scholarly journals Dengue fever and Aedes aegypti risk in the Galápagos Islands, Ecuador

2017 ◽  
Author(s):  
Ryan Nightingale ◽  
Catherine Lippi ◽  
Sadie J. Ryan ◽  
Mercy J. Borbor-Cordova ◽  
Marilyn Cruz B ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Dengue Fever ◽  
Mosquito Control ◽  
Dengue Infection ◽  
Human Movement ◽  
Galapagos Islands ◽  
Housing Conditions ◽  
Galápagos Islands ◽  
Household Level ◽  
Attitudes And Practices

AbstractIntroductionDengue fever is an emerging infectious disease in the Galápagos Islands of Ecuador, with the first cases reported in 2002 and periodic outbreaks since then. Here we report the results of a pilot study conducted in two cities in 2014: Puerto Ayora (PA) on Santa Cruz Island, and Puerto Baquerizo Moreno (PB) on Santa Cristobal Island. The aims of this study were to assess the social-ecological risk factors associated with dengue and mosquito presence at the household-level.MethodsIn 2014 we conducted 100 household surveys (50 on each island) in neighborhoods with prior reported dengue. Adult mosquitoes were collected inside and outside the home, larval indices were determined through container surveys, and heads of households were interviewed to determine demographics, prior dengue infections, housing conditions, and knowledge, attitudes and practices regarding dengue. Multimodel selection methods were used to derive best-fit generalized linear regression (GLM) models of prior dengue infection, and the presence of Ae. aegypti in the home.ResultsWe found that 24% of PB and 14% of PA respondents self-reported a prior dengue infection, and more PB homes than PA homes had Ae. aegypti. The top-ranked model for prior dengue infection included human movement – travel between neighborhoods, between islands, and to the mainland; demographics including salary level and education of the head of household, and increase with more people per room in a house, house condition, access to water quality issues, and dengue awareness. The top-ranked model for the presence of Ae. aegypti included housing conditions, including the presence of window screens and air conditioners, mosquito control actions, and dengue risk perception.Discussion/conclusionTo our knowledge, this is the first study of dengue risk and Aedes aegypti in the Galápagos Islands. The findings that human movement within and between islands, and to and from the mainland, were important to reported dengue cases confirms concerns of this route of introduction and repeated transmission.

scholarly journals Socio-Ecological Factors Associated with Dengue Risk and Aedes aegypti Presence in the Galápagos Islands, Ecuador

2019 ◽  
Vol 16 (5) ◽  
pp. 682 ◽  
Author(s):  
Sadie Ryan ◽  
Catherine Lippi ◽  
Ryan Nightingale ◽  
Gabriela Hamerlinck ◽  
Mercy Borbor-Cordova ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Dengue Infection ◽  
Galapagos Islands ◽  
Mosquito Vector ◽  
Housing Conditions ◽  
Galápagos Islands ◽  
Linear Regression Models ◽  
Factors Associated ◽  
Attitudes And Practices

Dengue fever is an emerging infectious disease in the Galápagos Islands of Ecuador, with the first cases reported in 2002 and subsequent periodic outbreaks. We report results of a 2014 pilot study conducted in Puerto Ayora (PA) on Santa Cruz Island, and Puerto Baquerizo Moreno (PB) on San Cristobal Island. To assess the socio-ecological risk factors associated with dengue and mosquito vector presence at the household level, we conducted 100 household surveys (50 on each island) in neighborhoods with prior reported dengue cases. Adult mosquitoes were collected inside and outside the home, larval indices were determined through container surveys, and heads of households were interviewed to determine demographics, self-reported prior dengue infections, housing conditions, and knowledge, attitudes, and practices regarding dengue. Multi-model selection methods were used to derive best-fit generalized linear regression models of prior dengue infection, and Aedes aegypti presence. We found that 24% of PB and 14% of PA respondents self-reported a prior dengue infection, and more PB homes than PA homes had Ae. aegypti. The top-ranked model for prior dengue infection included several factors related to human movement, household demographics, access to water quality issues, and dengue awareness. The top-ranked model for Ae. aegypti presence included housing conditions, mosquito control practices, and dengue risk perception. This is the first study of dengue risk and Ae. aegypti presence in the Galápagos Islands.

scholarly journals Tumbuhan Obat: Pendekatan Alternatif dalam Pengendalian Nyamuk Aedes aegypti dan Virus Dengue Penyebab Demam Dengue

