Mapping the risk of anaemia in preschool-age children: the contribution of malnutrition, malaria, and helminth infections in West Africa.
Mapping the risk of anaemia in preschool-age children: the contribution of malnutrition, malaria, and helminth infections in West Africa.
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DOI：
10.1371/journal.pmed.1000438
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发表时间：
2011-06
期刊：
影响因子：
15.8
通讯作者：
Clements AC
中科院分区：
文献类型：
--
作者：
Magalhães RJ;Clements AC
Ricardo Soares magalh<e:1>及其同事利用全国家庭人口健康调查绘制了布基纳法索、加纳和马里学龄前儿童贫血风险分布图。在撒哈拉以南非洲的大多数国家，儿童贫血被认为是一个严重的公共卫生问题。我们调查了西非1-4岁儿童（学龄前儿童）贫血患病率和平均血红蛋白浓度（Hb）的地理分布。目的是估计贫血的地理风险概况，包括营养不良、疟疾和寄生虫感染，这些因素导致的贫血风险，以及2011年学龄前儿童贫血病例数。2003-2006年，在布基纳法索、加纳和马里对7 147名1-4岁儿童进行了全国家庭人口健康横断面调查。建立贝叶斯地理统计模型，预测平均Hb和贫血风险的地理分布，调整学龄前儿童的营养状况，居住地，预测2至10岁年龄组（Pf PR2-10）的恶性疟原虫寄生虫率，并预测血血吸虫和钩虫感染的流行。在这四个国家中，布基纳法索的轻度、中度和重度贫血患病率分别为21%、66%和13%；加纳为28%，65%和7%，马里为26%，62%和12%。布基纳法索的平均Hb最低（89 g/l），男性最低（93 g/l）， 1-2岁儿童最低（88 g/l）。在西非，严重营养不良、Pf PR2-10以及血链球菌和钩虫感染之间的生物协同作用与贫血风险显著相关；据估计，分别有36.8%、14.9%、3.7%、4.2%和0.9%的贫血病例可通过治疗营养不良、疟疾、嗜血杆菌感染、钩虫感染和嗜血杆菌/钩虫共感染而得以避免。在布基纳法索和马里共有的地区，预计会出现低平均血红蛋白（<80 g/l）和最大贫血风险（>95%）的大空间集群。我们估计，2011年，在三个研究国家中，约有670万1-4岁儿童患有贫血症。通过绘制经营养不良和寄生虫感染调整后的学龄前儿童贫血风险分布图，我们提供了一种方法来确定贫血负担的地理限制以及营养不良和寄生虫对贫血的贡献。空间定向补充辅助微量营养素和控制其他贫血原因，如疟疾和寄生虫感染，可有助于有效减轻非洲学龄前儿童的贫血负担。请参见文章后面的编辑总结，1993-2005年期间的全球估计表明，全世界有近3亿儿童患有贫血，即血红蛋白水平低于110克/升。在撒哈拉以南非洲，三分之二的儿童患有贫血，即8350万儿童。这些统计数据很重要，因为婴儿期和儿童期的贫血与认知发育不良、生长迟缓、免疫功能问题有关，并最终导致生存率下降。营养不良（包括微量营养素缺乏，特别是铁、维生素A、维生素C和叶酸缺乏）、营养不良和传染病，特别是艾滋病毒、疟疾和蠕虫感染（由钩虫和血血吸虫引起，后者引起尿路血吸虫病）是儿童贫血的主要原因。虽然补充铁通常可以纠正贫血，但在某些情况下，缺铁可以预防常见的传染性病原体，在某些情况下，给铁可能会增加一些儿童传染病的严重程度。因此，注重治疗和预防引起贫血的传染病是治疗贫血的一项重要替代战略。针对撒哈拉以南非洲疟疾和寄生虫感染的干预措施的控制工具包括将统计模型与地理信息系统（类似于汽车导航系统中使用的系统）相结合的现代空间风险预测方法。然而，到目前为止，还没有研究使用这些工具来预测贫血风险的空间。此外，营养不良和感染对非洲总体贫血负担的影响在很大程度上是未知的。在这项研究中，研究人员使用这些工具来预测三个西非国家的贫血患病率，并估计由营养不良、疟疾和寄生虫感染引起的贫血的归因风险。研究人员使用了布基纳法索（2003年）、加纳（2003年）和马里（2006年）最近的人口与健康调查（DHS）的地理关联数据，其中包括毛细管血液取样和测试以及详细的人体测量（身高和体重）测量。这三个国家共有7147名1-4岁的儿童（3477名女孩和3670名男孩）被纳入分析。研究人员在地理信息系统中使用国土安全部集群坐标绘制了三个研究国家的国土安全部调查地点。利用来自疟疾地图集项目的数据，研究人员利用地理信息系统提取了每个DHS集群的恶性疟原虫寄生虫率的空间预测值，并使用先前报告的钩虫和血孢杆菌感染的寄生虫学调查数据来预测整个地区的寄生虫感染风险。然后，研究人员开发了空间预测模型，使用贝叶斯统计来估计贫血的特定预测因子的人口归因比例。来自人口与健康调查的数据显示，布基纳法索轻度、中度和重度贫血的患病率分别为21%、66%和13%；加纳为28%，65%和7%，马里为26%，62%和12%。研究区发育迟缓、消瘦和体重过轻的患病率分别为87.8%、89.7%和71.2%，平均恶性疟原虫感染率、血索菌感染率、钩虫感染率和血索菌/钩虫共感染率分别为52.0%、26.8%、8.2%和3.6%。总体结果表明，在这三个国家中，大约有670万1-4岁的儿童患有贫血。严重营养不良，恶性疟原虫感染，钩虫感染，血链球菌感染，钩虫/S。血球菌合并感染估计分别导致250万、100万、25万、28.5万和6.1万例贫血病例。布基纳法索中部和加纳南部的贫血儿童人数最多。这些结果增加了对三个西非国家不同地理区域内贫血患病率和贫血严重程度的了解和细节。贫血和平均血红蛋白预测图的结合确定了西非学龄前儿童发病率增加的社区。贫血地图的使用对这些国家的针对性控制具有重要的实际意义，例如指导营养补充剂和强化食品的有效分配，以及对不同原因导致的贫血进行风险评估，这反过来又将构成计算干预措施之间最佳平衡的证据基础。请通过本摘要的在线版本http://dx.doi.org/10.1371/journal.pmed.1000438访问这些网站。Abdisalan Noor在《公共科学图书馆医学展望》中进一步讨论了这项研究。世卫组织网站上有关于全球贫血流行情况的全面信息，有关于人口健康调查的更多信息，有关于全球疟疾预测的更多信息
