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Edillo F, Ymbong RR, Navarro AO, Cabahug MM, Saavedra K. Detecting the impacts of humidity, rainfall, temperature, and season on chikungunya, dengue and Zika viruses in Aedes albopictus mosquitoes from selected sites in Cebu city, Philippines. Virol J 2024; 21:42. [PMID: 38360693 PMCID: PMC10870450 DOI: 10.1186/s12985-024-02310-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 02/01/2024] [Indexed: 02/17/2024] Open
Abstract
BACKGROUND Aedes albopictus is the secondary vector for dengue virus (DENV) in the Philippines, and also harbors chikungunya (CHIKV) and Zika (ZIKV) viruses. This study aimed to determine the minimum infection rates (MIRs) of CHIKV, DENV serotypes, and ZIKV in Ae. albopictus collected from selected two-site categories by altitude (highland [H] and lowland [L] sites) in Cebu city, Philippines during the wet (WS) and dry seasons (DS) of 2021-2022, and to explore the relationships between these arboviral MIRs and the local weather. METHODS The viral RNA extracts in pooled and reared adult Ae. albopictus collected during the DS and WS from two-site categories were subjected to RT-PCR to amplify and detect gene loci specific for CHIKV, DENV-1 to DENV-4, and ZIKV and analyzed with the weather data. RESULTS The range of CHIKV MIRs was higher in the WS (13.61-107.38 infected individuals per 1,000 mosquitoes) than in the DS (13.22-44.12), but was similar between the two-site categories. Rainfall (RF) influenced the CHIKV MIR. The MIR ranges of both DENV-2 (WS: H = 0, L = 0; DS: H = 0-5.92; L = 0-2.6) and DENV-4 (WS: H = 0, L = 0-2.90; DS: H = 2.96-6.13, L = 0-15.63) differed by season but not between the two-site categories. Relative humidity (RH), RF, and temperature did not influence DENVs' MIRs. The MIR range of ZIKV was similar in both seasons (WS: 11.36-40.27; DS: 0-46.15) and two-site categories (H = 0-90.91, L = 0-55.56). RH and temperature influenced ZIKV MIR. CONCLUSIONS RF influenced CHIKV MIR in Ae. albopictus, whereas RH and temperature influenced that of ZIKV. Season influenced the MIRs of CHIKV and DENVs but not in ZIKV. Ae. albopictus were co-infected with CHIKV, DENVs, and ZIKV in both highland and lowland sites in Cebu city. Recommendations include all-year-round implementation of the Philippine Department of Health's 4S enhanced strategy and installation of water pipelines in rural highlands for vector and disease control. Our findings are relevant to protect public health in the tropics in this climate change.
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Affiliation(s)
- Frances Edillo
- Mosquito Research Laboratory, Department of Biology, University of San Carlos- Talamban Campus, 6000, Cebu city, Philippines.
| | - Rhoniel Ryan Ymbong
- Mosquito Research Laboratory, Department of Biology, University of San Carlos- Talamban Campus, 6000, Cebu city, Philippines
| | - Anthoddiemn Olin Navarro
- Mosquito Research Laboratory, Department of Biology, University of San Carlos- Talamban Campus, 6000, Cebu city, Philippines
- Department of Science and Technology, Science Education Institute, Taguig City, Metro Manila 1631, Philippines
| | - Maureen Mathilde Cabahug
- Mosquito Research Laboratory, Department of Biology, University of San Carlos- Talamban Campus, 6000, Cebu city, Philippines
| | - Kristilynn Saavedra
- Mosquito Research Laboratory, Department of Biology, University of San Carlos- Talamban Campus, 6000, Cebu city, Philippines
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Lu X, Bambrick H, Frentiu FD, Huang X, Davis C, Li Z, Yang W, Devine GJ, Hu W. Species-specific climate Suitable Conditions Index and dengue transmission in Guangdong, China. Parasit Vectors 2022; 15:342. [PMID: 36167577 PMCID: PMC9516795 DOI: 10.1186/s13071-022-05453-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 08/26/2022] [Indexed: 12/02/2022] Open
Abstract
Background Optimal climatic conditions for dengue vector mosquito species may play a significant role in dengue transmission. We previously developed a species-specific Suitable Conditions Index (SCI) for Aedes aegypti and Aedes albopictus, respectively. These SCIs rank geographic locations based on their climatic suitability for each of these two dengue vector species and theoretically define parameters for transmission probability. The aim of the study presented here was to use these SCIs together with socio-environmental factors to predict dengue outbreaks in the real world. Methods A negative binomial regression model was used to assess the relationship between vector species-specific SCI and autochthonous dengue cases after accounting for potential confounders in Guangdong, China. The potential interactive effect between the SCI for Ae. albopictus and the SCI for Ae. aegypti on dengue transmission was assessed. Results The SCI for Ae. aegypti was found to be positively associated with autochthonous dengue transmission (incidence rate ratio: 1.06, 95% confidence interval: 1.03, 1.09). A significant interaction effect between the SCI of Ae. albopictus and the SCI of Ae. aegypti was found, with the SCI of Ae. albopictus significantly reducing the effect of the SCI of Ae. aegypti on autochthonous dengue cases. The difference in SCIs had a positive effect on autochthonous dengue cases. Conclusions Our results suggest that dengue fever is more transmittable in regions with warmer weather conditions (high SCI for Ae. aegypti). The SCI of Ae. aegypti would be a useful index to predict dengue transmission in Guangdong, China, even in dengue epidemic regions with Ae. albopictus present. The results also support the benefit of the SCI for evaluating dengue outbreak risk in terms of vector sympatry and interactions in the absence of entomology data in future research. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05453-x.
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Affiliation(s)
- Xinting Lu
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Hilary Bambrick
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia.,National Centre for Epidemiology and Population Health, The Australian National University, Canberra ACT, Australia
| | - Francesca D Frentiu
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Xiaodong Huang
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Callan Davis
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Zhongjie Li
- Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning of Infectious Disease, Chinese Centre for Disease Control and Prevention, Beijing, China
| | - Weizhong Yang
- Division of Infectious Disease, Key Laboratory of Surveillance and Early Warning of Infectious Disease, Chinese Centre for Disease Control and Prevention, Beijing, China.,School of Population Medicine & Public Health, Chinese Academy of Medical Science, Peking Union Medical College, Beijing, China
| | - Gregor J Devine
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Wenbiao Hu
- School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia.
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Burkhalter KL, Savage HM. Laboratory Evaluation of the Rapid Analyte Measurement Platform Assay to Detect Dengue Virus in Mosquito Pools. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2021; 37:152-156. [PMID: 34407167 DOI: 10.2987/21-7013.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report the results of a laboratory sensitivity and specificity evaluation of the Rapid Analyte Measurement Platform (RAMP®) Dengue Virus (DENV) antigen detection assay, which is designed to detect all serotypes of DENV in mosquito pools. The RAMP DENV assay was able to detect geographically distinct strains of all 4 DENV serotypes in virus-spiked mosquito pools that contained at least 4.3 log10 plaque forming units/ml, although discrete sensitivity limits varied slightly for each serotype. The RAMP DENV assay also detected DENV 1-4 in mosquito pools containing a single infected mosquito and 24 laboratory-reared uninfected mosquitoes. No false positives were detected in negative control mosquito pools or in samples containing high titers of nontarget arboviruses. We found that while the kit-supplied RAMP buffer reduced the infectious titer of DENV, it did not completely inactivate all serotypes. We recommend adding a detergent, Triton X-100, to the buffer to ensure complete inactivation of DENV if the assay is to be conducted at a lower biosafety level than required for DENV handling.
