Update on Zika virus transmission in the Pacific islands, 2007 to February 2016 and failure of acute flaccid paralysis surveillance to signal Zika emergence in this setting

Abstract

Objective: To describe the distribution and magnitude of Zika virus (ZIKV) infections reported in the Pacific islands from 2007 to February 2016; and explore the utility of routine acute flaccid paralysis (AFP) surveillance to detect ZIKV emergence. Method: We searched for evidence of ZIKV cases and outbreaks in the Pacific using a PubMed search, reviewed Pacific peer communication channels and through personal communication with relevant WHO staff. Routine acute flaccid paralysis reporting data from 2000 to 2015 was reviewed to determine whether unexpected surveillance exceedances correlated with ZIKV emergence in specific Pacific island countries. Findings: We report nine ZIKV outbreaks in eight Pacific islands countries and areas (Yap State, Federal States of Micronesia (2007), French Polynesia (2013-14), Cook Islands (2014), Easter Island (2014), New Caledonia (2014 and 2015), Solomon Islands (2015) Tonga (2016) and American Samoa (2016), and a further three Pacific countries that detected cases (but have not reported domestic transmission): Vanuatu (2015), Fiji (2015), and Samoa (2015). Despite the reported increase in Guillain-Barre syndrome (AFP) in Latin America, review of fluctuations in detection rates in Pacific Islands found no correlation with ZIKV emergence. Conclusion: Although no spatial correlation between AFP surveillance data and reported Zika infections was found in the Pacific island context we recommend that the utility of such a surveillance strategy be further tested in countries that are vulnerable to ZIKV outbreak and have large populations under the age of 15 years.