Aedes hensilli as a Potential Vector of Chikungunya and Zika Viruses

Jeremy P Ledermann,Tai Ho-Chen,Mark R Duffy,Maria Marfel,Mary Tided,Paul Machieng,Anne Griggs,W Thane Hancock,Steven C Saweyog,Laurent Guillaumot,Lawrence Yug,Moses Pretrick,Ann M Powers,Martin Bel,Michael J Turell

doi:10.1371/journal.pntd.0003188

Abstract

An epidemic of Zika virus (ZIKV) illness that occurred in July 2007 on Yap Island in the Federated States of Micronesia prompted entomological studies to identify both the primary vector(s) involved in transmission and the ecological parameters contributing to the outbreak. Larval and pupal surveys were performed to identify the major containers serving as oviposition habitat for the likely vector(s). Adult mosquitoes were also collected by backpack aspiration, light trap, and gravid traps at select sites around the capital city. The predominant species found on the island was Aedes (Stegomyia) hensilli. No virus isolates were obtained from the adult field material collected, nor did any of the immature mosquitoes that were allowed to emerge to adulthood contain viable virus or nucleic acid. Therefore, laboratory studies of the probable vector, Ae. hensilli, were undertaken to determine the likelihood of this species serving as a vector for Zika virus and other arboviruses. Infection rates of up to 86%, 62%, and 20% and dissemination rates of 23%, 80%, and 17% for Zika, chikungunya, and dengue-2 viruses respectively, were found supporting the possibility that this species served as a vector during the Zika outbreak and that it could play a role in transmitting other medically important arboviruses.

Highlights

Outbreaks of arboviral disease have been documented in islands of the western Pacific including The Federated States of Micronesia (FSM) and Palau
In 2007, an outbreak of acute febrile illness characterized by rash, conjunctivitis, fever, and arthralgia was reported on the island of Yap in the Federated States of Micronesia
Chikungunya virus (CHIKV) was considered as the clinical presentation was representative of CHIKV infection and an ongoing epidemic of CHIKV was occurring in Southeast Asia

Summary

Introduction

Outbreaks of arboviral disease have been documented in islands of the western Pacific including The Federated States of Micronesia (FSM) and Palau. Multiple dengue outbreaks have been reported in the western pacific [1,2,3,4] with an outbreak of dengue 4 virus occurring in Palau in 1995 after a 7 year absence of dengue on this island [5]. In 2007, an outbreak of acute febrile illness characterized by rash, conjunctivitis, fever, and arthralgia was reported on the island of Yap in the Federated States of Micronesia. Zika virus (ZIKV) nucleic acid was detected in 14% of the samples tested and no evidence of alternate etiologies was identified [9]

Methods

Results

Conclusion