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Raccoons are host to diverse gastrointestinal parasites, but little is known about the ecology of these parasites in terms of their interactions with each other during coinfections, their interactions with host physiology and environmental factors, and their impact on raccoon health and survival. As a first step, we investigated the patterns of parasite infection and their demographic distribution in an urban-suburban population of raccoons trapped in the summers and autumns of 2018 and 2019. We collected faecal samples, demographic data, morphometric measurements, and blood smears, and used GPS data to classify trapping location by land cover type. Faecal floats were performed to detect and quantify gastrointestinal nematode eggs and coccidia oocysts, and white blood cell differentials were performed on blood smears to characterise white blood cell distributions. Data were analysed cross-sectionally and, where possible, longitudinally, using generalised linear models. Overall, 62.6% of sampled raccoons were infected with gastrointestinal nematodes, and 82.2% were infected with gastrointestinal coccidia. We analysed predictors of infection status and faecal egg count for three different morphotypes of nematode— Baylisascaris , strongyle, and capillariid nematodes—and found that infection status and egg count varied with Year, Month, Age class, Land cover, and coinfection status, though the significance of these predictors varied between nematode types. Gastrointestinal coccidia prevalence varied with Year, Month, Age class, strongyle infection status, and capillariid infection status. Coccidia oocyst counts were lower in adults and in October, but higher in females and in raccoons trapped in areas with natural land cover; furthermore, coccidia oocysts were positively associated with capillariid faecal egg counts. We found no evidence that gastrointestinal parasites influenced raccoon body condition or overwinter mortality, and so conclude that raccoons, though harbouring diverse and abundant gastrointestinal parasites, may be relatively tolerant of these parasites. [Display omitted] • Predictors of raccoon nematode infection vary but include Year, Month, Age class, Land cover, and coinfection status. • Coccidia infection status varies with Year, Month, Age class, strongyle infection status, and capillariid infection status. • Our results suggest that raccoons acquire immunity to nematodes but not coccidia. • Gastrointestinal parasites were not associated with body condition or juvenile overwinter mortality. [ABSTRACT FROM AUTHOR]

Immune responses to vaccination are heterogeneous between individuals; the same vaccine that provides protection in one circumstance may be ineffective in another. One factor that could influence the response to vaccination is concurrent or prior infection with unrelated parasites. Here, we review both the experimental and epidemiological literature on parasite-vaccine interactions, and present a meta-analysis of the published data. In total, our review returned 101 relevant articles, 50 of which met criteria for meta-analysis. Parasite factors potentially affecting vaccination include the type of parasite involved, the stage of infection, and the timing of infection relative to vaccination. Vaccine factors affecting likelihood of interference by parasites include vaccine formulation, route of administration, and the type of immune response required to provide protection against the target antigen. Our meta-analysis of these data show three key things: (1) parasite infections at the time of vaccination result in worse immunisation outcomes, (2) chronic helminth infections are more likely to negatively impact immunisation than acute helminth infections, and (3) thymus-dependent vaccines are more susceptible to parasite interference than thymus-independent vaccines. Our findings highlight the importance of considering and mitigating parasite infections: by taking parasites into account, it should be possible to more effectively immunise individuals and populations. [ABSTRACT FROM AUTHOR]

The ongoing West African Ebola epidemic highlights a recurring trend in the zoonotic emergence of virulent pathogens likely to come from bat reservoirs that has caused epidemiologists to ask ‘Are bats special reservoirs for emerging zoonotic pathogens?’ We collate evidence from the past decade to delineate mitochondrial mechanisms of bat physiology that have evolved to mitigate oxidative stress incurred during metabolically costly activities such as flight. We further describe how such mechanisms might have generated pleiotropic effects responsible for tumor mitigation and pathogen control in bat hosts. These synergisms may enable ‘special’ tolerance of intracellular pathogens in bat hosts; paradoxically, this may leave them more susceptible to immunopathological morbidity when attempting to clear extracellular infections such as ‘white-nose syndrome’ (WNS). [ABSTRACT FROM AUTHOR]

Many disease systems exhibit complexities not captured by current theoretical and empirical work. In particular, systems with multiple host species and multiple infectious agents (i.e., multi-host, multi-agent systems) require novel methods to extend the wealth of knowledge acquired studying primarily single-host, single-agent systems. We outline eight challenges in multi-host, multi-agent systems that could substantively increase our knowledge of the drivers and broader ecosystem effects of infectious disease dynamics. [ABSTRACT FROM AUTHOR]

