Aedes Spp Research Articles

Use of Ovitrap for The Spatial Mapping of Aedes spp. in The Endemic Area of Dengue Fever of Baitussalam District Aceh Besar

The strategy for controlling dengue vector through periodic monitoring is an effective mitigation effort. Periodic monitoring of dengue vectors is generally more often conducted in the larval stage rather than the egg stage. Monitoring Aedes eggs periodically using ovitraps is more effective because it is not restricted by season. The objective of this study is to conduct spatial mapping of Aedes spp. distribution using ovitraps in Baitussalam Subdistrict, Aceh Besar. This study used observational methods and purposive sampling to determine the sample houses for ovitrap placement. A total of 50 houses in 5 gampong/village were observed. Analysis was conducted using the GPS Essentials application and Google Earth Pro software. The results showed that there were 4 gampong with Aedes spp. egg distribution in Baitussalam Subdistrict, Aceh Besar, namely Gampong Blang Krueng, Gampong Baet, Gampong Kajhu, and Gampong Cadek, while in Gampong Lam Ujong, no ovitraps positive for Aedes eggs. Ovitraps are an effective method for mapping Aedes spp. in efforts to control dengue. Keyword: Aedes spp; Dengue fever; ovitrap; spatial mapping.

Survey Indeks Entomologi dan Identifikasi Larva Aedes Aegypti di Kelurahan Pampang Kecamatan Panakukkang Kota Makassar

One effort to control Aedes aedes. mosquitoes is by knowing the entomological index. The entomological index is an indicator of the density of Aedes aegypti larvae in a particular settlement which is an important consideration in determining effective vector control efforts. The success of larva monitoring is seen from the House Index (HI), Container Index (CI), Breteau Index (BI) and Larval Free Rate (ABJ), because these entomological indices are used to monitor the population density of Aedes spp in the spread of the dengue virus. The problem in this service is how to reduce the high number of dengue fever cases. This community service is to determine the larval density of the House Index, Container Index, and Breteau Index. The service methods used are surveys and observations. The results of the larval survey in Pampang subdistrict showed that the HI, CI and BI values ​​in Pampang subdistrict were respectively 26% (DF=4), 14.36% (DF=4) and 27.45 (DF=4) in the density category. moderate, while the larvae free rate (ABJ) is 79%, which still does not meet the Environmental Health Quality Standards standards in an area described as having an ABJ of less than 95%.

A Preliminary Survey on Geospatial Distribution of Aedes albopictusand Aedes aegyptiMosquitoes Found in Different Urban and Rural Locationsof Southern West Bengal, India

Aedes mosquitoes are globally known to transmit various arboviral diseases including Dengue fever. Historically considered an urban disease, Dengue fever has been reported in rural areas of different countries also. Two important species, Aedes aegypti, and Aedes albopictus, are rapidly spreading and invading new locations in India and risking human health more frequently each year. Since vector control has been proven to be the most effective measure to prevent such disease, knowing the vectors more, would help design successful methods to fight against the disease. In this survey, a cross-sectional inspection was conducted to look for the existence of Aedes spp. at 420 locations including urban and rural areas of 15 districts in Southern West Bengal, India, Morphological identification of collected specimens, comparative analyses of vector distribution and their breeding habitats, between districts, rural and urban locations as well as between different physiographic regions in this area were performed. The study revealed that sixty-four percent of the urban locations inspected and 22% of the rural locations inspected were positive for Aedes spp. Despite the region’s physiographic, climatic, and anthropogenic diversity, the districts shared a similar pattern of species distribution - A. albopictus was found in both rural and urban locations of all the districts while A. aegypti was observed in only urban locations of thirteen districts. In some locations, both species were found to be co-existing in the same habitat containers. Mean larval density and mean container index were both higher in urban habitats than in rural areas though few rural locations showed significantly high density of larval population. The current findings of this survey thus provide a comprehensive picture of Aedes distribution in the said area and may in turn act as a foundation for more effective surveillance to characterize these vectors and to identify potential dengue outbreak hotspots in Southern West Bengal.

Dengue and chikungunya: future threats for Northern Europe?