2018 ◽  
Vol 4 (2) ◽  
pp. 83-90
Author(s):  
Ign Joko Suyono ◽  
Aditya K. Karim
Keyword(s):  
Medicinal Plant ◽  
Aedes Aegypti ◽  
Dengue Fever ◽  
Mosquito Control ◽  
Dengue Shock Syndrome ◽  
Viral Disease ◽  
Mosquito Vector ◽  
Major Health ◽  
Alternative Approach ◽  
Control And Prevention

Dengue is the most important emerging tropical viral disease of humans in the world today. Aedes aegypti is a major mosquito vector responsible for transmitting many viral diseases and this mosquito that spreads major health problems like dengue fever. The resistance of Ae. aegypti to insecticides is already widespread and represents a serious problem for programmes aimed at the control and prevention of dengue in tropical countries. The search for compounds extracted from medicinal plant preparations as alternatives insecticide for mosquito control is in immediate need. Alternative approach for control Ae. aegypti dan virus dengue using the medicinal plant will be discussed in this paper.Key words: Medicinal plant, Aedes aegypti, dengue fever, dengue haemorragi fever, dengue shock syndrome

scholarly journals Genetic variation of Aedes aegypti populations from Ecuador

2019 ◽  
Author(s):  
Varsovia Cevallos ◽  
Denisse Benítez ◽  
Josefina Coloma ◽  
Andrés Carrazco ◽  
Chunling Wang ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Aedes Aegypti ◽  
Amazon Basin ◽  
Balancing Selection ◽  
Central Africa ◽  
Galapagos Islands ◽  
Galápagos Islands ◽  
Data Set ◽  
The Pacific ◽  
West And Central Africa

AbstractThis is the first genetic analysis in Ecuador of Aedes aegypti using fragments of mitochondrial genes, NADH dehydrogenase subunit 4 (ND4) and cytochrome oxidase subunit I (COI). A total of 154 mosquitoes from 23 localities were collected in the Pacific coastal lowlands, Amazon basin lowlands, and the Galápagos Islands from 2012 to 2019. The analysis of fragments of the genes COI (672 bp) and ND4 (262 bp) and concatenated analysis of both COI and ND4 showed two haplotypes (H1, H2) present in Ecuador mainland and the Galápagos Islands. The phylogenetic analysis identified two well-supported clades. Combined analysis of both genes from ten localities also resulted in two haplotypes. Nucleotide diversity, neutrality tests (Tajima’s test D, Fu and Li’s F*and D*) and AMOVA analysis of the entire data set suggest balancing selection for both genes. The results indicate genetic variation without geographical restriction. COI-H1 grouped with sequences from the Americas, West and Central Africa, East Africa, Asia, and Australia. ND4-H1 grouped with similar sequences from the Americas, Asia and West Africa. COI-H2 grouped with sequences from Asia and the Americas. ND4-H2 grouped with sequences from the Americas. We report overlapping peaks in four sequences that suggest heteroplasmy in the individuals. The origin of the populations of Aedes aegypti in Ecuador show African genetic origin and are widely present in several countries in the Americas. One of the genetic variants is more common in all the localities and the two haplotypes are distributed indistinctly in the three geographical sampled areas in Ecuador.

scholarly journals Knowledge, Attitudes and Practices Regarding Dengue Fever in a Cohort of Nursing Students

2019 ◽  
pp. 1-9
Author(s):  
Mansoor Shueai Al Awfi ◽  
Bushra Anaam AL Sharabi ◽  
Abdullah Al Alimi ◽  
Mohammed Abdo Abkar
Keyword(s):  
Nursing Students ◽  
Dengue Fever ◽  
Health Care Services ◽  
Dengue Infection ◽  
Chi Square ◽  
Attitudes And Practices ◽  
Care Services ◽  
Chi Square Test ◽  
Questionnaire Method ◽  
Knowledge Attitudes And Practices

Background: Good knowledge, attitudes and practices (KAP) on dengue fever will result a significant effect on prevention and control. Conversely, poor KAP help spread of dengue vectors and virus resulting in dengue epidemics. Objective: This study aimed to evaluate the knowledge, attitudes and practices regarding dengue fever among a cohort of nursing students in faculty of medicine and health sciences, Hodiedah University, Hodiedah, Yemen. Methods: Data was collected from 80 students using questionnaire method consists of a set of questions during 2016–2017educational year. KAP were assessed as satisfactory or unsatisfactory using a scoring system. Data was analyzed by using the Statistical Package for Social Sciences (SPSS®). Chi-square test was used for testing associations.  Results: According to KAP scores, 12.5%, 97.5% and 25% of respondents had satisfactory knowledge, attitudes and practices respectively. While 87.5%, 2.5% and 75% of them had unsatisfactory knowledge, attitudes and practices about dengue fever. There is significant association between knowledge and practices (p= 0.001). However, there is no significant association between knowledge and attitudes (p= 0.588) about dengue fever. Conclusion: Present study concluded that 87.5 % and 75% of participants nursing students have unsatisfactory knowledge and practices regarding dengue infection. Therefore, it is importance to enhance their knowledge and practices before graduation and employing them for health care services in the community.

