Clinton Health Access Initiative, Boston, USA.
Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA.
Malar J. 2022 Nov 14;21(1):330. doi: 10.1186/s12936-022-04368-3.
Many national malaria programmes have set goals of eliminating malaria, but realistic timelines for achieving this goal remain unclear. In this investigation, historical data are collated on countries that successfully eliminated malaria to assess how long elimination has taken in the past, and thus to inform feasible timelines for achieving it in the future.
Annual malaria case series were sought for 56 successful elimination programmes through a non-systematic review. Up to 40 years of annual case counts were compiled leading up to the first year in which zero locally acquired or indigenous cases were reported. To separate the period over which effective elimination efforts occurred from prior background trends, annual case totals were log transformed, and their slopes evaluated for a breakpoint in linear trend using the segmented package in R. The number of years from the breakpoint to the first year with zero cases and the decline rate over that period were then calculated. Wilcox-Mann-Whitney tests were used to evaluate whether a set of territory characteristics were associated with the timelines and decline rates.
Case series declining to the first year with zero cases were compiled for 45/56 of the candidate elimination programmes, and statistically significant breakpoints were identified for 42. The median timeline from the breakpoint to the first year with zero local cases was 12 years, over which cases declined at a median rate of 54% per year. Prior to the breakpoint, the median trend was slightly decreasing with median annual decline of < 3%. Timelines to elimination were fastest among territories that lacked land boundaries, had centroids in the Tropics, received low numbers of imported cases, and had elimination certified by the World Health Organization.
The historical case series assembled here may help countries with aspirations of malaria elimination to set feasible milestones towards this goal. Setting goals for malaria elimination on short timescales may be most appropriate in isolated, low importation settings, such as islands, while other regions aiming to eliminate malaria must consider how to sustainably fund and maintain vital case management and vector control services until zero cases are reached.
许多国家的疟疾规划都设定了消除疟疾的目标，但实现这一目标的现实时间表仍不清楚。在这项调查中，对成功消除疟疾的国家进行了历史数据汇总，以评估过去消除疟疾需要多长时间，从而为未来实现这一目标提供可行的时间表。
通过非系统性回顾，寻找 56 个成功消除疟疾规划的年度疟疾病例系列。收集了多达 40 年的年度病例数，直至报告首例本地获得性或本土病例的年份。为了将有效消除努力发生的时间段与之前的背景趋势区分开来，对年度病例总数进行对数转换，并使用 R 中的分段软件包评估线性趋势的断点。然后计算从断点到首例零病例年份的年数以及该期间的下降率。使用 Wilcox-Mann-Whitney 检验评估一组领土特征是否与时间线和下降率相关。
为 45/56 个候选消除规划编制了病例系列，这些规划的病例数呈下降趋势，直至首例零病例年份，并确定了 42 个具有统计学意义的断点。从断点到首例零本地病例年份的中位时间线为 12 年，在此期间病例以每年 54%的中位数下降率下降。在断点之前，中位趋势略有下降，每年的中位数下降率<3%。没有陆地边界、位于热带地区的中轴、输入病例数量较少且获得世界卫生组织消除认证的领土消除时间线最快。
这里汇编的历史病例系列可能有助于有消除疟疾愿望的国家为实现这一目标设定可行的里程碑。在孤立的低输入环境（如岛屿）中，将消除疟疾的目标设定在较短的时间范围内可能是最合适的，而其他地区要想消除疟疾，必须考虑如何可持续地为基本病例管理和病媒控制服务提供资金并维持这些服务，直到达到零病例为止。
