GeoComputation and Disease Ecology

The distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. Lizards (such as the western fence lizard; Sceloporus occidentalis ) play a unique role in Lyme disease ecology in the far-western United States. Lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks ( Ixodes pacificus —the vector for Lyme disease in that region) but are not competent reservoirs for the pathogen, Borrelia burgdorferi . Prior studies have suggested that the net effect of lizards is to reduce risk of human exposure to Lyme disease, a hypothesis that we tested experimentally. Following experimental removal of lizards, we documented incomplete host switching by larval ticks (5.19%) from lizards to other hosts. Larval tick burdens increased on woodrats, a competent reservoir, but not on deer mice, a less competent pathogen reservoir. However, most larvae failed to find an alternate host. This resulted in significantly lower densities of nymphal ticks the following year. Unexpectedly, the removal of reservoir-incompetent lizards did not cause an increase in nymphal tick infection prevalence. The net result of lizard removal was a decrease in the density of infected nymphal ticks, and therefore a decreased risk to humans of Lyme disease. Our results indicate that an incompetent reservoir for a pathogen may, in fact, increase disease risk through the maintenance of higher vector density and therefore, higher density of infected vectors.

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War and peace: social interactions in infections

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2013.0365 ◽

2014 ◽

Vol 369 (1642) ◽

pp. 20130365 ◽

Cited By ~ 36

Author(s):

Helen C. Leggett ◽

Sam P. Brown ◽

Sarah E. Reece

Keyword(s):

Species Interactions ◽

Disease Ecology ◽

Social Evolution ◽

Inclusive Fitness ◽

Experimental Tests ◽

Microbial Pathogens ◽

Emergent Properties ◽

Social Strategies ◽

Inclusive Fitness Theory ◽

Social Behaviours

One of the most striking facts about parasites and microbial pathogens that has emerged in the fields of social evolution and disease ecology in the past few decades is that these simple organisms have complex social lives, indulging in a variety of cooperative, communicative and coordinated behaviours. These organisms have provided elegant experimental tests of the importance of relatedness, kin discrimination, cooperation and competition, in driving the evolution of social strategies. Here, we briefly review the social behaviours of parasites and microbial pathogens, including their contributions to virulence, and outline how inclusive fitness theory has helped to explain their evolution. We then take a mechanistically inspired ‘bottom-up’ approach, discussing how key aspects of the ways in which parasites and pathogens exploit hosts, namely public goods, mobile elements, phenotypic plasticity, spatial structure and multi-species interactions, contribute to the emergent properties of virulence and transmission. We argue that unravelling the complexities of within-host ecology is interesting in its own right, and also needs to be better incorporated into theoretical evolution studies if social behaviours are to be understood and used to control the spread and severity of infectious diseases.

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Prevalence and Diversity of Avian Haematozoan Parasites in Wetlands of Bangladesh

Journal of Parasitology Research ◽

10.1155/2014/493754 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 8

Author(s):

Rubayet Elahi ◽

Ausraful Islam ◽

Mohammad Sharif Hossain ◽

Khaja Mohiuddin ◽

Andrea Mikolon ◽

...

Keyword(s):

Sample Size ◽

Disease Ecology ◽

Infection Intensity ◽

Wild Birds ◽

Wetland Birds ◽

Domestic Ducks ◽

Wide Range ◽

Unidentified Species ◽

Larger Sample ◽

Resident Bird

The parasites of generaHaemoproteus, Plasmodium,andLeucocytozoonare well-known avian haematozoa and can cause declined productivity and high mortality in wild birds. The objective of the study was to record the prevalence of haematozoan parasites in a wide range of wetland birds in Bangladesh. Six species ofHaemoproteus, seven species ofPlasmodium, one unidentified species ofLeucocytozoon, and one unidentified microfilaria of the genusParonchocercawere found. Data on the morphology, size, hosts, prevalence, and infection intensity of the parasites are provided. The overall prevalence among the birds was 29.5% (95 out of 322 birds). Of those, 13.2% (42 of 319) of birds were infected withHaemoproteusspp., 15.1% withPlasmodiumspp. (48 of 319) and 0.6% withLeucocytozoonspp. (2 of 319). Two birds were positive for bothHaemoproteussp. andPlasmodiumsp. A single resident bird,Ardeola grayii, was found positive for an unidentified microfilaria. Prevalence of infection varied significantly among different bird families. Wild birds of Bangladesh carry several types of haematozoan parasites. Further investigation with a larger sample size is necessary to estimate more accurately the prevalence of haematozoan parasites among wild birds as well as domestic ducks for better understanding of the disease ecology.

