analysis of FIV risk factors.

<p>analysis of FIV risk factors.</p

Projection of the confidence region of the model <i>H⁰</i> (including both males and females) on the parameter (<i>β_F</i>, <i>ε_F</i>) space for <i>p_NC</i> = 0.30.

<p>The plotted region represents all paired values (<i>β_F</i>,<i>ε_F</i>) for which there exist concomitant values of the parameters <i>β_M</i> and <i>ε_M,</i> such that the observed data are a plausible outcome of the model.</p

The study area.

<p>We identified three metapopulations (grey areas). Studied cat populations are represented with black rectangles and solid arrows represent the suspected interactions between the studied populations. Some unstudied populations may interact with the studied ones (dashed arrows) and are represented by white rectangles.</p

Total number of sampled cats, adult sex-ratio, number of FIV seropositive individuals (FIV+) and mean age of captured males and females in each population.

<p>Total number of sampled cats, adult sex-ratio, number of FIV seropositive individuals (FIV+) and mean age of captured males and females in each population.</p

Consistency of the different models with male prevalence data.

<p>95% confidence interval of FIV prevalence in the 15 population: with the dynamic epidemic model (a) and the binomial model (b). Crosses represent the mean of the distribution and black points the observed FIV prevalence data. (c) Comparison of the variance of male FIV prevalence between the 15 populations estimated from the field, and predicted by the binomial model and by the dynamic model. (d) Theoretical distribution of the estimated variance of FIV prevalence in males with the male transmission model. Black bar represents the observed value of this quantity.</p

Compartmental representation of the model.

<p>The model includes both males (susceptible, <i>S_M</i> or infected, <i>I_M</i>) and females (susceptible, <i>S_F</i> or infected, <i>I_F</i>). Dashed arrows illustrate the fact that infected males are responsible for FIV transmission to both susceptible males and females.</p

Results of the model.

<p>Parameter values: <i>β_M</i> = 0.025 and <i>M</i> = 50. (a) Distribution of FIV prevalence in males (solid line, <i>ε_M</i> = 0.01). A binomial distribution having the same mean is also represented (dashed line) and (b) the effect of the male external transmission rate (<i>ε_M</i>) on mean FIV prevalence conditioned to non-extinction (solid line, left axis, the grey area represents the standard deviation of FIV prevalence) and on the probability of FIV extinction (dashed line, right axis).</p

Confidence region of the (<i>β_M, ε_M</i>) space for the “male transmission model” parameters where the transmission coefficients are independent of risk factors.

<p>(a) For <i>p_NC</i> = 0.30; (b) effect of <i>p_NC</i> on the edge of the confidence region: <i>p_NC</i> = 0.15 (solid thin line), <i>p_NC</i> = 0.30 (bold solid line) and <i>p_NC</i> = 0.45 (dashed thin line) and (c) value of the coefficient <i>R</i> (represented as the intensity of the grey-scaled color, see color bar on the right) in the confidence region (for <i>p_NC</i> = 0.30).</p