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Carreto C, Gutiérrez-Romero R, Rodríguez T. Climate-driven mosquito-borne viral suitability index: measuring risk transmission of dengue, chikungunya and Zika in Mexico. Int J Health Geogr 2022; 21:15. [PMID: 36303147 PMCID: PMC9610358 DOI: 10.1186/s12942-022-00317-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 10/04/2022] [Indexed: 11/30/2022] Open
Abstract
Background Climate variability influences the population dynamics of the Aedes aegypti mosquito that transmits the viruses that cause dengue, chikungunya and Zika. In recent years these diseases have grown considerably. Dengue is now the fastest-growing mosquito-transmitted disease worldwide, putting 40 per cent of the global population at risk. With no effective antiviral treatments or vaccines widely available, controlling mosquito population remains one of the most effective ways to prevent epidemics. This paper analyses the temporal and spatial dynamics of dengue in Mexico during 2000–2020 and that of chikungunya and Zika since they first appeared in the country in 2014 and 2015, respectively. This study aims to evaluate how seasonal climatological variability affects the potential risk of transmission of these mosquito-borne diseases. Mexico is among the world’s most endemic countries in terms of dengue. Given its high incidence of other mosquito-borne diseases and its size and wide range of climates, it is a good case study. Methods We estimate the recently proposed mosquito-borne viral suitability index P, which measures the transmission potential of mosquito-borne pathogens. This index mathematically models how humidity, temperature and precipitation affect the number of new infections generated by a single infected adult female mosquito in a host population. We estimate this suitability index across all Mexico, at small-area level, on a daily basis during 2000–2020. Results We find that the index P predicted risk transmission is strongly correlated with the areas and seasons with a high incidence of dengue within the country. This correlation is also high enough for chikungunya and Zika in Mexico. We also show the index P is sensitive to seasonal climatological variability, including extreme weather shocks. Conclusions The paper shows the dynamics of dengue, chikungunya and Zika in Mexico are strongly associated with seasonal climatological variability and the index P. This potential risk of transmission index, therefore, is a valuable tool for surveillance for mosquito-borne diseases, particularly in settings with varied climates and limited entomological capacity. Supplementary Information The online version contains supplementary material available at 10.1186/s12942-022-00317-0.
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Affiliation(s)
- Constantino Carreto
- El Colegio de México (COLMEX), Carretera Picacho-Ajusco 20, Tlalpan, 14110, Mexico City, Mexico.
| | - Roxana Gutiérrez-Romero
- Queen Mary University of London (QMUL), Mile End Campus, Bancroft Building, 4th Floor, London, E1 4NS, UK.
| | - Tania Rodríguez
- Institute of Geography, Universidad Nacional Autónoma de México (UNAM), Investigación Científica, Ciudad Universitaria, C.U., Coyoacán, 04510, Mexico City, Mexico.
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Salgado BB, de Jesus Maués FC, Pereira RL, Chiang JO, de Oliveira Freitas MN, Ferreira MS, Martins LC, da Costa Vasconcelos PF, Ganoza C, Lalwani P. Prevalence of arbovirus antibodies in young healthy adult population in Brazil. Parasit Vectors 2021; 14:403. [PMID: 34391467 PMCID: PMC8363865 DOI: 10.1186/s13071-021-04901-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/28/2021] [Indexed: 11/15/2022] Open
Abstract
Background The emergence and re-emergence of infectious diseases are a cause for worldwide concern. The introduction of Zika and Chikungunya diseases in the Americas has exposed unforeseen medical and logistical challenges for public health systems. Moreover, the lack of preventive measures and vaccination against known and emerging mosquito-transmitted pathogens, and the occurrence of unanticipated clinical complications, has had an enormous social and economic impact on the affected populations. In this study, we aimed to measure the seroprevalence of endemic and emerging viral pathogens in military personnel stationed in Manaus, Amazonas state. Methods We measured the seropositivity of antibodies against 19 endemic and emerging viruses in a healthy military personnel group using a hemagglutination inhibition assay (HIA). Results Overall, DENV positivity was 60.4%, and 30.9% of the individuals reacted against ZIKV. Also, 46.6%, 54.7%, 51.3% and 48.7% individuals reacted against West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Ilheus virus (ILHV) and Rocio virus (ROCV), respectively. Individuals with high DENV HIA titer reacted more frequently with ZIKV or WNV compared to those with low HIA titers. Observed cross-reactivity between Flaviviruses varied depending on the virus serogroup. Additionally, 0.6% and 0.3% individuals were seropositive for Oropouche virus (OROV) and Catu virus (CATUV) from the family Peribunyaviridae, respectively. All samples were negative for Eastern Equine Encephalitis virus (EEEV), Western Equine Encephalomyelitis virus (WEEV), Mayaro virus (MAYV), Mucambo virus (MUCV) and CHIKV from the family Togaviridae. Conclusions A high proportion of individuals in our high-risk population (~ 60%) lacked antibodies against major endemic and emerging viruses, which makes them susceptible for further infections. Military personnel serving in the Amazon region could serve as sentinels to strengthen global infectious disease surveillance, particularly in remote areas. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04901-4.