Arthropod-borne viral diseases are likely to be affected by the consequences of climate change with an increase in their distribution and intensity. Among these infectious diseases, chikungunya and dengue viruses are two (re)emergent arboviruses transmitted by Aedes species mosquitoes and which have recently demonstrated their capacity for rapid expansion. They most often cause mild diseases, but they can both be associated with complications and severe forms. In Europe, following the establishment of invasive Aedes spp, the first outbreaks of autochtonous dengue and chikungunya have already occurred. Northern Europe is currently relatively spared, but climatic projections show that the conditions are permissive for the establishment of Aedes albopictus (also known as the tiger mosquito) in the coming decades. It is therefore essential to question and improve the means of surveillance in northern Europe, at the dawn of inevitable future epidemics.

Influence of dengue virus serotypes on the abundance of Aedes aegypti insect-specific viruses (ISVs).

A comprehensive understanding of the virome in mosquito vectors is crucial for assessing the potential transmission of viral agents, designing effective vector control strategies, and advancing our knowledge of insect-specific viruses (ISVs). In this study, we utilized Oxford Nanopore Technologies metagenomics to characterize the virome of Aedes aegypti mosquitoes collected in various regions of Colombia, a country hyperendemic for dengue virus (DENV). Analyses were conducted on groups of insects with previous natural DENV infection (DENV-1 and DENV-2 serotypes), as well as mosquito samples that tested negative for virus infection (DENV-negative). Our findings indicate that the Ae. aegypti virome exhibits a similar viral composition at the ISV family and species levels in both DENV-positive and DENV-negative samples across all study sites. However, differences were observed in the relative abundance of viral families such as Phenuiviridae, Partitiviridae, Flaviviridae, Rhabdoviridae, Picornaviridae, Bromoviridae, and Virgaviridae, depending on the serotype of DENV-1 and DENV-2. In addition, ISVs are frequently found in the core virome of Ae. aegypti, such as Phasi Charoen-like phasivirus (PCLV), which was the most prevalent and showed variable abundance in relation to the presence of specific DENV serotypes. Phylogenetic analyses of the L, M, and S segments of the PCLV genome are associated with sequences from different regions of the world but show close clustering with sequences from Brazil and Guadeloupe, indicating a shared evolutionary relationship. The profiling of the Ae. aegypti virome in Colombia presented here improves our understanding of viral diversity within mosquito vectors and provides information that opens the way to possible connections between ISVs and arboviruses. Future studies aimed at deepening our understanding of the mechanisms underlying the interactions between ISVs and DENV serotypes in Ae. aegypti could provide valuable information for the design of effective vector-borne viral disease control and prevention strategies.IMPORTANCEIn this study, we employed a metagenomic approach to characterize the virome of Aedes aegypti mosquitoes, with and without natural DENV infection, in several regions of Colombia. Our findings indicate that the mosquito virome is predominantly composed of insect-specific viruses (ISVs) and that infection with different DENV serotypes (DENV-1 and DENV-2) could lead to alterations in the relative abundance of viral families and species constituting the core virome in Aedes spp. The study also sheds light on the identification of the genome and evolutionary relationships of the Phasi Charoen-like phasivirus in Ae. aegypti in Colombia, a widespread ISV in areas with high DENV incidence.

Edukasi dan Pendampingan Pembuatan Ovitrap sebagai Upaya Pengendalian Demam Berdarah

<em>Dengue Hemorrhagic Fever (DHF) or Dengue Haemorhagic Fever (DHF) is one of several infectious diseases that are a health problem in the world, especially developing countries. Aedes spp mosquitoes are vectors of arbovirus diseases, including Yellow Fever, Dengue Fever, Dengue Hemorrhagic Fever (DHF), and Chikungunya. One method of controlling Aedes is the use of ovitrap. This service aims to provide education and assistance in the manufacture of ovitrap as one of the efforts to control DHF. This service is carried out by providing knowledge about dengue disease and its control and how to make simple ovitrap. Education is carried out by means of counseling which was previously given a pre-test and post-test as a measuring tool for increasing knowledge. The standard ovitrap is made with a small wide-mouthed glass/pot painted black on the outside and given gauze as an egg trap. The glass is half filled with water to part and placed inside and outside the house which is suspected to be the habitat of the Aedes mosquito. The results of education and assistance in making ovitrap for cadres in the Tamangapa sub-district were that participants benefited, namely increasing knowledge and increasing skills in making ovitrap. The conclusion of this activity is that the community gets an increase in general knowledge about DHF, Aedes Aegypty mosquitoes and how to control them and increases skills in making ovitrap</em>

House Condition Scoring Scale as a Risk Indicator of Infestation by Aedes in Two Mexican Localities.

