Intercepted Mosquitoes at New Zealand's Ports of Entry, 2001 to 2018: Current Status and Future Concerns.

Sherif E Ammar,Tom Swan,José G B Derraik,Mary Mclntyre,Julia Kasper,Simon Hales,Michael G Baker

doi:10.3390/tropicalmed4030101

Abstract

Mosquito vectors are extending their range via international travel and trade. Climate change makes New Zealand an increasingly suitable environment for less tropically adapted exotic mosquito vectors to become established. This shift will add a multiplier effect to existing risks of both the establishment of new species and of resident exotic species extending into new areas. We describe trends in the border interceptions of exotic mosquitoes and evaluate the role of imported goods as a pathway for these introductions. Ae. aegypti and Ae. albopictus, the two most commonly intercepted species, were only intercepted in Auckland. Used tyres and machinery were the main mode of entry for both species. The majority of Ae. albopictus were transported as larvae by sea, while most Ae. aegypti were transported as adults by air. Continuing introductions of these mosquitoes, mainly arriving via Japan or Australia, increase the risk of the local transmission of mosquito-borne diseases in New Zealand in general and in the Auckland region in particular. These findings reinforce the need for a high performing and adequately resourced national biosecurity system, particularly port surveillance and inspection. Recommended biosecurity improvements are described.

Highlights

The rate of introduction of exotic mosquito species in new geographic areas has increased notably in parallel with global trade and travel [1,2,3,4]
The spread of the container-breeding species Aedes albopictus and Aedes aegypti beyond their native range has been facilitated by the trade of goods, significantly in used tyres and machinery [5,6,7]
We describe trends in the border interceptions of exotic mosquitoes and evaluate the role of used tyre and vehicle imports as a means of transport

Summary

Introduction

The rate of introduction of exotic mosquito species in new geographic areas has increased notably in parallel with global trade and travel [1,2,3,4]. The spread of the container-breeding species Aedes albopictus and Aedes aegypti beyond their native range has been facilitated by the trade of goods, significantly in used tyres and machinery [5,6,7] These two species are a major public health concern, as they are the main vectors of the most important arboviral diseases, including yellow fever, dengue, chikungunya, and Zika [8]. Ae. albopictus is native to humid tropics of Southeast Asia It has expanded geographically during the last four decades [10,11] to mid-latitude temperate areas of all continents [12,13], making it the most invasive mosquito species in the world [13]. The main factor contributing to the aggressive colonizing capacity of Ae. albopictus seems to be its ability to adapt to different climates through the production of diapausing cold-resistant eggs, with temperate strains surviving cold winters in mid-latitudes [11,12]

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Discussion

Conclusion