1
|
Guerrero D, Lay S, Piv E, Chhin C, Leng S, Meng R, Mam KE, Pean P, Vantaux A, Boyer S, Missé D, Cantaert T. In-vitro assessment of cutaneous immune responses to aedes mosquito salivary gland extract and dengue virus in Cambodian individuals. Oxf Open Immunol 2024; 5:iqae003. [PMID: 38737941 PMCID: PMC11035005 DOI: 10.1093/oxfimm/iqae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/13/2024] [Accepted: 03/25/2024] [Indexed: 05/14/2024] Open
Abstract
Dengue virus (DENV) poses a global health threat, affecting millions individuals annually with no specific therapy and limited vaccines. Mosquitoes, mainly Aedes aegypti and Aedes albopictus worldwide, transmit DENV through their saliva during blood meals. In this study, we aimed to understand how Aedes mosquito saliva modulate skin immune responses during DENV infection in individuals living in mosquito-endemic regions. To accomplish this, we dissociated skin cells from Cambodian volunteers and incubated them with salivary gland extract (SGE) from three different mosquito strains: Ae. aegypti USDA strain, Ae. aegypti and Ae. albopictus wild type (WT) in the presence/absence of DENV. We observed notable alterations in skin immune cell phenotypes subsequent to exposure to Aedes salivary gland extract (SGE). Specifically, exposure lead to an increase in the frequency of macrophages expressing chemokine receptor CCR2, and neutrophils expressing CD69. Additionally, we noted a substantial increase in the percentage of macrophages that became infected with DENV in the presence of Aedes SGE. Differences in cellular responses were observed when Aedes SGE of three distinct mosquito strains were compared. Our findings deepen the understanding of mosquito saliva's role in DENV infection and skin immune responses in individuals regularly exposed to mosquito bites. This study provides insights into skin immune cell dynamics that could guide strategies to mitigate DENV transmission and other arbovirus diseases.
Collapse
Affiliation(s)
- David Guerrero
- Institut Pasteur du Cambodge, Immunology Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Sokchea Lay
- Institut Pasteur du Cambodge, Immunology Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Eakpor Piv
- Institut Pasteur du Cambodge, Malaria Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Chansophea Chhin
- Institut Pasteur du Cambodge, Malaria Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Sokkeang Leng
- Institut Pasteur du Cambodge, Medical and Veterinary Entomology Unit, Phnom Penh 12201, Cambodia
| | - Ratana Meng
- Institut Pasteur du Cambodge, Immunology Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Kim Eng Mam
- Crystal Esthetic Center, Phnom Penh 12201, Cambodia
| | - Polidy Pean
- Institut Pasteur du Cambodge, Immunology Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Amelie Vantaux
- Institut Pasteur du Cambodge, Malaria Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| | - Sebastien Boyer
- Institut Pasteur du Cambodge, Medical and Veterinary Entomology Unit, Phnom Penh 12201, Cambodia
- Unité Ecologie et Emergence des Pathogènes Transmis par les Arthropodes, Institut Pasteur, Paris, France
| | - Dorothée Missé
- MIVEGEC, Univ. Montpellier, IRD, CNRS, 34000, Montpellier, France
| | - Tineke Cantaert
- Institut Pasteur du Cambodge, Immunology Unit, Pasteur Network, Phnom Penh 12201, Cambodia
| |
Collapse
|
2
|
Bonnin L, Tran A, Herbreteau V, Marcombe S, Boyer S, Mangeas M, Menkes C. Predicting the Effects of Climate Change on Dengue Vector Densities in Southeast Asia through Process-Based Modeling. Environ Health Perspect 2022; 130:127002. [PMID: 36473499 PMCID: PMC9726451 DOI: 10.1289/ehp11068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Aedes aegypti and Ae. albopictus mosquitoes are major vectors for several human diseases of global importance, such as dengue and yellow fever. Their life cycles and hosted arboviruses are climate sensitive and thus expected to be impacted by climate change. Most studies investigating climate change impacts on Aedes at global or continental scales focused on their future global distribution changes, whereas a single study focused on its effects on Ae. aegypti densities regionally. OBJECTIVES A process-based approach was used to model densities of Ae. aegypti and Ae. albopictus and their potential evolution with climate change using a panel of nine CMIP6 climate models and climate scenarios ranging from strong to low mitigation measures at the Southeast Asian scale and for the next 80 y. METHODS The process-based model described, through a system of ordinary differential equations, the variations of mosquito densities in 10 compartments, corresponding to 10 different stages of mosquito life cycle, in response to temperature and precipitation variations. Local field data were used to validate model outputs. RESULTS We show that both species densities will globally increase due to future temperature increases. In Southeast Asia by the end of the century, Ae. aegypti densities are expected to increase from 25% with climate mitigation measures to 46% without; Ae. albopictus densities are expected to increase from 13%-21%, respectively. However, we find spatially contrasted responses at the seasonal scales with a significant decrease in Ae. albopictus densities in lowlands during summer in the future. DISCUSSION These results contrast with previous results, which brings new insight on the future impacts of climate change on Aedes densities. Major sources of uncertainties, such as mosquito model parametrization and climate model uncertainties, were addressed to explore the limits of such modeling. https://doi.org/10.1289/EHP11068.
