Human Social Behavior and Demography Drive Patterns of Fine-Scale Dengue Transmission in Endemic Areas of Colombia

PLoS One. 2015 Dec 14;10(12):e0144451. doi: 10.1371/journal.pone.0144451. eCollection 2015.

Abstract

Dengue is known to transmit between humans and A. aegypti mosquitoes living in neighboring houses. Although transmission is thought to be highly heterogeneous in both space and time, little is known about the patterns and drivers of transmission in groups of houses in endemic settings. We carried out surveys of PCR positivity in children residing in 2-block patches of highly endemic cities of Colombia. We found high levels of heterogeneity in PCR positivity, varying from less than 30% in 8 of the 10 patches to 56 and 96%, with the latter patch containing 22 children simultaneously PCR positive (PCR22) for DEN2. We then used an agent-based model to assess the likely eco-epidemiological context of this observation. Our model, simulating daily dengue dynamics over a 20 year period in a single two block patch, suggests that the observed heterogeneity most likely derived from variation in the density of susceptible people. Two aspects of human adaptive behavior were critical to determining this density: external social relationships favoring viral introduction (by susceptible residents or infectious visitors) and immigration of households from non-endemic areas. External social relationships generating frequent viral introduction constituted a particularly strong constraint on susceptible densities, thereby limiting the potential for explosive outbreaks and dampening the impact of heightened vectorial capacity. Dengue transmission can be highly explosive locally, even in neighborhoods with significant immunity in the human population. Variation among neighborhoods in the density of local social networks and rural-to-urban migration is likely to produce significant fine-scale heterogeneity in dengue dynamics, constraining or amplifying the impacts of changes in mosquito populations and cross immunity between serotypes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / virology
  • Animals
  • Child
  • Colombia
  • Dengue / transmission*
  • Dengue / virology
  • Dengue Virus / pathogenicity*
  • Disease Outbreaks
  • Humans
  • Insect Vectors / virology
  • Polymerase Chain Reaction
  • Population Density*
  • Population Dynamics
  • RNA, Viral / blood
  • Residence Characteristics*
  • Social Behavior*

Substances

  • RNA, Viral

Grants and funding

This work was funded by the Global Environmental Facility/World Bank through the Integrated National Adaptation Pilot, a project executed in the Instituto Nacional de Salud de Colombia. It also received funding from the National Virology Laboratory of the Instituto Nacional de Salud de Colombia, the Yale Climate and Energy Institute (grant awarded to MAD) and the National Socio-Environmental Synthesis Center (postdoctoral fellowships of HP, AB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.