High Triatoma brasiliensis Densities and Trypanosoma cruzi Prevalence in Domestic and Peridomestic Habitats in the State of Rio Grande do Norte, Brazil: The Source for Chagas Disease Outbreaks?

Abstract

A total of 2,431 were collected from 39 populations of Paraíba (PB) and Rio Grande do Norte (RN) states, Brazil. In PB, infection was not detected in either peridomestic or domestic vector populations. In contrast, in RN, was detected with high parasite prevalence in these ecotopes (30.7-40.0%). Moreover, peridomicile insect population densities were more than double the average densities of all other settings evaluated (19.17 versus< 8.94 triatomine/man-hour). Genotyped parasites evidenced a mix of lineages circulating in both peridomestic and sylvatic populations. Although vector control efforts have dramatically decreased Chagas disease transmission to humans, recent outbreaks have been detected in four municipalities of RN state. Our results clearly evidence a worrisome proximity between infected vectors and humans in RN. Indeed, finding of infected inside homes is routinely recorded by local vector control surveillance staff around the outbreak area, challenging the current and conventional view that vector transmissions are controlled in northeastern Brazil. This scenario calls for strengthening vector control surveillance and interventions to prevent further Chagas transmission, especially in RN State.

Dynamics of food sources, ecotypic distribution and Trypanosoma cruzi infection in Triatoma brasiliensis from the northeast of Brazil

“…There is higher circulation of T. cruzi in Rio Grande do Norte state in comparison to other states which have already been suggested [3]. It was also shown that this high prevalence of natural infection is combined with high populational densities of T. brasiliensis in this state if compared to Paraíba [8]. These findings were confirmed by several authors throughout multiples approaches [23,43,44,45,46,47].…”

“…This species remains an operational challenge for vector control because it continually invades and colonizes human domiciles [5,6]. This triatomine was probably involved in recent Chagas disease outbreaks [7] as it was found with high densities and T. cruzi prevalence in domestic and peridomestic habitats around the outbreak area [8]. The difficulty to control T. brasiliensis is attributed to its capacity to occupy the domestic, peridomestic and sylvatic environment [9].…”

Drivers of molecular and morphometric variation in Triatoma brasiliensis (Hemiptera: Triatominae): the resolution of geometric morphometrics for populational structuring on a microgeographical scale

“…For T. juazeirensis, a member of the T. brasiliensis complex, Carbajal de la Fuente et al [60] found more males than females in light traps, which capture flying insects (dispersants). Lilioso et al [61] captured T. brasiliensis via active search, and they found more than twice males than females in sylvatic environments. This may indicate the existence of distinct patterns of migration between sexes.…”

Multiple Approaches to Address Potential Risk Factors of Chagas Disease Transmission in Northeastern Brazil

“…Besides, in a recent Chagas disease outbreak in Rio Grande do Norte state, the involvement of T. brasiliensis has been suggested. 29 Home investigation and spraying are highly laborious and costly because native triatomines keep high pressure of domiciliary reinfestation after home spraying with chemical insecticides. Therefore, dwellings can be reinfested few months after treatment.…”

“…If on one hand T. infestans could be eliminated because it was restricted to domestic environments in Brazil, then on the other hand native triatomines represent a challenge because they keep foci in the sylvatic environment. Several authors 1,29,30 have stated that not only T. brasiliensis and T. pseudomaculata are able to infest homes in the region. Other local species such as Panstrongylus megistus, Rhodnius nasutus and P. lutzi are also frequently found in domiciles.…”