scholarly journals A comparative study of dengue virus vectors in major parks and adjacent residential areas in Ho Chi Minh City, Vietnam

2022 ◽  
Vol 16 (1) ◽  
pp. e0010119
Author(s):  
Trang Thi Thuy Huynh ◽  
Noboru Minakawa
Keyword(s):  
Dengue Virus ◽  
Vector Control ◽  
Aedes Albopictus ◽  
Urban Parks ◽  
Prevalence Ratio ◽  
Ho Chi Minh City ◽  
Adult Density ◽  
Residential Areas ◽  
Larval Habitats ◽  
Virus Vectors

The primary dengue virus vectors, Aedes aegypti and Aedes albopictus, are primarily daytime biting mosquitoes. The risk of infection is suspected to be considerable in urban parks due to visitor traffic. Despite the importance of vector control for reducing dengue transmission, little information is available on vector populations in urban parks. The present study characterized mosquito habitats and estimated vector densities in the major urban parks in Ho Chi Minh City, Vietnam and compared them with those in adjacent residential areas. The prevalences of habitats where Aedes larvae were found were 43% and 9% for the parks and residential areas, respectively. The difference was statistically significant (prevalence ratio [PR]: 5.00, 95% CI: 3.85–6.49). The prevalences of positive larval habitats were significantly greater in the parks for both species than the residential areas (PR: 1.52, 95% CI: 1.04–2.22 for A. aegypti, PR: 10.10, 95% CI: 7.23–14.12 for A. albopictus). Larvae of both species were positively associated with discarded containers and planters. Aedes albopictus larvae were negatively associated with indoor habitats, but positively associated with vegetation shade. The adult density of A. aegypti was significantly less in the parks compared with the residential areas (rate ratio [RR]; 0.09, 95% CI: 0.05–0.16), while the density of A. albopictus was significantly higher in the parks (RR: 9.99, 95% CI: 6.85–14.59). When the species were combined, the density was significantly higher in the parks (RR: 2.50, 95% CI: 1.92–3.25). The urban parks provide suitable environment for Aedes mosquitoes, and A. albopictus in particular. Virus vectors are abundant in the urban parks, and the current vector control programs need to have greater consideration of urban parks.

scholarly journals First two autochthonous dengue virus infections in metropolitan France, September 2010

2010 ◽  
Vol 15 (39) ◽  
Author(s):  
G La Ruche ◽  
Y Souarès ◽  
A Armengaud ◽  
F Peloux-Petiot ◽  
P Delaunay ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Vector Control ◽  
Dengue Fever ◽  
Aedes Albopictus ◽  
Case Finding ◽  
Control Measures ◽  
Active Case Finding ◽  
Virus Infections ◽  
First Time ◽  
Local Transmission

In September 2010, two cases of autochthonous dengue fever were diagnosed in metropolitan France for the first time. The cases occurring in Nice, south-east France, where Aedes albopictus is established, are evidence of dengue virus circulation in this area. This local transmission of dengue calls for further enhanced surveillance, active case finding and vector control measures to reduce the spread of the virus and the risk of an epidemic.

scholarly journals Additional evidence on the efficacy of different Akirin vaccines assessed on Anopheles arabiensis (Diptera: Culicidae)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Blaženka D. Letinić ◽  
Marinela Contreras ◽  
Yael Dahan-Moss ◽  
Ingrid Linnekugel ◽  
José de la Fuente ◽  
...  
Keyword(s):  
Vector Control ◽  
Aedes Albopictus ◽  
Malaria Vector ◽  
Vaccine Efficacy ◽  
Anopheles Arabiensis ◽  
Vaccine Development ◽  
Target Antigen ◽  
Control Methods ◽  
Protective Response ◽  
Current Vector

Abstract Background Anopheles arabiensis is an opportunistic malaria vector that rests and feeds outdoors, circumventing current indoor vector control methods. Furthermore, this vector will readily feed on both animals and humans. Targeting this vector while feeding on animals can provide an additional intervention for the current vector control activities. Previous results have displayed the efficacy of using Subolesin/Akirin ortholog vaccines for the control of multiple ectoparasite infestations. This made Akirin a potential antigen for vaccine development against An. arabiensis. Methods The efficacy of three antigens, namely recombinant Akirin from An. arabiensis, recombinant Akirin from Aedes albopictus, and recombinant Q38 (Akirin/Subolesin chimera) were evaluated as novel interventions for An. arabiensis vector control. Immunisation trials were conducted based on the concept that mosquitoes feeding on vaccinated balb/c mice would ingest antibodies specific to the target antigen. The antibodies would interact with the target antigen in the arthropod vector, subsequently disrupting its function. Results All three antigens successfully reduced An. arabiensis survival and reproductive capacities, with a vaccine efficacy of 68–73%. Conclusions These results were the first to show that hosts vaccinated with recombinant Akirin vaccines could develop a protective response against this outdoor malaria transmission vector, thus providing a step towards the development of a novel intervention for An. arabiensis vector control. Graphic Abstract

scholarly journals Transcriptome Analysis of Responses to Dengue Virus 2 Infection in Aedes albopictus (Skuse) C6/36 Cells