Do stress hormones, such as corticosterone, enhance bird susceptibility to mosquitoes in ways that enhance rates of co-infection? Does this then enhance pathogen emergence? [ABSTRACT FROM AUTHOR]

Concentrated monoclonal antibody (mAb) solutions can lead to high viscosity as a result of protein-protein interactions and pose challenges for manufacture. Dipicolinic acid (DPA, pyridine-2,6-dicarboxylic acid) is a potential excipient for reduction of protein solution viscosity and here we describe new DPA salts with improved aqueous solubility. Crystallinity and solubility screens identified ethanolamine and diethanolamine as two promising counterions which generated crystalline, high melting point, anhydrous salt forms of DPA at 2:1 M stoichiometry. These salts significantly reduced the solution viscosity of five mAbs, equal to or better than that for the addition of arginine hydrochloride at equivalent osmolality. The presence of the DPA salts in solution did not significantly perturb the melting point of the mAbs, as determined by calorimetry, indicating an absence of any destabilization of protein conformation. Addition of the DPA salts to the mAb solutions stored at 5 °C over 6 months did not cause additional loss of the monomer fraction, though evidence of increased aggregation and fragmentation for three of the five mAbs was observed during 40 °C (accelerated and stressed) storage. Overall, this study demonstrates that ethanolamine-DPA and diethanolamine-DPA can serve as two novel excipients for viscosity reduction and could be considered by formulation scientists when developing highly concentrated mAb formulations. [ABSTRACT FROM AUTHOR]

Madagascar is home to three endemic species of Old World Fruit Bat, which are important pollinators and seed dispersers. We aimed to quantitatively assess population trajectories for the two largest of these species, the IUCN-listed 'Vulnerable' Eidolon dupreanum and Pteropus rufus. To this end, we conducted a longitudinal field study, in which we live-captured E. dupreanum and P. rufus , estimated species-specific fecundity rates, and generated age-frequency data via histological analysis of cementum annuli layering in tooth samples extracted from a subset of individuals. We fit exponential models to resulting data to estimate annual survival probabilities for adult bats (s A =.794 for E. dupreanum ; s A =.511 for P. rufus), then applied Lefkovitch modeling techniques to infer the minimum required juvenile survival rate needed to permit longterm population persistence. Given estimated adult survival, population persistence was only possible for E. dupreanum when field-based fecundity estimates were replaced by higher values reported in the literature for related species. For P. rufus , tooth-derived estimates of adult survival were so low that even assumptions of perfect (100%) juvenile annual survival would not permit stable population trajectories. Age-based survival analyses were further supported by longitudinal exit counts carried out from 2013 to 2018 at three local P. rufus roost sites, which demonstrated a statistically significant, faintly negative time trend, indicative of subtle regional population declines. These results suggest that Malagasy fruit bat species face significant threats to population viability, with P. rufus particularly imperiled. Immediate conservation interventions, including habitat restoration and cessation of legally sanctioned bat hunting, are needed to protect Madagascar's fruit bats into the future. [ABSTRACT FROM AUTHOR]

Reducing threats to biodiversity is the key objective of ranger patrols in protected areas. However, efforts can be hampered by rangers' inability to detect threats, and poor understanding of threat abundance and distribution in a landscape. Snares are particularly problematic due to their cryptic nature and limited selectivity with respect to captured animals' species, sex, or age. Using an experimental approach, we investigated the effect of search effort, habitat, season, and team on rangers' detection of snares in a tropical forest landscape. We provide an effort-detection curve, and use our findings to make preliminary predictions about snare detection under different scenarios of patrol effort. Results suggest that the overall probability of a searcher detecting any given snare in a 0.25/km2 area, assuming 60 min (or approximately 2 km) of search effort is 20% (95% CI ± 15–25%), with no significant effect of season, habitat or team. Our models suggested this would increase by approximately 10% with an additional 30mins/1 km of search effort. Our preliminary predictions of the effectiveness of different patrolling scenarios show that detection opportunities are maximised at low effort levels by deploying multiple teams to a single area, but at high effort levels deploying single teams becomes more efficient. Our results suggest that snare detectability in tropical forest landscapes is likely to be low, and may not improve dramatically with increased search effort. Given this, managers need to consider whether intensive snare-removal efforts are the best use of limited resources; the answer will depend on their underlying objectives. [ABSTRACT FROM AUTHOR]