@article{fdi:010063658,
  title = {{A} spatially explicit metapopulation model and cattle trade analysis suggests key determinants for the recurrent circulation of rift valley fever virus in a pilot area of {M}adagascar highlands},
  author = {{N}icolas, {G}. and {C}hevalier, {V}. and {T}antely, {L}. {M}. and {F}ontenille, {D}idier and {D}urand, {B}.},
  editor = {},
  language = {{ENG}},
  abstract = {{R}ift {V}alley fever ({RVF}) is a vector-borne zoonotic disease that causes high morbidity and mortality in ruminants. {I}n 20082009, a {RVF} outbreak affected the whole {M}adagascar island, including the {A}njozorobe district located in {M}adagascar highlands. {A}n entomological survey showed the absence of {A}edes among the potential {RVF} virus ({RVFV}) vector species identified in this area, and an overall low abundance of mosquitoes due to unfavorable climatic conditions during winter. {N}o serological nor virological sign of infection was observed in wild terrestrial mammals of the area, suggesting an absence of wild {RVF} virus ({RVFV}) reservoir. {H}owever, a three years serological and virological follow-up in cattle showed a recurrent {RVFV} circulation. {T}he objective of this study was to understand the key determinants of this unexpected recurrent transmission. {T}o achieve this goal, a spatial deterministic discrete-time metapopulation model combined with cattle trade network was designed and parameterized to reproduce the local conditions using observational data collected in the area. {T}hree scenarios that could explain the {RVFV} recurrent circulation in the area were analyzed: (i) {RVFV} overwintering thanks to a direct transmission between cattle when viraemic cows calve, vectors being absent during the winter, (ii) a low level vector-based circulation during winter thanks to a residual vector population, without direct transmission between cattle, (iii) combination of both above mentioned mechanisms. {M}ulti-model inference methods resulted in a model incorporating both a low level {RVFV} winter vector-borne transmission and a direct transmission between animals when viraemic cows calve. {P}redictions satisfactorily reproduced field observations, 84% of cattle infections being attributed to vector-borne transmission, and 16% to direct transmission. {T}hese results appeared robust according to the sensitivity analysis. {I}nterweaving between agricultural works in rice fields, seasonality of vector proliferation, and cattle exchange practices could be a key element for understanding {RVFV} circulation in this area of {M}adagascar highlands.},
  keywords = {{MADAGASCAR}},
  booktitle = {},
  journal = {{P}los {N}eglected {T}ropical {D}iseases},
  volume = {8},
  numero = {12},
  pages = {e3346 [13 ]},
  ISSN = {1935-2735},
  year = {2014},
  DOI = {10.1371/journal.pntd.0003346},
  URL = {https://www.documentation.ird.fr/hor/fdi:010063658},
}