The effect of mixed Plasmodium infections on morbidity

混合疟原虫感染对发病率的影响

• 批准号: 6854839
• 负责人: IVO MUELLER
• 金额: $ 4.98万
• 依托单位: PAPUA NEW GUINEA INST/ MEDICAL RESEARCH
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6854839
• 关键词: Papua New Guinea; Plasmodium; Plasmodium falciparum; anemia; clinical research; comorbidity; emerging infectious disease; hemoglobin; human subject; light microscopy; longitudinal human study; malaria; polymerase chain reaction; preschool child (1-5)

DESCRIPTION (provided by applicant): The proposed study aims at deepening our understanding of the effect of interactions of different malaria species on incidence of malarial infections, and resulting morbidity by conducting a longitudinal follow-up study of children 1 - 4 years of age in a holoendemic are of Papua New Guinea. In particular we will determine patterns of acute simple malaria and anemia associated with prior and concurrent infections of different Plasmodium species and ascertain cross-species protection malarial morbidity and anemia test the hypothesis that co-infections with P. vivax and/or P. malariae reduce the incidence and severity of clinical disease with concurrent or subsequent P. falciparum infections. We will also assess potential interactions at the levels of asymptomatic infections. Better knowledge of potential cross-species protection is crucial to understanding the epidemiology of malarial morbidity and the possible effects of interventions, such as a malaria vaccine, primarily directed at one of the species. In order to achieve those aims we will follow-up 250 children with bi-monthly bleeds, fortnightly active morbidity surveillance and passive case detection at local health centers. All blood samples from cross-sectional bleeds and detected morbid episodes will be evaluated for malarial infections with both light microscopy and PCR-ligase detection reaction (LDR) assay. At the same time hemoglobin levels will be determined. Cross-species protection against morbidity and associations between heterologous infections will be analyzed with a mixture of standard methods for cohort studies and innovative approaches including mixed models and generalized estimating equations (GEE). The combination of a powerful longitudinal design, the best available methods of species identifications and sophisticated statistical analyses offers a unique opportunity for an in-depth examination of all aspects of cross-species interactions in the same individuals and thereby help to resolve this important aspect of malaria epidemiology.

描述（由申请人提供）：拟议的研究旨在通过对巴布亚新几内亚霍乱流行区 1 - 4 岁儿童进行纵向随访研究，加深我们对不同疟疾种类相互作用对疟疾感染发病率以及由此产生的发病率的影响的理解。特别是，我们将确定与不同疟原虫种类先前和并发感染相关的急性单纯性疟疾和贫血模式，并确定跨物种保护性疟疾发病率和贫血，测试以下假设：间日疟原虫和/或三日疟原虫合并感染可降低同时或随后恶性疟原虫感染的临床疾病的发生率和严重程度。我们还将评估无症状感染者水平上的潜在相互作用。更好地了解潜在的跨物种保护对于了解疟疾发病率的流行病学以及主要针对某一物种的疟疾疫苗等干预措施可能产生的影响至关重要。为了实现这些目标，我们将跟踪 250 名儿童，每两个月进行一次出血，每两周在当地卫生中心进行主动发病率监测和被动病例检测。来自横截面出血和检测到的病态发作的所有血液样本将通过光学显微镜和 PCR 连接酶检测反应 (LDR) 测定来评估疟疾感染。 同时将测定血红蛋白水平。将结合队列研究的标准方法和包括混合模型和广义估计方程（GEE）在内的创新方法来分析跨物种对发病率的保护以及异源感染之间的关联。强大的纵向设计、最佳可用的物种识别方法和复杂的统计分析相结合，为深入研究同一个体跨物种相互作用的各个方面提供了独特的机会，从而有助于解决疟疾流行病学的这一重要方面。