scholarly journals Entomological Risk Assessment for Dengue Virus Transmission during 2016–2020 in Kamphaeng Phet, Thailand

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1234
Author(s):  
Thanyalak Fansiri ◽  
Darunee Buddhari ◽  
Nattaphol Pathawong ◽  
Arissara Pongsiri ◽  
Chonticha Klungthong ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Dengue Virus ◽  
Case Reports ◽  
Virus Transmission ◽  
Denv Infection ◽  
Larval Abundance ◽  
Dengue Case ◽  
Vector Surveillance ◽  
Household Level ◽  
Dengue Transmission

Individual houses with high risks of dengue virus (DENV) transmission might be a source of virus transmission within the neighborhood. We conducted an entomological risk assessment for DENV transmission at the household level, comprising family cohort members residing in the same location, to assess the risk for dengue virus transmitted by mosquito vectors. The studies were conducted in Kamphaeng Phet Province, Thailand, during 2016–2020. Entomological investigations were performed in 35 cohort families on day 1 and day 14 after receiving dengue case reports. DENV was found in 22 Aedes samples (4.9%) out of 451 tested samples. A significantly higher DENV infection rate was detected in vectors collected on day 1 (6.64%) compared to those collected on day 14 (1.82%). Annual vector surveillance was carried out in 732 houses, with 1002 traps catching 3653 Aedes females. The majority of the 13,228 water containers examined were made from plastic and clay, with used tires serving as a primary container, with 59.55% larval abundance. Larval indices, as indicators of dengue epidemics and to evaluate disease and vector control approaches, were calculated. As a result, high values of larval indices indicated the considerably high risk of dengue transmission in these communities.

Geographical heterogeneity of dengue transmission in two villages in southern Vietnam

2009 ◽  
Vol 138 (4) ◽  
pp. 585-591 ◽  
Author(s):  
K. T. D. THAI ◽  
N. NAGELKERKE ◽  
H. L. PHUONG ◽  
T. T. T. NGA ◽  
P. T. GIAO ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Virus Transmission ◽  
Null Distribution ◽  
Household Level ◽  
Geographical Heterogeneity ◽  
Asymptomatic Children ◽  
Dengue Transmission ◽  
Risk Areas ◽  
Serological Data ◽  
And Control

SUMMARYThis study was performed to test the hypothesis that there are ‘hotspots’, i.e. geographical heterogeneity, of dengue transmission. Data from two repeat serosurveys in two villages in Vietnam were used to identify incident infections and to relate these to prevalence at baseline and thus assess geographical heterogeneity, i.e. clustering, in dengue transmission. A total of 400 households were surveyed; serological data from 521 children at baseline and from 119 children at follow-up were included in a spatial analysis. Geographical heterogeneity of dengue transmission was explored using a permutation null distribution test. This showed for the first time evidence of clustering of dengue virus transmission at the household level in asymptomatic children. Risk areas could be identified by seroprevalence surveys combined with mapping. Control of dengue virus transmission could be supported by identification and control of hotspots.

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 Entomological Surveillance for Zika and Dengue Virus in Aedes Mosquitoes: Implications for Vector Control in Thailand

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 442
Author(s):  
Nathamon Kosoltanapiwat ◽  
Jarinee Tongshoob ◽  
Preeraya Singkhaimuk ◽  
Chanyapat Nitatsukprasert ◽  
Silas A. Davidson ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Vector Control ◽  
Mosquito Control ◽  
Case Reports ◽  
Dengue Case ◽  
Prevention Measures ◽  
Entomological Surveillance ◽  
Vector Borne Diseases ◽  
Envelope Sequence ◽  
Surveillance Programs

Entomological surveillance for arthropod-borne viruses is vital for monitoring vector-borne diseases and informing vector control programs. In this study, we conducted entomological surveillance in Zika virus endemic areas. In Thailand, it is standard protocol to perform mosquito control within 24 h of a reported dengue case. Aedes females were collected within 72 h of case reports from villages with recent Zika–human cases in Kamphaeng Phet Province, Thailand in 2017 and 2018. Mosquitoes were bisected into head-thorax and abdomen and then screened for Zika (ZIKV) and dengue (DENV) viruses using real-time RT-PCR. ZIKV RNA was detected in three samples from two female Ae. aegypti (1.4%). A partial envelope sequence analysis revealed that the ZIKV sequences were the Asian lineage identical to sequences from ZIKV-infected cases reported in Thailand during 2016 and 2017. Dengue virus-1 (DENV-1) and dengue virus-4 (DENV-4) were found in four Ae. aegypti females (2.8%), and partial capsid sequences were nearly identical with DENV-1 and DENV-4 from Thai human cases reported in 2017. Findings in the current study demonstrate the importance of entomological surveillance programs to public health mosquito-borne disease prevention measures and control.