scholarly journals Dengue fever transmission between construction site and its surrounding communities in China

2020 ◽  
Author(s):  
Xingchun Liu ◽  
Meng Zhang ◽  
Qu Cheng ◽  
Yingtao Zhang ◽  
Guoqiang Ye ◽  
...  
Keyword(s):  
Dengue Fever ◽  
Attack Rate ◽  
Mosquito Control ◽  
Human Movement ◽  
Transmission Risk ◽  
Coefficient Of Determination ◽  
Transmission Route ◽  
Construction Site ◽  
Construction Sites ◽  
Reported Data

Abstract Background: Due to more mosquito habitats and the lack of basic mosquito control facilities, construction sites are more likely to have secondary cases after case importation, which may increase the number of cases entering the community and the chance of community transmission. For example, the outbreak in Zhanjiang Prefecture, China, 2018, started at a construction site, then occurred in the surrounding communities. This study aims to investigate how to effectively reduce the dengue transmission risk related to construction sites and the neighboring communities.Methods: The study was based on an outbreak of dengue fever (DF) occurred in Zhanjiang Prefecture, Guangdong Province in 2018. We simulated the transmission of dengue virus between human and mosquitoes at the construction site and in the neighboring community separately, as well between them by assuming human movement between the construction site and the neighboring community. Susceptible-Exposed-Infectious/Asymptomatic-Recovered (SEIAR) model was used for the human, while SEI model was used for the mosquitoes. We obtained the transmissibility parameters by fitting the model to observed number of locally acquired cases before local interventions started and the coefficient of determination (R2) was used to quantify the significance of the fit. We then evaluated the effectiveness of different intervention scenarios targeting at reducing the transmissibility between different human and mosquito subpopulations at different locations (i.e. construction sites and community) quantified by the total attack rate (TAR) and duration of the outbreak (DO).Results: A total of 467 DF cases were reported in Zhanjiang Prefecture in 2018, among which 102 were located at a construction site and 131 were located in the surrounding community. The values of R2 were 0.829 (P < 0.001) and 0.878 (P < 0.001) for the construction site and the community, respectively. The modelling outcome indicated that without interventions, the number of cases on the construction site would reach to 156, yielding a total attack rate (TAR) of 31.25% (95% confidence interval [CI]: 27.18%- 35.31%). In the community, the number of the cases would be much more than the reported data and up to 10796, yielding a TAR of 21.59% (95%CI: 21.23%- 21.95%). When the transmission route from mosquitoes to people is cut off in the community, the number of cases in the community would decrease to a minimum of 33 compared with other situations we simulated, yielding a TAR of 0.068% (95%CI: 0.05%- 0.09%) and a duration of outbreak (DO) of 60 days. When the transmission route from infectious mosquitoes in the community and the construction site to susceptible people on the construction site is cut off at the same time, the number of cases in the construction site would drop to a minimum of 74, yielding a TAR of 14.88% (95%CI: 11.76%- 18.00%) and a DO of 66 days.Conclusions: Without intervention, DF could spread rapidly in the densely populated communities around the construction site. To control the outbreak effectively for both the construction site and the community, interventions need to be taken to reduce the transmission within the community and from the community to the construction site. Only controlling the transmission within the construction site could not reduce the number of cases on the construction site, and controlling the transmission route within the construction site or between the construction site and the community could not lead to a reduction in the number of cases in the community.

scholarly journals Household and climate factors influence Aedes aegypti presence in the arid city of Huaquillas, Ecuador

2021 ◽  
Vol 15 (11) ◽  
pp. e0009931
Author(s):  
James L. Martin ◽  
Catherine A. Lippi ◽  
Anna M. Stewart-Ibarra ◽  
Efraín Beltrán Ayala ◽  
Erin A. Mordecai ◽  
...  
Keyword(s):  
Public Health ◽  
Aedes Aegypti ◽  
Disease Surveillance ◽  
Local Level ◽  
Human Movement ◽  
Breeding Habitat ◽  
Health Concern ◽  
Septic Systems ◽  
Household Level ◽  
Social Ecological

