Wolde Haileab Fekadu, Clements Archie C A, Gilmour Beth, Alene Kefyalew Addis
School of Population Health, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia.
Geospatial and Tuberculosis Team, Telethon Kids Institute, Nedlands, WA, Australia.
Sci Rep. 2024 Dec 30;14(1):31561. doi: 10.1038/s41598-024-68549-7.
While bacille-calmette-guerin (BCG) vaccination is one of the recommended strategies for preventing tuberculosis (TB), its coverage is low in several countries, including Ethiopia. This study investigated the spatial co-distribution and drivers of TB prevalence and low BCG coverage in Ethiopia. This ecological study was conducted using data from a national TB prevalence survey and the Ethiopian demographic and health survey (EDHS) to map the spatial co-distribution of BCG vaccination coverage and TB prevalence. A Bayesian geostatistical model was built to identify the drivers for the spatial distribution of TB prevalence and low BCG vaccination coverage. BCG vaccination coverage was defined as the number of children who received the vaccine divided by the total number of children born within five years preceding the EDHS surveys. Parameter estimation was done using binary logistic regression. Prediction maps for the co-distribution of high TB prevalence and low BCG vaccination coverage were created by overlying spatial prediction surfaces of the two outcomes. Posterior means and a 95% Bayesian credible interval (CrI) were used to summarize the parameters of the model. The national prevalence was 0.40% (95% confidence interval (CI) 0.34%, 0.47%) for TB and 47% (95% CI 46%, 48%) for vaccination coverage. Substantial spatial variation in TB prevalence and low BCG coverage was observed at a regional and local level, particularly in border areas of the country, including the Somali, Afar, and Oromia regions. Approximately 58% of the pixels (i.e., geographical area or spatial units) with high TB prevalence exhibited low BCG coverage in the same location. While travel time to cities (Mean = 0.28, 95% BCI: 0.15, 0.41) and distance to health facilities (Mean = 0.43, 95% CI 0.22, 0.63), were positively associated, population density (Mean = -0.04, 95% BCI -0.05, -0.02) was negatively associated, with the proportion of unvaccinated children for BCG indicating areas near health facilities and cities have better BCG coverage. However, there were no significant predictors for TB prevalence. Substantial spatial co-distribution between high TB prevalence and low BCG coverage was observed in some parts of the country, indicating that there are areas where the TB burden is not being adequately managed through the provision of vaccines in Ethiopia. Scaling up BCG vaccination coverage and TB diagnosis and treatment through improving access to health services in border regions such as Somalia and Afar would be important to reduce the prevalence of TB in Ethiopia.
虽然卡介苗（BCG）接种是预防结核病（TB）的推荐策略之一，但在包括埃塞俄比亚在内的几个国家，其接种覆盖率较低。本研究调查了埃塞俄比亚结核病患病率与卡介苗低接种覆盖率的空间共同分布及其驱动因素。这项生态学研究利用全国结核病患病率调查和埃塞俄比亚人口与健康调查（EDHS）的数据，绘制卡介苗接种覆盖率和结核病患病率的空间共同分布图。构建了贝叶斯地理统计模型，以确定结核病患病率空间分布和卡介苗低接种覆盖率的驱动因素。卡介苗接种覆盖率定义为接种疫苗的儿童数量除以EDHS调查前五年内出生的儿童总数。使用二元逻辑回归进行参数估计。通过叠加两个结果的空间预测表面，创建了高结核病患病率和低卡介苗接种覆盖率共同分布的预测图。使用后验均值和95%贝叶斯可信区间（CrI）来总结模型参数。全国结核病患病率为0.40%（95%置信区间（CI）0.34%，0.47%），接种覆盖率为47%（95%CI 46%，48%）。在区域和地方层面，特别是在该国边境地区，包括索马里、阿法尔和奥罗米亚地区，观察到结核病患病率和卡介苗低覆盖率存在显著的空间差异。在结核病患病率高的像素（即地理区域或空间单元）中，约58%在同一位置呈现卡介苗低覆盖率。虽然前往城市的时间（均值 = 0.28，95%BCI：0.15，0.41）和距离医疗机构的距离（均值 = 0.43，95%CI 0.22，0.63）呈正相关，但人口密度（均值 = -0.04，95%BCI -0.05，-0.02）呈负相关，这表明靠近医疗机构和城市的地区卡介苗接种覆盖率较好。然而，没有发现结核病患病率的显著预测因素。在该国一些地区观察到高结核病患病率和低卡介苗覆盖率之间存在显著的空间共同分布，这表明在埃塞俄比亚，有些地区通过提供疫苗并不能充分控制结核病负担。通过改善索马里和阿法尔等边境地区的医疗服务可及性，扩大卡介苗接种覆盖率以及结核病诊断和治疗，对于降低埃塞俄比亚的结核病患病率至关重要。