scholarly journals Administration of defective virus inhibits dengue transmission into mosquitoes

2019 ◽  
Author(s):  
Tarunendu Mapder ◽  
John Aaskov ◽  
Kevin Burrage
Keyword(s):  
Dengue Virus ◽  
Virus Transmission ◽  
Dengue Transmission ◽  
Dengue Outbreaks ◽  
Mosquito Pool ◽  
Bang Bang Control ◽  
Defective Virus ◽  
Successful Reduction ◽  
Transmission Models ◽  
Improve Disease Control

The host-vector shuttle and the bottleneck in dengue transmission is a significant aspect with regard to the study of dengue outbreaks. As mosquitoes require 100-1000 times more virus to become infected than human, the transmission of dengue virus from human to mosquito is a vulnerability that can be targeted to improve disease control. In order to capture the heterogeneity in the infectiousness of an infected patient population towards the mosquito pool, we calibrate a population of host-to-vector virus transmission models based on an experimentally quantified infected fraction of a mosquito population. Once the population of models is well-calibrated, we deploy a population of controls that helps to inhibit the human-to-mosquito transmission of the dengue virus indirectly by reducing the viral load in the patient body fluid. We use an optimal bang-bang control on the administration of the defective virus (transmissible interfering particles, known as TIPs) to symptomatic patients in the course of their febrile period and observe the dynamics in successful reduction of dengue spread into mosquitoes.

scholarly journals Administration of Defective Virus Inhibits Dengue Transmission into Mosquitoes

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 558
Author(s):  
Tarunendu Mapder ◽  
John Aaskov ◽  
Kevin Burrage
Keyword(s):  
Dengue Virus ◽  
Virus Transmission ◽  
Mosquito Population ◽  
Dengue Transmission ◽  
Dengue Outbreaks ◽  
Bang Bang Control ◽  
Defective Virus ◽  
Successful Reduction ◽  
Transmission Models ◽  
Improve Disease Control

The host-vector shuttle and the bottleneck in dengue transmission is a significant aspect with regard to the study of dengue outbreaks. As mosquitoes require 100–1000 times more virus to become infected than human, the transmission of dengue virus from human to mosquito is a vulnerability that can be targeted to improve disease control. In order to capture the heterogeneity in the infectiousness of an infected patient population towards the mosquito population, we calibrate a population of host-to-vector virus transmission models based on an experimentally quantified infected fraction of a mosquito population. Once the population of models is well-calibrated, we deploy a population of controls that helps to inhibit the human-to-mosquito transmission of the dengue virus indirectly by reducing the viral load in the patient body fluid. We use an optimal bang-bang control on the administration of the defective virus (transmissible interfering particles (TIPs)) to symptomatic patients in the course of their febrile period and observe the dynamics in successful reduction of dengue spread into mosquitoes.

scholarly journals Short Report: Adult Aedes abundance and risk of dengue transmission

2021 ◽  
Vol 15 (6) ◽  
pp. e0009475
Author(s):  
Janet Ong ◽  
Joel Aik ◽  
Lee Ching Ng
Keyword(s):  
Aedes Aegypti ◽  
Adult Female ◽  
Cluster Formation ◽  
Fold Increase ◽  
Short Report ◽  
Dengue Case ◽  
Vector Surveillance ◽  
Dengue Transmission ◽  
The Impact ◽  
Very High

Dengue is transmitted mainly by the adult female Aedes aegypti mosquito. However, little is known about the impact of adult Aedes abundance on the risk of dengue transmission. Here we analysed nationally representative dengue case and vector surveillance data collected from Singapore, to determine the effect of adult Aedes abundance on the risk of dengue transmission. A case was an area with active dengue transmission as indicated by the presence of dengue cluster. A control was an area where no dengue cluster was reported. Using multivariate logistic regression, we analysed 88 cases and 602 controls and estimated the odds of dengue cluster formation at various adult Aedes abundance levels, estimated by the mean number of adult female Aedes per Gravitrap per week and categorised into Low, Moderate, High and Very High abundance level. We found that the risk of dengue cluster formation was positively associated with adult Ae. aegypti abundance. We observed a three to four-fold increase in the odds of dengue clusters forming in areas with High (AOR: 3.40, 95% CI: 2.09, 5.52) and Very High (AOR: 3.99, 95% CI: 2.46, 6.46) adult Aedes aegypti abundance level compared to those with low Ae. aegypti abundance level. Our study strengthens the evidence for the use of adult Aedes indices for dengue risk assessment and early warning for dengue outbreaks. Entomological indicators of adult Ae. aegypti could be used to anticipate and prioritize areas for dengue control.

