Spatio-temporal and socio-demographic patterns of Chikungunya, Dengue, and Zikainfections in Mexico in 2016–2017

Purpose: Chikungunya, Dengue, and Zika viral infections are vector-borne diseases that are endemic in Mexico. Here we analyze the relationship between onset timing and climate data and socio-economic variables across the country. Methods & Materials: We collected weekly incidence data, daily climate data, and socio-economic status on each state of Mexico in 2016-2017. The data sources are Mexican surveillance system, the Weather Underground, OECD.org, and INEGI Mexico. We measured the direct distances from six southernmost states of Mexico (i.e. Campeche, Chiapas, Oaxaca, Quintanaroo, Tabasco, or Yucatan) to all other states and compared them with the timing of the state-level curves. Then we performed step-wise multivariate analysis on weather and socio-economic variables to find the ones that best predict the onset timing of the three infections. Results: Chikungunya and Dengue both showed “south-to-north” spreading patterns especially in the states that are located along the coast lines of Mexico. Low socio-economic status generally explained a significant fraction of the variation in epidemic onset compared to weather and geospatial variables (with the coefficients of determination, R2, on onset weeks of chikungunya, dengue, and Zika epidemics being 0.279, 0.501, and 0.788, respectively). Across diseases, these socio-economic status variables included maternal mortality rate, quality of housing, unemployment rate, and air pollution. Conclusion: The coastline and south-to-north patterns of spreading, as well as socio-economic factors, may be good predictors of epidemic onset for these vector-borne infectious diseases.