Jointly conducted by IRD and INSERM, this research explores the genetic diversity of Cryptococcus in Abidjan and their sensitivity to antifungals.
Kondo Kassi, researcher at TransVIHMI (Institut de Recherche pour le Développement).
Thesis defended in 2016 at the doctoral school École doctorale Sciences Chimiques et Biologiques pour la Santé (Montpellier ; 1992-....).
This research is the result of an international co-supervision between several partner institutions.
Referenced in the ABES/STAR network, this thesis meets the rigorous criteria of French higher education.
Neuromeningeal cryptococcosis (NCM) is a formidable opportunistic infection, particularly among patients living with HIV. This disease, caused by the fungus Cryptococcus neoformans and its related species, is particularly concerning in Africa, where it represents the fourth leading cause of death related to infectious diseases, with approximately 600,000 deaths per year. The severity of this situation is exacerbated by the fact that cryptococcosis is often underdiagnosed, due to a lack of access to care and appropriate diagnostics in many regions of the continent. This study, conducted in Abidjan, examines the genetic diversity of Cryptococcus isolates and their resistance to antifungals, a subject of crucial importance for public health in Côte d'Ivoire and beyond.
The results of this research reveal a high genotypic diversity among the studied isolates, with clinical and environmental isolates exhibiting distinct characteristics. The isolates were collected from 1,750 HIV-positive patients and 667 environmental samples, demonstrating a rigorous methodological approach. This work highlights the presence of several species of Cryptococcus in a single sample, an unprecedented observation in West Africa. This genetic diversity could have significant implications for the virulence and pathogenicity of the strains, making the fight against this infection even more complex.
Moreover, the isolation of Cryptococcus from pigeon droppings has been documented, but analyses show that these isolates differ significantly from those found in patients, thus excluding this source of contamination as a major vector in the transmission of the infection. This raises questions about other potential sources of environmental contamination, including soils and organic matter, which could also play a role in the transmission of this disease.
The variability in antifungal sensitivity is another crucial point of this study. Although the majority of isolates are sensitive to standard treatments, cases of resistance are emerging, complicating patient management. This resistance can be attributed to several factors, including inappropriate use of antifungals, lack of surveillance, and the selective pressure exerted by treatments. This situation underscores the importance of continuous monitoring and in-depth research on Cryptococcus strains in Côte d'Ivoire. It is imperative to establish treatment protocols based on local data regarding antifungal sensitivity, in order to optimize clinical outcomes for patients.
The implications of this study go beyond simple epidemiology. They raise questions about the management of opportunistic infections in the context of HIV and the need to adapt treatment strategies based on the genetic characteristics of the isolates. For example, personalized approaches could be developed to specifically target resistant strains, integrating alternative treatments or drug combinations. The fight against cryptococcosis requires an integrated approach, combining research, clinical care, and adapted public health policies.
It is also essential to strengthen the capacities of local health systems to address this threat. This could include training healthcare professionals on early diagnosis and treatment of cryptococcosis, as well as improving laboratory infrastructures to enable advanced genetic analyses. Furthermore, raising awareness among at-risk populations, particularly those living with HIV, is crucial to promote early screening and adequate management.
In conclusion, this study on the genetic diversity and antifungal sensitivity of Cryptococcus isolates in Abidjan is an important step towards a better understanding of cryptococcosis in West Africa. The results obtained highlight the need for concerted action to address this opportunistic infection, which continues to pose a major challenge for public health in the region. It is imperative that policymakers, researchers, and healthcare professionals collaborate to develop effective strategies that will reduce the impact of cryptococcosis on vulnerable populations.
Key Facts
- 600.000 : Number of annual deaths due to cryptococcosis in Africa.
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Sources and Access
Kondo Kassi. Diversité génétique et sensibilité aux antifongiques d’isolats cliniques et environnementaux de Cryptococcus à Abidjan, Côte d’Ivoire.. Maladies infectieuses. Université Montpellier; Université Félix Houphouët-Boigny (Abidjan, Côte d'Ivoire), 2016. Français. ⟨NNT : 2016MONT3521⟩. ⟨tel-01628628⟩