Risk of Dengue Spread from the Philippines through International Air Travel

Author(s):  
Lauren M. Gardner ◽  
Sahotra Sarkar

Epidemics of dengue fever occur every 3 to 4 years in the Philippines. The risk of a dengue fever outbreak in the Philippines has been heightened since Typhoon Haiyan struck the region in November 2013 because recovery efforts have been slow to progress. The structural damage caused by the typhoon resulted in an abundance of standing water, which can serve as mosquito breeding grounds. Should an outbreak of dengue occur, infected travelers departing the Philippines pose a risk because they may introduce the dengue virus into local vector populations (of Aedes aegypti and Aedes albopictus) at their destinations. This study quantifies the risk posed by potentially infected travelers departing the Philippines by using a network model that incorporates predictive species distribution models, demographic features of destination areas, and air traffic volumes. The analysis reveals that a majority of travelers departing Philippine airports deplane in regions suitable for harboring Aedes aegypti or Aedes albopictus; this factor increases the likelihood of further spread of the disease if an outbreak were to occur. Because it is impractical to implement all possible monitoring and control measures at all locations connected to the Philippines, this analysis ranks the set of candidates and thus allows surveillance resources to be optimally deployed.

Biomédica ◽  
2017 ◽  
Vol 37 ◽  
pp. 135 ◽  
Author(s):  
Andrés Gómez-Palacio ◽  
Juan Suaza-Vasco ◽  
Sandra Castaño ◽  
Omar Triana ◽  
Sandra Uribe

Introducción. Aedes aegypti y Ae. albopictus son reconocidos vectores de arbovirus como los del dengue, la fiebre amarilla, el chikungunya y el Zika, en regiones tropicales y subtropicales del mundo. En Colombia, la distribución geográfica de Ae. albopictus ha sufrido un incremento y hoy incluye ciudades como Cali y Medellín. Hasta ahora, sin embargo, no se ha recabado información concluyente sobre su infección viral y su capacidad de transmisión a los humanos.Objetivo. Determinar la infección natural por dengue en ejemplares de Ae. albopictus recolectados en un área urbana de Medellín.Materiales y métodos. Se recolectaron individuos de Ae. albopictus en el campus de la Universidad Nacional de Colombia, sede Medellín. Se confirmó su clasificación taxonómica mediante el análisis del gen citocromo oxidasa I (COI), y se extrajo el ARN total para la identificación del virus del dengue y de los respectivos serotipos. La presencia del genotipo DENV se infirió mediante el análisis del gen NS3.Resultados. El análisis del COI corroboró el estatus taxonómico de Ae. albopictus. Uno de los mosquitos procesados fue positivo para DENV-2 y el análisis del NS3 mostró una gran similitud con el genotipo asiático-americano.Conclusión. Se reporta la infección con DENV-2 en Ae. albopictus en Medellín, Colombia. La presencia del genotipo asiático-americano en una zona urbana sugiere su posible circulación entre humanos y en Ae. albopictus, lo cual alerta sobre su eventual papel en la transmisión del DENV-2, y sobre la necesidad de incluir esta especie en la vigilancia entomológica en Colombia.


2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Meiranty C. Pangerapan ◽  
Beivy J. Kolondam

Abstract: Dengue virus is a single-stranded RNA virus that belongs to Flaviviridae family. This virus causes dengue fever which is transmitted by Aedes aegypti dan Aedes albopictus. There are four serotypes of dengue virus; all of them can cause dengue fever. Understanding the genomics of dengue virus is important for research and diagnostics. The genome of dengue virus is 11 kilo-base long. It consists of 5’-untranslated region (5’-UTR), three structural genes (coding capsid protein, pre-membrane/membrane, and envelope), seven non-structural genes (coding NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5 proteins) and 3’-UTR. Non-structural genes are encoding proteins of viral RNA replication, interferon response, viral assembly and secretion, endoplasmic reticulum membrane invagination induction, immune-mediator induction, and RNA 5’-caping.Keywords: dengue virus, genome, structural genes, non-structural genes, untranslated region.Abstrak: Virus dengue merupakan virus RNA beruntai tunggal yang termasuk dalam famili Flaviviridae. Virus ini adalah penyebab penyakit demam berdarah dengue yang ditransmisikan melalui nyamuk Aedes aegypti dan Aedes albopictus. Ada empat serotipe virus dengue yang telah dikenal secara luas yang ada semuanya dapat menimbulkan penyakit demam berdarah. Pemahaman tentang genomik virus dengue sangat penting untuk pengembangan penelitian dan juga untuk keperluan diagnostik. Genom virus dengue memiliki panjang 11 kilo basa. Genomnya tersusun atas 5’-untranslated region (5’-UTR), tiga gen struktural (mengodekan protein kapsid, premembran/membran dan amplop), tujuh gen non-struktural (mengodekan protein NS1, NS2A, NS2B, NS3, NS4A, NS4B dan NS5) dan 3’-UTR. Gen-gen non-struktural mengodekan protein untuk replikasi RNA virus, respon interferon, perakitan, sekresi partikel virus, menginduksi invaginasi membran retikulum endoplasma, induksi imunomediator dan penambahan tudung pada ujung 5’ RNA.Kata kunci: virus dengue, genom, gen struktural, gen non-struktural, untranslated region