Ricardo Soares Magalhães and colleagues used national cross-sectional household-based demographic health surveys to map the distribution of anemia risk in preschool children in Burkina Faso, Ghana, and Mali. Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1–4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1–4 y in Burkina Faso, Ghana, and Mali in 2003–2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR2–10), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1–2 y (88 g/l). In West Africa, severe malnutrition, Pf PR2–10, and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (<80 g/l) and maximal risk of anaemia (>95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1–4 y are anaemic in the three study countries. By mapping the distribution of anaemia risk in preschool children adjusted for malnutrition and parasitic infections, we provide a means to identify the geographical limits of anaemia burden and the contribution that malnutrition and parasites make to anaemia. Spatial targeting of ancillary micronutrient supplementation and control of other anaemia causes, such as malaria and helminth infection, can contribute to efficiently reducing the burden of anaemia in preschool children in Africa. Please see later in the article for the Editors' Summary Global estimates for the time period 1993–2005 suggest that that worldwide, nearly 300 million children had anemia, that is, hemoglobin levels less than 110 g/l. In sub-Saharan Africa, two-thirds of all children were anemic, representing 83.5 million children. These statistics are important because anemia in infancy and childhood is associated with poor cognitive development, reduced growth, problems with immune function—and ultimately, decreased survival. Malnutrition (including micronutrient deficiency, especially of iron, vitamin A, vitamin C, and folate), undernutrition, and infectious diseases, particularly HIV, malaria, and helminth infections (caused by hookworm and Schistosoma haematobium—which causes urinary schistosomiasis), are major causes of anemia in children. Although iron supplementation can often correct anemia, in some circumstances, iron deficiency can protect against common infectious agents, and giving iron can, on occasion, increase the severity of infectious disease in some children. Focusing on the treatment and prevention of infectious diseases that cause anemia is therefore an important alternative strategy in the treatment of anemia. Control tools for targeting interventions for malaria and helminth infection in sub-Saharan Africa include modern spatial risk prediction methods that combine statistical models with geographical information systems (similar to those used in car navigation systems). However, to date no studies have used these tools to spatially predict the risk of anemia. Furthermore, the contribution that malnutrition and infections make to the overall anemia burden in Africa is largely unknown. In this study the researchers used these tools to predict the prevalence of anemia in three West African countries and to estimate the attributable risk of anemia due to malnutrition, malaria, and helminth infections. The researchers used geographically linked data from the most recent Demographic and Health Surveys (DHS) in Burkina Faso (2003), Ghana (2003), and Mali (2006), which included capillary blood sampling and testing and detailed anthropometric (height and weight) measurements. A total of 7,147 