M. Armstrong1,4,+, F.C. Coelho1, L. Bastos2, V. Saraceni3, C. Lemos3, M. Silva1, L. Sant’anna1, J Crespo1, M. Watanabe1
1Fundação Getulio Vargas Rio de Janeiro, Brazil 22250-900
2Fundação Oswaldo Cruz, Rio de Janeiro, Brazil, 21040-900
3Secretaria Municipal de Saude do Rio de Janeiro, Brazil, 20211-901
4MINES ParisTech, Paris, France, 75006
In Rio de Janeiro, cases of microcephaly started in late 2015, and during the first few months were concentrated in working class suburbs in the north with few in poorer favelas and none in the affluent Zona Sul. Socio-economic factors cannot explain this spatial concentration. We postulate that (1) the public transport system was the key factor in accelerating or delaying the propagation of Zika, and (2) the transport hub in the city center acted as the spatial equivalent of a super-spreader because it facilitated the transmission of Zika from one part of the city to another over longer distances than mosquitos can fly.
Using agent-based simulations we show that removing mosquitos from platforms in Zona Sul but not surrounding areas, delays the arrival of Zika (and hence microcephaly cases) by several months. Secondly removing mosquitos from platforms at the city centre transport hub would have significantly delayed the propagation of arboviruses throughout the city, possibly preventing epidemics. So mosquito elimination campaigns focus in tropical and subtropical cities should focus on transport hubs. In Rio de Janeiro the platforms at Centro should be air-conditioned to remove the vector, not just of Zika, but also dengue fever, chikungunya and yellow fever. This proposal does not require the use of insecticides which is an advantage because Aedes mosquitos in Brazil and many other countries are becoming increasingly resistant to insecticides.