2020 ◽  
Author(s):  
Karina Rossi da Silva ◽  
William Ribeiro da Silva ◽  
Bianca Piraccini Silva ◽  
Adriano Nobre Arcos ◽  
Francisco A. da Silva Ferreira ◽  
...  

AbstractThe control of arboviruses carried by Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) can be performed with tools that monitor and reduce the circulation of these vectors. Therefore, the efficiency of four types of traps in capturing A. aegypti and A. albopictus eggs and adults, with the biological product Vectobac WG®, was evaluated in the field. For this, 20 traps were installed in two locations, which were in the South (Londrina, Paraná) and North (Manaus, Amazonas) Regions of Brazil, from March to April 2017 and January to February 2018, respectively. The UELtrap-E and UELtrap-EA traps captured A. aegypti and A. albopictus eggs: 1703/1866 eggs in Londrina, and 10268/2149 eggs in Manaus, respectively, and presented high ovitraps positivity index (OPI) values (averages: 100%/100% in Londrina, and 100%/96% in Manaus, respectively); and high egg density index (EDI) values (averages: 68/75 in Londrina, and 411/89 in Manaus, respectively), so they had statistically superior efficiency to that of the CRtrap-E and CRtrap-EA traps in both regions, that captured less eggs and adults: 96/69 eggs in Londrina, and 1091/510 eggs in Manaus, respectively. Also presented lower OPI values (averages: 28%/4% in Londrina, and 88%/60% in Manaus, respectively); and lower EDI values (averages: 10.5/9 in Londrina, and 47/30 in Manaus, respectively). The capture ratios of Aedes adults in the UELtrap-EA and CRtrap-EA traps in Londrina and Manaus were 53.3%/29.5% and 0%/9.8%, respectively. UELtrap-E and UELtrap-EA can be adopted as efficient tools for Aedes monitoring due to their high sensitivity, low cost and ease of use.Author summaryAedes aegypti and Aedes albopictus are species of mosquitoes responsible for the transmission of several arboviruses that cause infections worldwide. However, there are still no effective and safe vaccines or medications to prevent or treat arboviruses transmitted by these vectors, except for yellow fever. Moreover, current methodologies for monitoring and controlling A. aegypti and A. albopictus are not fully effective, as evidenced by the increasing cases of the arbovirus transmitted by these mosquitoes or have incompatible costs with the socioeconomic conditions of a large number of people. Thus, the traps tested in this study can be used as more effective and economical tools for monitoring and controlling A. aegypti and A. albopictus, since they are made with low cost material and they showed high efficiency in the capture of eggs, evidenced by the high values of ovitraps positive index and eggs density index, besides that one of the models captured Aedes spp. adults in both regions where they were tested. Therefore, the traps have potential for reducing Aedes spp. eggs and adults in the environment and sensibility for determining the local infestation index, which can be reconciled with official government strategies for more accurate vector monitoring and control actions.


2021 ◽  
Author(s):  
Fawad Khalid Khan ◽  
Khurram Shahzad Akram ◽  
Ambreen Chaudhry ◽  
Mir Muhammad Hassan Bullo ◽  
zakir Hussain ◽  
...  