children aged 1–4 years (3,477 girls and 3,670 boys) in the three countries were included in the analysis. The researchers mapped DHS survey locations in the three study countries using DHS cluster coordinates in a geographic information system. Using data from the Malaria Atlas Project, the researchers extracted spatially predicted values of Plasmodium falciparum parasite rate for each DHS cluster using a geographical information system and used previously reported parasitological survey data of hookworm and S. haematobium infections to predict helminth infection risk across the region. Then the researchers developed spatial prediction models using Bayesian statistics to estimate of the population attributable fraction for specific predictors for anemia. Data from the DHS showed that the prevalence of mild, moderate, and severe anemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The prevalence of stunting, wasting, and being underweight in the study area was 87.8%, 89.7%, and 71.2%, respectively, and the mean P. falciparum parasite rate, and rates of S. haematobium infection, hookworm infection, and S. haematobium/hookworm coinfection for the study area were 52.0%, 26.8%, 8.2%, and 3.6%, respectively. The overall results indicate that in the three countries, approximately 6.7 million children aged 1–4 years have anemia. Severe malnutrition, P. falciparum infection, hookworm infection, S. haematobium infection, and hookworm/S. haematobium coinfection were responsible for an estimated 2.5 million, 1.0 million, 250,000, 285,000, and 61,000 anemia cases, respectively. Central Burkina Faso and southern Ghana had the highest number of anemic children. These results add insight and detail to anemia prevalence and anemia severity within different geographical areas in three West African countries. The combination of anemia and mean hemoglobin predictive maps identifies communities in West Africa where preschool-age children are at increased risk of morbidity. The use of anemia maps has important practical implications for targeted control in these countries, such as guiding the efficient allocation of nutrient supplements and fortified foods, and enabling risk assessment of anemia due to different causes, which would in turn constitute an evidence base to calculate the best balance between interventions. Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000438. This study is further discussed in a PLoS Medicine Perspective by Abdisalan Noor The WHO Web site has comprehensive information on the worldwide prevalence of anemia More information on Demographic Health Surveys is available More information on global predictions of malaria is available
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影响因子：
9.6
作者：
Brooker S;Hay SI;Bundy DA
通讯作者：
Bundy DA
影响因子：
15.8
作者：
Bates, Imelda;McKew, Stephen;Sarkinfada, Faruk
通讯作者：
Sarkinfada, Faruk
影响因子：
3.2
作者：
Fishman, Steven M.;Christian, Parul;West, Keith P., Jr.
通讯作者：
West, Keith P., Jr.
影响因子：
4.2
作者：
Grantham-McGregor, S;Ani, C
通讯作者：
Ani, C
DOI：
10.1016/s0035-9203(99)90007-x
发表时间：
1999-05-01
影响因子：
2.2
作者：
Brooker, S;Peshu, N;Snow, RW
通讯作者：
Snow, RW