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 343
Author(s):  
Manjin Li ◽  
Dan Xing ◽  
Duo Su ◽  
Di Wang ◽  
Heting Gao ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Aedes Albopictus ◽  
Bioinformatics Analysis ◽  
Interaction Mechanism ◽  
Transcriptional Analysis ◽  
Functional Verification ◽  
Mosquito Vector ◽  
Rna Seq ◽  
Sequencing Data ◽  
Qrt Pcr

Dengue virus (DENV), a member of the Flavivirus genus of the Flaviviridae family, can cause dengue fever (DF) and more serious diseases and thus imposes a heavy burden worldwide. As the main vector of DENV, mosquitoes are a serious hazard. After infection, they induce a complex host–pathogen interaction mechanism. Our goal is to further study the interaction mechanism of viruses in homologous, sensitive, and repeatable C6/36 cell vectors. Transcriptome sequencing (RNA-Seq) technology was applied to the host transcript profiles of C6/36 cells infected with DENV2. Then, bioinformatics analysis was used to identify significant differentially expressed genes and the associated biological processes. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to verify the sequencing data. A total of 1239 DEGs were found by transcriptional analysis of Aedes albopictus C6/36 cells that were infected and uninfected with dengue virus, among which 1133 were upregulated and 106 were downregulated. Further bioinformatics analysis showed that the upregulated DEGs were significantly enriched in signaling pathways such as the MAPK, Hippo, FoxO, Wnt, mTOR, and Notch; metabolic pathways and cellular physiological processes such as autophagy, endocytosis, and apoptosis. Downregulated DEGs were mainly enriched in DNA replication, pyrimidine metabolism, and repair pathways, including BER, NER, and MMR. The qRT-PCR results showed that the concordance between the RNA-Seq and RT-qPCR data was very high (92.3%). The results of this study provide more information about DENV2 infection of C6/36 cells at the transcriptome level, laying a foundation for further research on mosquito vector–virus interactions. These data provide candidate antiviral genes that can be used for further functional verification in the future.

scholarly journals On Transforming Unused Urban Spaces to Social Housing for Self-Employed People in Ho Chi Minh City: An Architectural Space Design Proposal

2021 ◽  
Vol 13 (21) ◽  
pp. 12175
Author(s):  
Le-Minh Ngo ◽  
Hai-Binh Nguyen ◽  
Thi-Phuong Uyen Nguyen ◽  
Thi-Minh Dieu Nguyen
Keyword(s):  
Low Income ◽  
Social Housing ◽  
Urban Areas ◽  
Low Cost ◽  
Legal Framework ◽  
Operating Conditions ◽  
Urban Spaces ◽  
Ho Chi Minh City ◽  
Residential Areas ◽  
Property Market

As with many metropolitan areas, social housing (SH) provision, which can improve living standards and social welfare, is crucial for urban socio-economic development strategies in Ho Chi Minh City (HCMC). However, there have been issues relating to promoting social housing in the Vietnamese context resulting from the property market and the design. The former is a failure to attract investors. The latter relates to lacking housing models for the mid- and low-income communities. Currently, many low-income families who have low access to the general job market in HCMC have to make a living by running their own business at home. This situation leads to low-income housing establishments in some residential areas. Thus, the planning approach in social housing needs to solve both the demand for low-cost housing and promoting self-employed activities. In this paper, mixed methods, including observation, questionnaires, interviews, data aggregation, and comparison, were conducted with supporting legal conditions and corresponding operating conditions to propose appropriate designs for the SH for self-employed people in HCMC. First, observing and analyzing urban spaces helped identify the unused urban areas that solve the investment issue. Then, after studying the development of social housing in different contexts via the questionnaire and in-depth interviews, self-employed households’ basic information and their business needs in using SH spaces were identified in some districts. Then, based on the legal framework and practical projects, optimal space designs were formed.

scholarly journals Entomological Status Based on Vector Density Index and Transovarial Infection on Aedes Sp. Mosquito in Meteseh Village, Semarang City

2020 ◽  
Vol 202 ◽  
pp. 12016
Author(s):  
Martini Martini ◽  
Zufri Armen ◽  
Kusariana Nissa ◽  
Hestiningsih Retno ◽  
Yuliawati Sri ◽  
...  
Keyword(s):  
Health Services ◽  
Dengue Virus ◽  
Aedes Albopictus ◽  
Research Method ◽  
Hemorrhagic Fever ◽  
Adult Mosquito ◽  
Elisa Method ◽  
Density Index ◽  
Egg Density ◽  
Descriptive Method

