Trypanosoma cruzi reservoir—triatomine vector co-occurrence networks reveal meta-community effects by synanthropic mammals on geographic dispersal

Abstract

Contemporary patterns of land use and global climate change are modifying regional pools of parasite host species. The impact of host community changes on human disease risk, however, is difficult to assess due to a lack of information about zoonotic parasite host assemblages. We have used a recently developed method to infer parasite-host interactions for Chagas Disease (CD) from vector-host co-occurrence networks. Vector-host networks were constructed to analyze topological characteristics of the network and ecological traits of species’ nodes, which could provide information regarding parasite regional dispersal in Mexico. Twenty-eight triatomine species (vectors) and 396 mammal species (potential hosts) were included using a data-mining approach to develop models to infer most-likely interactions. The final network contained 1,576 links which were analyzed to calculate centrality, connectivity, and modularity. The model predicted links of independently registered Trypanosoma cruzi hosts, which correlated with the degree of parasite-vector co-occurrence. Wiring patterns differed according to node location, while edge density was greater in Neotropical as compared to Nearctic regions. Vectors with greatest public health importance (i.e., Triatoma dimidiata, T. barberi, T. pallidipennis, T. longipennis, etc), did not have stronger links with particular host species, although they had a greater frequency of significant links. In contrast, hosts classified as important based on network properties were synanthropic mammals. The latter were the most common parasite hosts and are likely bridge species between these communities, thereby integrating meta-community scenarios beneficial for long-range parasite dispersal. This was particularly true for rodents, >50% of species are synanthropic and more than 20% have been identified as T. cruzi hosts. In addition to predicting potential host species using the co-occurrence networks, they reveal regions with greater expected parasite mobility. The Neotropical region, which includes the Mexican south and southeast, and the Transvolcanic belt, had greatest potential active T. cruzi dispersal, as well as greatest edge density. This information could be directly applied for stratification of transmission risk and to design and analyze human-infected vector contact intervention efficacy.

Sylvatic host associations of Triatominae and implications for Chagas disease reservoirs: a review and new host records based on archival specimens

“…New approaches for modeling networks of vector host interactions based on the co-occurrence of mammal and Triatominae species offer a promising method for understanding Triatominae ecology ( Ibarra-Cerdeña et al, 2017 ; Rengifo-Correa et al, 2017 ). Combining such studies with reviews of T. cruzi -infected mammals ( Browne et al, 2017 ) as well as documented host associations of individual species such as provided in our review offers a route for advancing our understanding of the spread of Trypanosoma cruzi .…”

Peer Review #1 of "Sylvatic host associations of Triatominae and implications for Chagas disease reservoirs: a review and new host records based on archival specimens (v0.2)"

“…Triatominae ecology [67,68]. Combining such studies with reviews of T. cruzi-infected mammals [69] as well as documented host associations of individual species such as provided in our review offers a route for advancing our understanding of the spread of Trypanosoma cruzi.…”

“Sweeter than a rose”, at least to Triatoma phyllosoma complex males (Triatominae: Reduviidae)

“…Triatoma phyllosoma , allopatric with T. longipennis and T. pallidipennis is confined to lower altitudes immediately east and south of the Zapotecan foothills west of the Tehuantepec Isthmus, in a geographically confined semi-arid region along the Pacific coast of Oaxaca in Mexico. This species is only sympatric with T. dimidiata haplogroup 2 in this region [ 19 , 24 ].…”

“…It only occurs in Mexico, broadly distributed from the northeastern Nearctic through to the northern Neotropical bioregion of Mexico, west of the Tehuantepec Isthmus/Chimalapas forest. Species of the phyllosoma complex are principal vectors of Trypanosoma cruzi in sylvatic and synanthropic habitats in Mexico, due to their broad opportunism for biotic interactions, and their amplification in modified habitats [ 20 – 24 ]. The most widely accepted taxonomic revision of the Triatominae returned all sub-species of the phyllosoma complex (described to that date) to species-level classification based on classical morphology (i.e.…”