Abstract:
The Western Pacific Region\'s pursuit of measles elimination has seen significant progress and setbacks. Mongolia and Cambodia were the first two middle-income countries in the Western Pacific to be verified as having eliminated measles by the Western Pacific Regional Verification Commission for Measles and Rubella Elimination, in March 2014 and 2015, respectively. However, both countries experienced large-scale or prolonged importation-related measles outbreaks shortly afterwards, leading to the re-establishment of endemic transmission. We describe the path to initial elimination in both countries and explore these outbreaks\' characteristics, factors contributing to the loss of elimination status, and implications for broader elimination efforts. Data sources include case-based epidemiological and laboratory surveillance reports, historical immunization coverage, genotype data, and published reports of in-depth outbreak investigations. In Mongolia, a single prolonged and large-scale outbreak revealed a hidden immunity gap among young adults and was driven in part by nosocomial transmission, leading to significant morbidity and mortality and loss of elimination status. Cambodia suffered multiple importations from neighboring endemic countries during the global measles resurgence in 2018-2019, complicated by cross-border mobility and significant nosocomial amplification, and the country was ultimately unable to sufficiently distinguish independent chains of transmission, leading to loss of elimination status. Our findings highlight the importance of broadening population immunity assessments beyond children to include adults and specific high-risk groups. Robust routine immunization programs, supplemented by tailored SIAs, are crucial for preventing and managing outbreaks. Additionally, strong outbreak preparedness plans, rapid response strategies, and cross-border collaboration and the global effort to prevent multiple resurgences and large-scale importation-induced outbreaks are vital for maintaining elimination status. The experiences of Mongolia and Cambodia underscore the challenges of sustaining measles elimination in the face of importation risks, shared borders with endemic countries, healthcare system gaps, and population movements. Strengthening the global coordination and synchronization of measles elimination activities is imperative to protect the gains achieved and prevent future setbacks.
摘要:
西太平洋区域对消除麻疹的追求取得了重大进展和挫折。蒙古和柬埔寨是西太平洋第一个被西太平洋消除麻疹和风疹区域核查委员会核实消除麻疹的两个中等收入国家,分别于2014年和2015年3月。然而,此后不久,这两个国家都经历了大规模或长期的与输入相关的麻疹疫情,导致地方性传播的重建。我们描述了这两个国家最初消除疫情的途径,并探讨了这些疫情的特征,导致淘汰状态丧失的因素,以及对更广泛的消除努力的影响。数据来源包括病例流行病学和实验室监测报告,历史免疫覆盖率,基因型数据,并发表了深入的疫情调查报告。在蒙古,一次长期和大规模的爆发揭示了年轻人之间隐藏的免疫差距,部分原因是医院传播,导致显著的发病率和死亡率以及消除状态的丧失。在2018-2019年全球麻疹复发期间,柬埔寨遭受了来自邻国流行国家的多次输入,并因跨境流动和重大医院放大而复杂化。该国最终无法充分区分独立的传播链,导致淘汰状态的丧失。我们的发现强调了将人群免疫评估范围扩大到儿童以外,包括成年人和特定高危人群的重要性。强大的常规免疫计划,由量身定制的SIA补充,对于预防和管理疫情至关重要。此外,强有力的疫情防范计划,快速反应策略,跨境合作和全球努力防止多次复活和大规模进口引起的爆发对于维持消除状态至关重要。蒙古和柬埔寨的经验强调了在面临输入风险的情况下持续消除麻疹的挑战,与流行国家共享边界,医疗保健系统的差距,和人口流动。加强消除麻疹活动的全球协调和同步对于保护已取得的成果和防止未来的挫折至关重要。