Dengue virus serotype 4 and chikungunya virus coinfection in a traveller returning from Luanda, Angola, January 2014 Parreira, R and Centeno-Lima, S and Lopes, A and Portugal-Calisto, D and Constantino, A and Nina, J, Eurosurveillance, 19, 20730 (2014), https://doi.org/10.2807/1560-7917.ES2014.19.10.20730