Collapse
Affiliation(s)
- Lucas Bonnin
- ENTROPIE (UMR 9220), IRD, Université de la Réunion, CNRS, Ifremer, Université de Nouvelle Calédonie, Nouméa, Nouvelle-Calédonie
| | - Annelise Tran
- CIRAD, UMR TETIS, Sainte-Clotilde, Reunion Island, France
- TETIS, Université Montpellier, AgroParisTech, CIRAD, CNRS, INRAE, Montpellier, France
- CIRAD, UMR ASTRE, Sainte-Clotilde, Reunion Island, France
- ASTRE, Université Montpellier, CIRAD, INRAE, Montpellier, France
| | - Vincent Herbreteau
- ESPACE-DEV, IRD, Université Antilles, Université Guyane, Université Montpellier, Université de la Réunion, Montpellier, France
- ESPACE-DEV, IRD, Université Antilles, Université Guyane, Université Montpellier, Université de la Réunion, Phnom Penh, Cambodia
| | - Sébastien Marcombe
- Medical Entomology and Vector-Borne Disease Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR
| | - Sébastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Morgan Mangeas
- ENTROPIE (UMR 9220), IRD, Université de la Réunion, CNRS, Ifremer, Université de Nouvelle Calédonie, Nouméa, Nouvelle-Calédonie
| | - Christophe Menkes
- ENTROPIE (UMR 9220), IRD, Université de la Réunion, CNRS, Ifremer, Université de Nouvelle Calédonie, Nouméa, Nouvelle-Calédonie
| |
Collapse
|
3
|
Abstract
Background Mangroves are an ecosystem interface between land and sea, forming distinctive shallow-water marine communities in tropical and subtropical waters. The mangrove forest surface in Cambodia is being reduced due to deforestation. Because the mangrove type of ecosystem generally hosts a great diversity of mosquitoes, the urbanization of these ecosystems will increase interactions between humans and wild mosquitoes, and might thus serve as a potential source of new infectious diseases. Understanding mosquito diversity and analyzing their virome is critical to estimate the risk of emergence or future outbreaks of mosquito-borne diseases. Objective To understand the mosquito diversity of mangrove forests of Koh Kong province (Cambodia). Methods In 2019, the mosquito fauna was sampled for 3 consecutive days using BG-Sentinel and light traps, in 3 locations in the mangrove forests of Koh Kong province (Cambodia) during both dry and rainy seasons. Results A total of 3107 samples were collected, belonging to 10 genera for 34 species. The Culex genus was the most diverse, accounting for 10 species. One species, Culex sitiens, represented over 60% of all collected mosquitoes. A total of 12 medically important species were recorded, 2 species, Aedes (Stegomyia) albopictus and Culex vishnui, were collected in all sites and during both the dry and rainy seasons, highlighting a potential risk of these species acting as bridge vectors. Conclusions If new arboviruses were to be recorded in this peculiar area, it would indicate that the mosquito species found have the potential to act as a bridge between sylvatic and anthropogenic arboviruses.
Collapse
Affiliation(s)
- Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh12201, Cambodia
| | - Chea Sokha
- Wildlife Health Program, Wildlife Conservation Society, Sangkat Tonle Bassac, Phnom Penh12000, Cambodia
| | - Sébastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh12201, Cambodia
| |
Collapse
|
4
|
Boyer S, Maquart PO, Chhuoy K, Suor K, Chhum M, Heng K, Leng S, Fontenille D, Marcombe S. Monitoring insecticide resistance of adult and larval Aedes aegypti (Diptera: Culicidae) in Phnom Penh, Cambodia. Parasit Vectors 2022; 15:44. [PMID: 35101104 PMCID: PMC8805314 DOI: 10.1186/s13071-022-05156-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/08/2022] [Indexed: 01/01/2023] Open
Abstract
Background Dengue fever is a major public health concern in Cambodia, with thousands of cases every year in urban, suburban and rural areas of the country. The main vector of dengue fever in Cambodia is Aedes aegypti. The organophosphate larvicide temephos and adulticides belonging to the pyrethroid family have been widely used for decades by public health authorities to fight dengue vectors, but resistance of Ae. aegypti to these insecticides has been previously described for Cambodia. Methods In order to adapt the vector control strategy presently used in Cambodia, we tested 14 adulticides belonging to the carbamate, organochlorine, organophosphate, and pyrethroid insecticide families and three larvicides [temephos, spinosad and Bacillus thuringiensis ser. israelensis (Bti)] belonging to three different insecticide families (organophosphates, spinosyns and entomopathogenic bacteria). The standard procedures used here to test the adults and larvae of an Ae. aegypti population from Phnom Penh followed World Health Organization guidelines. Results For adults, high mortality rates were observed with carbamate, organophosphate and organochlorine (with the exception of dichlorodiphenyltrichloroethane) insecticides (i.e. between 87.6 and 100%), while low mortality rates were observed with all of the tested pyrethroid insecticides (i.e. between 1 and 35%). For larvae, no resistance against Bti was detected [resistance ratio (RR90 < 1.6)], but moderate resistance was observed for temephos and spinosad (RR90 < 5.6). Conclusions The results of this study indicate that (i) Bti should be considered a serious alternative to temephos for the control of Ae. aegypti larvae; and (ii) the carbamate adulticides propoxur and bendiocarb should be employed instead of the widely used pyrethroid insecticides for the control of adult Ae. aegypti on land under mosaic farming and crop rotation in Cambodia, as the insects were found to be resistant to the latter types of insecticide. Research focusing on insecticide resistance and innovative and effective vector control strategies should be undertaken as a public health priority in Cambodia. Graphical abstract ![]()
Collapse
|