International collaboration and interdisciplinarity are key to better understand vector-borne diseases

Vector-borne diseases are infections caused by a number of pathogens that are transmitted to humans by infected arthropods, such as mosquitoes, flies and ticks. Some common examples are dengue fever, West Nile virus, malaria, leishmaniasis, Chagas disease, Lyme disease, and others. Due to the complexity of factors determining the risk of vector-borne diseases, we need strong interdisciplinary knowledge, coming from the scientific domains of environmental sciences, medicine, public health, and social sciences to ultimately be able to develop effective strategies of disease prevention and control.

We need strong interdisciplinary knowledge, coming from the scientific domains of environmental sciences, medicine, public health, and social sciences to ultimately be able to develop effective strategies of disease prevention and control.

In an attempt to bridge this knowledge gap, where researchers are traditionally trained within the limits of their focal disciplines, the international field course on Ecological Determinants of Vector-Borne Disease Dynamics (DetVetores) was created by Fiocruz, the main public health research institution in Latin America, with collaboration of the Barcelona Institute for Global Health (ISGlobal) and the University of Florida.

Reserva Ecológica de Guapiaçu, in the Atlantic forest of Rio de Janeiro, Brazil. Photo: IOC/Fiocruz

These diseases have been traditionally associated with tropical regions, where biodiversity is high and the complex interactions between species of vectors, hosts and pathogens determine multiple transmission cycles and disease emergence in humans. However, climate and environmental change associated with increasing trade and travel have facilitated the spread of invasive vector species in Europe. Increasingly favourable climatic conditions in Europe have allowed vectors and pathogens to survive winter and spread further north, such as the Asian tiger mosquito Aedes albopictus, vector of chikungunya, dengue, and Zika virus.

Most vector-borne diseases are climate-sensitive, thus climate change impacts their transmission by causing changes in vector distribution, density, biting behaviour, and the rate at which the pathogen develops within the vector. In fact, most human pathogenic diseases that can be aggravated by climate change are of vector-borne transmission. Climate, however, is far from being the only factor that determines vector-borne disease risk. Land cover and anthropogenic land use change (e.g. deforestation) also play an important role in defining inhabitable areas for these species. We also need to consider how human populations are socioeconomically diverse and are not homogeneously affected by these diseases. 

Interdisciplinary capacity building and international collaboration

The third international edition of the DetVetores course held last month (8-12 August 2022) at the Reserva Ecológica de Guapiaçu, an ecological reserve in the Atlantic forest of Rio de Janeiro, Brazil, was an unprecedented opportunity for graduate students to be in close contact with researchers from multiple countries and to plan future collaborations.

During the course, students worked on the identification of insects. Photo: IOC/Fiocruz

The course, organized by the Tropical Medicine Graduate Program of Fiocruz and the Florida Medical Entomology Laboratory (FMEL, University of Florida), has grown a lot since its creation, and we are certain that it can keep evolving, especially with the participation of students from different regions of the world. It is through interdisciplinary capacity building and international collaboration that we will further understand vector-borne diseases and their complex interactions with the environment. ISGlobal’s participation in the course strengthens its recently formed partnership with Fiocruz, and was supported by the Severo Ochoa program and by IOC/Fiocruz.

It is through interdisciplinary capacity building and international collaboration that we will further understand vector-borne diseases and their complex interactions with the environment.

This graduate course stands out for being an immersive field experience, where students and instructors are encouraged to interact and learn together outside the traditional classrooms. This year we had invited instructors from Fiocruz, FMEL, ISGlobal, the Federal University of Viçosa (UFV), the Federal University of Rio de Janeiro State (UNIRIO), and the State University of Rio de Janeiro (UERJ). The group had lectures about the ecology and evolution of vectors, the epidemiology of vector-borne diseases, landscape ecology, spatial modelling, sampling design, and others. Students had hands-on practice with a range of vector sampling methods and developed small research projects in the field, aimed at: comparing vector species diversity across environmental disturbance levels; assessing trapping efficacy between multiple capture methods and attractants; and assessing the presence of vectors in isolated habitat patches across a landscape of forest fragments.

Participants of the Detvetores course, August 2022. Photo: IOC/Fiocruz

By spending a week together in the field, both students and senior researchers learned a lot from sharing experiences and adapting to the unique and dynamic nature of field work. This third edition of the DetVetores international course was concluded with the certainty that it achieved its goals of capacity building and networking. We look forward to the next edition in 2023. Stay tuned for updates at the web pages of the Tropical Medicine Graduate Program of IOC/Fiocruz and of partner institutions!