Zika in travellers 1947-2017: a systematic review

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• International travel is a key factor in the rapid global spread of Zika virus (ZIKV).
• Travellers can act as sentinels, potentially identifying ZIKV transmission in areas without reported outbreaks.
• Understanding travel-associated ZIKV infections is crucial for global health surveillance.

Purpose of the Study:

• To describe the temporal burden of ZIKV infections in international travellers.
• To estimate the proportion of ZIKV-related birth defects in infants born to infected travellers.
• To assess the extent of sexual transmission and identify sentinel countries for ZIKV.

Main Methods:

• A systematic review of travel-associated ZIKV infections from 1947 to April 2017 was conducted.
• Published reports on autochthonous ZIKV transmission were compared with traveller exportations.
• Data from the GeoSentinel network were summarized.

Main Results:

• A significant increase in ZIKV-infected travellers was observed from 2013-2016, followed by a decline in 2017.
• Approximately 5% of pregnant travellers with ZIKV infection had infants with birth defects.
• An estimated 1% of ZIKV cases in the USA and Europe were sexually transmitted.
• Five countries were identified as potential sentinels for ZIKV export without reported local transmission.

Conclusions:

• Travel patterns aid in predicting ZIKV importation and spread.
• Studies on pregnant travellers enhance understanding of congenital Zika syndrome risks.
• The role of sexual transmission in ZIKV propagation is increasingly recognized.