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 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.

scholarly journals TRANSMISI TRANSOVARIAL VIRUS DENGUE PADA NYAMUKAEDES SPP.

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Angle M. H. Sorisi
Keyword(s):  
Dengue Virus ◽  
Vertical Transmission ◽  
Dengue Hemorrhagic Fever ◽  
Virus Transmission ◽  
Hemorrhagic Fever ◽  
Health Problems ◽  
Transovarial Transmission ◽  
Blood Sucking ◽  
Endemic Areas ◽  
And Control

Abstract: Dengue Hemorrhagic Fever (DHF) is one of the most serious health problems in Indonesia which often causes outbreaks with numerous deaths. The disease is transmitted byAedes sp.females. Generally, dengue virus transmission occurs horizontally from human carriers, and the dengue viruses are passed on bytheir vectors through blood sucking activity. After propagation in the mosquito, the viruses are transmitted to human recipients. In addition, there is a vertical transmission (transovarial) of dengue virusesin the ova of Aedes sp.females. The viruses propagate in the ova that undergo  metamorphosis to become larvae, pupae, and imagoes. The transovarial transmission of dengue virusesin its vectors in endemic areas could be a causative key which is responsible for the phenomenon of increasing cases of DHF. Any effort to prevent and control DHF requires a thorough understanding about virDen transmission, including this transovarial transmission in Aedes spfemales. Keywords: DHF, transovarial transmission, Aedes sp.     Abstrak: Penyakit Demam Berdarah Dengue (DBD) merupakan salah satu masalah kesehatan yang semakin serius di Indonesia dan sering menimbulkan suatu Kejadian Luar Biasa (KLB) dengan jumlah kematian tinggi. Penyakit ditularkan melalui Aedes sp.betina. Transmisi virus dengue umumnya terjadi secara horizontal, yaitu dari manusia pembawa virus dengue ke nyamuk vektor Aedes sp. melalui aktivitasnya mengisap darahSetelah mengalami propagasi  dalam  tubuh nyamuk, virus dengue ditularkan ke  manusia penerima. Selain itu, transmisi virus dapat terjadi secara vertikal (transovarial) yaitu virus dengue dalam tubuh nyamuk vektorAedes sp. betinake ovum, kemudian berpropagasi dalam ovum, larva, pupa, dan imago. Transmisi transovarial virus dengueke vektornya di daerah endemik bisa menjadi kunci penyebab yang bertanggung jawab terhadap fenomena peningkatan kasus deman berdarah dengue. Upaya pencegahan dan penanggulangan DBD memerlukan pengetahuan yang matang tentang adanya infeksi transovarial virDen pada nyamuk Aedes sp. Kata kunci : DBD, transmisi transovarial,  Aedes sp.

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.

Dengue and the introduction of mosquito-transmitted viruses into Australia

2016 ◽  
Vol 37 (4) ◽  
pp. 167
Author(s):  
Andrew F van den Hurk
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Virus Transmission ◽  
Current Situation ◽  
Mosquito Vector ◽  
And Control

Dengue virus outbreaks involving 100s of cases periodically occur in north Queensland, the area of Australia where the primary mosquito vector, Aedes aegypti, occurs. This article summarises the ecology, history, current situation and control of dengue virus transmission in Australia and examines the threat posed by newly emergent arboviruses, such as Zika and chikungunya viruses.

scholarly journals DETEKSI MOLEKULER VIRUS DENGUE SEROTIPE 3 PADA NYAMUK Aedes aegypti DI WILAYAH PURWOKERTO TIMUR

2020 ◽  
Vol 2 (2) ◽  
pp. 215
Author(s):  
Priskila Agnesia Prayitno ◽  
Endang Srimurni Kusmintarsih ◽  
Daniel Joko Wahyono
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Dengue Hemorrhagic Fever ◽  
Sampling Technique ◽  
Hemorrhagic Fever ◽  
The Body ◽  
Survey Method ◽  
Preliminary Information ◽  
Dengue Transmission ◽  
And Control