Dengue Hemorrhagic Fever (DHF) is a disease caused by Dengue virus. In 2016, the number of DHF patients in areas of Health services of Rowosari was 247 cases, IR 289.6/100.000 populations and the highest number of the patients was from Meteseh Village. The most usual mechanism happened in the vertical transmission, transovarial infection, from adult mosquito to the egg. The study was conducted to describe of entomological status of House Index (HI), Container Index (CI), Breteau Index (BI), House index (HI), Ovitrap Index (OI) of larvae as well as transovarial infection in Aedes sp. The research method was descriptive method by conducting test to the entomology status of DHF incidence. Based on the survey in Meteseh sub-village (XVI), a result found that average House Index 8.99%, Container Index 2.88%, Breteau Index 16.40%, HI 8,99 Ovitrap Index 35.46% with the egg density at 1.023 eggs. The identified mosquitoes were 30, and from the identification result of Aedes sp., two Aedes species were found, 28 Aedes aegypti,and only 2 Aedes albopictus. The transovarial infection in Aedes sp. using ELISA method was found 6 mosquito samples which were positive of dengue virus, with the detail in neighborhood 01 (1 sample), neighborhood 02 (2 samples), neighborhood 03 (3 samples). DHF in Meteseh Sub village in Semarang City was probably happened because correlated with transovarial infection.

scholarly journals Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes

2017 ◽  
Vol 22 (9) ◽  
pp. 1154-1165 ◽  
Author(s):  
Sylvia Joanne ◽  
Indra Vythilingam ◽  
Boon-Teong Teoh ◽  
Cherng-Shii Leong ◽  
Kim-Kee Tan ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Aedes Albopictus ◽  
Vector Competence ◽  
Dengue Virus Serotypes

scholarly journals Field- and clinically derived estimates of Wolbachia-mediated blocking of dengue virus transmission potential in Aedes aegypti mosquitoes

2017 ◽  
Vol 115 (2) ◽  
pp. 361-366 ◽  
Author(s):  
Lauren B. Carrington ◽  
Bich Chau Nguyen Tran ◽  
Nhat Thanh Hoang Le ◽  
Tai Thi Hue Luong ◽  
Truong Thanh Nguyen ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Virus Transmission ◽  
Field Testing ◽  
Denv Infection ◽  
Ho Chi Minh City ◽  
Wild Type ◽  
Transmission Potential ◽  
Blood Meals ◽  
Increased Susceptibility

The wMel strain of Wolbachia can reduce the permissiveness of Aedes aegypti mosquitoes to disseminated arboviral infections. Here, we report that wMel-infected Ae. aegypti (Ho Chi Minh City background), when directly blood-fed on 141 viremic dengue patients, have lower dengue virus (DENV) transmission potential and have a longer extrinsic incubation period than their wild-type counterparts. The wMel-infected mosquitoes that are field-reared have even greater relative resistance to DENV infection when fed on patient-derived viremic blood meals. This is explained by an increased susceptibility of field-reared wild-type mosquitoes to infection than laboratory-reared counterparts. Collectively, these field- and clinically relevant findings support the continued careful field-testing of wMel introgression for the biocontrol of Ae. aegypti-born arboviruses.

scholarly journals Bioassay and molecular monitoring of insecticide resistance status in Aedes albopictus populations from Greece, to support evidence-based vector control

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Sofia Balaska ◽  
Emmanouil A. Fotakis ◽  
Ilias Kioulos ◽  
Linda Grigoraki ◽  
Spyridoula Mpellou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Aedes Albopictus ◽  
Evidence Based ◽  
Molecular Monitoring ◽  
Support Evidence

scholarly journals Defining the larval habitat: abiotic and biotic parameters associated with Anopheles farauti productivity

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Kimberley McLaughlin ◽  
Thomas R. Burkot ◽  
Jance Oscar ◽  
Nigel W. Beebe ◽  
Tanya L. Russell
Keyword(s):  
Vector Control ◽  
Control Strategy ◽  
World Health ◽  
Effective Control ◽  
Biological Parameters ◽  
Insecticide Treated Nets ◽  
Larval Habitats ◽  
Anopheles Farauti ◽  
Larval Source Management ◽  
Source Management

Abstract Background In the Solomon Island, the dominant malaria vector, Anopheles farauti, is highly anthropophagic and increasingly exophilic and early biting. While long-lasting insecticide-treated nets remain effective against An. farauti, supplemental vector control strategies will be needed to achieve malaria elimination. Presently, the only World Health Organization recommended supplemental vector control strategy is larval source management (LSM). Effective targeted larval source management requires understanding the associations between abiotic, chemical and biological parameters of larval habitats with the presence or density of vector larvae. Methods Potential and actual An. farauti larval habitats were characterized for presence and density of larvae and associated abiotic, chemical and biological parameters. Results A third of all sampled potential habitats harboured An. farauti larvae with 80% of An. farauti positive habitats being in three habitat classifications (swamps/lagoons, transient pools and man-made holes). Large swamps were the most abundant positive habitats surveyed (43% of all An. farauti positive habitats). Habitats with An. farauti larvae were significantly associated with abiotic (pH, nitrate, ammonia and phosphate concentrations and elevated temperature) and biotic (predators) parameters. Conclusion Large swamps and lagoons are the largest and most abundant An. farauti habitats in the Solomon Islands. Positive habitats were more frequently associated with the presence of predators (vertebrates and invertebrates) and higher water temperatures. Cohabitation with predators is indicative of a complex habitat ecosystem and raises questions about the potential of biological control as an effective control strategy. Increased presence of An. farauti with higher water temperature suggests a potential explanation for the coastal distribution of this species which is not found inland at elevated altitudes where temperatures would be cooler.

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