Background: In the second week of October 2019, five suspected cases of dengue fever were reported from union council Sohan, Islamabad rural (population 45,747) to the health department, Islamabad Capital Territory (ICT).  Outbreak investigation was conducted with the objectives to identify risk factors and to recommend control measures. Methods: Outbreak investigation was conducted from 17 th October to 25 th November 2019. A case was defined as, “fever and two or more of the following signs/symptoms; headache, retro-orbital pain, joint/bone pain, myalgia and petechial rash with NS1 test (Nonstructural Protein 1) positive during 8 th October to 25 th November 2019 among residents of Sohan”. Age and sex-matched controls were recruited from the same neighborhood. All cases were positive for NS1 antigen. Blood samples from five suspected cases were collected and tested for laboratory confirmation. Results:   A total of 547 households were surveyed and 85 cases were identified. The mean age was 34.4 years + 16.05 (range 3-71 years). The attack rate was 0.19% whereas the most affected age group was the 45-54 years (AR 0.43%). Males were predominantly affected (n=48 56.5%). Among all cases, 32% (n=27)) had stagnant water inside or around their houses (aOR 2.65, CI 1.20-5.83, P= 0.005), 33% (n=28) were using mosquito repellent (aOR 0.35, CI 0.17-0.70, P <0.001), 31% (n=26) used indoor residual spray insecticide (aOR 0.48, CI 0.24-0.97, P =0.041), and 73% (n=62) used full protective clothing (aOR 0.17, CI 0.05-0.58, P <0.001). All five blood samples were tested positive for NS-1 antigen. Conclusion: The presence of accumulated rainwater in pools and empty receptacles around houses acted as breeding grounds for Aedes aegypti mosquitos and was the most probable cause of this outbreak. Following our recommendations, the health department-initiated mosquito breeding sites control activities through residual insecticide spray and advocacy on the use of protective measures against mosquito bites.


2018 ◽  
Vol 5 (4) ◽  
pp. 167-174 ◽  
Author(s):  
Kalarikkal Venugopalan Lakshmi ◽  
Ambalaparambil Vasu Sudhikumar ◽  
Embalil Mathachan Aneesh

Since Aedes aegypti is considered as the major vector of dengue fever, development of strategies to accomplish improved vector control without much interference in the environment composition are more common. As phytochemicals are now in the run for achieving this goal, this review is a humble attempt to recognize the plant species and their larvicidal efficacy with their inhibitory action on the life cycle of the species of interest, that has been documented through various studies conducted till date. Here we also discuss the synergistic impact of a number of phytoextracts which will provide more efficient control measures for mosquito vectors. All these studies are an exploration for a risk-free vector control tactic to replace the current chemical insecticide application for the betterment of our nature.


2021 ◽  
Vol 05 (02) ◽  
pp. 52-61
Author(s):  
Thi Thanh Huong Le ◽  
◽  
Quynh Nguyen ◽  
Saenthavisouk Vanhnasack ◽  
Sinh Nam Vu

Objectives: The elimination of key breeding sites of dengue vector is applied worldwide to control the vector density under the critical epidemic threshold. This study aimed to identify key breeding sites of Aedes mosquitos and associated factors in Huaylau village, Pakse city, Champasack province in Laos in 2019. Methods: This was a cross-sectional study, combining of immature stage survey of Aedes mosquitoes in all water and discarded containers and the community’s knowledge and practices on the prevention of dengue fever in all 240 households in Huaylau village. Multivariate logistic regression was applied to identify factors associated with the absence of Aedes larvae and pupae in the village. Statistical significance was set at a p-value less than 0.05. Results: Among the 720 water and discarded containers surveyed, the study found 654 Aedes larvae and pupae; of which 94.6% were immature Aedes aegypti. Key breeding sites of Aedes aegypti included water jars (34.2%), plastic drums (30.7%), tanks < 500 litter (14.7%), and discarded containers (12.6%), while that of all Aedes albopictus was discarded containers. The community’s better practices on the prevention of dengue fever contributed to the increased odds of the absence of Aedes larvae ad pupae by 1.612 (95%CI: 1.218-2.134, p<0.01), and the cleanliness of the house were associated with the increased odds of 4.072 of the absent Aedes larvae and pupae in the participated households (95%CI: 1.589-10.434, p<0.01). Conclusions: Aedes aegypti mosquitoes in the Huaylau village laid their eggs in various breeding sites, including water containers and discarded containers while discarded containers were the only key breeding site of Aedes albopictus. Better practices on dengue prevention and better hygiene conditions of the houses contributed to the absence of Aedes larvae and pupae. Special attention should be paid to the clearance of all discarded containers and education of the community people to cover water containers in the village. Keywords: key breeding sites, Aedes, mosquito, pupae, larvae, Champasack province, Lao PDR


2015 ◽  
Vol 8 (7) ◽  
pp. 543-548 ◽  
Author(s):  
Pham Thi Kim Lien ◽  
Vu Trong Duoc ◽  
Laurent Gavotte ◽  
Emmanuel Cornillot ◽  
Phan Thi Nga ◽  
...  

