University Of Sciences and Technology of Masuku
Gabon
Problem Statement
Since the 2000s, Aedes (Stegomyia) albopictus has become the dominant Stegomyia species in anthropogenic environments of Central-Africa, linked to dengue, chikungunya, and Zika outbreaks. Despite replacing native species, its bioecological drivers and genomic factors influencing its success and vector competence remain poorly understood. This project aims to elucidate these drivers.
Progress Highlights
We investigated Ae. albopictus ecological limits at two study sites, resulting in three published papers and the completion of four MSc programs. Key achievements include 3 lead author papers, 4 co-authored papers, and significant in progress in lab restoration and average in equipment acquisition.
Key Findings
We revealed that Ae. albopictus thrives in anthropogenic and forested areas, aided by human-altered microhabitats and natural ones like tree and rock holes. Its presence correlates with physicochemical features such as size, pH, redox potential, dissolved oxygen, and conductivity, showing a preference for larger, pH-neutral microhabitats.
Potential Impact
This project will allow characterization of Aedes albopictus relationship with native mosquito species sharing the same habitats and assess the arboviruses emergence risk. This will ultimately contribute effectively to the development of the arboviruses' control strategies in Gabon and inform preventive policies against zoonotic risks.
Summary
Since its introduction in Central Africa, the tiger mosquito, Aedes albopictus, spread gradually to become the major dengue, chikungunya, and Zika vector in the region. Its spread continued across remote sylvan ecosystems, with the risk of bridging zoonotic viruses between wild forests and contiguous anthropogenic areas. Dr Obame-Nkoghe’s research, conducted in Gabon, will investigate the underlying drivers, including response to environmental stressors and the genetic variability of this species that could explain its invasive success and influence its vector role for health-threatening viruses in invaded territories, in order to improve control measure against Ae. albopictus-driven vector-borne and zoonotic threats.
Grantee Description
Dr Judicaël Obame-Nkoghe is a medical entomologist researcher and lecturer at the University of Science and Technology of Masuku in Gabon. He obtained his Ph.D. in Medical Entomology in 2016. His research focuses on understanding vector systems (ecology, adaptation, vector invasions, vector transmission of pathogens) and how they model the epidemiological patterns of vector-borne infectious diseases.
Dr Obame-Nkoghe’s long-term aspiration is to continuously expand and embrace new biostatistics, genetics and modelling methodologies in studying vector-borne and zoonotic diseases. He aims to build research capacities and advance a research niche on vector-borne and zoonotic diseases in Africa. He aspires to train young African scientists, promote research excellence and leadership, and conduct research informing policy decisions to improve human health.
Project: What are the bioecological drivers underlying the invasive success of Aedes albopictus, and risks of arbovirus emergence in Gabon, Central-Africa
Ongoing studies in Central Africa revealed that the spread of Aedes albopictus continued across remote sylvan ecosystems in absence of humans, showing thus a relatively large ecological plasticity. This plasticity presupposes its predisposition to cross the bioecological barriers encountered during its invasion process, as well as its potential to be a bridge-vector for several zoonotic-emerging viruses between wild and anthropogenic compartments. While studies in Central Africa revealed a distribution of Ae.albopictus tending to be associated with a decline or replacement of native mosquito species populations (e.g., Ae.aegypti), the bioecological drivers, including response to biological, physicochemical stressors, and the Ae.albopictus genetic variability that could explain its invasive success and influence its vector competence for health-threatening viruses in Gabon, across different environmental contexts, remained poorly explored. Characterizing these drivers underlying the invasive success of Ae. albopictus is crucial for effective vector control measures against emerging arboviruses. The Dr Obame-Nkoghe’s research will uncover and dissect those drivers with the specific objectives to evaluate the bioecological limits, the genetic structuration and bases of the adaptation of Ae. albopictus populations following an ecological gradient. The project will also allow to characterize its relationships with native mosquito species sharing the same habitats and assess, based on virus screening and vector competence assays associated to modelling technics, the arboviruses’ emergence risk. The project will ultimately contribute effectively to the development of arboviruses’ control strategies in this part of the world.
