The impact of weather and storm water management ponds on the transmission of West Nile virus.

Yiyuan Wang,Huaiping Zhu,Wendy Pons,Jessica Fang

doi:10.1098/rsos.170017

Abstract

West Nile virus (WNV) is the most widely distributed arbovirus in the world and the spread is influenced by complex factors including weather conditions and urban environmental settings like storm water management ponds (SWMP). The purpose of this work was to develop an ordinary differential equation model to explore the impacts of SWMP, temperature and precipitation on WNV vector abundance and the transmission of WNV between mosquito and bird populations. The model was used to analyse how weather conditions and SWMP can influence the basic reproduction number. The results found that an excess of precipitation and fiercer intraspecific competition will reduce vector population and the peak value of infectious vectors and birds. This information can be used to identify measures that would be useful to control larval abundance in SWMP and the transmission of WNV.

Highlights

West Nile virus (WNV) is primarily a bird pathogen and a mosquito-borne arbovirus belonging to the genus Flavivirus
Sensitivity analysis indicates that Culex mosquito biting rate, oviposition rate, maturation rate, mortality rates and intraspecific competition rate significantly influence both mosquito abundance Nm and an indicator of local WNV activity level R0; and the effects of weather factors reflected by these rates
Mathematical model (2.3.4) shows that moderate temperature and precipitation, as well as a smaller intraspecific competition rate are more likely to result in the basic reproduction number greater than one, resulting in an outbreak of WNV

Summary

Introduction

West Nile virus (WNV) is primarily a bird pathogen and a mosquito-borne arbovirus belonging to the genus Flavivirus. WNV is the most widely distributed emerging arbovirus, with no specific treatment or vaccine for humans [4]. In North America, the first WNV case was detected in New York City in 1999; the virus spread rapidly throughout the continent and appeared in Ontario in 2001 [5,6]. Since 2001, human infections have occurred yearly in Ontario; the number of cases varies based on the time at which WNV becomes endemic and the peak value of infections (figure 1).

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