Arboviruses transmitted by Aedes aegypti (e.g., dengue, chikungunya, Zika) are of major public health concern on the arid coastal border of Ecuador and Peru. This high transit border is a critical disease surveillance site due to human movement-associated risk of transmission. Local level studies are thus integral to capturing the dynamics and distribution of vector populations and social-ecological drivers of risk, to inform targeted public health interventions. Our study examines factors associated with household-level Ae. aegypti presence in Huaquillas, Ecuador, while accounting for spatial and temporal effects. From January to May of 2017, adult mosquitoes were collected from a cohort of households (n = 63) in clusters (n = 10), across the city of Huaquillas, using aspirator backpacks. Household surveys describing housing conditions, demographics, economics, travel, disease prevention, and city services were conducted by local enumerators. This study was conducted during the normal arbovirus transmission season (January—May), but during an exceptionally dry year. Household level Ae. aegypti presence peaked in February, and counts were highest in weeks with high temperatures and a week after increased rainfall. Univariate analyses with proportional odds logistic regression were used to explore household social-ecological variables and female Ae. aegypti presence. We found that homes were more likely to have Ae. aegypti when households had interruptions in piped water service. Ae. aegypti presence was less likely in households with septic systems. Based on our findings, infrastructure access and seasonal climate are important considerations for vector control in this city, and even in dry years, the arid environment of Huaquillas supports Ae. aegypti breeding habitat.

scholarly journals Autochthonous dengue fever in Croatia, August–September 2010

2011 ◽  
Vol 16 (9) ◽  
Author(s):  
I Gjenero-Margan ◽  
B Aleraj ◽  
D Krajcar ◽  
V Lesnikar ◽  
A Klobučar ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Dengue Fever ◽  
Health Professionals ◽  
Mosquito Control ◽  
Dengue Infection ◽  
Control Measures ◽  
Dengue Case ◽  
The Public

After information about a dengue case in Germany acquired in Croatia, health professionals and the public in Croatia were alerted to assess the situation and to enhance mosquito control, resulting in the diagnosis of a second case of autochthonous dengue fever in the same area and the detection of 15 persons with evidence of recent dengue infection. Mosquito control measures were introduced. The circumstances of dengue virus introduction to Croatia remain unresolved.

scholarly journals Exploring the utility of social-ecological and entomological risk factors for dengue infection as surveillance indicators in the dengue hyper-endemic city of Machala, Ecuador

2020 ◽  
Author(s):  
Catherine Lippi ◽  
Anna M. Stewart-Ibarra ◽  
Timothy P. Endy ◽  
Mark Abbott ◽  
Cinthya Cueva ◽  
...  
Keyword(s):  
Risk Factors ◽  
Aedes Aegypti ◽  
Dengue Infection ◽  
Good Condition ◽  
Ecological Factors ◽  
Dengue Case ◽  
Infection Status ◽  
Household Level ◽  
Targeted Interventions ◽  
Social Ecological

The management of mosquito-borne diseases is a challenge in southern coastal Ecuador, where dengue is hyper-endemic and co-circulates with other arboviral diseases. Prior work in the region has explored social-ecological factors, dengue case data, and entomological indices. In this study, we bring together entomological and epidemiological data to describe links between social-ecological factors associated with risk of dengue transmission at the household level in Machala, Ecuador. Households surveys were conducted from 2014-2016 to assess the presence of adult Aedes aegypti (collected via aspiration) and to enumerate housing conditions, demographics, and mosquito prevention behaviors. Household-level dengue infection status was determined by laboratory diagnostics in 2014-2015. Logistic models and multimodel selection were used to identify social-ecological variables associated with household presence of female Ae. aegypti and household dengue infection status, respectively. We identified significant risk factors for household-level dengue infection reflecting household condition, including bamboo cane construction material, shaded patios, and adjacency to abandoned properties, while housing structures in good condition were identified as protective against dengue infection. Aedes aegypti presence was associated with a greater than average number people per household and interrupted water supply, but was not associated with household level dengue infections. Models of Ae. aegypti presence were unstable, and not well resolved in ranking of competing models, suggesting that highly localized entomological surveillance indicators may not be indicative of risk in communities with hyperendemic dengue fever. These findings add to our understanding of the systems of mosquito-borne disease transmission in Machala, and in the larger region of southern Ecuador, aiding in the development of improved vector surveillance efforts, and targeted interventions.

