Ovitrap Index Research Articles

Presence of Arboviral Vector in Tourist Attractions and Public Places: Abundance, Associated Factors and Susceptibility to Temephos.

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Aedes&lt;/i&gt; mosquito is a competent vector of arboviruses, mainly dengue, chikungunya, Zika and yellow fever. The high incidence of arboviral infections among travelers indicated the vulnerability of tourist attractions and public places visitors to arboviral infections. This study aimed to determine the presence and population density of &lt;i&gt;Aedes&lt;/i&gt; mosquitoes at the places, as well as the susceptibility to temephos larvicide. &lt;b&gt;Materials and Methods:&lt;/b&gt; A total of 17 tourist attractions and public places in four districts/cities of Central Java Province were selected as study sites and 25-40 ovitraps were installed in each location for three days. The coordinates, altitude, vegetation density, shade, wind speed, air temperature and humidity were recorded. Ovistrips and water of each ovitrap were observed in the laboratory to determine the ovitrap index (OI) and egg density index (EDI), mosquito species and their susceptibility to temephos. &lt;b&gt;Results:&lt;/b&gt; A total of 12,231 eggs were obtained with a range, OI and EDI of 0-1,024, 42% and 31.93 eggs/trap, respectively. Vegetation density, shade and wind speed were significantly associated with the presence of &lt;i&gt;Aedes &lt;/i&gt;eggs in the ovitraps (p<0.05), while altitude, temperature and air humidity were correlated with the average of &lt;i&gt;Aedes&lt;/i&gt; eggs per ovitrap. &lt;b&gt;Conclusion:&lt;/b&gt; Although &lt;i&gt;Aedes&lt;/i&gt; larvae in all study sites were susceptible to temephos 0.02 mg/L the results indicated the vulnerability of visitors to &lt;i&gt;Aedes&lt;/i&gt;-borne diseases. Further investigation of arbovirus infections in &lt;i&gt;Aedes&lt;/i&gt; mosquitoes at tourist attractions and public places is necessary conducted to evaluate the potential and risk of pathogen transmission to visitors.

Ovitrap Index Measurement of Aedes sp. in Kertasari Urban Village, Ciamis Sub-District Ciamis District

Aedes sp. mosquitoes are insects that can transmit dengue fever to humans. Transmission is caused by mosquito bites and mosquito population density in an area can illustrate the potential for dengue transmission. Ovitrap index measurement can be used as one of the efforts to control and prevent dengue fever. This study aims to determine the presence and density of Aedes sp. mosquitoes by the percentage value of the Ovitrap Index (OI) in the Pasirangin neighborhood. In the study, the descriptive method was used by observing ovitraps and calculating the Ovitrap Index on ovitraps in Pasirangin Neighbourhood, RW 09 Kertasari Village. Ovitrap installation was placed inside and outside the house as many as 20 houses. The results showed that of the 40 ovitraps installed, the number of positive ovitraps was 15. Based on the calculation of the overall OI percentage, the result was 37.5 %. The ovitrap index criteria for the research location has a score of 3 (OI below 40 %), which indicates that the area has a moderate potential for dengue disease vulnerability

Sterile Insect Technique (SIT) field trial targeting the suppression of Aedes albopictus in Greece.

The sterile insect technique (SIT) involves releasing large numbers of sterile males to outcompete wild males in mating with females, leading to a decline in pest populations. In the current study, we conducted a suppression trial in Greece against the invasive dengue vector mosquito Aedes albopictus (Skuse) through the weekly release of sterile males for 22 weeks from June to September 2019. Our approach included the long-distance transport of sterile mosquitoes, and their release at a density of 2,547±159 sterile males per hectare per week as part of an area-wide integrated pest management strategy (AW-IPM). The repeated releases of sterile males resulted in a gradual reduction in egg density, reaching 78% from mid-June to early September. This reduction remained between 70% and 78% for four weeks after the end of the releases. Additionally, in the SIT intervention area, the ovitrap index, representing the percentage of traps containing eggs, remained lower throughout the trial than in the control area. This trial represents a significant advance in the field of mosquito control, as it explores the viability and efficacy of producing and transporting sterile males from a distant facility to the release area. Our results provide valuable insights for future SIT programmes targeting Ae. Albopictus, and the methodology we employed can serve as a starting point for developing more refined and effective release protocols, including the transportation of sterile males over long distances from production units to intervention areas.

