Zika virus transmission in Angola and the potential for further spread to other African settings.

Moritz U G Kraemer,Kamran Khan,Alexander Watts,Matthew German,Oliver J Brady,Isaac I Bogoch,Simon I Hay

doi:10.1093/trstmh/try001

Abstract

BackgroundCases of Zika virus were recently detected in Luanda, Angola, a major travel hub in Africa. The risk of Zika virus transmission throughout the continent from Angola is evaluated.MethodsTravel volumes were assessed using monthly passenger-level flight data from Luanda to all locations throughout Africa. Travel data was superimposed onto seasonal environmental suitability maps that predict the potential for subsequent Zika virus transmission.Results and ConclusionsWindhoek, Maputo, Durban and Kinshasa have the greatest potential for Zika virus introduction and transmission during the southern hemisphere summer months, and Nairobi during the northern hemisphere summer months.

Highlights

Zika virus (ZIKV), originally endemic to parts of Africa and Asia, has spread throughout most of Latin America and the Caribbean, and has infected millions of individuals
ZIKV has spread internationally due to the movement of infected individuals and autochthonous transmission is occurring in several regions that have suitable conditions, namely the appropriate climate and Aedes mosquito vectors
To estimate the potential for local virus transmission arising from ZIKV introduction, we combined predictions of local monthly variation in ZIKV transmission suitability,[4] and show seasonal variation in local transmission risk for the 10 most visited African cities from Luanda, Angola

Summary

Methods

We analysed monthly passenger-level flight data from Luanda (where two ZIKV cases were recently detected)[1] to all locations throughout Africa. Johannesburg and Cape Town (South Africa) both had the highest number of passengers arriving from Luanda, but did not have Aedes aegypti suitability for subsequent ZIKV transmission. Areas that have high risk of ZIKV introduction and potential for local transmission are Windhoek, Maputo, Durban and Kinshasa (all during the southern hemisphere summer months, between November and February, inclusive). Transmission potential is expected to shift to the northern hemisphere during their spring and summer months. In this analysis, Nairobi had both the highest potential of ZIKV introduction reflected by the number of arriving passengers coupled with suitable environmental potential for local transmission (Figure 1)

Introduction

Johannesburg 0