More Like this

1. Costs and drivers of helminth parasite infection in wild female baboons

   https://doi.org/10.1111/1365-2656.12994  

   Akinyi, Mercy Y. ; Jansen, David ; Habig, Bobby ; Gesquiere, Laurence R. ; Alberts, Susan C. ; Archie, Elizabeth A. ; Cattadori, ed., Isabella ( May 2019 , Journal of Animal Ecology)

   Helminth parasites can have wide‐ranging, detrimental effects on host reproduction and survival. These effects are best documented in humans and domestic animals, while only a few studies in wild mammals have identified both the forces that drive helminth infection risk and their costs to individual fitness.

   Working in a well‐studied population of wild baboons (Papio cynocephalus) in the Amboseli ecosystem in Kenya, we pursued two goals, to (a) examine the costs of helminth infections in terms of female fertility and glucocorticoid hormone levels and (b) test how processes operating at multiple scales—from individual hosts to social groups and the population at large—work together to predict variation in female infection risk.

   To accomplish these goals, we measured helminth parasite burdens in 745 faecal samples collected over 5 years from 122 female baboons. We combine these data with detailed observations of host environments, social behaviours, hormone levels and interbirth intervals (IBIs).

   We found that helminths are costly to female fertility: females infected with more diverse parasite communities (i.e., higher parasite richness) exhibited longer IBIs than females infected by fewer parasite taxa. We also found that females exhibiting highTrichuris trichiuraegg counts also had high glucocorticoid levels. Female infection risk was best predicted by factors at the host, social group and population level: females facing the highest risk were old, socially isolated, living in dry conditions and infected with other helminths.

   Our results provide an unusually holistic understanding of the factors that contribute to inter‐individual differences in parasite infection, and they contribute to just a handful of studies linking helminths to host fitness in wild mammals.

    

   more » « less
2. Ecology eclipses phylogeny as a major driver of nematode parasite community structure in a graminivorous primate

   https://doi.org/10.1111/1365-2435.13603  

   Schneider‐Crease, India ; Beehner, Jacinta C. ; Bergman, Thore J. ; Gomery, Megan A. ; Koklic, Lia ; Lu, Amy ; Snyder‐Mackler, Noah ; Barribeau, ed., Seth ( June 2020 , Functional Ecology)

   Understanding how ecology and phylogeny shape parasite communities can inform parasite control and wildlife conservation initiatives while contributing to the study of host species evolution.

   We tested the relative strengths of phylogeny and ecology in driving parasite community structure in a host whose ecology diverges significantly from that of its closest phylogenetic relatives.

   We characterized the gastrointestinal (GI) parasite community of wild geladasTheropithecus gelada, primates that are closely related to baboons but specialized to graminovory in the Ethiopian Highlands.

   Geladas exhibited very constrained GI parasite communities: only two genera (OesophagostomumandTrichostrongylus) were identified across 305 samples. This is far below the diversity reported for baboons (Papiospp.) and at the low end of the range of domestic grazers (e.g.Bos taurus,Ovis aries) inhabiting the same region and ecological niche.

   Using deep amplicon sequencing, we identified 15 amplicon sequence variants (ASVs) within the two genera, seven of which matched toOesophagostomumsp., seven toTrichostrongylussp., and one toT. vitrinus.

   Population was an important predictor of ASV richness. Geladas in the most ecologically disturbed area of the national park exhibited approximately four times higher ASV richness than geladas at a less disturbed location within the park.

   In this system, ecology was a stronger predictor of parasite community structure than was phylogeny, with geladas sharing more elements of their parasite communities with other grazers in the same area than with closely related sister taxa.

   A freePlain Language Summarycan be found within the Supporting Information of this article.

    

   more » « less
3. The socioecology of parasite infection in wild Bornean orangutans (Pongo pygmaeus wurmbii) in Gunung Palung National Park, West Kalimantan, Indonesia

   O’Connell, Caitlin A. ; Robinson, Natalie ; Karimah, Ishma Fatiha ; Susanto, Tri Wahyu ; Foitova, Ivona ; Knott, Cheryl D. ( February 2020 , American journal of physical anthropology)