Effectiveness of Ovitrap as a Control Tool Population Aedes Spp. In Areas Endemic to Dengue Fever Ternate City

The mosquito ovitrap is often used in dengue fever (DF) vector surveillance, but it has never been reported in control programs to reduce the vector population. This study aims to determine the ovitrap effectiveness as a vector control instrument for DF. The research was carried out from January to March 2021 in Bastiong Talangame Village, one of the DF endemic villages, which is a densed settlement in Ternate City. This research was a quantitative pre-experimental design type one group pre-test and post-test . Measurement of the density of Aedes spp. larvae presented in the House Index (HI), Container Index (CI), and Breteau Index (BI) were carried out four times before and after ovitrap installation. The installation of ovitraps was carried out in 100 houses, where four ovitraps were installed in each house with an installation time of four weeks. The results showed that the ovitrap index value decreased until it reached the moderate category in the last week of observation. The density of larvae based on the calculation of HI, CI, BI showed a significant decrease (p = 0.0001) before and after ovitrap installation, with the density figure value of the high category being the medium category. The use of ovitrap was effective in reducing the population of Aedes spp. so it should be considered in the dengue vector control strategy

Entomological risk assessment for transmission of arboviral diseases by Aedes mosquitoes in a domestic and forest site in Accra, Ghana

Dengue, Zika and chikungunya are Aedes-borne viral diseases that have become great global health concerns in the past years. Several countries in Africa have reported outbreaks of these diseases and despite Ghana sharing borders with some of these countries, such outbreaks are yet to be detected. Viral RNA and antibodies against dengue serotype-2 have recently been reported among individuals in some localities in the regional capital of Ghana. This is an indication of a possible silent transmission ongoing in the population. This study, therefore, investigated the entomological transmission risk of dengue, Zika and chikungunya viruses in a forest and domestic population in the Greater Accra Region, Ghana. All stages of the Aedes mosquito (egg, larvae, pupae and adults) were collected around homes and in the forest area for estimation of risk indices. All eggs were hatched and reared to larvae or adults for morphological identification together with larvae and adults collected from the field. The forest population had higher species richness with 7 Aedes species. The predominant species of Aedes mosquitoes identified from both sites was Aedes aegypti (98%). Aedes albopictus, an important arbovirus vector, was identified only in the peri-domestic population at a prevalence of 1.5%, significantly higher than previously reported. All risk indices were above the WHO threshold except the House Index for the domestic site which was moderate (19.8). The forest population recorded higher Positive Ovitrap (34.2% vs 26.6%) and Container (67.9% vs 36.8%) Indices than the peri-domestic population. Although none of the mosquito pools showed the presence of dengue, chikungunya or Zika viruses, all entomological risk indicators showed that both sites had a high potential arboviral disease transmission risk should any of these viruses be introduced. Continuous surveillance is recommended in these and other sites in the Metropolis to properly map transmission risk areas to inform outbreak preparedness strategies.

Temperature Influence on Aedes aegypti Oviposition in the San Joaquin Valley of California.

The establishment and oviposition of Aedes aegypti can vary from one location to another partially due to differing temperature and precipitation. In 2017, Ae. aegypti was first detected in Merced in the Central Valley of California. The objectives of this study were to examine the influence of temperature and precipitation on oviposition of Ae. aegypti, and to determine the beginning and end of the seasonal activity of Ae. aegypti in Merced. The study site consisted of a residential area in the north-east region of Merced where Ae. aegypti was first detected in Merced County. Fifty-four residences were randomly selected as ovitrap sites. Ovitraps were placed at field sites weekly for 12 months, from September 27, 2017, to September 27, 2018. Each week, ovitraps were inspected for the presence of mosquito eggs. Egg counts were used to calculate the following oviposition indices: the ovitrap index (OI) (percent of traps positive) and the egg density index (EDI) (eggs/positive traps). Oviposition occurred primarily from May through October, above a minimum temperature of 10°C, and when almost no rainfall occurred (0.5 mm total). During the year, the percent of positive traps per month ranged from approximately 1.2-67.3%, with highest values in June to October (43.9-67.3%). The highest mean monthly EDI was from July to October (34-44.6) and peaked in October at 44.6 eggs/trap. The EDI values are similar to other locations where Ae. aegypti transmits endemic vector-borne disease. These findings provide baseline data for Ae. aegypti control in Merced and the Central Valley of California.

