Swiss Tropical and Public Health Institute, Basel, Switzerland.
University of Basel, Basel, Switzerland.
PLoS Negl Trop Dis. 2019 Aug 9;13(8):e0007580. doi: 10.1371/journal.pntd.0007580. eCollection 2019 Aug.
In South Asia, hundreds of millions of people are infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura). However, high-resolution risk profiles and the estimated number of people infected have yet to be determined. In turn, such information will assist control programs to identify priority areas for allocation of scarce resource for the control of soil-transmitted helminth infection.
We pursued a systematic review to identify prevalence surveys pertaining to soil-transmitted helminth infections in four mainland countries (i.e., Bangladesh, India, Nepal, and Pakistan) of South Asia. PubMed and ISI Web of Science were searched from inception to April 25, 2019, without restriction of language, study design, and survey date. We utilized Bayesian geostatistical models to identify environmental and socioeconomic predictors, and to estimate infection risk at high spatial resolution across the study region.
A total of 536, 490, and 410 georeferenced surveys were identified for A. lumbricoides, hookworm, and T. trichiura, respectively. We estimate that 361 million people (95% Bayesian credible interval (BCI) 331-395 million), approximately one-quarter of the South Asia population, was infected with at least one soil-transmitted helminth species in 2015. A. lumbricoides was the predominant species. Moderate to high prevalence (>20%) of any soil-transmitted helminth infection was predicted in the northeastern part and some northern areas of the study region, as well as the southern coastal areas of India. The annual treatment needs for the school-age population requiring preventive chemotherapy was estimated at 165 million doses (95% BCI: 146-185 million).
CONCLUSIONS/SIGNIFICANCE: Our risk maps provide an overview of the geographic distribution of soil-transmitted helminth infection in four mainland countries of South Asia and highlight the need for up-to-date surveys to accurately evaluate the disease burden in the region.
在南亚，数亿人感染了土壤传播的蠕虫（蛔虫、钩虫和鞭虫）。然而，尚未确定高分辨率的风险概况和估计的感染人数。反过来，这些信息将有助于控制计划确定优先领域，以便为控制土壤传播的蠕虫感染分配稀缺资源。
我们进行了系统评价，以确定南亚四个大陆国家（孟加拉国、印度、尼泊尔和巴基斯坦）有关土壤传播的蠕虫感染的流行情况调查。从开始到 2019 年 4 月 25 日，我们在 PubMed 和 ISI Web of Science 上进行了搜索，没有语言、研究设计和调查日期的限制。我们利用贝叶斯地统计模型来确定环境和社会经济预测因素，并在整个研究区域内以高空间分辨率估计感染风险。
分别为蛔虫、钩虫和鞭虫鉴定了 536、490 和 410 个地理参考调查。我们估计，2015 年，约有 3.61 亿人（95%贝叶斯可信区间（BCI）为 3.31-3.95 亿人）感染了至少一种土壤传播的蠕虫，占南亚人口的四分之一左右。蛔虫是主要的物种。在研究区域的东北部和一些北部地区以及印度南部沿海地区，预测到任何土壤传播的蠕虫感染的中度至高度流行率（>20%）。需要对学龄人口进行预防性化疗的年度治疗需求估计为 1.65 亿剂（95%BCI：1.46-1.85 亿剂）。
结论/意义：我们的风险图提供了南亚四个大陆国家土壤传播的蠕虫感染的地理分布概述，并强调需要进行最新调查以准确评估该地区的疾病负担。
