McClure Max, Arinaitwe Emmanuel, Kamya Moses R, Rosenthal Philip J, Nankabirwa Joaniter, Kilama Maxwell, Musiime Alex, Dorsey Grant, Greenhouse Bryan, Rodriguez-Barraquer Isabel
Department of Medicine, San Francisco General Hospital, University of California, San Francisco, San Francisco, USA.
Infectious Diseases Research Collaboration, Kampala, Uganda.
Malar J. 2025 Aug 14;24(1):261. doi: 10.1186/s12936-025-05504-5.
The gold standard measure of malaria exposure is the entomological inoculation rate (EIR), or the number of infectious bites an individual receives over a given period. Nevertheless, it is unclear whether EIR measured in the households of individuals reflects heterogeneity in those individuals' infection risk.
To investigate this relationship, this study used data collected from a cohort of 439 children aged 0.5-5 years in 239 households from 2011-2016 in three Ugandan districts: low-EIR Jinja, intermediate-EIR Kanungu and high-EIR Tororo. Participants underwent passive and quarterly active surveillance for clinical malaria, defined as fever with positive thick blood smear. Monthly vector densities and sporozoite rates in participating households were estimated using CDC light traps. The association between spatiotemporally smoothed household log-transformed EIR and individual malaria incidence was assessed using Poisson generalized additive mixed effects models.
Comparison across sites suggested an increasing relationship between average EIR and malaria incidence. Within-site relationships, however, varied by site, with a positive association in Kanungu (incidence rate ratio [IRR] 1.09, 95% credible interval 1.04-1.14) but none in Jinja (1.02, 0.774-1.26) or Tororo (1.02, 0.986-1.06).
These results show the relationship between measured EIR and malaria incidence may depend on site-specific transmission dynamics and be strongest at intermediate EIR, while underscoring the challenges of using household-level measures of exposure.
疟疾暴露的金标准衡量指标是昆虫学接种率（EIR），即个体在给定时期内接受的感染性叮咬次数。然而，在个体家庭中测量的EIR是否反映了这些个体感染风险的异质性尚不清楚。
为了研究这种关系，本研究使用了2011年至2016年期间在乌干达三个地区的239户家庭中收集的439名0.5至5岁儿童队列的数据：低EIR的金贾、中等EIR的卡农古和高EIR的托罗罗。参与者接受了临床疟疾的被动和季度主动监测，临床疟疾定义为厚血涂片阳性的发热。使用疾控中心光诱捕器估计参与家庭的每月媒介密度和子孢子率。使用泊松广义相加混合效应模型评估时空平滑的家庭对数转换EIR与个体疟疾发病率之间的关联。
各地点之间的比较表明，平均EIR与疟疾发病率之间存在递增关系。然而，地点内的关系因地点而异，卡农古呈正相关（发病率比[IRR]1.09，95%可信区间1.04 - 1.14），而金贾（1.02，0.774 - 1.26）或托罗罗（1.02，0.986 - 1.06）则无相关性。
这些结果表明，测量的EIR与疟疾发病率之间的关系可能取决于特定地点的传播动态，并且在中等EIR时最强，同时强调了使用家庭层面暴露测量方法的挑战。