The Use of Ovitrap and the Female &lt;i&gt;Aedes&lt;/i&gt; sp. Density in the Tamansari Village of Bandung City

Dengue hemorrhagic fever (DHF) incidence in Indonesia, which become one of the mortality causes, is relatively high. Therefore, the government launched the mosquito nest eradication (MNE) movement with an indicator of the larva-free rate to reduce the incidence of DHF. Another effort in vector control is using ovitrap to break the life chain of dengue vectors. This study aimed to determine the effect of using ovitrap on the female Aedes sp. density in the Tamansari village area of Bandung city. This quantitative experimental study was conducted on 60 houses in two neighborhood associations in the Tamansari village area. Both community groups were assessed for ovitrap index and the number of eggs trapped on ovitrap filter paper before and after treatment. The treatment group consisting of 30 houses was given one ovitrap inside and one ovitrap outside the house for four weeks. Ovitrap is changed every five days. The second group is the control community. The data obtained were analyzed using the Wilcoxon and chi-square tests with a degree of confidence of 0.05. In this study, the ovitrap index of this area was found between 0.67–0.80, which indicates that this area is at high risk of DHF transmission. Statistical tests showed that the use of ovitrap did not affect female Aedes sp. density as assessed by the ovitrap index. The results showed that using ovitrap could not control the population of Aedes sp.

The relative importance of key meteorological factors affecting numbers of mosquito vectors of dengue fever

Although single factors such as rainfall are known to affect the population dynamics of Aedes albopictus, the main vector of dengue fever in Eurasia, the synergistic effects of different meteorological factors are not fully understood. To address this topic, we used meteorological data and mosquito-vector association data including Breteau and ovitrap indices in key areas of dengue outbreaks in Guangdong Province, China, to formulate a five-stage mathematical model for Aedes albopictus population dynamics by integrating multiple meteorological factors. Unknown parameters were estimated using a genetic algorithm, and the results were analyzed by k-Shape clustering, random forest and grey correlation analysis. In addition, the population density of mosquitoes in 2022 was predicted and used for evaluating the effectiveness of the model. We found that there is spatiotemporal heterogeneity in the effects of temperature and rainfall and their distribution characteristics on the diapause period, the numbers of peaks in mosquito densities in summer and the annual total numbers of adult mosquitoes. Moreover, we identified the key meteorological indicators of the mosquito quantity at each stage and that rainfall (seasonal rainfall and annual total rainfall) was more important than the temperature distribution (seasonal average temperature and temperature index) and the uniformity of rainfall annual distribution (coefficient of variation) for most of the areas studied. The peak rainfall during the summer is the best indicator of mosquito population development. The results provide important theoretical support for the future design of mosquito vector control strategies and early warnings of mosquito-borne diseases.

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&gt;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.

Evaluation of superabsorbent polymer (SAP) in oviposition traps used in the integrated control of Aedes aegypti (Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) (Diptera:Culicidae)

Egg collection traps have been studied to assist in the integrated control of arbovirus vectors. Many enhancements have been made over the years. This study evaluated the use of a hydrated superabsorbent polymer (SAP) in the egg collection of Aedes aegypti and Aedes albopictus in ovitraps. An experiment was conducted in the laboratory to determine the minimum concentration of the product to be used in traps in the field to prevent the development of larvae into adults. In the field, the use of polymers has been evaluated using a traditional model of ovitraps. The positive ovitrap index and mean number of eggs per trap indicator were calculated. In the laboratory, the larvae did not successfully develop to the adult stage, even at the lowest SAP concentration. In the field, the results showed that ovitraps with SAP proved to be effective for egg collection from both species. It was possible to identify sites with the highest concentration of species and expose the ovitraps for a longer period without larval development. There is a need for studies on the adequacy of this technology for control programs. However, the results showed that ovitraps with hydrogel were potentiated to capture eggs, configuring themselves as another tool for vector control.

Weather-Based Prediction Models for the Prevalence of Dengue Vectors Aedes aegypti and Ae. albopictus.