Mexico has shown an increase in dengue incidence rates. There are factors related to the location that determine housing infestation by Aedes. This study aimed to determine factors associated with housing infestation by immature forms of Aedes spp. in the dengue endemic localities of Axochiapan and Tepalcingo, Mexico, from 2014 to 2016. A cohort study was carried out. Surveys and inspections of front- and backyards were conducted every 6 months, looking for immature forms of Aedes spp. A house condition scoring scale was developed using three variables (house maintenance, tidiness of the front- and backyards, and shading of the front- and backyards). Multiple and multilevel regression logistic analysis were conducted considering the housing infestation as the outcome and the household characteristics observed 6 months before the outcome as factors; this was adjusted by time (seasonal and cyclical variations of the vector). The infestation oscillated between 5.8% of the houses in the second semester of 2015 and 29.3% in the second semester of 2016. The factors directly associated with housing infestation by Aedes were the house condition score (adjusted odds ratio [aOR]: 1.64; 95% CI: 1.40-1.91) and the previous record of housing infestation (aOR: 2.99; 95% CI: 2.00-4.48). Moreover, the breeding-site elimination done by house residents reduced the housing infestation odds by 81% (95% CI: 25-95%). These factors were independent of the seasonal and cyclical variations of the vector. In conclusion, our findings could help to focalize antivectorial interventions in dengue-endemic regions with similar demographic and socioeconomic characteristics.

Aktivitas Menggigit Nyamuk Aedes spp di Tiban Baru, Kota Batam

Tiban Baru area is one of the endemic areas of Dengue Fever (DHF) in Batam City. Previous studies have reported nocturnal blood-sucking activities of Aedes spp mosquitoes in several regions in Indonesia. The behavioral change of the blood-sucking activity of Aedes spp mosquitoes may impact the transmission of dengue fever. The study aimed to determine the activity of Aedes spp, a vector of DHF in the Tiban Baru area, Batam City. The research was descriptive with a cross-sectional design. This study was conducted in 25 houses, with mosquito collection in the field using the resting mosquito collection method starting from 6:00 pm to 6:00 am. Measurement of environmental parameters including temperature and humidity in the environment around the study. The results stated that there was a change in the blood-sucking activity of Aedes spp mosquitoes from 16.00 to 17.00 to 18.00 to 21.00. The distribution of Aedes albopictus mosquitoes in the Tiban Baru area was 89.4% of the total Aedes spp mosquitoes collected with a Man Bitting Rate (MBR) value of 56.6%. The average temperature and humidity in the Tiban Baru area were 280C and 75%. Changes in the blood-sucking activity of Aedes spp mosquitoes can increase the risk of dengue transmission so efforts are needed for the prevention and control of dengue vectors in the study area.

Effectiveness of indoor and outdoor larvitrap modified jars and paralon hit for <i>Aedes</i> spp. control

Background. Dengue hemorrhagic fever (DHF) is a disease caused by the dengue virus which is transmitted by the mosquito vector Aedes spp. Efforts to control dengue vectors using chemical methods such as the use of larvicides and fogging with insecticides can result in the risk of environmental pollution and also resistance to Aedes spp. Objective. This study aimed to analyze the effectiveness of indoor and outdoor modified larvitrap made from jars and black paralon as well as attractants to control Aedes spp. Methods. This research is applied research in society. Indoor and outdoor larvitrap is made using clear jars and black paralon. The attractants used were Imperata cylindrica soaking water, rice straw, and sugarcane leaves with concentrations of 20 and 30%. Indoor and outdoor larvitrap was installed in the respondent's house in a dengue-endemic area in Pandak village, Banyumas, Indonesia. Observations were carried out on the number of Aedes spp. larvae trapped by larvitrap. Results. The results showed that outdoor larvitraps caught fewer Aedes spp. larvae (46.8%) than indoor larvitraps (61.6%). The use of attractants between Imperata, rice straw, and sugarcane leaves has a different effect on the number of larvae caught. Most of the Aedes spp. larvae were caught in Imperata soaking water with a concentration of 30% installed in an indoor larvitrap. Conclusion. The use of indoor and outdoor larvitrap modified jars and black paralon at research sites can be effective for controlling Aedes spp. Imperata soaking water with a concentration of 30% proved to be the most effective attractant.