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Affiliation(s)
- Kristen L Burkhalter
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Road, Fort Collins, CO 80521
| | - Harry M Savage
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, 3156 Rampart Road, Fort Collins, CO 80521
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4
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Balingit JC, Carvajal TM, Saito-Obata M, Gamboa M, Nicolasora AD, Sy AK, Oshitani H, Watanabe K. Surveillance of dengue virus in individual Aedes aegypti mosquitoes collected concurrently with suspected human cases in Tarlac City, Philippines. Parasit Vectors 2020; 13:594. [PMID: 33239063 PMCID: PMC7687837 DOI: 10.1186/s13071-020-04470-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 11/05/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Vector control measures are critical for the prevention and reduction of dengue virus (DENV) transmission. Effective vector control is reliant not only on knowledge of mosquito abundance, but also on the timely and accurate detection of mosquito-borne infection. Mosquito-based virus surveillance programs typically rely on pool-based mosquito testing, although whether individual-based mosquito testing is a feasible alternative to this has not been widely studied. Applying an individual-based mosquito testing approach, we conducted a 1-month surveillance study of DENV in adult Aedes aegypti mosquitoes in homes of suspected dengue patients during the 2015 peak dengue season in Tarlac City, Philippines to more accurately assess the mosquito infection rate and identify the DENV serotypes and genotypes concurrently co-circulating in mosquitoes and patients there. METHODS We performed a one-step multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for the simultaneous detection and serotyping of DENV in patients and individual female Ae. aegypti mosquitoes. Additionally, we performed sequencing and phylogenetic analyses to further characterize the detected DENV serotypes in mosquitoes and patients at the genotype level. RESULTS We collected a total of 583 adult Ae. aegypti mosquitoes, of which we individually tested 359 female mosquitoes for the presence of DENV. Ten (2.8%) of the 359 female mosquitoes were positive for the presence of DENV. We detected DENV-1, DENV-2, and DENV-4 in the field-collected mosquitoes, which was consistent with the serotypes concurrently found in infected patients. Sequencing and phylogenetic analyses of the detected DENV serotypes based on the partial sequence of the evelope (E) gene revealed three genotypes concurrently present in the sampled mosquitoes and patients during the study period, namely DENV-1 genotype IV, DENV-2 Cosmopolitan genotype, and DENV-4 genotype II. CONCLUSIONS We demonstrated the utility of a one-step multiplex real-time RT-PCR assay for the individual-based DENV surveillance of mosquitoes. Our findings reinforce the importance of detecting and monitoring virus activity in local mosquito populations, which are critical for dengue prevention and control.
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Affiliation(s)
- Jean Claude Balingit
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
| | - Thaddeus M. Carvajal
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Taft Avenue, Manila, Philippines
| | - Mariko Saito-Obata
- Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Miyagi Japan
- Tohoku-RITM Collaborative Research Center on Emerging and Reemerging Infectious Diseases, Muntinlupa, Metro Manila Philippines
| | - Maribet Gamboa
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
| | - Amalea Dulcene Nicolasora
- Molecular Biology Laboratory, Research Institute for Tropical Medicine, Muntinlupa, Metro Manila Philippines
| | - Ava Kristy Sy
- Virology Department, Research Institute for Tropical Medicine, Muntinlupa, Metro Manila Philippines
| | - Hitoshi Oshitani
- Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Miyagi Japan
| | - Kozo Watanabe
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime Japan
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime Japan
- Biological Control Research Unit, Center for Natural Science and Environmental Research, De La Salle University, Taft Avenue, Manila, Philippines
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Rahayu A, Saraswati U, Supriyati E, Kumalawati DA, Hermantara R, Rovik A, Daniwijaya EW, Fitriana I, Setyawan S, Ahmad RA, Wardana DS, Indriani C, Utarini A, Tantowijoyo W, Arguni E. Prevalence and Distribution of Dengue Virus in Aedes aegypti in Yogyakarta City before Deployment of Wolbachia Infected Aedes aegypti. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16101742. [PMID: 31100967 PMCID: PMC6571630 DOI: 10.3390/ijerph16101742] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/06/2019] [Accepted: 05/12/2019] [Indexed: 12/17/2022]
Abstract
Indonesia is one of the countries where dengue infection is prevalent. In this study we measure the prevalence and distribution of dengue virus (DENV) DENV-infected Aedes aegypti in Yogyakarta City, Indonesia, during the wet season when high dengue transmission period occurred, as baseline data before implementation of a Wolbachia-infected Aedes aegypti trial for dengue control. We applied One-Step Multiplex Real Time PCR (RT-PCR) for the type-specific-detection of dengue viruses in field-caught adult Aedes aegypti mosquitoes. In a prospective field study conducted from December 2015 to May 2016, adult female Aedes aegypti were caught from selected areas in Yogyakarta City, and then screened by using RT-PCR. During the survey period, 36 (0.12%) mosquitoes from amongst 29,252 female mosquitoes were positive for a DENV type. In total, 22.20% of dengue-positive mosquitoes were DENV-1, 25% were DENV-2, 17% were DENV-3, but none were positive for DENV-4. This study has provided dengue virus infection prevalence in field-caught Aedes aegypti and its circulating serotype in Yogyakarta City before deployment of Wolbachia-infected Aedes aegypti.
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Affiliation(s)
- Ayu Rahayu
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Utari Saraswati
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Endah Supriyati
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Dian Aruni Kumalawati
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Rio Hermantara
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Anwar Rovik
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Edwin Widyanto Daniwijaya
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Iva Fitriana
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Sigit Setyawan
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Riris Andono Ahmad
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Dwi Satria Wardana
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Citra Indriani
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Adi Utarini
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
- Department of Health Policy and Management, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Warsito Tantowijoyo
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
| | - Eggi Arguni
- Centre of Tropical Medicine, World Mosquito Program Yogyakarta, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
- Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.