Dengue is an important vector-borne disease transmitted by the mosquitoes Aedes aegypti and Ae. albopictus. In the absence of an effective vaccine, vector control has become the key intervention tool in controlling the disease. Vector densities are significantly affected by the changing weather patterns of a region. The present study was conducted in three selected localities, i.e., urban Bandaranayakapura, semiurban Galgamuwa, and rural Buluwala in the Kurunegala district of Sri Lanka to assess spatial and temporal distribution of dengue vector mosquitoes and to predict vector prevalence with respect to changing weather parameters. Monthly ovitrap surveys and larval surveys were conducted from January to December 2019 and continued further in the urban area up to December 2021. Aedes aegypti was found moderately in the urban area and to a lesser extent in semiurban but not in the rural area. Aedes albopictus had the preference for rural over urban areas. Aedes aegypti preferred indoor breeding, while Ae. albopictus preferred both indoor and outdoor. For Ae. albopictus, ovitrap index (OVI), premise index (PI), container index (CI), and Breteau index (BI) correlated with both the rainfall (RF) and relative humidity (RH) of the urban site. Correlations were stronger between OVI and RH and also between BI and RF. Linear regression analysis was fitted, and a prediction model was developed using BI and RF with no lag period (R 2 (sq) = 86.3%; F = 53.12; R 2 (pred) = 63.12%; model: Log10 (BI) = 0.153 + 0.286 ∗ Log10 (RF); RMSE = 1.49). Another prediction model was developed using OVI and RH with one month lag period (R 2 (sq) = 70.21%; F = 57.23; model: OVI predicted = 15.1 + 0.528 ∗ Lag 1 month RH; RMSE = 2.01). These two models can be used to monitor the population dynamics of Ae. albopictus in urban settings to predict possible dengue outbreaks.

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.

Low level of dengue infection and transmission risk in Hong Kong: an integrated analysis of temporal seroprevalence results and corresponding meteorological data

ABSTRACT Hong Kong is an Asia-Pacific City with low incidence but periodic local outbreaks of dengue. A mixed-method assessment of the risk of expansion of dengue endemicity in such setting was conducted. Archived blood samples of healthy adult blood donors were tested for anti-dengue virus IgG at 2 time-points of 2014 and 2018/2019. Data on the monthly notified dengue cases, meteorological and vector (ovitrap index) variables were collected. The dengue virus (DENV) IgG seroprevalence of healthy adults in 2014 was 2.2% (95%C.I. = 1.8–2.8%, n = 3827) whereas that in 2018/2019 was 1.7% (95%C.I. = 1.2–2.3%, n = 2320). Serotyping on 42 sera in 2018/2019 showed that 22 (52.4%) were DENV-2. In 2002–2019, importation accounted for 95.3% of all reported cases. By wavelet analysis, local cases were in weak or no association with meteorological and vector variables. Without strong association between local cases and meteorological/vector variables, there was no evidence of increasing level of dengue infection in Hong Kong.

Density Of Eggs and Larvae of Aedes Spp. and the Characteristics of their Larvae Habitat in Endemic Dengue Area In 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 egg and larval Aedes spp. stages and the characteristics of their habitat in dengue-endemic areas in Ternate City in September 2021. Methods: the research was conducted in four dengue-endemic villages in Ternate City, including Sangaji, Maliaro, Bastiong Karance, and Bastiong Talangame. In 80 households, egg density was determined utilizing ovitrap placement of up to two pieces per dwelling, one inside and one outside the house. After a week of ovitrap installation, the filter paper 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 sub-districts 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&gt;0.05) between the types and the materials of containers in each village in DF endemic areas. The high density of the egg and larval stage and the information characteristic of habitat Aedes spp. Could be considered the basis of information dengue vector prevention and control in Ternate City.

Aedes Mosquito Surveillance Using Ovitraps, Sweep Nets, and Biogent Traps in the City of Yaoundé, Cameroon.