The First Genomic Characterization of the Chikungunya Virus in Saudi Arabia

BackgroundChikungunya is an arboviral infection caused by the Chikungunya virus (CHIKV) transmitted to humans by mosquitoes of Aedes spp. CHIKV has been confined to African countries and South-East Asia up to 2004, but since then, the pathogen has become more global, and its high morbidity rate has become more visible. Saudi Arabia is not an endemic region of CHIKV, and the virus’s origin is not yet fully understood. This study aimed to characterize the genome of CHIKV from samples detected in Jeddah in 2018.MethodTwenty-two sets of primers were designed to amplify near-full length genome of CHIKV. RT-PCR was conducted from clinical samples. Two samples were used for studying near complete genome sequence while the remaining samples were used to study the E1 gene. Different bioinformatics tools were utilized.ResultsPhylogenetic analysis showed that the CHIKV strains clustered with strains isolated from Kenya during 2017–2018 and belonged to ECSA genotype. E1: L136F, K211E and I317V mutations were identified in our strains. Also, E2: M74I, A76T, and V264A mutations were documented. Additionally, the capsid N79S substitution was also detected.ConclusionThe genome of CHIKV was analyzed for the first time in Saudi Arabia to better understand the origin of the CHIKV and its genetic diversity, which showed high similarity with IE—a subclade of CHIKV strains detected in Mombasa (Kenya) indicating its possible origin.

Role of the Microbiome in Aedes spp. Vector Competence: What Do We Know?

Aedes aegypti and Aedes albopictus are the vectors of important arboviruses: dengue fever, chikungunya, Zika, and yellow fever. Female mosquitoes acquire arboviruses by feeding on the infected host blood, thus being able to transmit it to their offspring. The intrinsic ability of a vector to infect itself and transmit a pathogen is known as vector competence. Several factors influence the susceptibility of these females to be infected by these arboviruses, such as the activation of the innate immune system through the Toll, immunodeficiency (Imd), JAK-STAT pathways, and the interference of specific antiviral response pathways of RNAi. It is also believed that the presence of non-pathogenic microorganisms in the microbiota of these arthropods could influence this immune response, as it provides a baseline activation of the innate immune system, which may generate resistance against arboviruses. In addition, this microbiome has direct action against arboviruses, mainly due to the ability of Wolbachia spp. to block viral genome replication, added to the competition for resources within the mosquito organism. Despite major advances in the area, studies are still needed to evaluate the microbiota profiles of Aedes spp. and their vector competence, as well as further exploration of the individual roles of microbiome components in activating the innate immune system.

Sex-structured model of Wolbachia invasion and design of sex-biased release strategies in Aedes spp mosquitoes populations

Laboratory experiments as well as some field essays have revealed that the intracellular bacterium Wolbachia, deliberately introduced in Aedes spp female mosquitoes, drastically reduces their vector competence for dengue virus and, also, other mosquito-borne viral diseases. However, female mosquitoes infected with Wolbachia still need to ingest human blood while male mosquitoes, either wild or Wolbachia-carrying, do not bite people. As such, Wolbachia-carrying females may transmit the virus to people during blood-feeding, even though with far less probability than the wild ones. Therefore, massive releases of Wolbachia-carrying females may increase both the nuisance and the epidemiological risk among human residents. With the goal of exploring in depth the practical aspects of sex-biased releases, we introduce in this paper a simple sex-structured model of Wolbachia invasion that brings forward the possibility of developing male-biased release strategies of Wolbachia-carriers leading to Wolbachia invasion. Thanks to this model, we study at length the minimal amount of mosquitoes necessary to complete this task, according to the relative sex-ratio of the released mosquitoes and the release schedule. We also pay attention to the estimate of the time needed to achieve the ultimate population replacement.

