Department of Public Health and Clinical Medicine, Division of Occupational and Environmental Medicine, Umeå University, Umeå, 901 87, Sweden.
Science Division, National Food Agency, Uppsala, Sweden.
Water Res. 2016 Oct 1;102:263-270. doi: 10.1016/j.watres.2016.06.018. Epub 2016 Jun 11.
Outbreaks of acute gastrointestinal illnesses (AGI) have been linked to insufficient drinking water treatment on numerous occasions in the industrialized world, but it is largely unknown to what extent public drinking water influences the endemic level of AGI. This paper aimed to examine endemic AGI and the relationship with pathogen elimination efficacy in public drinking water treatment processes. For this reason, time series data of all telephone calls to the Swedish National Healthcare Guide between November 2007 and February 2014 from twenty Swedish cities were obtained. Calls concerning vomiting, diarrhea or abdominal pain (AGI calls) were separated from other concerns (non-AGI calls). Information on which type of microbial barriers each drinking water treatment plant in these cities have been used were obtained, together with the barriers' theoretical pathogen log reduction efficacy. The total log reduction in the drinking water plants varied between 0.0 and 6.1 units for viruses, 0.0-14.6 units for bacteria and 0.0-7.3 units regarding protozoans. To achieve one general efficacy parameter for each plant, a weighted mean value of the log reductions (WLR) was calculated, with the weights based on how commonly these pathogen groups cause AGI. The WLR in the plants varied between 0.0 and 6.4 units. The effect of different pathogen elimination efficacy on levels of AGI calls relative non-AGI calls was evaluated in regression models, controlling for long term trends, population size, age distribution, and climatological area. Populations receiving drinking water produced with higher total log reduction was associated with a lower relative number of AGI calls. In overall, AGI calls decreased by 4% (OR = 0.96, CI: 0.96-0.97) for each unit increase in the WLR. The findings apply to both groundwater and surface water study sites, but are particularly evident among surface water sites during seasons when viruses are the main cause of AGI. This study proposes that the endemic level of gastroenteritis can indeed be reduced with more advanced treatment processes at many municipal drinking water treatment plants.
急性胃肠道疾病（AGI）的爆发已在工业化世界的许多场合与饮用水处理不足有关，但公众饮用水对 AGI 的流行程度的影响程度在很大程度上尚不清楚。本文旨在研究地方 AGI 以及与公共饮用水处理过程中病原体消除功效的关系。为此，从 2007 年 11 月至 2014 年 2 月，从瑞典的 20 个城市获得了瑞典国家医疗保健指南的所有电话的时间序列数据。将涉及呕吐、腹泻或腹痛（AGI 电话）的电话与其他关注电话（非 AGI 电话）分开。从这些城市的每个饮用水处理厂获得了使用的微生物屏障类型的信息，以及屏障的理论病原体对数减少功效。饮用水厂的总对数减少量因病毒而异，为 0.0 至 6.1 个单位，因细菌而异，为 0.0 至 14.6 个单位，因原生动物而异，为 0.0 至 7.3 个单位。为了为每个工厂计算一个通用功效参数，计算了对数减少量的加权平均值（WLR），权重基于这些病原体组引起 AGI 的频率。工厂中的 WLR 介于 0.0 至 6.4 个单位之间。在回归模型中评估了不同病原体消除功效对 AGI 呼叫相对于非 AGI 呼叫水平的影响，控制了长期趋势、人口规模、年龄分布和气候区域。接收具有更高总对数减少量的饮用水的人群与 AGI 呼叫的相对数量较低有关。总体而言，WLR 每增加一个单位，AGI 呼叫就会减少 4%（OR=0.96，CI：0.96-0.97）。这些发现适用于地下水和地表水研究地点，但在病毒是 AGI 主要原因的季节，地表水地点的情况尤为明显。本研究表明，通过许多市政饮用水处理厂更先进的处理工艺，确实可以降低胃肠炎的地方流行水平。