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6
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Perez F, Llau A, Gutierrez G, Bezerra H, Coelho G, Ault S, Barbiratto SB, de Resende MC, Cerezo L, Kleber GL, Pacheco O, Perez OL, Picos V, Rojas DP, Siqueira JB, Suarez MF, Harris E, Castellanos LG, Espinal C, Martin JLS. The decline of dengue in the Americas in 2017: discussion of multiple hypotheses. Trop Med Int Health 2019; 24:442-453. [PMID: 30624838 PMCID: PMC6850595 DOI: 10.1111/tmi.13200] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Objective Since the 1980s, dengue incidence has increased 30‐fold. However, in 2017, there was a noticeable reduction in reported dengue incidence cases within the Americas, including severe and fatal cases. Understanding the mechanism underlying dengue's incidence and decline in the Americas is vital for public health planning. We aimed to provide plausible explanations for the decline in 2017. Methods An expert panel of representatives from scientific and academic institutions, Ministry of Health officials from Latin America and PAHO/WHO staff met in October 2017 to propose hypotheses. The meeting employed six moderated plenary discussions in which participants reviewed epidemiological evidence, suggested explanatory hypotheses, offered their expert opinions on each and developed a consensus. Results The expert group established that in 2017, there was a generalised decreased incidence, severity and number of deaths due to dengue in the Americas, accompanied by a reduction in reported cases of both Zika and chikungunya virus infections, with no change in distribution among age groups affected. This decline was determined to be unlikely due to changes in epidemiological surveillance systems, as similar designs of surveillance systems exist across the region. Although sudden surveillance disruption is possible at a country or regional level, it is unlikely to occur in all countries simultaneously. Retrospective modelling with epidemiological, immunological and entomological information is needed. Host or immunological factors may have influenced the decline in dengue cases at the population level through immunity; however, herd protection requires additional evidence. Uncertainty remains regarding the effect on the outcome of sequential infections of different dengue virus (DENV) types and Zika virus (ZIKV), and vice versa. Future studies were recommended that examine the epidemiological effect of prior DENV infection on Zika incidence and severity, the epidemiological effect of prior Zika virus infection on dengue incidence and severity, immune correlates based on new‐generation ELISA assays, and impact of prior DENV/other arbovirus infection on ZIKV immune response in relation to number of infections and the duration of antibodies in relation to interval of protection. Follow‐up studies should also investigate whether increased vector control intensification activities contributed to the decline in transmission of one or more of these arboviruses. Additionally, proposed studies should focus on the potential role of vector competence when simultaneously exposed to various arboviruses, and on entomological surveillance and its impact on circulating vector species, with a goal of applying specific measures that mitigate seasonal occurrence or outbreaks. Conclusions Multifactorial events may have accounted for the decline in dengue seen in 2017. Differing elements might explain the reduction in dengue including elements of immunity, increased vector control, and even vector and\or viruses changes or adaptations. Most of the results of this expert consensus group meeting are hypothetical and based on limited evidence. Further studies are needed.
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Affiliation(s)
- Freddy Perez
- Communicable Diseases and Environmental Determinants of Health Department, PAHO, Washington, DC, USA
| | - Anthony Llau
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA
| | - Gamaliel Gutierrez
- Neglected, Tropical and Vector-borne Diseases, PAHO, Washington, DC, USA
| | - Haroldo Bezerra
- Neglected, Tropical and Vector-borne Diseases, PAHO, Washington, DC, USA
| | - Giovanini Coelho
- Neglected, Tropical and Vector-borne Diseases, PAHO, Washington, DC, USA
| | - Steven Ault
- Department of Epidemiology and Biostatistics, University of Maryland, College Park, MD, USA
| | | | | | - Lizbeth Cerezo
- National Epidemiology Department, Ministry of Health of Panama, Panama City, Panama
| | - Giovanni Luz Kleber
- Departamento de Infectologia, Universidade Federal do Rio Grande do Norte Hospital, Natal, Brazil
| | - Oscar Pacheco
- Public Health Prevention and Surveillance, Ministry of Health, Bogota, Colombia
| | | | - Victor Picos
- Research Laboratory of Dengue and other Viral Diseases, Ministry of Health, Maracay, Venezuela
| | - Diana P Rojas
- Department of Biostatistics, University of Florida, Gainesville, FL, USA
| | | | | | - Eva Harris
- Center for Global Public Health, University of California, Berkeley, CA, USA
| | | | - Carlos Espinal
- Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA
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7
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Lam-Phua SG, Yeo H, Lee RML, Chong CS, Png AB, Foo SY, Liew C, Ng LC, Tang CS, Rueda LM, Pecor JE, Harrison BA. Mosquitoes (Diptera: Culicidae) of Singapore: Updated Checklist and New Records. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:103-119. [PMID: 30169704 PMCID: PMC6324193 DOI: 10.1093/jme/tjy154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Indexed: 05/16/2023]
Abstract
Prior to 1965, Singapore was part of the Malaya (now Malaysia) and was usually not mentioned when mosquito records were reported for Malaya. Consequently, many species that occurred in Singapore were not listed in the world mosquito catalog, and the available checklist for Singapore since 1986 is incomplete, with some imprecise species information. In updating this checklist, we examined and verified mosquito specimens collected from Singapore in various depositories, including a thorough review of past taxonomic literature. Here, we report a checklist of 182 mosquito species, 33 new distribution records, and a consolidated status list of vectors for Singapore. As Singapore is a travel hub and hosts one of the busiest container ports in the world, there is a risk of introducing mosquito species and their associated pathogens of human disease to the country. Hence, the distribution records are important to increase our knowledge on mosquito ecology as well as to understand the risk of newly introduced vectors and their associated pathogens.
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Affiliation(s)
- Sai-Gek Lam-Phua
- Environmental Health Institute, National Environment Agency, Singapore
| | - Huiqing Yeo
- Environmental Health Institute, National Environment Agency, Singapore
| | - Ruth Mee-Lian Lee
- Environmental Health Institute, National Environment Agency, Singapore
| | - Chee-Seng Chong
- Environmental Health Institute, National Environment Agency, Singapore
| | - Ah-Bah Png
- Environmental Health Institute, National Environment Agency, Singapore
| | - Siew-Yoong Foo
- Environmental Health Institute, National Environment Agency, Singapore
| | - Christina Liew
- Environmental Health Institute, National Environment Agency, Singapore
| | - Lee-Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Choon-Siang Tang
- Environmental Public Health Operations, National Environment Agency, Singapore
| | - Leopoldo M Rueda
- Department of Entomology, Walter Reed Biosystematics Unit, Smithsonian Institution, Museum Support Center (MRC534), Suitland, MD
| | - James E Pecor
- Department of Entomology, Walter Reed Biosystematics Unit, Smithsonian Institution, Museum Support Center (MRC534), Suitland, MD
| | - Bruce A Harrison
- Department of Entomology, Walter Reed Biosystematics Unit, Smithsonian Institution, Museum Support Center (MRC534), Suitland, MD
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8
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Kobayashi D, Murota K, Fujita R, Itokawa K, Kotaki A, Moi ML, Ejiri H, Maekawa Y, Ogawa K, Tsuda Y, Sasaki T, Kobayashi M, Takasaki T, Isawa H, Sawabe K. Dengue Virus Infection in Aedes albopictus during the 2014 Autochthonous Dengue Outbreak in Tokyo Metropolis, Japan. Am J Trop Med Hyg 2018; 98:1460-1468. [PMID: 29557338 DOI: 10.4269/ajtmh.17-0954] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In 2014 in Japan, 162 autochthonous dengue cases were reported for the first time in nearly 70 years. Here, we report the results of the detection and isolation of dengue virus (DENV) from mosquitoes collected in Tokyo Metropolis in 2014 and 2015. The phylogenetic relationship among DENV isolates from mosquitoes and from patients based on both the entire envelope gene and whole coding sequences was evaluated. Herein, 2,298 female and 956 male Aedes albopictus mosquitoes were collected at six suspected locations of DENV infection in Tokyo Metropolis from August to October in 2014 and grouped into 124 and 35 pools, respectively, for viral genome detection and DENV isolation. Dengue virus RNA was detected using reverse transcription polymerase chain reaction and TaqMan assays from 49 female pools; 16 isolates were obtained using C6/36 and Vero cells. High minimum infection rates (11.2-66.7) persisted until mid-September. All DENV isolates belonged to the genotype I in serotype 1 (DENV-1), and its sequences demonstrated > 99% homology to the sequence of the DENV isolated from a patient in the vicinity of Tokyo Metropolis in 2014. Therefore, Ae. albopictus was a major DENV vector, and a single DENV-1 strain circulated in Tokyo Metropolis in 2014. Dengue virus was not detected from male mosquitoes in 2014 and wild larvae in April 2015. Thus, the possibility of both vertical transmission and overwintering of DENV was extremely low, even in dengue-epidemic areas. This study reports the first entomological information on a dengue outbreak in a temperate region, where no Aedes aegypti mosquitoes are distributed.
