A simulation study of effects of host availability on the bite rate of Aedes albopictus (Skuse) (Diptera: Culicidae) and the risk of dengue outbreaks in non-endemic areas

抄録

Aedes albopictus is an important vector of dengue fever and tends to ambush blood host in a single place. Thus, host contact frequency may affect the bite rate and risk of disease outbreak, although no studies have examined these parameters. The present study used a simple model to clarify the fundamental relationship between host availability, bite rate, and risk of dengue outbreaks in non-endemic areas. A hypothetical isolated mosquito population was divided into “ambush” and “resting” subpopulations, and human hosts were modeled as visiting mosquito population at constant intervals. A single infectious human who only visited the mosquito population once was responsible for mosquito infections and the secondary infections among humans who subsequently visit the area after the incubation period. The results confirmed that the bite rate per host increased with decreasing host availability. The number of secondary infections among hosts exhibited a unimodal relationship with the frequency of host visits, with a maximum value at host visits every 24 h. Furthermore, when host availability was not very low, the bite rate was a good indicator of the potential risk of dengue outbreaks. Therefore, human-bait-sweep collection data may be useful for monitoring the risk of dengue outbreaks.