2020 ◽  
Vol 28 (2) ◽  
pp. 801
Author(s):  
Paulo Roberto Gonçalves-Segundo

Abstract: This paper aims to discuss both a typology of articulation between verbal and pictorial modalities in the construal of metaphors and the potential pragmatic and rhetorical effects of the activation of multimodal metaphors in practical argumentation. To do so, we analyze six texts from governmental health campaigns in Brazil oriented towards the elimination of Aedes aegypti breeding grounds, the mosquito mainly responsible for the transmission of dengue fever, chikungunya and zika in the country. In terms of the expression of metaphorical vehicles and topics in each modality, we could identify, as a result, three main modes of articulation: autonomy, correlation and interdependence. For each mode, we showed some pragmatic and semantic effects, such as increasing metaphoricity, inducing reframing and refining referentiality. We frame this discussion by critically considering a series of different frameworks on metaphor studies, such as Lakoff and Johnson (1980), Forceville (2007), Müller (2008), Vereza (2007, 2017, 2018), Gonçalves-Segundo and Zelic (2016) and Steen (2017). In terms of argumentative roles, we concluded that multimodal metaphors were relevant in construing the Negative Consequences of inaction in regard to the elimination of breeding grounds, hyperbolizing the lethal potential of the infections; in inducing the reader’s readiness and tendency towards working collectively to achieve the campaign’s intended Goals; and, finally, in generating humor in the construal of the campaign’s Motivating Circumstances, in order to draw the reader’s attention and identification towards this necessary social action. To support this debate, we drew mainly on Fairclough and Fairclough (2012), Macagno and Walton (2019) and Gonçalves-Segundo (2019).Keywords: multimodal metaphor; multimodality; metaphor; argumentation; practical argumentation.Resumo: Nosso objetivo, neste artigo, é discutir tanto uma tipologia de articulação entre as modalidades verbal e imagética na construção de metáforas quanto os potenciais efeitos pragmáticos e retóricos da ativação de metáforas multimodais na argumentação prática. Para isso, analisamos seis textos de campanhas governamentais de saúde brasileiras orientadas à eliminação de focos de reprodução do mosquito Aedes aegypti, o principal responsável pela transmissão da dengue, da chikungunya e da zika no país. No que diz respeito à expressão de veículos e tópicos metafóricos em cada modalidade, identificamos, como resultado, três principais formas de articulação: autonomia, correlação e interdependência. Para cada uma dessas formas, mostramos alguns efeitos semântico-pragmáticos, como aumento de metaforicidade, indução de reenquadramento e refinamento de referencialidade. Tecemos essa discussão a partir de um diálogo crítico com diversas perspectivas, em especial Lakoff e Johnson (1980), Forceville (2007), Müller (2008), Vereza (2007, 2017, 2018), Gonçalves-Segundo e Zelic (2016) e Steen (2017). Em termos de funções argumentativas, concluímos que as metáforas multimodais foram relevantes na construção das Consequências Negativas da inação no tocante à eliminação dos focos de reprodução do mosquito, hiperbolizando o potencial letal das infeções; na indução de um estado de prontidão e de trabalho coletivo no sentido de atingir os Objetivos da campanha; e, finalmente, em gerar humor na construção das Circunstâncias Motivadoras da campanha, para obter a atenção e a identificação do leitor em relação a essa ação social necessária. Para enquadrar esse debate, valemo-nos especialmente de Fairclough e Fairclough (2012), Macagno e Walton (2019) e Gonçalves-Segundo (2019).Palavras-chave: metáfora multimodal; multimodalidade; metáfora; argumentação; argumentação prática.


2019 ◽  
Vol 2019 ◽  
pp. 1-2
Author(s):  
I. Ranathunga ◽  
L. S. Kannangara ◽  
K. A. S Bandara ◽  
S. B. Gunatilake

Dengue fever caused by dengue virus is a common tropical infection transmitted by the mosquitos Aedes aegypti and Aedes albopictus. Four strains of the genus flavivirus is responsible for the epidemics of varying severity. Hepatitis A caused by hepatitis A virus is spread by faecal-oral route. The culprit virus is a hepatovirus. Coinfection with dengue virus and hepatitis A virus is rare and is a diagnostic as well as management challenge to the medical professional. We report a patient who presented to us with dengue virus and hepatitis A virus coinfection.


2013 ◽  
Vol 8 (1) ◽  
pp. 255 ◽  
Author(s):  
Jennifer Duncombe ◽  
Fe Espino ◽  
Kristian Marollano ◽  
Aldwin Velazco ◽  
Scott A. Ritchie ◽  
...  

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