Biology subjects

Selland, E.

Publications and source records attributed to Selland, E..

3 recordsLinked to original sources

bioRxiv2026

A Common Agrochemical Mixture Increases Snail Hosts and Ecological Drivers of Schistosomiasis Risk

O_LIAgricultural intensification is accelerating across tropical regions, increasing fertilizer and pesticide inputs into freshwater ecosystems that regulate the transmission of many environmentally mediated diseases. For schistosomiasis, a major neglected tropical disease, transmission risk is strongly governed by the abundance of freshwater snail intermediate hosts and their aquatic habitat, yet most agrochemical studies have focused on single compounds rather than realistic mixtures. C_LIO_LIUsing replicated semi-natural aquatic microcosms, we experimentally tested how nitrogen- urea fertilizer and the widely used herbicide atrazine, applied alone and in combination at environmentally relevant concentrations, alter snail hosts (Biomphalaria glabrata), submerged aquatic vegetation (Ceratophyllum demersum), and algal resources that underpin schistosomiasis transmission. C_LIO_LIFertilizer and atrazine, both singly and together, increased snail habitat (C. demersum) and adult snail abundance. By reducing phytoplankton, atrazine likely alleviated shading on vegetation, thereby promoting habitat that supported snails through indirect bottom-up pathways. Agrochemical mixtures produced non-additive effects on host and habitat dynamics, indicating that transmission-relevant ecological responses cannot be predicted from single-compound exposures alone. Although parasite infection levels were low, the observed increases in snail hosts and habitat represent reliable ecological drivers of schistosomiasis risk. C_LIO_LISynthesis and applications. Our findings demonstrate that common agrochemical mixtures can restructure freshwater food webs in ways likely to elevate disease risk, highlighting the need to incorporate mixture-driven ecological responses into agrochemical risk assessment and agricultural management strategies in disease-endemic regions. C_LI

ecology↗

bioRxiv2025

Rice-Fish Co-Culturing for Sustainability, Food Security, and Disease and Poverty Reduction

Over 140 million households cultivate rice worldwide. However, rice production contributes to exceedances of planetary boundaries, such as freshwater use and biogeochemical flows. Additionally, rice-farming families may face increased risk of acquiring schistosomiasis, a parasitic disease transmitted by freshwater snails that contributes to reinforcing cycles of poverty and disease. Using data from 405 households in rural Senegal, we show that children in rice-farming households had higher Schistosoma mansoni prevalence and S. haematobium intensities than non-farming peers. To address this environmental-health challenge, we integrated native Nile Tilapia (Oreochromis niloticus) and African Bonytongue (Heterotis niloticus) into rice fields. The fish thrived, suppressed insects and snail pests, improved soil nutrients, and boosted rice yields by >25% with a net benefit of 1,805-3,415 USD/ha/year (benefit-to-cost ratio = 7.42). Hence, low-input rice-fish co-culturing offers a scalable planetary health solution that simultaneously advances sustainability, nutrition, health, and rural livelihoods. ResumePlus de 140 millions de foyers a travers le monde cultivent du riz. Cependant, cette production exerce une pression importante sur les ressources naturelles, notamment les reserves deau douce. Par ailleurs, les menages pratiquant la riziculture peuvent etre plus exposes au risq ue de bilharziose, une maladie parasitaire transmise par des escargots deau douce, qui contribue au cycle de pauvrete. A partir de donnees collectees aupres de 405 menages dans des villages senegalais, nous montrons que les enfants issus de familles pratiquant la riziculture presentent une prevalence plus elevee dinfection a Shistosoma mansoni et des intensites dinfection a S. haematobium plus importantes que ceux issues de familles ne cultivant pas le riz. Pour remedier a cela, nous avons integre deux especes locales de poissons, le tilapia du Nil (Oreochromis niloticus) et lHeterotis (Heterotis niloticus), dans les rizieres, afin de reduire les population descargots hotes, ameliorer les rendements agricoles et augmenter les revenus. Ces poissons ont montre une bonne croissance, ont contribue a la regulation des insectes et des escargots nuisibles, ont enrichi le sol en nutriments, et accru les rendements rizicoles de plus de 25%, avec un benefice net estime entre 1 805 et 3 415 USD/ha/an (ratio benefice-cout = 7,42). Ainsi, la co-culture riz-poisson a faibles intrants constitue une solution reproductible en faveur de la sante publique, permettant de concilier durabilite, nutrition et amelioration des moyens de subsistance en milieu rural.

ecology↗

bioRxiv2022

Global change drivers and the risk of infectious disease

Anthropogenic change is contributing to the rise in emerging infectious diseases, but it remains unclear which global change drivers most increase disease and under what contexts. We amassed a dataset from the literature that includes 1,832 observations of infectious disease responses to global change drivers across 1,202 host-parasite combinations. We found that biodiversity loss, climate change, and introduced species were associated with increases in disease-related endpoints or harm (i.e., enemy release for introduced species), whereas urbanization was associated with decreases in disease endpoints. Natural biodiversity gradients, deforestation, forest fragmentation, and most classes of chemical contaminants had non-significant effects on these endpoints. Overall, these results were consistent across human and non-human diseases. Context-dependent effects of the global change drivers on disease were common and are discussed. These findings will help better target disease management and surveillance efforts towards global change drivers that increase disease. One-Sentence SummaryHere we quantify which global change drivers increase infectious diseases the most to better target global disease management and surveillance efforts.

ecology↗