Dengue Hemorrhagic Fever (DHF) is an infectious disease caused by the Dengue virus and transmitted through by bite of Ae. aegypti. This mosquito is the main vector transmission of DENV with characteristics of the body and limbs are covered with scales silvery white lines. Mosquitoes are widespread in tropical and subtropical regions, and Purwokerto is an endemic of DHF and at the same time found mosquitoes as the vectors. East Purwokerto is the highest region of DHF cases in Banyumas, and the outbreak was happened in Sokanegara on 2016 until cause death. Based on previous research states that the most found Dengue virus in Purwokerto is serotype 3. Therefore, detection molecular of Ae. aegypti need to be carried out in relation to prediction of dengue transmission to obtain preliminary information on the prevention and control of DENV. The purpose of this research is to detects Dengue virus in adult mosquitoes Ae. Aegypti as vector of DENV. The research method used is survey method withcross sectional and purposive sampling technique. The parameter observed is a positivity DENV serotype 3 on mosquitoes. The analysis of the survey data is a positivity DENV of mosquitoes. The results of the research showed that based on entomological survey in East Purwokerto, DENV serotype 3 was not detected in mosquitoes. Key Words :  Aedes aegypti, dengue hemorrhagic fever, DENV

scholarly journals Using paired serology and surveillance data to quantify dengue transmission and control during a large outbreak in Fiji

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Adam J Kucharski ◽  
Mike Kama ◽  
Conall H Watson ◽  
Maite Aubry ◽  
Sebastian Funk ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Surveillance Data ◽  
Control Measures ◽  
Major Health ◽  
Dengue Transmission ◽  
Before And After ◽  
Large Outbreak ◽  
Serological Data ◽  
And Control ◽  
Additional Reduction

Dengue is a major health burden, but it can be challenging to examine transmission and evaluate control measures because outbreaks depend on multiple factors, including human population structure, prior immunity and climate. We combined population-representative paired sera collected before and after the 2013/14 dengue-3 outbreak in Fiji with surveillance data to determine how such factors influence transmission and control in island settings. Our results suggested the 10–19 year-old age group had the highest risk of infection, but we did not find strong evidence that other demographic or environmental risk factors were linked to seroconversion. A mathematical model jointly fitted to surveillance and serological data suggested that herd immunity and seasonally varying transmission could not explain observed dynamics. However, the model showed evidence of an additional reduction in transmission coinciding with a vector clean-up campaign, which may have contributed to the decline in cases in the later stages of the outbreak.

scholarly journals Using paired serology and surveillance data to quantify dengue transmission and control during a large outbreak in Fiji

2018 ◽  
Author(s):  
Adam J Kucharski ◽  
Mike Kama ◽  
Conall H Watson ◽  
Maite Aubry ◽  
Sebastian Funk ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Virus Transmission ◽  
Surveillance Data ◽  
Control Measures ◽  
Major Health ◽  
Dengue Transmission ◽  
Before And After ◽  
Large Outbreak ◽  
And Control ◽  
Additional Reduction

AbstractDengue is a major health burden, but it can be challenging to examine transmission dynamics and evaluate control measures because outbreaks depend on multiple factors, including human population structure, prior immunity and climate. We combined population-representative paired sera collected before and after the major 2013/14 dengue-3 outbreak in Fiji with surveillance data to determine how such factors influence dengue virus transmission and control in island settings. Our results suggested the 10-19 year-old age group had the highest risk of acquiring infection, but we did not find strong evidence that other demographic or environmental risk factors were linked to seroconversion. Mathematical modelling showed that temperature-driven variation in transmission and herd immunity could not fully explain observed dynamics. However, there was evidence of an additional reduction in transmission coinciding with a vector clean-up campaign, which may have contributed to the decline in cases and prevented transmission continuing into the following season.

Green peach aphid and potato leafroll virus: transmission and control

2020 ◽  
Author(s):  
R.A. Bagrov ◽  
◽  
V.I. Leunov
Keyword(s):  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Virus Transmission ◽  
Potato Leafroll Virus ◽  
Factors Affecting ◽  
Potato Viruses ◽  
Tuber Necrosis ◽  
Aphid Vectors ◽  
Leafroll Virus ◽  
And Control

The mechanisms of transmission of potato viruses from plants to aphid vectors and from aphids to uninfected plants are described, including the example of the green peach aphid (Myzus persicae, GPA). Factors affecting the spreading of tuber necrosis and its manifestation on plants infected with potato leafroll virus (PLRV) are discussed. Recommendations for PLRV and GPA control in the field are given.

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