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Affiliation(s)
- Daisuke Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan.,Department of Environmental Parasitology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Katsunori Murota
- Department of Research Promotion, Japan Agency for Medical Research and Development, Tokyo, Japan.,Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ryosuke Fujita
- Isotope Imaging Laboratory, Creative Research Institution, Hokkaido University, Hokkaido, Japan.,Department of Research Promotion, Japan Agency for Medical Research and Development, Tokyo, Japan.,Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kentaro Itokawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Akira Kotaki
- Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Meng Ling Moi
- Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.,Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hiroko Ejiri
- Division of Infectious Diseases Epidemiology and Control, National Defense Medical Research Institute, National Defense Medical College, Saitama, Japan.,Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yoshihide Maekawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kohei Ogawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yoshio Tsuda
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Toshinori Sasaki
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Mutsuo Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tomohiko Takasaki
- Kanagawa Prefectural Institute of Public Health, Kanagawa, Japan.,Department of Virology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Haruhiko Isawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kyoko Sawabe
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Department of Medical Entomology, National Institute of Infectious Diseases, Tokyo, Japan
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9
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Seidahmed OME, Lu D, Chong CS, Ng LC, Eltahir EAB. Patterns of Urban Housing Shape Dengue Distribution in Singapore at Neighborhood and Country Scales. GEOHEALTH 2018; 2:54-67. [PMID: 32159000 PMCID: PMC7007139 DOI: 10.1002/2017gh000080] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 11/15/2017] [Accepted: 12/15/2017] [Indexed: 05/07/2023]
Abstract
Dengue is the most important human arboviral disease in Singapore. We classified residential areas into low-rise and high-rise housing and investigated the influence of urban drainage on the distribution of dengue incidence and outdoor breeding at neighborhood and country scales. In Geylang area (August 2014 to August 2015), dengue incidence was higher in a subarea of low-rise housing compared to high-rise one, averaging 26.7 (standard error, SE = 4.83) versus 2.43 (SE = 0.67) per 1,000 people. Outdoor breeding drains of Aedes aegypti have clustered in the low-rise housing subarea. The pupal density per population was higher in the low-rise blocks versus high-rise ones, 246 (SE = 69.08) and 35.4 (SE = 25.49) per 1,000 people, respectively. The density of urban drainage network in the low-rise blocks is double that in the high-rise ones, averaging 0.05 (SE = 0.0032) versus 0.025 (SE = 0.00245) per meter. Further, a holistic analysis at a country-scale has confirmed the role of urban hydrology in shaping dengue distribution in Singapore. Dengue incidence (2013-2015) is proportional to the fractions of the area (or population) of low-rise housing. The drainage density in low-rise housing is 4 times that corresponding estimate in high-rise areas, 2.59 and 0.68 per meter, respectively. Public housing in agglomerations of high-rise buildings could have a positive impact on dengue if this urban planning comes at the expense of low-rise housing. City planners in endemic regions should consider the density of drainage networks for both the prevention of flooding and the breeding of mosquitoes.
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Affiliation(s)
| | - Deng Lu
- Environmental Health InstituteNational Environment AgencySingapore
| | - Chee Seng Chong
- Environmental Health InstituteNational Environment AgencySingapore
| | - Lee Ching Ng
- Environmental Health InstituteNational Environment AgencySingapore
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10
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Mier-y-Teran-Romero L, Tatem AJ, Johansson MA. Mosquitoes on a plane: Disinsection will not stop the spread of vector-borne pathogens, a simulation study. PLoS Negl Trop Dis 2017; 11:e0005683. [PMID: 28672006 PMCID: PMC5510898 DOI: 10.1371/journal.pntd.0005683] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/14/2017] [Accepted: 06/07/2017] [Indexed: 11/19/2022] Open
Abstract
Mosquito-borne diseases are increasingly being recognized as global threats, with increased air travel accelerating their occurrence in travelers and their spread to new locations. Since the early days of aviation, concern over the possible transportation of infected mosquitoes has led to recommendations to disinsect aircraft. Despite rare reports of mosquitoes, most likely transported on aircraft, infecting people far from endemics areas, it is unclear how important the role of incidentally transported mosquitoes is compared to the role of traveling humans. We used data for Plasmodium falciparum and dengue viruses to estimate the probability of introduction of these pathogens by mosquitoes and by humans via aircraft under ideal conditions. The probability of introduction of either pathogen by mosquitoes is low due to few mosquitoes being found on aircraft, low infection prevalence among mosquitoes, and high mortality. Even without disinsection, introduction via infected human travelers was far more likely than introduction by infected mosquitoes; more than 1000 times more likely for P. falciparum and more than 200 times more likely for dengue viruses. Even in the absence of disinsection and under the most favorable conditions, introduction of mosquito-borne pathogens via air travel is far more likely to occur as a result of an infected human travelling rather than the incidental transportation of infected mosquitoes. Thus, while disinsection may serve a role in preventing the spread of vector species and other invasive insects, it is unlikely to impact the spread of mosquito-borne pathogens.
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Affiliation(s)
- Luis Mier-y-Teran-Romero
- Dengue Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, San Juan, PR
| | - Andrew J. Tatem
- WorldPop, Department of Geography and Environment, University of Southampton, Southampton, United Kingdom
- Flowminder Foundation, Stockholm, Sweden
| | - Michael A. Johansson
- Dengue Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, San Juan, PR
- Center for Communicable Disease Dynamics, Harvard TH Chan School of Public Health, Boston, Massachusetts
- * E-mail:
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11
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Tsai PJ, Teng HJ. Role of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in local dengue epidemics in Taiwan. BMC Infect Dis 2016; 16:662. [PMID: 27829399 PMCID: PMC5103501 DOI: 10.1186/s12879-016-2002-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 10/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aedes mosquitoes in Taiwan mainly comprise Aedes albopictus and Ae. aegypti. However, the species contributing to autochthonous dengue spread and the extent at which it occurs remain unclear. Thus, in this study, we spatially analyzed real data to determine spatial features related to local dengue incidence and mosquito density, particularly that of Ae. albopictus and Ae. aegypti. METHODS We used bivariate Moran's I statistic and geographically weighted regression (GWR) spatial methods to analyze the globally spatial dependence and locally regressed relationship between (1) imported dengue incidences and Breteau indices (BIs) of Ae. albopictus, (2) imported dengue incidences and BI of Ae. aegypti, (3) autochthonous dengue incidences and BI of Ae. albopictus, (4) autochthonous dengue incidences and BI of Ae. aegypti, (5) all dengue incidences and BI of Ae. albopictus, (6) all dengue incidences and BI of Ae. aegypti, (7) BI of Ae. albopictus and human population density, and (8) BI of Ae. aegypti and human population density in 348 townships in Taiwan. RESULTS In the GWR models, regression coefficients of spatially regressed relationships between the incidence of autochthonous dengue and vector density of Ae. aegypti were significant and positive in most townships in Taiwan. However, Ae. albopictus had significant but negative regression coefficients in clusters of dengue epidemics. In the global bivariate Moran's index, spatial dependence between the incidence of autochthonous dengue and vector density of Ae. aegypti was significant and exhibited positive correlation in Taiwan (bivariate Moran's index = 0.51). However, Ae. albopictus exhibited positively significant but low correlation (bivariate Moran's index = 0.06). Similar results were observed in the two spatial methods between all dengue incidences and Aedes mosquitoes (Ae. aegypti and Ae. albopictus). The regression coefficients of spatially regressed relationships between imported dengue cases and Aedes mosquitoes (Ae. aegypti and Ae. albopictus) were significant in 348 townships in Taiwan. The results indicated that local Aedes mosquitoes do not contribute to the dengue incidence of imported cases. The density of Ae. aegypti positively correlated with the density of human population. By contrast, the density of Ae. albopictus negatively correlated with the density of human population in the areas of southern Taiwan. The results indicated that Ae. aegypti has more opportunities for human-mosquito contact in dengue endemic areas in southern Taiwan. CONCLUSIONS Ae. aegypti, but not Ae. albopictus, and human population density in southern Taiwan are closely associated with an increased risk of autochthonous dengue incidence.
