A scientific paper offers new insights on the spread of Zika virus in the Americas

In 2016, Zika virus (ZIKV) quickly spread throughout the Americas, with 47 countries and territories in the region reporting autochthonous transmission. Many countries with ZIKV outbreaks have reported cases of microcephaly and other birth defects associated with ZIKV infection during pregnancy, and the epidemic has been under close scrutiny by all of the major public health agencies around the world. A new scientific paper, co-authored by ISI Foundation researcher Luca Rossi and ISI Scientific Advisory Board vice-chair Alessandro Vespignani, analyzes the spatial and temporal dynamics of the Zika virus epidemic in the Americas, showing the power of a detailed computational model to tie together disparate empirical observations.

Published in PNAS, Spread of Zika virus in the Americas provides probability distributions for the time and place of introduction of Zika in Brazil (suggested between August 2013 and April 2014 in a number of potential locations, including Rio de Janeiro, Brasilia, Fortaleza, and Salvador), the estimate of the attack rate, timing of the epidemic in the affected countries, and the projected number of newborns from women infected by Zika.

To analyze the spread of the virus, scientists use the Global Epidemic and Mobility Model (GLEAM), a data-driven global stochastic and spatial epidemic model developed by ISI Foundation together with Northeastern University, that integrates high-resolution demographic, human mobility, socioeconomic, and temperature data. The framework emerging from the numerical results may help in the interpretation of observed surveillance data and provide indications for the magnitude and timing of the epidemic, as well as aid in planning for international and local outbreak response. Besides, it could potentially be generalized to other diseases, such as dengue and chikungunya.

Spread of Zika virus in the Americas, Qian Zhang, Kaiyuan Sun, Matteo Chinazzi, Ana Pastore y Piontti, Natalie E. Dean, Diana Patricia Rojas, Stefano Merler, Dina Mistry, Piero Poletti, Luca Rossi, Margaret Bray, M. Elizabeth Halloran, Ira M. Longini Jr., and Alessandro Vespignani. PNAS – Proceedings of the National Academy of Sciences of the United States of America, May 30, 2017.