*Metabarcoding and Digital PCR (dPCR): Application in the Study of Neglected Tropical Diseases DOI: http://dx.doi.org/10.5772/intechopen.106272*

programs isolated from health services and operational personnel far away or oblivious to the needs of the communities, are not having an impact on the profile epidemiology of each of the NTDs such as dengue, Chagas disease, and malaria to mention some NTDs [118, 119]. Based on these needs, the Ecohealth model emerges, incorporating a transdisciplinary approach in the study and care of DNTs, emphasizing social participation as a central actor in the solutions to these health problems, and proposes an approach to inequality of gender as an element to insert in prevention and control programs. The model demands a multi- and intersectoral vision to contain them in a sustainable manner and provides evidence to strengthen operational programs [120]. In this sense, NSG and dPCR can easily be very powerful tools for the comprehensive study of DNTs from an Ecohealth point of view. For example, using next-generation sequencing metagenomic analysis, a variety of viral families in mammals and rodents were studied, and the results obtained allowed us to know the viral community in wildlife that at a given moment could become a critical point for the development of an emerging disease [121]. Other work on the presence of enteroviruses (EV) in nonhuman primates through phylogenetic analysis revealed that one virus strain was related to human clinical isolates, suggesting zoonotic behavior [122]. Studies related to Chagas disease vectors have made it possible to analyze the blood-feeding sources of multiple species of triatomines with much greater sensitivity and also to identify multiclonal infections with *T. cruzi*, which must be taken into account to develop transmission networks and characterize the risk of human infection, eventually leading to better control of disease transmission [69, 123–125]. These studies represent a powerful approach to unravel and understand transmission dynamics at microgeographic levels of Chagas disease.

On the other hand, ddPCR, which is considered a biotechnological refinement of conventional polymerase chain reaction methods that can be used to directly quantify and clonally amplify DNA, has been widely used in the detection of lowabundance nucleic acids and is useful in diagnosing infectious diseases including

### **Figure 5.**

*The promotion of research with ecosystem approaches to human health (EcoHealth) is of great importance to contribute to improving the health of communities in the poorest regions of the world, for example, in Chagas disease, where new technologies, such as NSG and ddPCR, may have a better scope for a better understanding of the disease and thus propose new intervention policies. This strategy should be applicable to the study of all NTDs.*

viral, bacterial, and parasitic infections, concluding that ddPCR provides a more sensitive, accurate, and reproducible detection of low-abundance pathogens [126, 127]. For example, Multiplex RT-ddPCR could help characterize defective genomes by simultaneously quantifying multiple regions of the same DENV RNA molecule, and in samples where quantities are limited, the application of RT-ddPCR could identify patients with burdens. Elevated viral levels, especially during the first days of the disease, could not be carried out with other methodologies due to the scarcity of the sample [75]. Therefore, the inclusion of NSG and dPCR techniques should be used jointly for the comprehensive study of NTDs so that in the future they allow the generation of interventions or sustainable strategies for vector control and transmission prevention of the NTDs (**Figure 5**).
