Seroprevalence of <i>Toxoplasma gondii</i>.

<p>Data from 11 study sites with varying degrees of domestic cat presence, (NS = Not samples).</p

Effects of landscape variables on seroprevalence.

<p>A) Observed seroprevalence in mink and otter by study site. B) Observed seroprevalence by degree of presence of domestic cat. C) Observed seroprevalence by habitat. * Number above bars indicate sample size. Y axis show mean seroprevalence.</p

Study area.

<p>Eleven study sites, grouped into four study areas in Southern Chile, between latitude 39°-45° S. Area 1, represents an Andean foothill ecosystem (1:Liquiñe, 2:Neltume, 3:Choshuenco, 4:Todos los Santos); area 2, represents a marine coastal ecosystem (5:Maullín, 7:Puyuhuapi, 8:Puerto Cisnes, 9:Rio-Cisnes); area 3, represents Southern Andean mountain valleys (6:Palena, 10:Rio-Cisnes-Alto); area 4, represents an island (11:Magdalena Island). Red: High degree of presence human-domestic cat. Orange: Medium degree of presence human-domestic cat. Green: Low degree of presence human-domestic cat.</p

Variable importance analysis performed using random forest.

<p>The set of four categorical variables (age, species, habitat type, sex) and two continuous variables (human presence and cat density) used for classification the seropositivity to <i>Toxoplasma gondii</i>. Variables are ordered by their importance from top to bottom as estimated by the random forest model and denoted using an Gini index ranging from 0 to 100.</p

Land cover change and <i>Toxoplasma gondii</i> reports.

<p>Positive (red crosses) and negative (white crosses) reports of <i>T</i>. <i>gondii</i> in wildlife compared with vegetation change represented in the second principal component of the EVI 2002 and 2012. Change was denoted as areas of vegetation gain (green) and stability (light blue), and considerable vegetation loss (dark blue).</p

Diet reconstruction with Bayesian mixing model: percentage of use of main food sources for each breeding colony and year.

<p>Given values are medians, with 95% credibility intervals in brackets. Values in bold represent the main food source; underlined values represent the secondary source.</p

<i>Toxoplasma gondii</i> Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources

<div><p>Understanding the spread of <i>Toxoplasma gondii</i> (<i>T</i>. <i>gondii</i>) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (<i>Larus michahellis</i>) and Audouin’s gull (<i>L</i>. <i>audouinii</i>)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against <i>T</i>. <i>gondii</i>. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall <i>T</i>. <i>gondii</i> seroprevalence was 21.0% (IC_95% 17.5–24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of <i>T</i>. <i>gondii</i>. Year differences could indicate fluctuating rates of exposure of seagull chicks to <i>T</i>. <i>gondii</i>. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report <i>T</i>. <i>gondii</i> antibodies in Yellow-legged and Audouin’s gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology.</p></div

Seroprevalence of <i>Toxoplasma gondii</i> in seagulls from Spain.

<p>Seroprevalence of <i>Toxoplasma gondii</i> in seagulls from Spain.</p

Logistic regression analysis of potential risk factors associated with <i>T. gondii</i> seropositivity in wild birds in Spain.

<p>*Reference category.</p

Seropositivity of <i>Toxoplasma gondii</i> (95% confidence limits) in wild birds from Spain among periods (years) of sampling.

<p>Seropositivity of <i>Toxoplasma gondii</i> (95% confidence limits) in wild birds from Spain among periods (years) of sampling.</p