Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i) endemicity is favoured by intermediate host population sizes, (ii) in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii) the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar.
@article{gascuel_host_2013,
Author = {Gascuel, Fanny and Choisy, Marc and Duplantier,
Jean-Marc and Débarre, Florence and Brouat, Carine},
Title = {Host resistance, population structure and the
long-term persistence of bubonic plague: contributions
of a modelling approach in the {Malagasy} focus},
Journal = {PLoS computational biology},
Volume = {9},
Number = {5},
Pages = {e1003039},
Keywords = {Animals, Computer Simulation, Disease Resistance,
Ecology, Endemic Diseases, Fertility, Madagascar,
Markov Chains, Models, Biological, Plague, Rats,
Siphonaptera},
abstract = {Although bubonic plague is an endemic zoonosis in many
countries around the world, the factors responsible for
the persistence of this highly virulent disease remain
poorly known. Classically, the endemic persistence of
plague is suspected to be due to the coexistence of
plague resistant and plague susceptible rodents in
natural foci, and/or to a metapopulation structure of
reservoirs. Here, we test separately the effect of each
of these factors on the long-term persistence of
plague. We analyse the dynamics and equilibria of a
model of plague propagation, consistent with plague
ecology in Madagascar, a major focus where this disease
is endemic since the 1920s in central highlands. By
combining deterministic and stochastic analyses of this
model, and including sensitivity analyses, we show that
(i) endemicity is favoured by intermediate host
population sizes, (ii) in large host populations, the
presence of resistant rats is sufficient to explain
long-term persistence of plague, and (iii) the
metapopulation structure of susceptible host
populations alone can also account for plague
endemicity, thanks to both subdivision and the
subsequent reduction in the size of subpopulations, and
extinction-recolonization dynamics of the disease. In
the light of these results, we suggest scenarios to
explain the localized presence of plague in Madagascar.},
doi = {10.1371/journal.pcbi.1003039},
issn = {1553-7358},
language = {eng},
pmcid = {PMC3649974},
pmid = {23675291},
shorttitle = {Host resistance, population structure and the
long-term persistence of bubonic plague},
year = 2013
}
