Transcriptome Analysis of Aedes albopictus (Diptera: Culicidae) Larvae Exposed With a Sublethal Dose of Haedoxan A

Aedes albopictus is the vector of arbovirus diseases including yellow fever, dengue, Zika virus, and chikungunya fever, and it poses an enormous threat to human health worldwide. Previous studies have revealed that haedoxan A (HA), which is an insecticidal sesquilignan from Phryma leptostachya L., is a highly effective natural insecticide for managing mosquitoes and houseflies; however, the mechanisms underlying the response of Ae. albopictus after treatment with sublethal concentrations of HA is not clear. Here, high-throughput sequencing was used to analyze the gene expression changes in Ae. albopictus larvae after treatment with the LC30 of HA. In total, 416 differentially expressed genes (DEGs) were identified, including 328 upregulated genes and 88 downregulated genes. Identification and verification of related DEGs were performed by RT-qPCR. The results showed that two P450 unigenes (CYP4C21 and CYP304A1), one carboxylesterase, and one ABC transporter (ABCG1) were induced by HA, which indicated that these detoxifying enzyme genes might play a major role in the metabolic and detoxification processes of HA. Additionally, acetylcholine receptor subunit ɑ2 (AChRα2), AChRα5, AChRα9, and the glutamate receptor ionotropic kainate 2 (GRIK2) were found to be upregulated in HA-treated larvae, suggesting that HA affected the conduction of action potentials and synaptic transmission by disrupting the function of neural receptors. These results provide a foundation for further elucidating the target of HA and the mechanism of detoxification metabolism in Ae. albopictus.

Comparison of the temporal efficacy of Aquatain surface films for the control of Anopheles arabiensis and Ochlerotatus caspius larvae from Sudan

Aquatain mosquito formulation (AMF) is a surfactant that spreads across the surface of water bodies to produce a monomolecular film. This study experimentally evaluates the temporal efficacy of AMF against aquatic stages of Anopheles arabiensis and Ochlerotatus caspius under laboratory conditions. Using the recommended application dose of 1 ml m −2 , a large species-specific difference in the median lethal time for L3–L4 larvae was observed. The median lethal time to 50% mortality (LT50) and 90% mortality (LT90) was 1.3 h, 95% CI [1.2, 1.4] and 3.8 h, 95% CI [3.6, 4.0], respectively, for Oc. caspius . The corresponding values for An. arabiensis were 8.1 h, 95% CI [7.3, 9.0] and 59.6 h, 95% CI [48.5, 76.2]. Based on data from published laboratory studies for a total of seven mosquito species, drawn from four genera, results in the following three groups, [LT50 = 1–2 h, Culex quinquefasciatus , Ochlerotatus caspius ] [LT50 = 8–24, hours, Anopheles minimus , Anopheles arabiensis, Anopheles gambiae s.s.] and [LT50 = 72–143 h, Anopheles stephensi , Aedes aegypti ]. In all experiments, 100% mortality was achieved given sufficient time. The potential relevance of mortality rate estimates, in the context of other studies, on the use of monomolecular films for the control of malaria and arbovirus diseases is discussed.

Nanoparticles as Vaccines to Prevent Arbovirus Infection: A Long Road Ahead

Arthropod-borne viruses (arboviruses) are a significant public health problem worldwide. Vaccination is considered one of the most effective ways to control arbovirus diseases in the human population. Nanoparticles have been widely explored as new vaccine platforms. Although nanoparticles’ potential to act as new vaccines against infectious diseases has been identified, nanotechnology’s impact on developing new vaccines to prevent arboviruses is unclear. Thus, we used a comprehensive bibliographic survey to integrate data concerning the use of diverse nanoparticles as vaccines against medically important arboviruses. Our analysis showed that considerable research had been conducted to develop and evaluate nanovaccines against Chikungunya virus, Dengue virus, Zika virus, Japanese encephalitis virus, and West Nile virus. The main findings indicate that nanoparticles have great potential for use as a new vaccine system against arboviruses. Most of the studies showed an increase in neutralizing antibody production after mouse immunization. Nevertheless, even with significant advances in this field, further efforts are necessary to address the nanoparticles’ potential to act as a vaccine against these arboviruses. To promote advances in the field, we proposed a roadmap to help researchers better characterize and evaluate nanovaccines against medically important arboviruses.

