Counts of Dengue hemorrhagic fever reported in CAMBODIA: 2001-2009

Project Tycho datasets contain case counts for reported disease conditions for countries around the world. The Project Tycho data curation team extracts these case counts from various reputable sources, typically from national or international health authorities, such as the US Centers for Disease Control or the World Health Organization. These original data sources include both open- and restricted-access sources. For restricted-access sources, the Project Tycho team has obtained permission for redistribution from data contributors. All datasets contain case count data that are identical to counts published in the original source and no counts have been modified in any way by the Project Tycho team. The Project Tycho team has pre-processed datasets by adding new variables, such as standard disease and location identifiers, that improve data interpretabilty. We also formatted the data into a standard data format.Each Project Tycho dataset contains case counts for a specific condition (e.g. measles) and for a specific country (e.g. The United States). Case counts are reported per time interval. In addition to case counts, datsets include information about these counts (attributes), such as the location, age group, subpopulation, diagnostic certainty, place of aquisition, and the source from which we extracted case counts. One dataset can include many series of case count time intervals, such as "US measles cases as reported by CDC", or "US measles cases reported by WHO", or "US measles cases that originated abroad", etc.Depending on the intended use of a dataset, we recommend a few data processing steps before analysis:- Analyze missing data: Project Tycho datasets do not inlcude time intervals for which no case count was reported (for many datasets, time series of case counts are incomplete, due to incompleteness of source documents) and users will need to add time intervals for which no count value is available. Project Tycho datasets do include time intervals for which a case count value of zero was reported.- Separate cumulative from non-cumulative time interval series. Case count time series in Project Tycho datasets can be "cumulative" or "fixed-intervals". Cumulative case count time series consist of overlapping case count intervals starting on the same date, but ending on different dates. For example, each interval in a cumulative count time series can start on January 1st, but end on January 7th, 14th, 21st, etc. It is common practice among public health agencies to report cases for cumulative time intervals. Case count series with fixed time intervals consist of mutually exxclusive time intervals that all start and end on different dates and all have identical length (day, week, month, year). Given the different nature of these two types of case count data, we indicated this with an attribute for each count value, named "PartOfCumulativeCountSeries".

第谷计划（Project Tycho）数据集收录了全球各国上报的各类疾病病症的病例数数据。第谷计划数据整理团队从各类权威来源提取此类病例数，来源通常为国家或国际卫生机构，例如美国疾病控制与预防中心（US Centers for Disease Control）、世界卫生组织（World Health Organization）。这些原始数据源涵盖开放获取与受限获取两类。针对受限获取数据源，第谷计划团队已获得数据贡献方的再分发许可。所有数据集内的病例数数据均与原始来源发布的计数完全一致，第谷计划团队未对任何计数进行修改。
第谷计划团队已对数据集进行预处理，包括新增标准化疾病与位置标识符等变量，以提升数据可解释性；同时将数据格式统一为标准数据格式。每个第谷计划数据集仅针对特定疾病（如麻疹）与特定国家（如美国）收录病例数数据，病例数按时间间隔上报。除病例数外，数据集还包含此类计数的相关属性信息，例如地点、年龄组、亚人群、诊断确定性、感染地点以及数据提取来源等。一个数据集可包含多组病例数时间序列，例如“美国疾病控制与预防中心上报的美国麻疹病例数”“世界卫生组织上报的美国麻疹病例数”“境外输入性美国麻疹病例数”等。
根据数据集的预期用途，我们建议在分析前完成以下数据处理步骤：
- 分析缺失数据：第谷计划数据集未包含无病例数上报的时间间隔（部分数据集的病例数时间序列因源文档不完整而存在缺失，用户需补充无计数值的时间间隔）；而数据集已包含病例数为0的时间间隔。
- 区分累积型与非累积型时间序列：第谷计划数据集中的病例数时间序列可分为“累积型”与“固定间隔型”两类。累积型病例数时间序列由重叠的病例统计区间构成，所有区间均起始于同一日期，但结束日期各不相同。例如，某累积计数序列的每个区间均始于1月1日，结束日期则分别为1月7日、14日、21日等。公共卫生机构通常会上报累积时间区间内的病例数。固定间隔型病例数序列由互斥的时间区间构成，所有区间的起始与结束日期均不相同，但时长一致（如日、周、月、年）。鉴于这两类病例数数据的性质存在差异，我们为每个计数值添加了名为“PartOfCumulativeCountSeries”的属性以标识其类型。