   The socioecological model predicts that food availability and risk of parasite transmission influence sociality in primates. As a semi-solitary ape inhabiting the masting forests of Southeast Asia, orangutans provide a unique opportunity to compare social and non-social periods and highly variable foraging conditions within one population. This study compared two data collection periods when fruit availability differed markedly to determine whether sociality and parasite prevalence decrease as expected during periods of fruit scarcity. Fecal samples were analyzed using direct smear and fecal concentration techniques on-site at Cabang Panti Research Station from 2013-2014 and 2018-2019. From the high fruit period to the low fruit period, sociality decreased from 54% of focal follows containing a social event to 29%, while overall parasite prevalence remained the same at 100%. Interesting differences arose for certain parasite species, however. Enterobius sp. prevalence decreased during the low fruit period for both sexes but even more so for males (50% to 29% for females; 56% to 0 for males). Prevalence of Trichuris sp. increased for females during the low fruit period (5% to 43%) while prevalence among males remained the same. These results lend support to the prediction that social contact influences transmission risk for some parasite species, while other parasites may be more responsive to factors such as changes in reproductive state. These findings suggest that differences in the behavioral strategies of the sexes and the differential energetic demands of life history stages have an influence on parasitic infection patterns. 

   more » « less
4. Neotropical migratory and resident birds occurring in sympatry during winter have distinct haemosporidian parasite assemblages

   https://doi.org/10.1111/jbi.13760  

   Soares, Leticia ; Latta, Steven C. ; Ricklefs, Robert E. ( December 2019 , Journal of Biogeography)

   We compared the parasite assemblages of over‐wintering migratory birds and permanent residents on the wintering grounds. We determined whether parasite sharing between migratory and resident birds is influenced by host phylogenetic relatedness. We then inferred whether migratory birds transport haemosporidian parasite lineages between the breeding and wintering grounds.

   Sierra de Bahoruco National Park, Dominican Republic, Hispaniola.

   Migratory and resident birds (primarily Aves: Passeriformes) and their haemosporidian parasites (order Haemosporida,Plasmodium,HaemoproteusandParahaemoproteus).

   We used mist nets to capture birds in thorn scrub, broadleaf dry forests and pine forests during midwinter. We used molecular methods to recognize haemosporidian parasites in blood samples, and genotyped infections based on the nucleotide differences in a region of the parasite cytochromebgene.

   We identified 505 infections by 32 haemosporidian parasite lineages in 1,780 blood samples from 37 resident species, and in 901 blood samples from 14 overwintering migratory species, over five years at the same sites. Infection prevalence varied among migratory species from zero to 13%, whereas infection prevalence among resident species ranged up to 77%. Host relatedness did not predict parasite assemblage similarity. We discuss four hypotheses for the rarity of haemosporidian infections in migratory birds during winter, and for the infrequency of parasite sharing between migratory and resident birds: (a) relative abundance and host preferences of dipteran vectors lower parasite transmission to migratory birds; (b) parasite lineages adapted to infect endemic Caribbean hosts are unable to infect migratory species; (c) the physiology of migratory birds after migration and during winter reduces parasite survival; and (d) infected individuals suffer more pronounced mortality rates during migration. We highlight the link between host–parasite coevolution and the physiological adaptations associated with avian seasonal migration.

    

   more » « less
5. Predictors of zoonotic potential in helminths

   https://doi.org/10.1098/rstb.2020.0356  

   Majewska, Ania A. ; Huang, Tao ; Han, Barbara ; Drake, John M. ( November 2021 , Philosophical Transactions of the Royal Society B: Biological Sciences)

   Helminths are parasites that cause disease at considerable cost to public health and present a risk for emergence as novel human infections. Although recent research has elucidated characteristics conferring a propensity to emergence in other parasite groups (e.g. viruses), the understanding of factors associated with zoonotic potential in helminths remains poor. We applied an investigator-directed learning algorithm to a global dataset of mammal helminth traits to identify factors contributing to spillover of helminths from wild animal hosts into humans. We characterized parasite traits that distinguish between zoonotic and non-zoonotic species with 91% accuracy. Results suggest that helminth traits relating to transmission (e.g. definitive and intermediate hosts) and geography (e.g. distribution) are more important to discriminating zoonotic from non-zoonotic species than morphological or epidemiological traits. Whether or not a helminth causes infection in companion animals (cats and dogs) is the most important predictor of propensity to cause human infection. Finally, we identified helminth species with high modelled propensity to cause zoonosis (over 70%) that have not previously been considered to be of risk. This work highlights the importance of prioritizing studies on the transmission of helminths that infect pets and points to the risks incurred by close associations with these animals. This article is part of the theme issue ‘Infectious disease macroecology: parasite diversity and dynamics across the globe’. 

   more » « less