PENYULUHAN KESEHATAN DEMAM BERDARAH DENGUE DI MASA PANDEMI COVID-19

Dengue Hemorrhagic Fever (DHF) is caused by the dengue virus and is still a public health problem today, especially in urban areas. The death rate caused by this disease is very high if not treated immediately. Dengue virus is mainly transmitted by female mosquitoes Aedes aegypty and Aedes. albopictus. Aedes spp mosquitoes are mosquitoes that have the ability to reproduce quickly because the eggs of these mosquitoes can live in dry conditions. Indonesia implements the Jumantik program (Larva Monitoring staff) as a way of eradicating mosquitoes. However, with the current implementation of PSBB (Large-Scale Social Restrictions) in DKI Jakarta, this program has become a bit difficult to implement. This counseling was carried out as part of increasing public literacy in understanding dengue fever from symptoms to prevention at the household level, so that people became aware of this disease even in the midst of the Covid-19 pandemic. The counseling was conducted online and prior to the counseling, an initial survey of understanding about DHF was conducted and a final survey was conducted after the counseling to assess the level of public understanding about DHF. The results achieved in the form of benefits, especially for the community, namely residents understand about dengue fever and its prevention through eradicating mosquito larvae in their respective homes, which in turn can reduce the number of dengue cases in Jakarta.

Density Of Eggs and Larvae of Aedes Spp and the Characteristics of their Larvae Habitat in Endemic Dengue Area of Ternate City

Introduction: Dengue Fever (DF) is a disease spread by Aedes spp. caused by dengue virus infection. The study aimed to identify the density of Aedes spp eggs and larvas stages and the characteristics of their habitat in dengue-endemic areas in Ternate City in September-December 2021. Methods: the research was conducted in four dengue-endemic villages in Ternate City, namely Sangaji, Maliaro, Bastiong Karance, and Bastiong Talangame village. In 80 households, egg density was determined by placing 2 ovitraps in each house, one inside and one outside the house. After a week, the filter paper which is a medium mosquito to lay their eggs in the ovitrap was collected, and the ovitrap index value was calculated. The value of the House Index (HI), Container Index (CI), and Breuteu Index (BI) was used to calculate the larval density. The type and materials of the containers were used to assess the parameters of the larval environment. Results: The ovitrap index value in the four villages was categorized as moderate level 3 (27.50% -36.25%). The highest larval density was found in Sangaji Village (HI = 81%), while the lowest was in Bastion Talangame Village (HI = 70%). The highest CI and BI values were found in Bastiong Karance Village (CI=51.5% and BI=190%), and the lowest was in Maliaro Village (CI=37.5% and BI=128%). Density figures in all endemic villages have a high larval density with a value of 8. Conclusion: There was no significant difference (p>0.05) between the types and the materials of containers in each village in Dengue endemic areas. The high density of the egg and larval stage and the information characteristic of habitat Aedes spp. could be considered as basic information for dengue vector control in Ternate City.

Determinants of exposure to Aedes mosquitoes: A comprehensive geospatial analysis in peri-urban Cambodia

Aedes mosquitoes are some of the most important and globally expansive vectors of disease. Public health efforts are largely focused on prevention of human-vector contact. A range of entomological indices are used to measure risk of disease, though with conflicting results (i.e. larval or adult abundance does not always predict risk of disease). There is a growing interest in the development and use of biomarkers for exposure to mosquito saliva, including for Aedes spp, as a proxy for disease risk. In this study, we conduct a comprehensive geostatistical analysis of exposure to Aedes mosquito bites among a pediatric cohort in a peri‑urban setting endemic to dengue, Zika, and chikungunya viruses. We use demographic, household, and environmental variables (the flooding index (NFI), land type, and proximity to a river) in a Bayesian geostatistical model to predict areas of exposure to Aedes aegypti bites. We found that hotspots of exposure to Ae. aegypti salivary gland extract (SGE) were relatively small (< 500 m and sometimes < 250 m) and stable across the two-year study period. Age was negatively associated with antibody responses to Ae. aegypti SGE. Those living in agricultural settings had lower antibody responses than those living in urban settings, whereas those living near recent surface water accumulation were more likely to have higher antibody responses. Finally, we incorporated measures of larval and adult density in our geostatistical models and found that they did not show associations with antibody responses to Ae. aegypti SGE after controlling for other covariates in the model. Our results indicate that targeted house- or neighborhood-focused interventions may be appropriate for vector control in this setting. Further, demographic and environmental factors more capably predicted exposure to Ae. aegypti mosquitoes than commonly used entomological indices.

