TY - JOUR
T1 - Risk analysis of the re-emergence of Plasmodium vivax malaria in Japan using a stochastic transmission model
AU - Bitoh, Tomoyuki
AU - Fueda, Kaoru
AU - Ohmae, Hiroshi
AU - Watanabe, Mamoru
AU - Ishikawa, Hirofumi
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/5
Y1 - 2011/5
N2 - Objectives This study analyzed the risk of infection with Plasmodium vivax in local residents through a stochastic simulation in which an infected tourist, local resident, or immigrants from an endemic area would visit Himi-shi, Toyama prefecture, which is a formerly endemic area in Japan. Methods In Toyama, the habitats of Anopheles sinensis, which can transmit P. vivax, have been examined previously. We constructed a stochastic model of P. vivax transmission that can handle small numbers of infected persons and infected mosquitoes. The seasonal fluctuation in the numbers of captured An. sinensis was taken into account in the model. Results Ten thousand trial simulations were carried out stochastically with a range of human blood indexes (HBI) of 1-10% for a range of months (June-September). The simulation results for a realistic assumption of a 1% HBI showed that the risk of infection for local residents was low (below 1%) except for the immigrants scenario. Conclusions The risk of infection among local residents (second cycle) was estimated to be very low for all situations. Therefore, there is little possibility for P. vivax infection to become established in this area of Japan.
AB - Objectives This study analyzed the risk of infection with Plasmodium vivax in local residents through a stochastic simulation in which an infected tourist, local resident, or immigrants from an endemic area would visit Himi-shi, Toyama prefecture, which is a formerly endemic area in Japan. Methods In Toyama, the habitats of Anopheles sinensis, which can transmit P. vivax, have been examined previously. We constructed a stochastic model of P. vivax transmission that can handle small numbers of infected persons and infected mosquitoes. The seasonal fluctuation in the numbers of captured An. sinensis was taken into account in the model. Results Ten thousand trial simulations were carried out stochastically with a range of human blood indexes (HBI) of 1-10% for a range of months (June-September). The simulation results for a realistic assumption of a 1% HBI showed that the risk of infection for local residents was low (below 1%) except for the immigrants scenario. Conclusions The risk of infection among local residents (second cycle) was estimated to be very low for all situations. Therefore, there is little possibility for P. vivax infection to become established in this area of Japan.
KW - Anopheles sinensis
KW - Plasmodium vivax
KW - Re-emergence
KW - Stochastic simulation
KW - Toyama
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U2 - 10.1007/s12199-010-0184-8
DO - 10.1007/s12199-010-0184-8
M3 - Article
C2 - 21431796
AN - SCOPUS:79961181523
VL - 16
SP - 171
EP - 177
JO - Environmental Health and Preventive Medicine
JF - Environmental Health and Preventive Medicine
SN - 1342-078X
IS - 3
ER -