scholarly journals The Use of Insecticide-Treated Curtains for Control ofAedes aegyptiand Dengue Virus Transmission in “Fraccionamiento” Style Houses in México

2018 ◽  
Vol 2018 ◽  
pp. 1-22
Author(s):  
Maria A. Loroño-Pino ◽  
Ana Uitz-Mena ◽  
Claudia M. Carrillo-Solís ◽  
Rocío J. Zapata-Gil ◽  
Dora M. Camas-Tec ◽  
...  
Keyword(s):  
Public Health ◽  
Dengue Virus ◽  
Rural Areas ◽  
Pyrethroid Resistance ◽  
Virus Transmission ◽  
Denv Infection ◽  
Mosquito Abundance ◽  
Suburban Areas ◽  
Significant Public Health ◽  
Study Sites

Dengue, chikungunya, yellow fever, and Zika viruses transmitted byAedes aegyptimosquitoes are major public health threats in the tropical and subtropical world. In México, construction of large tracts of “fraccionamientos” high density housing to accommodate population growth and urbanization has provided fertile ground forAe. aegypti-transmitted viruses. We investigated the utility of pyrethroid-treated window curtains to reduce both the abundance ofAe. aegyptiand to prevent dengue virus (DENV) transmission in fraccionamiento housing. Windows and doors of fraccionamiento homes in urban/suburban areas, whereAe. aegyptipyrethroid resistance associated with the Ile1016 knock down resistance (kdr) mutation in the voltage gated sodium channel gene was high, and in rural areas, where kdr resistance was low, were fitted with either insecticide-treated curtains (ITCs) or non-treated curtains (NTCs). The homes were monitored for mosquito abundance and DENV infection. ITCs reduced the indoor abundance ofAe. aegyptiand the number of DENV-infected mosquitoes in homes in rural but not in urban/suburban study sites.The presence of non-treated screens also was associated with reduced numbers of mosquitoes in homes. “Super-infested” homes, yielding more than 50 mosquitoes, including DENV-infected mosquitoes, provide a significant public health risk to occupants, visitors, and people in neighboring homes.

scholarly journals PENYEBARAN VIRUS DENGUE SECARA TRANSOVARIAL PADA VEKTOR DEMAM BERDARAH DENGUE NYAMUK Aedes aegypti

2019 ◽  
Vol 12 (4) ◽  
pp. 216-223
Author(s):  
Devita Febriani Putri ◽  
Nurhaida Widiani ◽  
Debi Arivo
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Prediction Models ◽  
Virus Transmission ◽  
Hemorrhagic Fever ◽  
Transovarial Transmission ◽  
Scientific Article ◽  
Vector Surveillance ◽  
Population Vector ◽  
Dengue Outbreaks

