Infectious diseases are known to regulate population dynamics, an observation that underlies the use of pathogens as control agents of unwanted populations. Sterilizing rather than lethal pathogens are often suggested so as to avoid unnecessary suffering of the infected hosts. Until recently, models used to assess plausibility of pathogens as potential pest control agents have not included a possibility that reduced fecundity of the infected individuals may save their energy expenditure on reproduction and thus increase their longevity relative to the susceptible ones. Here, we develop a model of host-pathogen interaction that builds on this idea. We analyze the model for a variety of infection transmission functions, revealing that the indirect effect of sterilizing pathogens on mortality of the infected hosts, mediated by a fecundity-longevity trade-off, may cause hosts at endemic equilibria to attain densities higher than when there is no effect of pathogens on host mortality. On the other hand, an opposite outcome occurs when the fecundity-longevity trade-off is concave or when the degree of fecundity reduction by the pathogen is high enough. This points to a possibility that using sterilizing pathogens as agents of pest control may actually be less effective than previously thought, the more so since we also suggest that if sexual selection acts on the host species then the presence of sterilizing pathogens may even enhance host densities above the levels achieved without infection.
- MeSH
- dlouhověkost * MeSH
- energetický metabolismus * MeSH
- fertilita * MeSH
- interakce hostitele a patogenu * MeSH
- kontrola škůdců MeSH
- populační dynamika MeSH
- sterilizace MeSH
- teoretické modely * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Infectious diseases can seriously impact dynamics of their host species. In this study, we model and analyze an interaction between a sexually transmitted infection and its animal host population affected by a mate-finding Allee effect. Since mating drives both host reproduction and infection transmission, the Allee effect shapes the transmission rate of the infection which we show takes a saturating form. Our model combining sexually transmitted infections with the mate-finding Allee effect in the host produces quite rich dynamics, including oscillations, several multistability regimes, and infection-induced host extinction. However, many of these complex patterns are restricted to a relatively narrow parameter range. We find that the host extinction occurs at intermediate levels of infection virulence, as well as for Allee effect strengths much lower than when the infection is absent. In both cases, a sequence of events comprising destabilization of an endemic equilibrium, growth of oscillation amplitude, and a heteroclinic bifurcation forms an underlying mechanism. We apply our model to the feline immunodeficiency virus (FIV) in domestic cats.
- MeSH
- biologické modely * MeSH
- hustota populace MeSH
- infekční nemoci MeSH
- interakce hostitele a patogenu * MeSH
- kočičí AIDS přenos virologie MeSH
- kočky MeSH
- populační dynamika MeSH
- populační růst MeSH
- sexuálně přenosné nemoci MeSH
- virus kočičí imunodeficience * MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- chemické techniky analytické metody normy MeSH
- chromatografie plynová metody využití MeSH
- fyzikální chemie metody normy MeSH
- gelová chromatografie metody využití MeSH
- klinické laboratorní techniky využití MeSH
- kontaminace potravin analýza MeSH
- pesticidy analýza chemie MeSH
- polychlorované bifenyly analýza chemie MeSH
- Geografické názvy
- Česká republika MeSH
The multiresidue method using multisolvent extraction, SPE cleanup of the extract, HPLC with the use of OPA post-column reaction and fluorescence detection for the determination of N-methylcarbamate pesticides in food products was used. A matrix solid phase dispersion method of the isolation and extraction of carbamates was alternatively applied. In the introductory study 44 items of the food basket for the Czech Republic were analysed. In the major part of the studied samples, the considerable part of which was culinary treated, the concentration of the target carbamates was below the limit of the used detection method. In the concentration range of 10–100 μg/kg in the analysed samples of the studied analytes, aldicarb and its metabolites, e.g. methomyl and methiocarb were being found most frequently.