Arbovirus diseases represent a significant public health problem in Cameroon and vector surveillance is a key component of prevention strategies. However, there is still not enough evidence of the efficacy of different sampling methods used to monitor Aedes mosquito population dynamic in different epidemiological settings. The present study provides data on the evaluation of ovitraps and different adult sampling methods in the city of Yaoundé and its close vicinity. Entomological surveys were carried out from February 2020 to March 2021 in two urban (Obili, Mvan), two peri-urban (Simbock, Ahala), and two rural (Lendom, Elig-essomballa) sites in the city of Yaoundé. The efficacy of three sampling methods, namely ovitraps, Biogent Sentinel trap, and sweep nets, was evaluated. Different ovitrap indices were used to assess the infestation levels across study sites; a general linear model was used to determine if there are statistical differences between positive ovitraps across ecological zones. A total of 16,264 Aedes mosquitoes were collected during entomological surveys. Ovitraps provided the highest mosquito abundance (15,323; 91.14%) and the highest species diversity. Of the five Aedes species collected, Aedes albopictus (59.74%) was the most commonly recorded in both urban and rural settings. Different Aedes species were collected in the same ovitrap. The ovitrap positivity index was high in all sites and varied from 58.3% in Obili in the urban area to 86.08% in Lendom in the rural area. The egg density index varied from 6.42 in Mvan (urban site) to 13.70 in Lendom (rural area). Adult sampling methods recorded mostly Aedes albopictus. The present study supports high infestation of Aedes species in the city of Yaoundé. Ovitraps were highly efficient in detecting Aedes distribution across study sites. The situation calls for regular surveillance and control of Aedes population to prevent sudden occurrence of outbreaks.

Status Resistensi dan Keberadaan Virus Dengue pada Nyamuk Aedes Sp di Kelurahan Pinang Kencana, Kota Tanjungpinang, Kepulauan Riau

Tanjungpinang Timur Village is an endemic area, and every year there is a death rate due to dengue fever. This study aimed to map the resistance and presence of the dengue virus in Aedes sp mosquitoes in Pinang Kencana Village. This research was observational with a descriptive approach. The samples were mosquitoes bred in the Vector Laboratory of Poltekkes, Ministry of Health, Tanjungpinang, from eggs trapped in ovitraps distributed in the study area. A total of 78 ovitraps were placed inside the house, 45 were positive, while 45 positive ovitraps were placed outside the house out of a total of 84 ovitraps. Ovitrap index numbers outside (57.7%) and inside the house (53.6%) with an overall ovitrap index of 55.6%. The resistance test results using the CDC bottle bioassay method showed that Aedes sp mosquitoes from Pinang Kencana Village were resistant to the pesticide deltamethrin dose of 10 g/bottle with a diagnosis time of 30 minutes with a mosquito mortality percentage of 68.33%. The PCR results for dengue virus in the sample mosquitoes showed no presence of dengue virus in the mosquito samples, both DEN-1, DEN-2, DEN-3, and DEN-4 serotypes.

Dengue virus transovarial transmission detection in Aedes aegypti from dengue hemorrhagic fever patients' residences in Denpasar, Bali.

Background and Aim:To effectively control dengue hemorrhagic fever (DHF), it is necessary to assess the risk of vertical virus transmission in Aedes aegypti mosquitoes. This study aimed to detect dengue virus (DENV) transovarial transmission in A. aegypti collected from DHF patients’ residences in Denpasar, Bali.Materials and Methods:A. aegypti samples were acquired by rearing A. aegypti eggs collected from ovitraps placed in the homes of DHF patients. Ovitraps were installed for 7 days and viewed using a loupe to determine whether there were Aedes spp. eggs present. An immunocytochemical method was utilized with 200 samples, and virus detection was performed using a reverse transcriptase-polymerase chain reaction (RT-PCR).Results:Of the 10 DHF patient houses fitted with ovitraps, four produced positive ovitraps from which larvae developed (house index=40%). Of the 50 ovitraps mounted in the 10 homes, 14 ovitraps were positive and contained A. aegypti eggs (ovitrap index=28%). Of these 14 positive ovitraps containing A. aegypti eggs, 10 ovitraps produced larvae. Immunocytochemical tests were conducted on A. aegypti eggs from the four houses under study. It was found that from the 200 samples collected, 197 samples could be observed, and 11 samples (5.6%) were positive for DENV antigen. RT-PCR examination conducted on mosquitoes reared from the four houses studied obtained a negative virus content result.Conclusion:This study found the presence of DENV antigen to be as high as 5.6%. This means that potential for transovarial transmission exists within DHF patients’ homes in Denpasar, Bali. Aedes control strategy in Denpasar should address this finding, in addition to the current approaches which have focused primarily on the elimination of larval breeding habitats and control of adults using insecticidal fogging during outbreaks.