TRANSOVARIAL TRANSMISSION OF DENV IN AEDES AEGYPTI Background: Transovarial transmission of dengue virus in Aedes aegypti mosquitoes is a vertical transmission of dengue virus infection in female Ae. aegypti mosquitoes to the offspring. The phenomenon of transovarial dengue virus transmission in Dengue Hemorrhagic Fever (DHF) vectors has been proven by laboratory and nature, which indicates the transovarial transmission of dengue virus has an important role in maintaining the dengue epidemic. DHF vector control especially Ae. aegypti mosquitoes is an effective method of stopping transmission and expansion of dengue cases.Purpose: This scientific article aims to understand the spread of dengue virus transovarially in dengue mosquito vectors, and its relation to the prediction of outbreak dengue cases as information on DHF vector surveillance so that it can make the appropriate control program.Methods: Collecting several scientific articles to obtain information on the studies that have been done and summarizing the results of the study.Results: Several result of study are proving that transovarial transmission of dengue virus in Aedes spp. mosquitoes  can predict dengue outbreaks case by monitoring the stadium immature Aedes sp., but it need further comprehension statistically about occurrence of dengue outbreaks and the increasing of dengue virus infections in immature stadium of mosquitoes.Discussion: Transovarial transmission rates from Ae. aegypti mosquito sample obtained from nature may be lower than in the laboratory, because laboratory condition can be controlled in accordande with the development of viruses in mosquito bodies. The dengue virus is proven to be able to spread between stages from eggs, larvae, pupae to imago and Ae. aegypti mosquitoes can act as reservoirs for  dengue virus until the 7th progeni.Conclusion: Dispersion dengue virus through transovarial in Ae. aegypti mosquito playing important role in viruses maintained in nature during absence of viremic vertebrata host or when the climate condition are not favorable for that viruses. Continuous monitoring of Ae. aegypti mosquitoes population vector related the early detection of virus circulation may contribute to the prediction models for dengue outbreaks, so that DHF control can be more effective.Pendahuluan: Penularan virus dengue secara transovarial pada nyamuk Aedes aegypti adalah transmisi secara vertikal dari nyamuk Ae. aegypti betina yang infektif virus dengue kepada keturunannya. Fenomena penularan transovarial virus dengue pada vektor Demam Berdarah Dengue (DBD) telah banyak dibuktikan skala laboratorium dan secara natural di alam, yang mengindikasikan penularan transovarial virus dengue memiliki peranan penting dalam mempertahankan epidemik DBD. Pengendalian vektor DBD khususnya nyamuk Ae. aegypti merupakan salah satu metode efektif dalam menghentikan penularan dan perluasan kasus DBD.Tujuan: Studi ini untuk memahami penyebaran virus dengue secara transovarial  pada vektor nyamuk DBD, serta kaitannya  terhadap prediksi kasus luar biasa (KLB) DBD sebagai informasi surveilans vektor DBD sehingga dapat membuat program pengendalian yang tepat.Metode: Dengan mengumpulkan beberapa artikel ilmiah untuk mendapatkan informasi studi yang telah dilakukan sebelumnya dan membuat ringkasan dari hasil studi tersebut.Hasil: Beberapa studi membuktikan penelitian transovarial virus dengue pada nyamuk Aedes spp. dapat memprediksi kasus KLB DBD dengan cara memonitoring stadium immature Aedes sp., namun perlu dilakukan studi statistik lebih lanjut untuk membuktikan hubungan terjadinya KLB DBD dan meningkatnya infeksi virus dengue pada stadium immature nyamuk.Pembahasan: Angka infeksi penularan transovarial virus dengue dari sampel nyamuk Ae. aegypti yang didapatkan langsung dari alam lebih rendah dari skala laboratorium, dikarenakan kondisi laboratorium dapat dikendalikan sesuai dengan perkembangan virus ditubuh nyamuk. Virus dengue terbukti dapat menyebar antar stadium dari telur, larva, pupa, sampai imago dan nyamuk Ae. aegypti dapat menjadi reservoir virus dengue sampai progeni ke 7.Kesimpulan: Penyebaran virus dengue secara transovarial pada nyamuk Ae. aegypti berperan penting dalam mempertahankan keberadaan virus di alam khususnya dimana tidak ada hospes vertebrata yang viremik atau ketika  keadaan (kondisi iklim) yang tidak menguntungkan virus tersebut di alam. Pemantauan berkelanjutan pada vektor demam berdarah nyamuk Ae. aegypti terkait deteksi dini sirkulasi virus dengue dapat berkontribusi pada pengembangan model prediksi KLB DBD, sehingga pengendalian DBD dapat lebih efektif.

Aedes Aegypti in Puerto Rico: Environmental Determinants of Larval Abundance and Relation to Dengue Virus Transmission *

1978 ◽  
Vol 27 (6) ◽  
pp. 1225-1231 ◽  
Author(s):  
Chester G. Moore ◽  
Barnett L. Cline ◽  
Ernesto Ruiz-Tibén ◽  
Efrain Rivera-Correa ◽  
Dwayne Lee ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Virus Transmission ◽  
Larval Abundance ◽  
Environmental Determinants

scholarly journals Impact of human mobility on the emergence of dengue epidemics in Pakistan

2015 ◽  
Vol 112 (38) ◽  
pp. 11887-11892 ◽  
Author(s):  
Amy Wesolowski ◽  
Taimur Qureshi ◽  
Maciej F. Boni ◽  
Pål Roe Sundsøy ◽  
Michael A. Johansson ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Mobile Phone ◽  
Human Mobility ◽  
Virus Transmission ◽  
Human Populations ◽  
Dengue Case ◽  
Mosquito Vector ◽  
Mobility Data ◽  
Recent Emergence ◽  
Large Outbreak

The recent emergence of dengue viruses into new susceptible human populations throughout Asia and the Middle East, driven in part by human travel on both local and global scales, represents a significant global health risk, particularly in areas with changing climatic suitability for the mosquito vector. In Pakistan, dengue has been endemic for decades in the southern port city of Karachi, but large epidemics in the northeast have emerged only since 2011. Pakistan is therefore representative of many countries on the verge of countrywide endemic dengue transmission, where prevention, surveillance, and preparedness are key priorities in previously dengue-free regions. We analyze spatially explicit dengue case data from a large outbreak in Pakistan in 2013 and compare the dynamics of the epidemic to an epidemiological model of dengue virus transmission based on climate and mobility data from ∼40 million mobile phone subscribers. We find that mobile phone-based mobility estimates predict the geographic spread and timing of epidemics in both recently epidemic and emerging locations. We combine transmission suitability maps with estimates of seasonal dengue virus importation to generate fine-scale dynamic risk maps with direct application to dengue containment and epidemic preparedness.

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