Background: Entomological indicators are essential to guide surveillance and control of vector-borne diseases. Indicators of Chagas disease vector surveillance such as infestation, colonization, and density depend on wide surveys performed by trained health agents that are difficult to maintain in endemic countries; now, surveillance is mainly based on community participation. Thus, the development of an index that aggregates variables of vectorial potential and occurrence and triatomine species may be useful.
Objective: To develop an index for triatomine bug surveillance.
Methods: The index was developed based on entomological surveillance data from the State of Bahia, Brazil, between 2006 and 2019. For each triatomine species, the following data were analyzed: a) relative abundance; b) geographic distribution, c) proportion of nymphs; d) Trypanosoma cruzi infection; e) human contact/ blood meal sources. Values were assigned to each of these variables and the sum of the values generated the index (TriatoIndex = Ti) that ranged from 0 to 15. Subsequently, the municipalities' Ti value was calculated, based on the sum of the Ti values of the species registered in each municipality. RESULTS: From the 26 species of triatomines in Bahia, 20 (77%) presented Ti <10. Triatoma infestans (15), T. sordida (14), T. brasiliensis (13), T. pseudomaculata (12), T. melanica (10), and T. juazeirensis (10) presented the highest values of Ti in the studied area. The Ti values in the municipalities in the central and northeastern regions of Bahia were high; these areas were considered hotspots for the occurrence of the main important vectors.
Conclusions: The index presented takes into account the geographical distribution and vectorial potential of triatomines within the region. TriatoIndex is a promising tool for targeted surveillance of T. cruzi vectors.