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Affiliation(s)
- Pui-Jen Tsai
- Center for General Education, Aletheia University, New Taipei City, 25103, Taiwan, ROC.
| | - Hwa-Jen Teng
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Taipei, Taiwan, ROC
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12
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Ansori A, Sucipto T, Deka P, Ahwanah N, Churrotin S, Kotaki T, Soegijanto S. Differences of Universal and Multiplex Primer for Detection of Dengue Virus from Patients Suspected Dengue Hemorrhagic Fever (DHF) in Surabaya. INDONESIAN JOURNAL OF TROPICAL AND INFECTIOUS DISEASE 2015. [DOI: 10.20473/ijtid.v5i6.594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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13
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Olson KE, Blair CD. Arbovirus-mosquito interactions: RNAi pathway. Curr Opin Virol 2015; 15:119-26. [PMID: 26629932 DOI: 10.1016/j.coviro.2015.10.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Revised: 10/01/2015] [Accepted: 10/04/2015] [Indexed: 10/22/2022]
Abstract
Arthropod-borne (arbo) viruses infect hematophagous arthropods (vectors) to maintain virus transmission between vertebrate hosts. The mosquito vector actively controls arbovirus infection to minimize its fitness costs. The RNA interference (RNAi) pathway is the major antiviral response vectors use to restrict arbovirus infections. We know this because depleting RNAi gene products profoundly impacts arbovirus replication, the antiviral RNAi pathway genes undergo positive, diversifying selection and arboviruses have evolved strategies to evade the vector's RNAi responses. The vector's RNAi defense and arbovirus countermeasures lead to an arms race that prevents potential virus-induced fitness costs yet maintains arbovirus infections needed for transmission. This review will discuss the latest findings in RNAi-arbovirus interactions in the model insect (Drosophila melanogaster) and in specific mosquito vectors.
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Affiliation(s)
- Ken E Olson
- Arthropod-borne and Infectious Diseases Laboratory, Mail Delivery 1692, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
| | - Carol D Blair
- Arthropod-borne and Infectious Diseases Laboratory, Mail Delivery 1692, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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14
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Lau SM, Vythilingam I, Doss JI, Sekaran SD, Chua TH, Wan Sulaiman WY, Chinna K, Lim YAL, Venugopalan B. Surveillance of adult Aedes mosquitoes in Selangor, Malaysia. Trop Med Int Health 2015; 20:1271-80. [PMID: 26094839 DOI: 10.1111/tmi.12555] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the effectiveness of using sticky traps and the NS1 dengue antigen kit for the surveillance of Aedes mosquitoes for dengue control. METHODS Apartments were selected in a dengue-endemic area, and sticky traps were set to capture adult Aedes mosquitoes. NS1 dengue antigen kit was used to detect dengue antigen in mosquitoes, and positive mosquitoes were serotyped using real-time RT-PCR. RESULTS The sticky traps were effective in capturing Aedes aegypti, and a minimum of three traps per floor was sufficient. Multiple serotypes were found in individual mosquitoes. CONCLUSION The sticky trap and the NS1 dengue antigen test kit can be used as surveillance tool in dengue control programmes. This proactive method will be better suited for control programmes than current reactive methods.
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Affiliation(s)
- Sai-Ming Lau
- State Vector Borne Disease Control Unit, Selangor State Health Department, Selangor, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Jonathan Inbaraj Doss
- Julius Centre, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Shamala Devi Sekaran
- Department of Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Tock H Chua
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, University of Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Wan Yusof Wan Sulaiman
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Karuthan Chinna
- Julius Centre, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yvonne Ai-Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Balan Venugopalan
- State Vector Borne Disease Control Unit, Selangor State Health Department, Selangor, Malaysia
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15
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Harrington LC, Fleisher A, Ruiz-Moreno D, Vermeylen F, Wa CV, Poulson RL, Edman JD, Clark JM, Jones JW, Kitthawee S, Scott TW. Heterogeneous feeding patterns of the dengue vector, Aedes aegypti, on individual human hosts in rural Thailand. PLoS Negl Trop Dis 2014; 8:e3048. [PMID: 25102306 PMCID: PMC4125296 DOI: 10.1371/journal.pntd.0003048] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 06/13/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mosquito biting frequency and how bites are distributed among different people can have significant epidemiologic effects. An improved understanding of mosquito vector-human interactions would refine knowledge of the entomological processes supporting pathogen transmission and could reveal targets for minimizing risk and breaking pathogen transmission cycles. METHODOLOGY AND PRINCIPAL FINDINGS We used human DNA blood meal profiling of the dengue virus (DENV) vector, Aedes aegypti, to quantify its contact with human hosts and to infer epidemiologic implications of its blood feeding behavior. We determined the number of different people bitten, biting frequency by host age, size, mosquito age, and the number of times each person was bitten. Of 3,677 engorged mosquitoes collected and 1,186 complete DNA profiles, only 420 meals matched people from the study area, indicating that Ae. aegypti feed on people moving transiently through communities to conduct daily business. 10-13% of engorged mosquitoes fed on more than one person. No biting rate differences were detected between high- and low-dengue transmission seasons. We estimate that 43-46% of engorged mosquitoes bit more than one person within each gonotrophic cycle. Most multiple meals were from residents of the mosquito collection house or neighbors. People ≤ 25 years old were bitten less often than older people. Some hosts were fed on frequently, with three hosts bitten nine times. Interaction networks for mosquitoes and humans revealed biologically significant blood feeding hotspots, including community marketplaces. CONCLUSION AND SIGNIFICANCE High multiple-feeding rates and feeding on community visitors are likely important features in the efficient transmission and rapid spread of DENV. These results help explain why reducing vector populations alone is difficult for dengue prevention and support the argument for additional studies of mosquito feeding behavior, which when integrated with a greater understanding of human behavior will refine estimates of risk and strategies for dengue control.
