Supplemented nutrition decreases helminth burden and increases drug efficacy in a natural host–helminth system

Gastrointestinal helminths are common parasites of humans, wildlife, and livestock, causing chronic infections. In humans and wildlife, poor nutrition or limited resources can compromise individuals’ immune response, predisposing them to higher helminth burdens. This relationship has been tested in laboratory models by investigating infection outcomes following reductions of specific nutrients. However, much less is known about how diet supplementation can impact susceptibility to infection, acquisition of immunity, and drug efficacy in natural host-helminth systems. We experimentally supplemented the diet of wood mice Apodemus sylvaticus) with high quality nutrition and measured resistance to the common gastrointestinal nematode Heligmosomoides polygyrus. To test whether diet can enhance immunity to reinfection, we also administered anthelmintic treatment at random in both natural and captive populations. Supplemented wood mice were more resistant to H. polygyrus infection, cleared worms more efficiently after treatment, avoided a post-treatment infection rebound, produced stronger general and parasite-specific antibody responses, and maintained better body condition. In addition, when applied in conjunction with anthelmintic treatment, supplemented nutrition significantly reduced H. polygyrus transmission potential. These results show the rapid and extensive benefits of a well-balanced diet and have important implications for both disease control and wildlife health under changing environmental conditions

Association between anthropization and rodent reservoirs of zoonotic pathogens in Northwestern Mexico.

The world is facing a major pulse of ecological and social changes that may favor the risk of zoonotic outbreaks. Such risk facilitation may occur through the modification of the host's community diversity and structure, leading to an increase in pathogen reservoirs and the contact rate between these reservoirs and humans. Here, we examined whether anthropization alters the relative abundance and richness of zoonotic reservoir and non-reservoir rodents in three Socio-Ecological Systems. We hypothesized that anthropization increases the relative abundance and richness of rodent reservoirs while decreasing non-reservoir species. We first developed an Anthropization index based on 15 quantitative socio-ecological variables classified into five groups: 1) Vegetation type, 2) Urbanization degree, 3) Water quality, 4) Potential contaminant sources, and 5) Others. We then monitored rodent communities in three regions of Northwestern Mexico (Baja California, Chihuahua, and Sonora). A total of 683 rodents of 14 genera and 27 species were captured, nine of which have been identified as reservoirs of zoonotic pathogens (359 individuals, 53%). In all regions, we found that as anthropization increased, the relative abundance of reservoir rodents increased; in contrast, the relative abundance of non-reservoir rodents decreased. In Sonora, reservoir richness increased with increasing anthropization, while in Baja California and Chihuahua non-reservoir richness decreased as anthropization increased. We also found a significant positive relationship between the anthropization degree and the abundance of house mice (Mus musculus) and deer mice (Peromyscus maniculatus), the most abundant reservoir species in the study. These findings support the hypothesis that reservoir species of zoonotic pathogens increase their abundance in disturbed environments, which may increase the risk of pathogen exposure to humans, while anthropization creates an environmental filtering that promotes the local extinction of non-reservoir species

The rising global economic costs of invasive Aedes mosquitoes and Aedes-borne diseases

The database of the economic costs, including the database descriptors and the full list of references (Data S1), the database of Aedes invasions (Data S2), data sources for Aedes-borne disease incidence estimates (Data S3), and the Code for the analysis and graphs in R (Data S4) can be downloaded from the following Dryad repository (https://datadryad.org/stash/share/AJJnBnPHBWuRNBdCyKi2U1txf2YLUGHXU2daAXC1G9Q).International audienceHighlights: • Dengue, Zika and chikungunya are transmitted by Aedes aegypti and Aedes albopictus. • These invasive species carry a significant but not well-characterized economic cost. • Our study reports costs from 166 countries and territories, spanning 45 years. • The cumulative reported cost amounted to at least US dollars 94.7 billion. • Costs are increasing and only a modest proportion (1/10) is invested in prevention.Abstract: Invasive Aedes aegypti and Aedes albopictus mosquitoes transmit viruses such as dengue, chikungunya and Zika, posing a huge public health burden as well as having a less well understood economic impact. We present a comprehensive, global-scale synthesis of studies reporting these economic costs, spanning 166 countries and territories over 45 years. The minimum cumulative reported cost estimate expressed in 2022 US dollars was 94.7 billion, although this figure reflects considerable underreporting and underestimation. The analysis suggests a 14-fold increase in costs, with an average annual expenditure of US dollars 3.1 billion, and a maximum of US dollars 20.3 billion in 2013. Damage and losses were an order of magnitude higher than investment in management, with only a modest portion allocated to prevention. Effective control measures are urgently needed to safeguard global health and well-being, and to reduce the economic burden on human societies. This study fills a critical gap by addressing the increasing economic costs of Aedes and Aedes-borne diseases and offers insights to inform evidence-based policy.Graphical abstract: https://ars.els-cdn.com/content/image/1-s2.0-S0048969724032017-ga1.jp

Overdispersion evaluation for GLMM with Poisson distribution.

Overdispersion evaluation for GLMM with Poisson distribution.</p

Anthropization variables.

We evaluated 15 variables classified into five groups. Most of the variables were derived from repositories and databases.</p

PCA-Biplot of variables and sites.

The small symbols represent the sites in each region and are contained in an ellipse, representing the 95% Confidence Intervals (CI) for each region. The larger, centered symbols in each ellipse represent the average of the scores for each region.</p

S1 File -

Database of a) site coordinates, b) Anthropization Index variables, c) anthropization degree of sites, and d) rodent monitoring. (XLSX)</p

List of rodent species captured in the survey.

Number of individuals of each species for each region and both sampling seasons.</p

GLMM’s prediction plot of rodent richness.

Predicted counts of the association between anthropization and non-reservoir richness in BC+CHI. Grey shadows represent CI 95%.</p

GLMM’s prediction plots of the effect of anthropization on the RA of rodents.

(A) Predicted probabilities for reservoir species and (B) predicted probabilities for non-reservoir species in BC+CHI. Grey shadows represent CI 95%.</p