A Review: Autodissemination of Pyriproxyfen as Novel Strategy to Control Dengue Outbreaks

The new emergence and re-emergence of arbovirus infections transmitted by Aedes mosquitoes have been spreading across Southeast Asia, Central Africa, United States, tropical Oceania and has become a major of public health concern. These arbovirus diseases were found to have a similar vector, symptoms, and environments. The situation is complex due to no specific vaccine or treatments being available for the diseases. Therefore, vector control is currently the best defense against arbovirus diseases, but with its own challenges such as the difficulty in controlling scattered breeding sites and biological behavior. Herein, we present a literature review of studies on current techniques proposed to combat dengue transmission that can fill a crucial gap in vector control programs, which is the inability of conventional control methods to eliminate and destroy cryptic breeding sites. In particular, we focused on the concept of autodissemination, which is a self-delivery technique by manipulating the behavior of mosquitoes, carrying the insecticide and disseminating it to cryptic breeding sites. This technique has shown promising results in some countries and can be considered as an additional tool in a vector control program. Therefore, we conducted Boolean searches in several electronic databases including Google Scholar, PubMed, SciELO and ScienceDirect to identify relevant published data regarding dengue and autodissemination techniques.

Awareness of African Horse Sickness as an Emerging Arbovirus Disease

African horse sickness (AHS) is one of the important arbovirus diseases in horse. The disease is fatal and should be transmitted by vector. This disease is potential to spread rapidly and has impacts in public health and socio-economic, especially in the international trade of horses and its products. The paper describes AHS, some factors that influence the disease, how to control the disease and its current situation in Indonesia. African horse sickness has been declared as notifiable disease in OIE list, therefore, the disease becomes strategic in the country that has high horse population. Climate changes affect vector population and spreading of the disease. In order to anticipate the entering of AHS infection in Indonesia, the government needs to facilitate the research on horse diseases including the safe laboratory facilities to handle exotic diseases and provide diagnostic tool for early detection.

Phylogenetically based establishment of a dengue virus panel, representing all available genotypes, as a tool in dengue drug discovery

Dengue fever is the most widespread of the human arbovirus diseases, with approximately one third of the world’s population at risk of infection. Dengue viruses are members of the genus Flavivirus (family Flaviviridae) and, antigenically, they separate as four closely related serotypes (1-4) that share 60 to 75 % amino acid homology. This genetic diversity complicates the process of antiviral drug discovery. Thus, currently no approved dengue-specific therapeutic treatments are available. With the aim of providing an efficient tool for dengue virus drug discovery, a collection of nineteen dengue viruses, representing the genotypic diversity within the four serotypes, was developed. After phylogenetic analysis of the full-length genomes, we selected relevant strains from the EVAg collection at Aix-Marseille University and completed the virus collection, using a reverse genetic system based on the infectious sub-genomic amplicons technique. Finally, we evaluated this dengue virus collection against three published dengue inhibitory compounds. NITD008, which targets the highly conserved active site of the viral NS5 polymerase enzyme, exhibited similar antiviral potencies against each of the different dengue genotypes in the panel. Compounds targeting less conserved protein subdomains, such as the capsid inhibitor ST-148, or SDM25N, a ∂ opioid receptor antagonist which indirectly targets NS4B, exhibited larger differences in potency against the various genotypes of dengue viruses. These results illustrate the importance of a phylogenetically based dengue virus reference panel for dengue antiviral research. The collection developed in this study, which includes such representative dengue viruses, has been made available to the scientific community through the European Virus Archive to evaluate novel DENV antiviral candidates.

Complete Genome Sequence of Human Coronavirus Strain 229E Isolated from Plasma Collected from a Haitian Child in 2016

ABSTRACT Human coronavirus strain 229E (HCoV-229E) and human alphaherpesvirus 1 were isolated from the plasma of a Haitian child in 2016 with suspected arbovirus diseases. To our knowledge, this is the first description of HCoV-229E in human plasma, which is the focus of this article.

Vector Control of Zoonotic Arbovirus Disease in Indonesia

Zoonotic Arbovirus diseases which are caused by the genus of Flavivirus, Alphavirus, and Bunyavirus, are transmitted through potential vectors. These diseases are commonly occurred, especially in tropical countries, including Indonesia. They can affect the economic development because of the high morbidity and mortality. This paper describes the incidence of zoonotic Arbovirus in Indonesia and the strategy to control its vector. Factors that support the occurrence of zoonotic Arbovirus diseases are environmental, demographic and behavioral changes, as well as advanced technology, transportation and global trade. These diseases would not occur without the role of vectors. Vector control can be carried out effectively through longitudinal surveillance to identify types of potential vectors in the area. Therefore to prevent the increased incidence of the diseases, controlling the vector is necessary.