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Setting the Terms for Zoonotic Diseases: Effective Communication for Research, Conservation, and Public Policy

Viruses ◽

10.3390/v13071356 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1356

Author(s):

Julie Teresa Shapiro ◽

Luis Víquez-R ◽

Stefania Leopardi ◽

Amanda Vicente-Santos ◽

Ian H. Mendenhall ◽

...

Keyword(s):

Public Policy ◽

Interdisciplinary Research ◽

Disease Ecology ◽

Wildlife Conservation ◽

Research Problem ◽

Zoonotic Diseases ◽

Biological Processes ◽

Language Experience ◽

The Public ◽

Key Concepts

Many of the world’s most pressing issues, such as the emergence of zoonotic diseases, can only be addressed through interdisciplinary research. However, the findings of interdisciplinary research are susceptible to miscommunication among both professional and non-professional audiences due to differences in training, language, experience, and understanding. Such miscommunication contributes to the misunderstanding of key concepts or processes and hinders the development of effective research agendas and public policy. These misunderstandings can also provoke unnecessary fear in the public and have devastating effects for wildlife conservation. For example, inaccurate communication and subsequent misunderstanding of the potential associations between certain bats and zoonoses has led to persecution of diverse bats worldwide and even government calls to cull them. Here, we identify four types of miscommunication driven by the use of terminology regarding bats and the emergence of zoonotic diseases that we have categorized based on their root causes: (1) incorrect or overly broad use of terms; (2) terms that have unstable usage within a discipline, or different usages among disciplines; (3) terms that are used correctly but spark incorrect inferences about biological processes or significance in the audience; (4) incorrect inference drawn from the evidence presented. We illustrate each type of miscommunication with commonly misused or misinterpreted terms, providing a definition, caveats and common misconceptions, and suggest alternatives as appropriate. While we focus on terms specific to bats and disease ecology, we present a more general framework for addressing miscommunication that can be applied to other topics and disciplines to facilitate more effective research, problem-solving, and public policy.

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White Syndrome-Affected Corals Have a Distinct Microbiome at Disease Lesion Fronts

Applied and Environmental Microbiology ◽

10.1128/aem.02799-16 ◽

2016 ◽

Vol 83 (2) ◽

Cited By ~ 19

Author(s):

F. Joseph Pollock ◽

Naohisa Wada ◽

Gergely Torda ◽

Bette L. Willis ◽

David G. Bourne

Keyword(s):

Disease Ecology ◽

Tissue Loss ◽

Coral Tissue ◽

Health States ◽

Host Coral ◽

Tissue Samples ◽

Content Type ◽

White Syndrome ◽

Community Profiling

ABSTRACT Coral tissue loss diseases, collectively known as white syndromes (WSs), induce significant mortality on reefs throughout the Indo-Pacific, yet definitive confirmation of WS etiologies remains elusive. In this study, we integrated ecological disease monitoring, bacterial community profiling, in situ visualization of microbe-host interactions, and cellular responses of the host coral through an 18-month repeated-sampling regime. We assert that the observed pathogenesis of WS lesions on acroporid corals at Lizard Island (Great Barrier Reef) is not the result of apoptosis or infection by Vibrio bacteria, ciliates, fungi, cyanobacteria, or helminths. Histological analyses detected helminths, ciliates, fungi, and cyanobacteria in fewer than 25% of WS samples, and helminths and fungi were also observed in 12% of visually healthy samples. The abundances of Vibrio-affiliated sequences (assessed using 16S rRNA amplicon sequencing) did not differ significantly between health states and never exceeded 3.3% of reads in any individual sample. In situ visualization detected Vibrio bacteria only in summer WS lesion samples and revealed no signs of these bacteria in winter disease samples (or any healthy tissue samples), despite continued disease progression year round. However, a 4-fold increase in Rhodobacteraceae-affiliated bacterial sequences at WS lesion fronts suggests that this group of bacteria could play a role in WS pathogenesis and/or serve as a diagnostic criterion for disease differentiation. While the causative agent(s) underlying WSs remains elusive, the microbial and cellular processes identified in this study will help to identify and differentiate visually similar but potentially distinct WS etiologies. IMPORTANCE Over the past decade, a virulent group of coral diseases known as white syndromes have impacted coral reefs throughout the Indian and Pacific Oceans. This article provides a detailed case study of white syndromes to combine disease ecology, high-throughput microbial community profiling, and cellular-scale host-microbe visualization over seasonal time scales. We provide novel insights into the etiology of this devastating disease and reveal new diagnostic criteria that could be used to differentiate visually similar but etiologically distinct forms of white syndrome.

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