Transmission potential of Zika virus infection in the South Pacific

Hiroshi Nishiura; Ryo Kinoshita; Kenji Mizumoto; Yohei Yasuda; Kyeongah Nah

doi:10.1016/j.ijid.2016.02.017

Transmission potential of Zika virus infection in the South Pacific

Int J Infect Dis. 2016 Apr:45:95-7. doi: 10.1016/j.ijid.2016.02.017. Epub 2016 Feb 26.

Authors

Hiroshi Nishiura¹, Ryo Kinoshita², Kenji Mizumoto³, Yohei Yasuda⁴, Kyeongah Nah²

Affiliations

¹ Graduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kita-ku, Sapporo-shi, Hokkaido 060-8638, Japan; CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan; Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 1130033, Japan. Electronic address: nishiurah@gmail.com.
² Graduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kita-ku, Sapporo-shi, Hokkaido 060-8638, Japan; CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan; Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 1130033, Japan.
³ Graduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kita-ku, Sapporo-shi, Hokkaido 060-8638, Japan; Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 1130033, Japan; Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan.
⁴ Graduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kita-ku, Sapporo-shi, Hokkaido 060-8638, Japan.

PMID: 26923081
DOI: 10.1016/j.ijid.2016.02.017

Abstract

Objectives: Zika virus has spread internationally through countries in the South Pacific and Americas. The present study aimed to estimate the basic reproduction number, R0, of Zika virus infection as a measurement of the transmission potential, reanalyzing past epidemic data from the South Pacific.

Methods: Incidence data from two epidemics, one on Yap Island, Federal State of Micronesia in 2007 and the other in French Polynesia in 2013-2014, were reanalyzed. R0 of Zika virus infection was estimated from the early exponential growth rate of these two epidemics.

Results: The maximum likelihood estimate (MLE) of R0 for the Yap Island epidemic was in the order of 4.3-5.8 with broad uncertainty bounds due to the small sample size of confirmed and probable cases. The MLE of R0 for French Polynesia based on syndromic data ranged from 1.8 to 2.0 with narrow uncertainty bounds.

Conclusions: The transmissibility of Zika virus infection appears to be comparable to those of dengue and chikungunya viruses. Considering that Aedes species are a shared vector, this finding indicates that Zika virus replication within the vector is perhaps comparable to dengue and chikungunya.

Keywords: Basic reproduction number; Epidemic; Statistical estimation; Transmissibility; Zika virus.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Basic Reproduction Number*
Epidemics
Incidence
Likelihood Functions
Micronesia / epidemiology
Polynesia / epidemiology
Zika Virus Infection / transmission*