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Affiliation(s)
- Laura C. Harrington
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Andrew Fleisher
- Department of Entomology, University of California, Davis, Davis, California, United States of America
| | - Diego Ruiz-Moreno
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Francoise Vermeylen
- Cornell Statistical Consulting Unit, Cornell University, Ithaca, New York, United States of America
| | - Chrystal V. Wa
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Rebecca L. Poulson
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - John D. Edman
- Department of Entomology, University of California, Davis, Davis, California, United States of America
| | - John M. Clark
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - James W. Jones
- Department of Enteric Diseases, USAMC-AFRIMS, Bangkok, Thailand
| | - Sangvorn Kitthawee
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Thomas W. Scott
- Department of Entomology, University of California, Davis, Davis, California, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
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16
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Yang CF, Hou JN, Chen TH, Chen WJ. Discriminable roles of Aedes aegypti and Aedes albopictus in establishment of dengue outbreaks in Taiwan. Acta Trop 2014; 130:17-23. [PMID: 24161880 DOI: 10.1016/j.actatropica.2013.10.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/10/2013] [Accepted: 10/12/2013] [Indexed: 10/26/2022]
Abstract
Aedes aegypti and Aedes albopictus were reported to be significant as vectors of dengue fever. In Taiwan, the latter is distributed throughout the island while the former appears only south of the Tropic of Cancer; i.e., 23.5°N. In the past decade, there were five outbreaks with over 1000 cases of dengue fever in Taiwan. Without exception, these outbreaks all occurred in the south where the two Aedes mosquitoes are sympartic. According to the Center for Disease Control of Taiwan, imported cases are thought to provide the seeds of dengue outbreaks every year. Mostly, the number of imported cases is greater in northern island, probably due to a larger population of travelers and imported workers from endemic countries. Looking at the example in 2002, northern, central, and southern parts of Taiwan reported 28, 11, and 13 imported cases, respectively. However, 54, 21, and 5309 total cases were confirmed in the corresponding regions over the entire year, indicating a significant skew of case distributions. A hypothesis is thus inspired that the existence of Ae. aegypti is a prerequisite to initiate a dengue outbreak, while participation of Ae. albopictus expands or maintains the scale until the de novo herd immunity reaches high level.
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17
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Vu HH, Okumura J, Hashizume M, Tran DN, Yamamoto T. Regional differences in the growing incidence of dengue Fever in Vietnam explained by weather variability. Trop Med Health 2013; 42:25-33. [PMID: 24808744 PMCID: PMC3965842 DOI: 10.2149/tmh.2013-24] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 10/08/2013] [Indexed: 11/15/2022] Open
Abstract
Dengue fever is a major health problem in Vietnam, but its incidence differs from province to province. To understand this at the local level, we assessed the effect of four weather components (humidity, rainfall, temperature and sunshine) on the number of dengue cases in nine provinces of Vietnam. Monthly data from 1999 to 2009 were analysed by time-series regression using negative binomial models. A test for heterogeneity was applied to assess the weather-dengue association in the provinces. Those associations were significantly heterogeneous (for temperature, humidity, and sunshine: P < 0.001 heterogeneity test; for rainfall: P = 0.018 heterogeneity test). This confirms that weather components strongly affect dengue transmission at a lag time of 0 to 3 months, with considerable variation in their influence among different areas in Vietnam. This finding may promote the strategic prevention of dengue disease by suggesting specific plans at the local level, rather than a nationally unified approach.
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Affiliation(s)
- Ha Hai Vu
- National Institute of Hygiene and Epidemiology, 1-Yecxanh, Hai Ba Trung, Ha Noi 112800, Vietnam ; Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan ; Department of International Health, Graduate School of Biomedical Science, Nagasaki University, Nagasaki, Japan
| | - Junko Okumura
- National Institute of Hygiene and Epidemiology, 1-Yecxanh, Hai Ba Trung, Ha Noi 112800, Vietnam
| | - Masahiro Hashizume
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan
| | - Duong Nhu Tran
- National Institute of Hygiene and Epidemiology, 1-Yecxanh, Hai Ba Trung, Ha Noi 112800, Vietnam
| | - Taro Yamamoto
- Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan ; Department of International Health, Graduate School of Biomedical Science, Nagasaki University, Nagasaki, Japan
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18
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Bernhardt SA, Simmons MP, Olson KE, Beaty BJ, Blair CD, Black WC. Rapid intraspecific evolution of miRNA and siRNA genes in the mosquito Aedes aegypti. PLoS One 2012; 7:e44198. [PMID: 23028502 PMCID: PMC3448618 DOI: 10.1371/journal.pone.0044198] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/30/2012] [Indexed: 12/23/2022] Open
Abstract
RNA silencing, or RNA interference (RNAi) in metazoans mediates development, reduces viral infection and limits transposon mobility. RNA silencing involves 21-30 nucleotide RNAs classified into microRNA (miRNA), exogenous and endogenous small interfering RNAs (siRNA), and Piwi-interacting RNA (piRNA). Knock-out, silencing and mutagenesis of genes in the exogenous siRNA (exo-siRNA) regulatory network demonstrate the importance of this RNAi pathway in antiviral immunity in Drosophila and mosquitoes. In Drosophila, genes encoding components for processing exo-siRNAs are among the fastest evolving 3% of all genes, suggesting that infection with pathogenic RNA viruses may drive diversifying selection in their host. In contrast, paralogous miRNA pathway genes do not evolve more rapidly than the genome average. Silencing of exo-siRNA pathway genes in mosquitoes orally infected with arboviruses leads to increased viral replication, but little is known about the comparative patterns of molecular evolution among the exo-siRNA and miRNA pathways genes in mosquitoes. We generated nearly complete sequences of all exons of major miRNA and siRNA pathway genes dicer-1 and dicer-2, argonaute-1 and argonaute-2, and r3d1 and r2d2 in 104 Aedes aegypti mosquitoes collected from six distinct geographic populations and analyzed their genetic diversity. The ratio of replacement to silent amino acid substitutions was 1.4 fold higher in dicer-2 than in dicer-1, 27.4 fold higher in argonaute-2 than in argonaute-1 and similar in r2d2 and r3d1. Positive selection was supported in 32% of non-synonymous sites in dicer-1, in 47% of sites in dicer-2, in 30% of sites in argonaute-1, in all sites in argonaute-2, in 22% of sites in r3d1 and in 55% of sites in r2d2. Unlike Drosophila, in Ae. aegypti, both exo-siRNA and miRNA pathway genes appear to be undergoing rapid, positive, diversifying selection. Furthermore, refractoriness of mosquitoes to infection with dengue virus was significantly positively correlated for nucleotide diversity indices in dicer-2.
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Affiliation(s)
- Scott A Bernhardt
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
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García-Rejón JE, Loroño-Pino MA, Farfán-Ale JA, Flores-Flores LF, López-Uribe MP, Najera-Vazquez MDR, Nuñez-Ayala G, Beaty BJ, Eisen L. Mosquito infestation and dengue virus infection in Aedes aegypti females in schools in Merida, Mexico. Am J Trop Med Hyg 2011; 84:489-96. [PMID: 21363990 DOI: 10.4269/ajtmh.2011.10-0654] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We determined abundance of Aedes aegypti mosquitoes and presence of dengue virus (DENV) in females collected from schools in Mérida, México, during 2008 and 2009. Backpack aspiration from 24 schools produced 468 females of Ae. aegypti and 1,676 females of another human biter, Culex quinquefasciatus. Ae. aegypti females were collected most commonly from classrooms followed by offices and bathrooms. Of these females, 24.7% were freshly fed. Examination of 118 pools of Ae. aegypti females (total of 415 females) for presence of DENV RNA produced 19 positive pools (16.1%). DENV-infected pools were detected from 11 (45.8%) of 24 schools and came from different room types, including classrooms, offices, and bathrooms. The overall rate of DENV infection per 100 Ae. aegypti females was 4.8. We conclude that schools in Mérida present a risk environment for students, teachers, and other personnel to be exposed to mosquitoes and bites of DENV-infected Ae. aegypti females.
