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. 2017 Nov 16;12(11):e0188002. doi: 10.1371/journal.pone.0188002

Fig 4. Geographic pattern of ZIKV and CHIKV incidence.

Fig 4

(A) High correlation between the incidence of ZIKV and CHIKV in the Metro 2 health region, which comprises the eastern half of the metropolitan area of the city of Rio de Janeiro. This geographic overlap between the viruses could have led to competition in Aedes aegypti. The correlation is moderate but lower in the Metro 1 region. The Metro 1 and 2 regions represent 80% of the state’s population and 90% of the samples in this analysis. The correlation is also high in the North and Coastal regions, whereas in other health regions, ZIKV and CHIKV appear not to be correlated. However, the lower sample sizes outside the metropolitan area make it difficult to draw robust conclusions about the correlation in these regions. (B) Relative proportion of ZIKV and CHIKV. ZIKV dominates over CHIKV in the Rio de Janeiro metropolitan area and the Coastal and North health regions. (C) Human population density.