Detection of Dengue Virus Transovarial Transmission in Dengue Hemorrhagic Fever Endemic Areas

Dengue virus is a group of RNA viruses that are highly pathogenic in humans and spread quickly through the bites of Aedes aegypti and Aedes albopictus mosquitoes, especially in tropical countries. More than half a billion out of 100 countries worldwide are at serious risk of dengue virus infection. Vector surveillance activities with Ovitrap and detection of dengue virus types in Aedes aegypti and Aedes albopictus have never been carried out in Pontianak City. It is important in early alert systems at transmission foci. The purpose of this study was to prove the transovarial transmission of dengue virus in Aedes aegypti and Aedes albopictus mosquitoes with a transovarial transmission index (TTI) in endemic areas in Pontianak City, West Kalimantan. The method used in this research is descriptive observational, viral examination method with immunocytochemistry streptavidin-biotin peroxidase complex (ISBPC) and Polymerase Chain Reaction Transcription Reaction (PCR) aimed at proving the presence of transovarial transmission of dengue virus in the same period. The conclusion in this study is that there is evidence of transovarial transmission of dengue virus in Aedes mosquitoes in endemic areas by 29.3% in Sungai Jawi Dalam sub-district, West Pontianak sub-district, and 39.6% in Batu Layang sub-district, North Pontianak sub-district, mosquito density from the results of the Ovitrap Index measurement (OI) in Batu Layang Village is denser, namely 41.3%, compared to Sungai Jawi Village, which is 38.22% and has succeeded in identifying the type of dengue virus, namely the Dengue virus strain, in the two research locations.

Evaluation of insecticide treated window curtains and water container covers for dengue vector control in a large-scale cluster-randomized trial in Venezuela.

Following earlier trials indicating that their potential in dengue vector control was constrained by housing structure, a large-scale cluster-randomized trial of insecticide treated curtains (ITCs) and water jar covers (ITJCs) was undertaken in Venezuela. In Trujillo, Venezuela, 60 clusters (6223 houses total) were randomized so that 15 clusters each received either PermaNet insecticide-treated window curtains (ITCs), permanent insecticide-treated water storage jar covers (ITJCs), a combination of both ITCs and ITJCs, or no insecticide treated materials (ITMs). A further 15 clusters located at least 5km from the edge of the study site were selected to act as an external control. Entomological surveys were carried out immediately before and after intervention, and then at 6-month intervals over the following 27 months. The Breteau and House indices were used as primary outcome measures and ovitrap indices as secondary. Negative binomial regression models were used to compare cluster-level values of these indices between the trial arms. Reductions in entomological indices followed deployment of all ITMs and throughout the trial, indices in the external control arm remained substantially higher than in the ITM study arms including the internal control. Comparing the ratios of between-arm means to summarise the entomological indices throughout the study, the combined ITC+ITJC intervention had the greatest impact on the indices, with a 63% difference in the pupae per person indices between the ITC+ITJC arm and the internal control. However, coverage had fallen below 60% by 14-months post-intervention and remained below 40% for most of the remaining study period. ITMs can impact dengue vector populations in the long term, particularly when ITCs and ITJCs are deployed in combination. ClinicalTrials.gov ISRCTN08474420; www.isrctn.com.

Arboviral vectors dispersal and density in storey buildings: the association of light intensity and air temperature.

Aedes mosquito is the most common arboviral vector in the tropic and subtropic regions that it was dispersed in high-rise buildings up to many storeys. A study reported that similar condition in Indonesia is still limited, although the high-rise buildings are also growing rapidly throughout the country. This study aimed to understand the dispersal and density index of Aedes mosquitoes among storey buildings at the campus of Universitas Muhammadiyah Semarang, Indonesia. A cross-sectional study was conducted among four of nine-storey buildings. Eight ovitraps were placed in each storey to collect the mosquito eggs by placing them along the building corridor and near the toilet rooms. Ovistrip from each ovitrap was collected every three days, and the attached mosquito eggs were observed and counted under a microscope in the laboratory to calculate the density index. Aedes mosquitoes were found in all buildings up to the highest storey where the Ovitrap Index (OI) is the opposite of height, while the Eggs Density Index (EDI) differs according to the location of the building. OI at the 1st and 4th floor ranged between 63-100% and 38-50%. Eggs density was associated with the light intensity and air temperature. Two Aedes species were identified where Aedes aegypti was more dominant than Aedes albopictus. All high-rise buildings are exposed to Aedes mosquitoes, thus opening up opportunities for dengue virus transmission. Further study is necessarily conducted to understand the inter-storeys migration pathway of mosquitoes, preference habitats, and the highest storey exposed for control.