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Affiliation(s)
- Julián E García-Rejón
- Laboratorio de Arbovirología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán, Centro, Mérida, Yucatán, México.
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Sutherland IW, Mori A, Montgomery J, Fleming KL, Anderson JM, Valenzuela JG, Severson DW, Black WC. A linkage map of the Asian tiger mosquito (Aedes albopictus) based on cDNA markers. J Hered 2010; 102:102-12. [PMID: 21148282 DOI: 10.1093/jhered/esq105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Asian tiger mosquito, Aedes (Stegomyia) albopictus (Skuse), is an important vector of a number of arboviruses, and populations exhibit extreme variation in adaptive traits such as egg diapause, cold hardiness, and autogeny (ability to mature a batch of eggs without blood feeding). The genetic basis of some of these traits has been established, but lack of a high-resolution linkage map has prevented in-depth genetic analyses of the genes underlying these complex traits. We report here on the breeding of 4 F(1) intercross mapping families and the use of these to locate 35 cDNA markers to the A. albopictus linkage map. The present study increases the number of markers on the A. albopictus cDNA linkage map from 38 to 73 and the density of markers from 1 marker/5.7 cM to 1 marker/2.9 cM and adds 9, 16, and 10 markers to the 3 linkage groups, respectively. The overall lengths of the 3 linkage groups are 64.5, 76.5, and 71.6 cM, respectively, for a combined length of 212.6 cM. Despite conservation in the order of most genes among the 4 families and a previous mapping family, we found substantial heterogeneity in the amount of recombination among markers. This was most marked in linkage group I, which varied between 16.7 and 69.3 cM. A map integrating the results from these 4 families with an earlier cDNA linkage map is presented.
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Affiliation(s)
- Ian W Sutherland
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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21
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Vanwambeke SO, Bennett SN, Kapan DD. Spatially disaggregated disease transmission risk: land cover, land use and risk of dengue transmission on the island of Oahu. Trop Med Int Health 2010; 16:174-85. [PMID: 21073638 DOI: 10.1111/j.1365-3156.2010.02671.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vector-borne diseases persist in transmission systems that usually comprise heterogeneously distributed vectors and hosts leading to a highly heterogeneous case distribution. In this study, we build on principles of classical mathematical epidemiology to investigate spatial heterogeneity of disease risk for vector-borne diseases. Land cover delineates habitat suitability for vectors, and land use determines the spatial distribution of humans. We focus on the risk of exposure for dengue transmission on the Hawaiian island of Oahu, where the vector Aedes albopictus is well established and areas of dense human population exist. In Hawai'i, dengue virus is generally absent, but occasionally flares up when introduced. It is therefore relevant to investigate risk, but difficult to do based on disease incidence data. Based on publicly available data (land cover, land use, census data, surveillance mosquito trapping), we map the spatial distribution of vectors and human hosts and finally overlay them to produce a vector-to-host ratio map. The resulting high-resolution maps indicate a high spatial variability in vector-to-host ratio suggesting that risk of exposure is spatially heterogeneous and varies according to land cover and land use.
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Affiliation(s)
- Sophie O Vanwambeke
- Georges Lemaître Centre for Earth and Climate Research, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
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Chen CF, Shu PY, Teng HJ, Su CL, Wu JW, Wang JH, Lin TH, Huang JH, Wu HS. Screening of dengue virus in field-caught Aedes aegypti and Aedes albopictus (Diptera: Culicidae) by one-step SYBR green-based reverse transcriptase-polymerase chain reaction assay during 2004-2007 in Southern Taiwan. Vector Borne Zoonotic Dis 2010; 10:1017-25. [PMID: 21128850 DOI: 10.1089/vbz.2008.0069] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We carried out virological surveillance of dengue virus (DENV) in field-caught Aedes mosquitoes during 2004-2007 to estimate the monthly prevalence of infected females in dengue high-risk areas of Taiwan. A total of 92,892 Aedes aegypti (43,133 females and 49,759 males) and 79,315 Aedes albopictus (57,319 females and 21,996 males) adults were collected, grouped into 25,654 pools, and processed for virus detection using a one-step SYBR Green-based real-time reverse transcriptase-polymerase chain reaction assay. DENVs were periodically and sympatrically detected in Ae. aegypti females in accordance with major dengue outbreaks and the corresponding dengue serotypes. Only 0.2% of 7628 pools of Ae. aegypti females were positive for DENVs. This resulted in an overall estimated infection rate (maximum likelihood estimation) of 0.970 per 1000 mosquitoes (95% confidence interval [CI] = 0.53-1.65). The total monthly infection rates ranged from 0.50 to 2.23 per 1000 mosquitoes (95% CI = 0.03-10.71). When sampling areas were scaled down to the city level, monthly infection rates increased to 0.73-12.59 (95% CI = 0.06-59.19). Monthly infection rates over all sampling areas and at the city level increased significantly by month. All positive pools were collected in July (one pool), August (two pools), September (one pool), October (three pools), November (four pools), and December (one pool). All four virus serotypes were detected in mosquitoes, which were consistent with dengue serotypes infecting humans in 2004 (DENV-4), 2005 and 2006 (DENV-2 and DENV-3), and 2007 (DENV-1). Our results provide supporting evidence that, in general, DENV infection rates were low in local Aedes mosquito population during 2004-2007 and that transovarial transmission may not be occurring or is occurring at much lower rates than evidenced in some endemic countries.
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Affiliation(s)
- Chien-Fu Chen
- Research and Diagnostic Center, Centers for Disease Control , Department of Health, Taipei, Taiwan
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Yang T, Lu L, Fu G, Zhong S, Ding G, Xu R, Zhu G, Shi N, Fan F, Liu Q. Epidemiology and vector efficiency during a dengue fever outbreak in Cixi, Zhejiang Province, China. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2009; 34:148-154. [PMID: 20836815 DOI: 10.1111/j.1948-7134.2009.00018.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An emigrant worker returning from Southeast Asia triggered the outbreak of a DF epidemic in Zhejiang province, China, in October, 2004. Eighty-three cases, mainly young and middle-aged people between 20 and 50 (78.3%), were reported in the area of Cixi. There were no obvious occupational patterns. The majority of cases were female, with a sex ratio of 1:1.86 (m:f). The dengue virus (DENV) strains from the epidemic area were isolated and identified as DENV-1, which belongs to Asian strain 1. According to the epidemiological investigation, the incidence of DF had no relationship to temperature, humidity, or precipitation, and the Breteau index of larvae showed a clear relationship only with the House Index and Container Index. Recent dengue problems in the town have been associated with the complex social factors and hygienic conditions for endemic villagers and immigrant workers. Some hygienic measures should be taken by the local government to reduce the risk of mosquito-borne disease. These measures should aim to eliminate the breeding sites of the vector Aedes albopictus in indoor and outdoor containers filled with rainwater and thus reducing the risk of DF transmission.