scholarly journals Applying health belief model for the assessment of community knowledge, attitude and prevention practices following a dengue epidemic in a township in Selangor, Malaysia

2019 ◽  
Vol 6 (3) ◽  
pp. 958 ◽  
Author(s):  
Hidayatulfathi Othman ◽  
Zul-'Izzat Ikhwan Zaini ◽  
Norhafizah Karim ◽  
Nor Azimah Abd Rashid ◽  
Muhammad Badrul Hisham Abas ◽  
...  
Keyword(s):  
Dengue Fever ◽  
Self Efficacy ◽  
Dengue Infection ◽  
Health Belief ◽  
Health Concern ◽  
Sources Of Information ◽  
Cross Sectional ◽  
Attitudes And Practices ◽  
Modes Of Transmission ◽  
Knowledge Attitudes And Practices

Background: Dengue fever is endemic in Malaysia and continues to be a public health concern. Selangor was the top hit and there is a paucity of information on knowledge, attitudes, and practices (KAP) of Bandar Baru Bangi residents regarding dengue infection. Therefore, the objective of this study is to describe dengue related knowledge, attitudes and practices (KAP) of residents of Bandar Baru Bangi.Methods: A cross-sectional questionnaire survey of 152 residents from Section 3 and Section 8, Bandar Baru Bangi attending the dengue awareness events was conducted. The information on socio-demographic characteristics of the participants and their knowledge, attitude and practice on dengue fever was collected using a structured questionnaire.Results: The results showed that the residents only 52% had sufficient knowledge about the dengue vectors, signs, symptoms, and modes of transmission. However, approximately all the respondents considered dengue as serious but preventable disease to which they are vulnerable to. Television/radio was the predominant sources of information about dengue fever. Knowledge on dengue is associated with prevention practice. But the self-efficacy has a significant impact between the owner and tenant house (p=0.010, p<0.05). Female has higher self-efficacy compare to male.Conclusions: As conclusion, findings suggest that despite the residents of Bandar Baru Bangi have moderate knowledge level about dengue fever nevertheless; they still adopted the preventive measures suggested by the guidelines from Ministry of Health. Therefore, health program planners and practitioners need to identify why the dengue fever still rampant among the population.

scholarly journals Larvicidal, adulticidal, and oviposition-deterrent activity of Piper betle L. essential oil to Aedes aegypti

2019 ◽  
Vol 12 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Riesna Martianasari ◽  
Penny Humaidah Hamid
Keyword(s):  
Essential Oil ◽  
Aedes Aegypti ◽  
Dengue Fever ◽  
Larvicidal Activity ◽  
Mosquito Control ◽  
Activity Index ◽  
Piper Betle ◽  
Primary Vector ◽  
Aegypti Population ◽  
Deterrent Activity

Background and Aim: Aedes aegypti is a primary vector of many arthropod-borne diseases. One of the diseases, dengue fever, is an endemic disease in Indonesia causing high mortalities for decades. There are no preventive and specific treatments for dengue so far. Therefore, prevention of this disease largely depends on the mosquito control. Since resistance to chemical insecticides occurred worldwide, the study on alternate and new mosquito insecticides are mandatory. This study aimed to demonstrate the effect of essential oil from P. betle L. in the larval and adult stages, as well as its influence on oviposition activity of A. aegypti mosquito. Materials and Methods: P. betle efficacy was evaluated in various stages of A. aegypti development. For the larvicidal activity, larvae instar III stage was used. Adulticidal assay in this experiment was performed using newly emerged A. aegypti. For oviposition assay, mated A. aegypti was tested for their responses to P. betle-treated and non-treated ovitraps. Results: P. betle L. - adulticide activity was effective with a concentration of 2.5 μl/ml, caused 100% mortality within 15-30 min. Larvicide activity was observed after 1 h, 24 h, and 48 h post-treatment with LC50183, 92.7, and 59.8 ppm and LC90> 637, 525, and 434.7 ppm, respectively. Oviposition activity index was −0.917 in 1000 ppm. In addition, the eggs number of A. aegypti oviposition with 100 ppm of essential oil P. betle L. was 5 times lower than the control. Conclusion: This study demonstrated clearly that essential oil derived from P. betle L. potentially acts as alternate bioinsecticide to control A. aegypti population. The application can be varied or combined in different stages of mosquito development.

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