Investigating Cement-Based Surfaces as a Sustainable Flooring Solution to Improve Ascaris Egg Removal and Inactivation in Low-Resource Settings

Soil-transmitted helminths, like Ascaris , are significant contributors to disease burden in low- and middle-income countries (LMICs). Infections are associated with growth faltering and mortality in children and are often transmitted through contact with eggs in fecally contaminated soil. Interventions, like replacing household soil floors with cement-based alternatives, may reduce exposure to Ascaris eggs, but there are currently no estimates on the removal or survival of Ascaris eggs on cement-based surfaces. This study addresses that knowledge gap by evaluating the removal of Ascaris eggs from mopping and the survival of Ascaris eggs on two cement-based mixes: an Ordinary Portland Cement (OPC) mortar and an OPC mortar with fly ash, which provides a more sustainable alternative to the OPC mortar mix. We assessed egg survival at two temperatures representing the dry (15°C) and wet (34°C) seasons in Bangladesh using two different egg enumeration methods. After mopping, over 92% of viable eggs were removed from surfaces, with no significant differences between cement-based mixes (p = 0.51). The first-order decay rate constants ( k ) of Ascaris eggs were similar between mix designs (p = 0.62) but varied significantly between temperatures (p = 4.2 x 10-25) and egg enumeration methods (p = 2.4 x 10-8). The k values were of greater magnitude at 34°C compared to at 15°C. At 15°C, k values were not significantly different from zero, indicating no inactivation. The k values we obtained were comparable to those reported in previous studies for different matrices, indicating comparable inactivation of Ascaris eggs on cement-based surfaces compared to liquid and semi-solid matrices. These results provide some of the first estimates of removal efficiencies and inactivation times in realistic environmental conditions for Ascaris on surfaces while supporting the use of OPC mortar mix designs with fly ash in interventions to reduce Ascaris transmission in rural LMIC households.