Occurrence of Some Mosquito Species in Tha-Ma-Nya Village, Hpa-an Township, Kayin State in Myanmar

Among the numerous species of blood-sucking insects, mosquitoes stand out as most offensive to man and other warm-blooded animals. Mosquitoes were collected by indoor and outdoor CDC light traps in randomly selected household and larvae were collected in and around 3 Kilo meter radius from the study site. A total of 14 species, five genera under family Culicidae were recorded in Tha-ma-nya village. Recorded species included two species under genus Aedes, three species under genus Culex one species under the genus Armigeres, one species under the genus Toxorhynchities and 7 species under genus Anopheles. Species inentification was done according to different morphological keys. Altogether seven out of 14 recorded mosquito species were medically important vector species. Aedes aegypti and Ae. albopictus were primary and secondary vectors of dengue fever. Culex quinquefasciatus is a microfilariasis vector. The important vectors of Japanese encephalitis are Culex tritaeniorhynchus and Culex gelidus. High density of malaria vector Anopheles dirus was collected in outdoor light trap than An. minimus, although An. minimus was collected high density by indoor CDC light traps. Virus of Japanese encephalitis could transmit from rearing pig and ducks to persons living in the study area. Indoor clear water containers serve as the favorable places for living Aedes spp. Outdoor water storage concrete tanks provided stagnant water to breed Culex and Anopheles species. Water pools, rock pools and rice fields water were found high preferences for breeding of malaria vectors An. dirus and An. minimus larvae and An. dirus larvae was also collected from concrete tanks. Microfilariasis vector Cx. quinquefqsciatus and JE vector Cx. tritaeniorhynchus larvae were collected from polluted water pools and Dengue vector larvae as Aedes larvae were collected from metal drums, bago jars and concrete tanks. Status of the mosquito species composition in the Tha-ma-nya village provided database not only for further researches but also for giving good knowledge and practice in health workers for effective control of vector borne diseases.

Penyuluhan Tentang Demam Berdarah Dan Pencegahannya

Dengue hemorhagic fever (DHF) is an infection caused by dengue virus. Dengue is a virus that is transmitted from Aedes Spp mosquito, the fastest growing mosquito in the world and has transmitted dengue virus. The prevalence of DHF until July 2020 has reached 71.633 in Indonesia, and 4.227 cases only in DKI Jakarta province. We usually don’t find new case on July, but this year we still find new cases on July. This should increase our vigilance, especially at this time when there is a pandemic of COVID-19 cases. The purpose of this activity is to increase public knowledge about dengue fever so that they can prevent dengue fever in their area. This activity is carried out through seminar using the zoom application because conditions in the field do not allow offline activities to be held. The activity will be held on Saturday, April 23, 2022. The results obtained through this PKM activity is an increase in the level of participants' knowledge about DHF as evidenced by an increase in post-test scores after attending the seminar. The conclusion of this PKM activity went well because of the support from all related parties from institutions, solid teams, and partners who actively participated. The shortage of this PKM activity is that the activities are carried out online because the conditions are still not conducive to do an offline activity. The advice we can give is to carry out PKM activities again with the same partner with different health topics according to the conditions that exist in the partners.

