How much effort is required to accurately describe the complex ecology of a rodent‐borne viral disease?

Abstract

We use data collected on 18,1-ha live trapping grids monitored from 1994 through 2005 and on five of those grids through 2013 in the mesic northwestern US to illustrate the complexity of the deer mouse (Peromyscus maniculatus)/Sin Nombre virus (SNV) host-pathogen system. Important factors necessary to understand zoonotic disease ecology include those associated with distribution and population dynamics of reservoir species as well as infection dynamics. Results are based on more than 851,000 trap nights, 16,608 individual deer mice and 10,572 collected blood samples. Deer mice were distributed throughout every habitat we sampled and were present during every sampling period in all habitats except high altitude habitats over1900 m. Abundance varied greatly among locations with peak numbers occurring mostly during fall. However, peak rodent abundance occurred during fall, winter and spring during various years on three grids trapped 12 mo/yr. Prevalence of antibodies to SNV averaged 3.9% to 22.1% but no grids had mice with antibodies during every month. The maximum period without antibody-positive mice ranged from one month to 52 months, or even more at high altitude grids where deer mice were not always present. Months without antibody-positive mice were more prevalent during fall than spring. Population fluctuations were not synchronous over broad geographic areas and antibody prevalences were not well spatially consistent, differing greatly over short distances. We observed an apparently negative, but non-statistically significant relationship between average antibody prevalence and average deer mouse population abundance and a statistically significant positive relationship between the average number of antibody positive mice and average population abundance. We present data from which potential researchers can estimate the effort required to adequately describe the ecology of a rodent-borne viral system. We address different factors affecting population dynamics and hantavirus antibody prevalence and discuss the path to understanding a complex rodent-borne disease system as well as the obstacles in that path.

Movimientos de roedores intra- e inter-ambiente y riesgo de exposición al Hantavirus "Andes" en Patagonia norte, Argentina

“…El esfuerzo de muestreo necesario para describir la ecología de un sistema roedorHantavirus es alto, ya que existen varios factores que modulan las dinámicas poblacionales del reservorio y de la prevalencia de infección (Douglass and Vadell 2016). En este contexto, estudios a largo plazo de marcado y recaptura de roedores Armien et al 2009;Piudo et al 2011) resultan relevantes eco-epidemiológicamente, ya que intentan clarificar alguno de esos aspectos como el de la prevalencia de anticuerpos y la ecología espacial de los roedores reservorio en sistemas silvestre-doméstico.…”

“…En este contexto, estudios a largo plazo de marcado y recaptura de roedores Armien et al 2009;Piudo et al 2011) resultan relevantes eco-epidemiológicamente, ya que intentan clarificar alguno de esos aspectos como el de la prevalencia de anticuerpos y la ecología espacial de los roedores reservorio en sistemas silvestre-doméstico. Además, permiten modelar evitando las generalizaciones de la extrapolación, lo que los hace marcadamente más útiles en el contexto local (Mills et al 2010;Douglass and Vadell 2016). De este modo, en el escenario general de nuestra área de estudio, el riesgo de infección por Hantavirus podría reducirse drásticamente mediante la remoción sistemática de roedores en ambientes domésticos con la previa hermetización de las viviendas rurales y una política de ordenamiento territorial local en las construcciones domésticas evitando la entrada y permanencia de nuevos roedores silvestres.…”

A damped precipitation-driven, bottom-up model for deer mouse population abundance in the northwestern United States

“…), which were only present sporadically on the grids. Small‐mammal communities at our study sites were relatively simple compared to studies conducted in the US southwest (Douglass & Vadell, ). Therefore, although competition (either by aggressive interference or by simply getting to the food first) may have occurred at some point on some of our grids, we can expect that it was not a strong factor determining deer mouse abundance at our study sites.…”

“…We sampled three grids per site over 12–17 years (Table ). Except for high‐altitude grids (>1,590 m), deer mice were present during all sampling periods at all locations (Douglass & Vadell, ).…”

“…In contrast, in the mesic parts of the US west, deer mouse populations tend to be nearly ubiquitous, although at varying abundance regardless of climatic changes (Douglass & Vadell, ; Douglass et al., ). Mesic habitats (coniferous forests, grasslands, and sagebrush) present situations where plant productivity in response to climate conditions is likely to be much less dramatic than in the arid US southwest.…”