Occurrence and spatial distribution of triatomines (Hemiptera: Reduviidae) in the urban area of the municipality of Montes Claros, Northern Minas Gerais, Brazil

Abstract

The north of the Brazilian state of Minas Gerais is classified as an area of high risk of vectorial transmission of Chagas disease (CD) or of reestablishing transmission in the home, but the Chagas disease control programme is disjointed. The study evaluated the occurrence, natural infection and the spatial distribution of species of triatomines associated with climatic variations in the urban area of Montes Claros, a municipality endemic to CD in the north of Minas Gerais, Brazil. Triatomine data were obtained from passive entomological surveillance actions of the Chagas Disease Control Program (Programa de Controle de Doença de Chagas-PCDCh), registered by the Zoonosis Control Center (Centro de Controle de Zoonoses-CCZ) from 2009 to 2019. A total of 277 triatomines belonging to eight species were collected, and of these, 203 insects were examined. It was found that 46.2% of triatomines were captured inside the home and 8.3% around the home. The natural infection rate was 6.9%; 14 specimens showed natural infection by Trypanosoma cruzi (12 females and 2 males), and of these, 13 were found in the home and one in an uninformed location. The number of triatomine records collected was significantly higher in the month of September (p = .01), and there was an inverse correlation between the number of triatomines and the relative humidity of the air (p < .001). It was verified that the highest triatomine densities are located in transition areas between urban infrastructure (32.12%) and pasture (25.72%). The diversity of species of triatomines infected with T. cruzi in residential units in urban areas in the municipality of Montes Claros is worrying, as it suggests a potential risk of transmission of the parasite to domestic animals and humans.

Keywords: Trypanosoma cruzi; Chagas disease; one health; spatial analysis; triatomines; urbanization.

Figure 1-

Triatomines captured in the urban area of Montes Claros (2009–2019).

Figure 2-

Seasonal distribution of triatomines delivered by the population to the PITs, between the years 2009 to 2019, in the city of Montes Claros, Minas Gerais, Brazil.

Figure 3 -

Generalized Linear Model for correlation between the number of notificatins of triatomines delivered by the population and relative air humidity between the years 2009 to 2019, in the city of Montes Claros, Minas Gerais, Brazil.

Figure 4 -

K-function expressed in L function values according to the distances between buildings infested by triatomines in the municipality of Montes Claros, in the state of Minas Gerais, Brazil, 2009–2019. Subtitle: A- Triatoma sordida; B- T. melanocephala; C- T. pseudomaculata; D- Panstrongylus geniculatus; E- P. diasi; F- Rhodnius neglectus.

Figure 5 -

Spatial density of triatomines captured in the urban perimeter of the city of Montes Claros, Minas Gerais, between the years 2009 to 2019. Subtitle: (A) Triatoma sordida (B) T. melanocephala, (C) T. pseudomaculata, (D) Panstrongylus geniculatus, (E) P. diasi, (F) Rhodnius neglectus, (G) Classification of land use and land cover.