Anopheles mosquitoes in Morocco: implication for public health and underlined challenges for malaria re-establishment prevention under current and future climate conditions.

BACKGROUND: The potential reappearance and/or expansion of vector-borne diseases is one of the terrifying issues awaiting humanity in the context of climate change. The presence of competent Anopheles vectors, as well as suitable environmental circumstances, may result in the re-emergence of autochthonous Malaria, after years of absence. In Morocco, international travel and migration movements from Malaria-endemic areas have recently increased the number of imported cases, raising awareness of Malaria's possible reintroduction. Using machine learning we developed model predictions, under current and future (2050) climate, for the prospective distribution of Anopheles claviger, Anopheles labranchiae, Anopheles multicolor, and Anopheles sergentii implicated or incriminated in Malaria transmission. RESULTS: All modelled species are expected to find suitable habitats and have the potential to become established in the northern and central parts of the country, under present-day conditions. Distinct changes in the distributions of the four mosquitoes are to be expected under climate change. Even under the most optimistic scenario, all investigated species are likely to acquire new habitats that are now unsuitable, placing further populations in danger. We also observed a northward and altitudinal shift in their distribution towards higher altitudes. CONCLUSION: Climate change is expected to expand the potential range of malaria vectors in Morocco. Our maps and predictions offer a way to intelligently focus efforts on surveillance and control programmes. To reduce the threat of human infection, it is crucial for public health authorities, entomological surveillance teams, and control initiatives to collaborate and intensify their actions, continuously monitoring areas at risk. © 2023 Society of Chemical Industry.

Modeling and mapping the habitat suitability and the potential distribution of Arboviruses vectors in Morocco.

Mosquitoes transmit several agents of diseases and the presence of different species represents a threat to animal and public health. Aedes and Culex mosquitoes are of particular concern giving their potential vector competence for Arbovirus transmission. In Morocco, the lack of detailed information related to their spatial distribution raises major concerns and hampers effective vector surveillance and control. Using maximum entropy (Maxent) modeling, we generated prediction models for the potential distribution of Arboviruses vectors (Aedes aegypti, Ae. vexans, Ae. caspius, Ae. detritus, and Culex pipiens) in Morocco, under current climatic conditions. Also, we investigated the habitat suitability for the potential occurrence and establishment of Ae. albopictus and Ae. vittatus recorded only once in the country. Prediction models for these last two species were generated considering occurrence datasets from close countries of the Mediterranean Basin, where Ae. albopictus is well established, and from a worldwide database for the case of Ae. vittatus (model transferability). With the exception of Ae. vittatus, the results identify potential habitat suitability in Morocco for all mosquitos considered. Existing areas with maximum risk of establishment and high potential distribution were mainly located in the northwestern and central parts of Morocco. Our results essentially underline the assumption that Ae. albopictus, if not quickly controlled, might find suitable habitats and has the potential to become established, especially in the northwest of the country. These findings may help to better understand the potential distribution of each species and enhance surveillance efforts in areas identified as high risk.

TITLE: Modélisation et cartographie de l'aptitude de l'habitat et de la distribution potentielle des vecteurs d'Arbovirus au Maroc. ABSTRACT: Les moustiques transmettent plusieurs agents de maladies et la présence de différentes espèces représente une menace pour la santé animale et publique. Les moustiques Aedes et Culex sont particulièrement préoccupants compte tenu de leur compétence de vecteur potentiel pour la transmission des Arbovirus. Au Maroc, le manque d'informations détaillées relatives à leur répartition spatiale soulève des préoccupations majeures et entrave une surveillance et un contrôle efficaces des vecteurs. En utilisant la modélisation de l'entropie maximale (Maxent), nous avons généré des modèles de prédiction pour la distribution potentielle des vecteurs d'Arbovirus (Aedes aegypti, Ae. vexans, Ae. caspius, Ae. detritus et Culex pipiens) au Maroc, dans les conditions climatiques actuelles. De plus, nous avons étudié l'adéquation de l'habitat pour l'occurrence et l'établissement potentiels d'Ae. albopictus et Ae. vittatus signalés une seule fois dans le pays. Des modèles de prévision pour ces deux dernières espèces ont été générés en tenant compte des ensembles de données d'occurrence des pays voisins du bassin méditerranéen, où Ae. albopictus est bien établi et provient d'une base de données mondiale pour le cas d'Ae. vittatus (transférabilité du modèle). À l'exception d'Ae. vittatus, les résultats identifient la pertinence potentielle de l'habitat au Maroc pour tous les moustiques considérés. Les zones existantes présentant un risque maximal d'établissement et une distribution à fort potentiel étaient principalement situées dans le nord-ouest et le centre du Maroc. Nos résultats soulignent essentiellement l'hypothèse qu'Ae. albopictus, s'il n'est pas rapidement contrôlé, pourrait trouver des habitats convenables et a le potentiel de s'établir, en particulier dans le nord-ouest du pays. Ces résultats peuvent aider à mieux comprendre la répartition potentielle de chaque espèce et à renforcer les efforts de surveillance dans les zones identifiées comme à haut risque.