Lutzomyia longipalpis Presence and Abundance Distribution at Different Micro-spatial Scales in an Urban Scenario

PLoS Negl Trop Dis. 2015 Aug 14;9(8):e0003951. doi: 10.1371/journal.pntd.0003951. eCollection 2015.

Abstract

The principal objective of this study was to assess a modeling approach to Lu. longipalpis distribution in an urban scenario, discriminating micro-scale landscape variables at microhabitat and macrohabitat scales and the presence from the abundance of the vector. For this objective, we studied vectors and domestic reservoirs and evaluated different environmental variables simultaneously, so we constructed a set of 13 models to account for micro-habitats, macro-habitats and mixed-habitats. We captured a total of 853 sandflies, of which 98.35% were Lu. longipalpis. We sampled a total of 197 dogs; 177 of which were associated with households where insects were sampled. Positive rK39 dogs represented 16.75% of the total, of which 47% were asymptomatic. Distance to the border of the city and high to medium density vegetation cover ended to be the explanatory variables, all positive, for the presence of sandflies in the city. All variables in the abundance model ended to be explanatory, trees around the trap, distance to the stream and its quadratic, being the last one the only one with negative coefficient indicating that the maximum abundance was associated with medium values of distance to the stream. The spatial distribution of dogs infected with L. infantum showed a heterogeneous pattern throughout the city; however, we could not confirm an association of the distribution with the variables assessed. In relation to Lu. longipalpis distribution, the strategy to discriminate the micro-spatial scales at which the environmental variables were recorded allowed us to associate presence with macrohabitat variables and abundance with microhabitat and macrohabitat variables. Based on the variables associated with Lu. longipalpis, the model will be validated in other cities and environmental surveillance, and control interventions will be proposed and evaluated in the microscale level and integrated with socio-cultural approaches and programmatic and village (mesoscale) strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Distribution / physiology*
  • Animals
  • Argentina / epidemiology
  • Cities*
  • Dog Diseases / epidemiology
  • Dog Diseases / parasitology
  • Dog Diseases / transmission
  • Dogs
  • Ecosystem
  • Female
  • Insect Vectors / physiology*
  • Leishmaniasis, Visceral / epidemiology
  • Leishmaniasis, Visceral / transmission
  • Leishmaniasis, Visceral / veterinary
  • Male
  • Models, Biological
  • Population Density
  • Psychodidae / physiology*
  • Satellite Imagery
  • Spatial Analysis
  • Species Specificity

Grants and funding

This study was developed with research funding provided in 2011 by the National Ministry of Health and the National Ministry of Science, Technology and Productive Innovation (PICTO-2011- 0161) which title is Eco-epidemiología, biología y distribución de Phlebotominae vectores de las Leishmania sp., en las regiones NOA, NEA y Chaqueña. The main objective of this project is to elaborate disease risk maps and predictive models so as to design surveillance, prevention and control programs in Argentina. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. http://www.agencia.mincyt.gob.ar/frontend/agencia/fondo/foncyt