Comparison of the Aedes spp Eggs Number Trapped in Ovitrap Using Rainwater and Municipal Water

Dengue Hemorrhagic Fever (DHF) is still a public health problem in Indonesia. The number of sufferers and the area of their distribution is increasing along with the increasing mobility and population density. The purpose of this study was to compare the number of eggs trapped in the ovitrap using rainwater and PDAM water. This type of research was a quasi-experimental design with a post-test-only design. Determination of the sampling location was done by determining the point of the house of DHF sufferers and their surroundings. The total number of eggs trapped in the ovitrap was 3829 eggs. The number of rainwater ovitraps (2279) traps more Aedes spp mosquito eggs than PDAM water ovitraps (1553). Ovitrap index of 61% in this study was included in the level 4 category or high above 40%. The results of the Mann-Whitney analysis with p-value = 0.637 &gt; 0.05 means that it did not showed a significant difference between the number of eggs trapped in the rainwater ovitrap and PDAM water. There was no difference in the average number of eggs in rainwater and PDAM water ovitrap media. The community of RT 2 and RT 3 RW 1 are expected to always carry out the Mosquito Nest Eradication (PSN) movement at least once a week to reduce the proliferation of the DHF vector.

Study of Dengue Virus Transovarial Transmission in Aedes spp. in Ternate City Using Streptavidin-Biotin-Peroxidase Complex Immunohistochemistry.

Aedes aegypti is the most dominant vector in the transmission of dengue hemorrhagic fever (DHF). In addition to Ae. aegypti, Ae. albopictus is a secondary vector of the dengue virus, and both species are widespread in Indonesia. The dengue virus is transmitted from person to person through the bite of an Aedes spp. The vertical (transovarial) transmission of the dengue virus from infective female mosquitoes to their offspring is one of the means by which the dengue virus maintains its existence in nature. Transovarial dengue virus transmission in Aedes spp. mosquitoes contributes to the spread and maintenance of the dengue epidemic. This study employed a qualitative survey to detect dengue virus transovarial transmission in Ternate using the streptavidin-biotin-peroxidase complex (ISBPC) immunohistochemical test. The ISBPC examination of samples collected from the four subdistricts in Ternate revealed a positive result for transovarial transmission of dengue virus. Four Aedes spp., including two Ae. aegypti females, one Ae. albopictus female, and one Ae. albopictus male, tested positive for transovarial transmission of dengue virus in the district of North Ternate. Four Aedes spp., including three Ae. aegypti females and one Ae. aegypti male, were found to be positive for the transovarial transmission of dengue virus in the Central Ternate district. Seven Aedes spp., including five Ae. aegypti females, one Ae. aegypti male, and one Ae. albopictus female, tested positive for transovarial transmission of the dengue virus in the district of South Ternate city. One Ae. aegypti male showed positive results for transovarial transmission of dengue virus in the Ternate Island District. In this study, the transovarial transmission of the dengue virus occurred in both Aedes spp. female and male mosquitoes. It was demonstrated that Aedes spp. carry the dengue virus in their ovaries and can pass it on to their offspring. As a result, the cycle of passing the dengue virus on to local mosquito populations in the city of Ternate is not going to end just yet.

Zika Virus Exploits Lipid Rafts to Infect Host Cells

Several flaviviruses such as Hepatitis C virus, West Nile virus, Dengue virus and Japanese Encephalitis virus exploit the raft platform to enter host cells whereas the involvement of lipid rafts in Zika virus–host cell interaction has not yet been demonstrated. Zika virus disease is caused by a flavivirus transmitted by Aedes spp. Mosquitoes, although other mechanisms such as blood transfusion, sexual and maternal–fetal transmission have been demonstrated. Symptoms are generally mild, such as fever, rash, joint pain and conjunctivitis, but neurological complications, including Guillain-Barré syndrome, have been associated to this viral infection. During pregnancy, it can cause microcephaly and other congenital abnormalities in the fetus, as well as pregnancy complications, representing a serious health threat. In this study, we show for the first time that Zika virus employs cell membrane lipid rafts as a portal of entry into Vero cells. We previously demonstrated that the antifungal drug Amphotericin B (AmphB) hampers a microbe–host cell interaction through the disruption of lipid raft architecture. Here, we found that Amphotericin B by the same mechanism of action inhibits both Zika virus cell entry and replication. These data encourage further studies on the off-label use of Amphotericin B in Zika virus infections as a new and alternate antiviral therapy.