Anderson Claire E, Hernandez Jason, Hanif Suhi, Owens Lauren, Crider Yoshika, Billington Sarah L, Lepech Michael, Boehm Alexandria B, Benjamin-Chung Jade
Department of Civil and Environmental Engineering, Stanford University, Stanford, California, USA.
Department of Epidemiology and Population Health, Stanford University, Stanford, California, USA.
Appl Environ Microbiol. 2025 Apr 23;91(4):e0213124. doi: 10.1128/aem.02131-24. Epub 2025 Mar 10.
Soil household floors are common in low- and middle-income countries (LMICs) and can serve as reservoirs of enteric pathogens. Cement-based floors may interrupt pathogen transmission, but little is known about pathogen survival or removal from cement-based surfaces. This study investigated the survival of , an indicator of fecal contamination, on cement-based surfaces and evaluated its reduction through common household activities (mopping, sweeping, and walking). We compared fate on three mixes: (i) ordinary Portland cement (OPC) concrete (used in the United States), (ii) OPC mortar (used in Bangladesh), and (iii) OPC mortar with fly ash (a sustainable alternative to the Bangladesh mix). Additionally, we compared outcomes on cement-based surfaces with and without soil and at two temperatures representing the dry and wet seasons in Bangladesh. After 4 hours on the cement-based surfaces, decayed more than 1.1 log(/) under all conditions tested, which is significantly faster than in bulk soils. The higher temperature increased the decay rate constant ( = 5.56 × 10) while soil presence decreased it ( = 2.80 × 10). Sweeping and mopping resulted in high levels of removal for all mixes, with a mean removal of 71% and 78%, respectively, versus 22% for walking. The concrete and mortar mix designs did not impact survival or removal ( > 0.20). Cement-based floors made with a fly ash mix performed similarly to traditional cement-based floors, supporting their potential use as a more sustainable intervention to reduce fecal contamination in rural LMIC household settings.
Cement-based surfaces may serve as a health intervention to reduce the fecal-oral transmission of pathogens in household settings, but there is a critical lack of evidence about the fate of indicator organisms on these surfaces, especially in field-relevant conditions. This study provides some of the first insights into survival on cement-based surfaces and the effectiveness of daily activities for removing . Additionally, this study explores the fate of on cement-based surfaces made with fly ash (which contributes fewer CO emissions) versus traditional cement mixes. We found that had similar survival and removal efficiencies across all mix designs, demonstrating that fly ash mixes are feasible for use in household settings (e.g., in floors). The findings enhance understanding of fecal-oral transmission pathways and support the use of fly ash mixes in cement-based flooring in future epidemiologic studies assessing effects on enteric disease burdens.
在低收入和中等收入国家（LMICs），土壤家居地面很常见，可作为肠道病原体的储存库。水泥地面可能会中断病原体传播，但对于病原体在水泥地面上的存活或清除情况知之甚少。本研究调查了粪便污染指标菌在水泥地面上的存活情况，并评估了通过常见家庭活动（拖地、扫地和行走）对其的减少效果。我们比较了该指标菌在三种混合物上的情况：（i）普通波特兰水泥（OPC）混凝土（在美国使用），（ii）OPC砂浆（在孟加拉国使用），以及（iii）含粉煤灰的OPC砂浆（孟加拉国混合物的可持续替代物）。此外，我们还比较了有土和无土水泥地面以及代表孟加拉国干湿季节的两种温度下的结果。在水泥地面上放置4小时后，在所有测试条件下，该指标菌衰减超过1.1 log(/)，这比在块状土壤中衰减得明显更快。较高温度增加了衰减速率常数（ = 5.56 × 10），而有土壤存在则降低了该常数（ = 2.80 × 10）。扫地和拖地对所有混合物的清除率都很高，平均清除率分别为71%和78%，而行走的清除率为22%。混凝土和砂浆的混合设计对该指标菌的存活或清除没有影响（ > 0.20）。含粉煤灰混合物制成的水泥地面与传统水泥地面表现相似，支持其作为一种更可持续的干预措施，用于减少低收入和中等收入国家农村家庭环境中的粪便污染。
水泥地面可作为一种健康干预措施，减少家庭环境中病原体的粪口传播，但关于指示生物在这些表面上的命运，尤其是在与实地相关的条件下，严重缺乏证据。本研究首次提供了一些关于该指标菌在水泥地面上存活情况以及日常活动清除该指标菌有效性的见解。此外，本研究探讨了该指标菌在含粉煤灰（二氧化碳排放量较少）制成的水泥地面与传统水泥混合物上的命运。我们发现，在所有混合设计中，该指标菌的存活和清除效率相似，表明粉煤灰混合物可用于家庭环境（如地面）。这些发现增进了对粪口传播途径的理解，并支持在未来评估对肠道疾病负担影响的流行病学研究中，将粉煤灰混合物用于水泥地面铺设。
