McClure Max, Arinaitwe Emmanuel, Kamya Moses R, Rosenthal Philip J, Nankabirwa Joaniter, Maxwell Kilama, Musiime Alex, Dorsey Grant, Greenhouse Bryan, Rodriguez-Barraquer Isabel
University of California, San Francisco.
Infectious Diseases Research Collaboration.
Res Sq. 2025 Feb 4:rs.3.rs-5914493. doi: 10.21203/rs.3.rs-5914493/v1.
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 household EIR reflects heterogeneity in individual infection risk.
To investigate this relationship, we used data collected from a cohort of 439 children aged 0.5-5 years in 239 households from 2011-2017 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. We assessed the association between spatiotemporally smoothed household log-transformed EIR and individual malaria incidence 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 local transmission dynamics and be strongest at intermediate EIR, while underscoring the challenges of using household-level measures of exposure.
疟疾暴露的金标准测量方法是昆虫接种率（EIR），即个体在给定时期内接受的感染性叮咬次数。然而，尚不清楚家庭EIR是否反映个体感染风险的异质性。
为了研究这种关系，我们使用了2011年至2017年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。使用疾控中心诱蚊灯估计参与家庭的月度媒介密度和子孢子率。我们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当地的传播动态，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。
