Community-based surveillance of Chagas Disease: Characterization and use of Triatomine Information Posts (TIPs) in a high-risk area for triatomine reinfestation in Latin America

Abstract

Background: In Brazil, vector surveillance with public participation is a prioritized action in the primary prevention of Chagas Disease (CD). It is anchored in the implementation of Triatomine Information Posts (TIPs), spaces recognized by health surveillance for receiving insects suspected of being triatomines. For the first time in the scientific literature, a study is dedicated to characterizing TIPs operationally, structurally, and functionally, as well as understanding the factors that hinder their sustainability.

Methodology: The study was conducted in one of the most vulnerable regions for CD in the Americas. Using mixed approaches applied to health, an electronic form was sent to the municipal coordinators of endemic diseases to characterize the implementation, operational status, and description of TIPs. Data from an information system were accessed to analyze their productivity. Lastly, five focus groups were conducted to capture the perception of the endemic disease coordinators regarding TIPs.

Principal findings: 100% of the municipalities did not maintain documentary records of the use and productivity of TIPs, 40% of municipalities had never implemented a TIP; of those implemented, more than 30% were deactivated, with a significant portion located in rural areas. TIPs located in areas shared with Primary Health Care facilities showed lower deactivation rates. Key factors hindering the functioning and sustainability of TIPs included the population's lack of awareness about them, the need for increased publicity of these locations, a shortage of qualified professionals, TIP distribution in hard-to-access areas, and the absence of feedback on insect examinations to residents.

Conclusions/significance: A scenario of heterogeneous distribution was revealed in the implementation/functioning of TIPs, as well as low public engagement and usage. There is an urgent need for health systems to be organized to regulate surveillance with public participation and to conduct awareness campaigns aimed at preventing future household reinfestations by triatomines and the resurgence of CD transmission in endemic areas.

Fig 1. Study area.

Below and to the right is the map of Minas Gerais, highlighting the study area in red outline, corresponding to the 123 municipalities belonging to the four Regional Health Offices and one Regional Health Superintendence.

Fig 2. Percentage of municipalities from different RHOs or the RHS that had at least one TIP installed from the 1990s until June 2021.

At the top of the bars, the absolute number of municipalities from the health regions is indicated. The absolute number of municipalities based on the evaluated situation is shown within the bars.

Fig 3. Spatial distribution of TIPs installed in high-risk areas for triatomine reinfestation in household units of Minas Gerais.

The location of the municipal headquarters is indicated by black dots, and the centers of the RHUs are identified by white dots with black outlines.

Fig 4. Distribution (percentage) of TIPs installed in high-risk areas for triatomine reinfestation in Minas Gerais (73 municipalities) according to their location zone (urban or rural).

Fig 5. Spatial distribution of TIPs installed in high-risk areas for triatomine reinfestation in Minas Gerais based on the location area.

Panel A shows the number of TIPs installed in rural areas, while map B highlights the number of TIPs installed in urban areas.

Fig 6. Operational status (active or deactivated) of TIPs installed in areas of high risk for triatomine reinfestation in Minas Gerais (73 municipalities) according to the health region area.

Numbers outside and inside the bars indicate the total number of TIPs installed and the operational status of TIPs in June 2021.

Fig 7. Spatial distribution of TIPs in high-risk areas for triatomine reinfestation in Minas Gerais based on operational status.

Panel A shows the number of TIPs that remain active in the municipalities, while panel B shows the number of TIPs that are deactivated in the municipalities.

Fig 8. Percentage of active and deactivated TIPs in relation to rural and urban areas in high-risk areas for triatomine reinfestation in Minas Gerais (73 municipalities), according to data collected in June 2021.

Fig 9. Percentage of active and deactivated TIPs in relation to rural and urban zones in the high-risk area for triatomine reinfestation in Minas Gerais (73 municipalities), according to the health region.

The absolute number of TIPs in the health regions is indicated outside the bars. The absolute number of TIPs is shown inside the bars based on their operational status.

Fig 10. Map highlighting the 123 municipalities in Minas Gerais located in areas of high risk for domestic triatomine reinfestation.

The TIPs located in areas shared with PHC are marked in green. The map in the lower right corner shows the five health regions of the study area.

Fig 11. Operational status of TIPs installed in common areas of PHC across different health regions with a high risk of triatomine reinfestation in Minas Gerais (39 municipalities).

Fig 12. Spatial distribution of TIPs located in common areas to the Family Health Strategy in areas of high risk for triatomine reinfestation in Minas Gerais based on their operational status.

Panel A shows the number of TIPs that remain active in the municipalities, and Panel B shows the number of TIPs that remain deactivated in the municipalities.

Fig 13. Spatial distribution of TIPs installed in Family Health Strategy in high-risk areas based on location zone.

Panel A shows the TIPs installed in rural areas, and Panel B shows the number of TIPs installed in urban areas.

Fig 14. Number of municipalities reporting the delivery of suspected insects at TIPs between 2015 and 2021 in the Montes Claros RHS.

Fig 15. Number of control actions of Chagas Disease performed in the territories according to the participants.

Codes: TIPs – Triatomine Information Posts; AS – active search; SP – spraying; TE – triatomine examination; GR – geographic reconnaissance; TIT – taxonomic identification of triatomines; HE – health and education.