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Affiliation(s)
- Tianci Yang
- Institute of Vector Control, Zhejiang Center for Disease Control and Prevention, 630 Xincheng Road of Binjiang Area, Hangzhou, Zhejiang Province 310051, PR China
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24
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Cecílio AB, Campanelli ES, Souza KPR, Figueiredo LB, Resende MC. Natural vertical transmission by Stegomyia albopicta as dengue vector in Brazil. BRAZ J BIOL 2009; 69:123-7. [PMID: 19347154 DOI: 10.1590/s1519-69842009000100015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Accepted: 04/24/2007] [Indexed: 11/21/2022] Open
Abstract
The mosquito Stegomyia albopicta is among the most important arbovirus vectors in the world, particularly for Dengue viruses. Their natural history suggests that biologically these viruses are highly adapted to their mosquito hosts and they were most likely mosquito viruses prior to becoming adapted to lower primates and humans. As well as being maintained by transmission among susceptible humans, Dengue viruses may also be maintained by vertical transmission in mosquitoes during inter-epidemic periods. The larvae and mosquitoes of Stegomyia albopicta were used to identify the vertical transmission of the dengue virus in nature and to confirm the vectorial capacity concerning the Dengue virus type 2 infection. The minimum infection rate concerning S. albopicta infection with the Dengue virus was 1:36.45. In Brazil this was the first time that high minimum infection rates of vertical transmission of S. albopicta were detected in this species.
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Affiliation(s)
- A B Cecílio
- Molecular Microbiology and Virology Lab, Ezequiel Dias Foundation, Belo Horizonte, MG, Brazil.
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Pepin KM, Hanley KA. Density-dependent competitive suppression of sylvatic dengue virus by endemic dengue virus in cultured mosquito cells. Vector Borne Zoonotic Dis 2009; 8:821-8. [PMID: 18620509 DOI: 10.1089/vbz.2008.0016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Mosquito-borne dengue viruses are maintained in two discrete transmission cycles: a sylvatic cycle between nonhuman primates and sylvatic Aedes mosquitoes, and an endemic cycle between humans and peridomestic Aedes (primarily Ae. aegypti and Ae. albopictus). Most sylvatic strains are genetically distinct from endemic strains, and human infections with sylvatic strains have been detected only rarely. Interestingly, sylvatic strains replicate as well as endemic strains in Ae. aegypti and experimental models of replication in humans, suggesting that adaptive constraints may not explain the limited spillover of sylvatic strains into the endemic cycle. Within-host competition is another mechanism known to decrease emergence of strains into occupied niches. In the current study, we examined the magnitude of competitive suppression between sylvatic and endemic dengue strains of different serotypes in pair-wise mixed infections of cultured Ae. albopictus cells to test whether the ecotype or the initial ratio of the two strains influenced the outcome of competition. Strains isolated from nonhuman primates were competitively inferior to those isolated from humans. Moreover, competition was density-dependent; the magnitude of suppression increased as the starting density of a strain relative to its competitor decreased. These data suggest that competitive inferiority in endemic vectors coupled with a numerical disadvantage relative to resident endemic strains could restrict reemergence of sylvatic strains into the endemic cycle and contribute to the ecologically correlated genetic divergence between sylvatic and endemic strains.
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Affiliation(s)
- Kim M Pepin
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, USA.
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26
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Egger JR, Ooi EE, Kelly DW, Woolhouse ME, Davies CR, Coleman PG. Reconstructing historical changes in the force of infection of dengue fever in Singapore: implications for surveillance and control. Bull World Health Organ 2008; 86:187-96. [PMID: 18368205 DOI: 10.2471/blt.07.040170] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 04/02/2007] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To reconstruct the historical changes in force of dengue infection in Singapore, and to better understand the relationship between control of Aedes mosquitoes and incidence of classic dengue fever. METHODS Seroprevalence data were abstracted from surveys performed in Singapore from 1982 to 2002. These data were used to develop two mathematical models of age seroprevalence. In the first model, force of infection was allowed to vary independently each year, while in the second it was described by a polynomial function. Model-predicted temporal trends were analysed using linear regression. Time series techniques were employed to investigate periodicity in predicted forces of infection, dengue fever incidence and mosquito breeding. FINDINGS Force of infection estimates showed a significant downward trend from 1966, when vector control was instigated. Force of infection estimates from both models reproduced significant increases in the percentage and average age of the population susceptible to dengue infections. Importantly, the year-on-year model independently predicted a five to six year periodicity that was also displayed by clinical incidence but absent from the Aedes household index. CONCLUSION We propose that the rise in disease incidence was due in part to a vector-control-driven reduction in herd immunity in older age groups that are more susceptible to developing clinical dengue.
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Affiliation(s)
- Joseph R Egger
- Disease Control and Vector Biology Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, England.
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McAvin JC, Powers MD, Blow JA, Putnam JL, Huff WB, Swaby JA. Deployable, field-sustainable, reverse transcription-polymerase chain reaction assays for rapid screening and serotype identification of dengue virus in mosquitoes. Mil Med 2007; 172:329-34. [PMID: 17436782 PMCID: PMC7110365 DOI: 10.7205/milmed.172.3.329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Dengue virus universal and serotype 1 to 4 fluorogenic probe hydrolysis, reverse transcription (RT)-polymerase chain reaction (PCR) assays and positive-control RNA template were freeze-dried in a thermally stable, hydrolytic enzyme-resistant format and deployed for testing in a dengue fever-endemic region of Thailand. The study site presented austere testing conditions. Field-collected Aedes aegypti mosquitoes spiked with inoculated A. aegypti mosquitoes and individual and pooled, field-collected, A. aegypti, A. albopictus, and Culex tritaeniorhynchus mosquitoes were used for RT-PCR assay evaluations. For dengue virus-inoculated A. aegypti mosquitoes and spiked samples, in vitro sensitivity and specificity results for all five assays were concordant with indirect fluorescent antibody assay results. A single pool of field-collected, female, A. aegypti mosquitoes was identified as dengue virus positive. Cross-reactivity was not observed across heterologous serotypes, mosquito vectors, or human DNA. The limit of detection was >7 to ≤70 genomic equivalents. Sample processing and analysis required <2 hours. These results show promise of field-formatted RT-PCR reagents for rapid, sensitive, specific dengue virus screening and serotype identification in mosquitoes under field-deployed conditions.
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Affiliation(s)
- James C McAvin
- U.S. Air Force Institute for Operational Health, Brooks City-Base, San Antonio, TX 78235-5237, USA
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Pinheiro VCS, Tadei WP, Barros PMSS, Vasconcelos PFC, Cruz ACR. Detection of dengue virus serotype 3 by reverse transcription-polymerase chain reaction in Aedes aegypti (Diptera, Culicidae) captured in Manaus, Amazonas. Mem Inst Oswaldo Cruz 2005; 100:833-9. [PMID: 16444413 DOI: 10.1590/s0074-02762005000800003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The detection of dengue virus serotypes from Aedes aegypti in Manaus, state of Amazonas was carried out using the reverse transcription-polymerase chain reaction technique. Fourteen pools out 82 (17.1%) were positive for DENV3, providing a minimal infection rate of 2.1% of all analyzed infected female specimens of three different areas of the city.
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Affiliation(s)
- Valéria C S Pinheiro
- Laboratório de Malária e Dengue, Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, Brazil.
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Wagatsuma Y, Breiman RF, Hossain A, Rahman M. Dengue fever outbreak in a recreation club, Dhaka, Bangladesh. Emerg Infect Dis 2004; 10:747-50. [PMID: 15200876 PMCID: PMC3323095 DOI: 10.3201/eid1004.030330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An outbreak of dengue fever occurred among employees of a recreation club in Bangladesh. Occupational transmission was characterized by a 12% attack rate, no dengue among family contacts, and Aedes vectors in club areas. Early recognition of the outbreak likely limited its impact.
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Affiliation(s)
- Yukiko Wagatsuma
- ICDDR,B-Centre for Health and Population Research, Dhaka, Bangladesh
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