgence of measles. With over 21,000 confirmed cases and 31 deaths reported in 2026 across 17 countries, this represents a significant increase compared to the previous year. Mexico, Guatemala, the United States, and Canada account for the vast majority of these cases. Young children, especially infants under one year old, are disproportionately affected, with approximately 85% of confirmed cases being unvaccinated. This global trend highlights the critical role of vaccination programs in preventing outbreaks and protecting the most vulnerable. The measles-mumps-rubella (MMR) vaccine is highly effective and safe, offering robust protection against the virus. Achieving and maintaining high vaccination rates in the population is the most effective way to prevent measles outbreaks and protect those who are too young to be vaccinated or cannot be vaccinated due for medical reasons. ## Pertussis (Whooping Cough): Protecting Our Youngest Pertussis, commonly known as whooping cough, is a highly contagious bacterial infection of the respiratory system that can be particularly severe for infants and young children. It begins with cold-like symptoms, followed by severe coughing fits that often end with a distinctive 'whooping' sound as the person tries to inhale. These coughing spells can be exhausting and lead to complications such as pneumonia, seizures, and brain damage, especially in babies. Guam is seeing ongoing pertussis transmission, with 17 cases reported in 2026 so far, including some requiring hospitalisation. Cases affect a wide age range, with a notable proportion among those who are unvaccinated or only partially vaccinated. The Department of Public Health and Social Services (DPHSS) in Guam is actively promoting vaccination for all age groups, including through community immunisation clinics, and encouraging early medical care for compatible symptoms. Vaccination is crucial not only for the individual but also to create a protective barrier around vulnerable infants who are too young to complete their full vaccination course. New Zealand is also experiencing a national pertussis epidemic, which began in October 2024. As of late May 2026, the country has reported over 4,500 cases since the start of the epidemic, including more than 400 hospitalisations and one death. While weekly case numbers fluctuate, the overall trend indicates persistent transmission across the nation. Infants under one year and children aged one to four years continue to have the highest notification rates, underscoring the severe impact this disease can have on the youngest members of the community. The pertussis vaccine (often part of the DTaP for children and Tdap for adolescents and adults) is the most effective way to prevent whooping cough. Vaccination is especially recommended for pregnant women during their third trimester to pass protective antibodies to their babies before birth. Close contacts of infants, such as parents, grandparents, and caregivers, should also ensure they are up-to-date with their Tdap vaccine to prevent unknowingly transmitting the illness. ## The Power of Prevention: Vaccination and Community Action These ongoing health alerts in the Pacific region highlight a clear and consistent message: prevention is paramount. For vaccine-preventable diseases like measles and pertussis, ensuring high vaccination coverage across all age groups is the single most effective strategy. Vaccines are safe, effective, and crucial for building community immunity, protecting not only ourselves but also those who cannot be vaccinated due to age or medical conditions. For diseases like dengue fever, where a widely available vaccine is not yet the primary tool for prevention, community engagement in mosquito control is vital. Simple actions such as regularly checking for and eliminating standing water, using mosquito nets, and applying repellents can significantly reduce transmission. Promptly seeking medical advice for any concerning symptoms is also critical for early diagnosis and effective management, preventing severe outcomes and further spread. Public health agencies across the Pacific, often working collaboratively through networks like the Pacific Public Health Surveillance Network (PPHSN), play a crucial role in monitoring these outbreaks, disseminating information, and coordinating response efforts. However, their success relies heavily on the active participation and cooperation of every individual and community. By staying informed, following public health advice, and taking proactive measures, we can collectively strengthen our defenses against these communicable diseases and foster healthier communities throughout the region. ## Staying Informed and Safe Being aware of the current health landscape in your region and when traveling is crucial. Public health notices are designed to keep communities informed and empower individuals to make choices that protect their health and the health of those around them. This includes understanding the risks, knowing the symptoms, and taking recommended preventive actions, whether it's getting vaccinated, controlling mosquito populations, or seeking timely medical care. The ongoing alerts for dengue, measles, and pertussis serve as a reminder that infectious diseases are a constant presence. Our best defense lies in a combination of strong public health infrastructure, readily available vaccines, community-wide prevention efforts, and informed individual action. By working together, we can reduce the burden of these diseases and build more resilient, healthier societies in the Pacific and beyond. **Sources:** * Alerte DASS – Épidémie de dengue (24 May 2026) * La dengue | Direction des Affaires Sanitaires et Sociales de Nouvelle-Calédonie * Dengue Fever Outbreak Situation Report in Samoa, Issue No. 59 (Accessed 09 June 2026) * Measles alert for Sydney Airport and Sydney CBD, NSW Health (5 June 2026) * National Communicable Disease Surveillance Dashboard (Accessed 09 June 2026) * DPHSS Pertussis Update (8 June 2026) * Epi Reports | Epidemiology and Laboratory Capacity (ELC) Guam – DPHSS * Pertussis dashboard and Pertussis Report 2–29 May 2026 (Accessed 09 June 2026) * NZ Arbovirus Notifications by Country (22: 30/05/2026–05/06/2026) * Vanuatu Dengue Situation Update 02 * Situation Report No. 4 – Measles in the Region of the Americas, PAHO/WHO (4 June 2026)