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Affiliation(s)
| | | | - Renato Lemos Pereira
- Instituto Leônidas e Maria Deane (ILMD), Fiocruz Amazônia, Manaus, Amazonas, Brazil.,Centro de Instrução de Guerra na Selva (CIGS), Manaus, Amazonas, Brazil
| | - Jannifer Oliveira Chiang
- Instituto Evandro Chagas (IEC), Seção de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | | | - Milene Silveira Ferreira
- Instituto Evandro Chagas (IEC), Seção de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | - Lívia Caricio Martins
- Instituto Evandro Chagas (IEC), Seção de Arbovirologia e Febres Hemorrágicas, Ananindeua, Pará, Brazil
| | | | - Christian Ganoza
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Pritesh Lalwani
- Instituto Leônidas e Maria Deane (ILMD), Fiocruz Amazônia, Manaus, Amazonas, Brazil.
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Ong J, Aik J, Ng LC. Short Report: Adult Aedes abundance and risk of dengue transmission. PLoS Negl Trop Dis 2021; 15:e0009475. [PMID: 34081695 PMCID: PMC8205144 DOI: 10.1371/journal.pntd.0009475] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 06/15/2021] [Accepted: 05/12/2021] [Indexed: 11/18/2022] Open
Abstract
Dengue is transmitted mainly by the adult female Aedes aegypti mosquito. However, little is known about the impact of adult Aedes abundance on the risk of dengue transmission. Here we analysed nationally representative dengue case and vector surveillance data collected from Singapore, to determine the effect of adult Aedes abundance on the risk of dengue transmission. A case was an area with active dengue transmission as indicated by the presence of dengue cluster. A control was an area where no dengue cluster was reported. Using multivariate logistic regression, we analysed 88 cases and 602 controls and estimated the odds of dengue cluster formation at various adult Aedes abundance levels, estimated by the mean number of adult female Aedes per Gravitrap per week and categorised into Low, Moderate, High and Very High abundance level. We found that the risk of dengue cluster formation was positively associated with adult Ae. aegypti abundance. We observed a three to four-fold increase in the odds of dengue clusters forming in areas with High (AOR: 3.40, 95% CI: 2.09, 5.52) and Very High (AOR: 3.99, 95% CI: 2.46, 6.46) adult Aedes aegypti abundance level compared to those with low Ae. aegypti abundance level. Our study strengthens the evidence for the use of adult Aedes indices for dengue risk assessment and early warning for dengue outbreaks. Entomological indicators of adult Ae. aegypti could be used to anticipate and prioritize areas for dengue control.
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Affiliation(s)
- Janet Ong
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Joel Aik
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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Marin-Lopez A, Jiang J, Wang Y, Cao Y, MacNeil T, Hastings AK, Fikrig E. Aedes aegypti SNAP and a calcium transporter ATPase influence dengue virus dissemination. PLoS Negl Trop Dis 2021; 15:e0009442. [PMID: 34115766 PMCID: PMC8195420 DOI: 10.1371/journal.pntd.0009442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/04/2021] [Indexed: 11/19/2022] Open
Abstract
Dengue virus (DENV) is a flavivirus that causes marked human morbidity and mortality worldwide, and is transmitted to humans by Aedes aegypti mosquitoes. Habitat expansion of Aedes, mainly due to climate change and increasing overlap between urban and wild habitats, places nearly half of the world's population at risk for DENV infection. After a bloodmeal from a DENV-infected host, the virus enters the mosquito midgut. Next, the virus migrates to, and replicates in, other tissues, like salivary glands. Successful viral transmission occurs when the infected mosquito takes another blood meal on a susceptible host and DENV is released from the salivary gland via saliva into the skin. During viral dissemination in the mosquito and transmission to a new mammalian host, DENV interacts with a variety of vector proteins, which are uniquely important during each phase of the viral cycle. Our study focuses on the interaction between DENV particles and protein components in the A. aegypti vector. We performed a mass spectrometry assay where we identified a set of A. aegypti salivary gland proteins which potentially interact with the DENV virion. Using dsRNA to silence gene expression, we analyzed the role of these proteins in viral infectivity. Two of these candidates, a synaptosomal-associated protein (AeSNAP) and a calcium transporter ATPase (ATPase) appear to play a role in viral replication both in vitro and in vivo, observing a ubiquitous expression of these proteins in the mosquito. These findings suggest that AeSNAP plays a protective role during DENV infection of mosquitoes and that ATPase protein is required for DENV during amplification within the vector.
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Affiliation(s)
- Alejandro Marin-Lopez
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Junjun Jiang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yuchen Wang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- State Key Laboratory of Virology, College of Life Science, Wuhan University, Wuhan, Hubei, China
| | - Yongguo Cao
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Clinical Veterinary Medicine, and Key Laboratory for Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Tyler MacNeil
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Andrew K. Hastings
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
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Boyce RM, Collins M, Muhindo R, Nakakande R, Ciccone EJ, Grounds S, Espinoza D, Zhu Y, Matte M, Ntaro M, Nyehangane D, Juliano JJ, Mulogo EM. Dengue in Western Uganda: a prospective cohort of children presenting with undifferentiated febrile illness. BMC Infect Dis 2020; 20:835. [PMID: 33176708 PMCID: PMC7661220 DOI: 10.1186/s12879-020-05568-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/30/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The spatial distribution and burden of dengue in sub-Saharan Africa remains highly uncertain, despite high levels of ecological suitability. The goal of this study was to describe the epidemiology of dengue among a cohort of febrile children presenting to outpatient facilities located in areas of western Uganda with differing levels of urbanicity and malaria transmission intensity. METHODS Eligible children were first screened for malaria using rapid diagnostic tests. Children with a negative malaria result were tested for dengue using a combination NS1/IgM/IgG rapid test (SD Bioline Dengue Duo). Confirmatory testing by RT-PCR was performed in a subset of participants. Antigen-capture ELISA was performed to estimate seroprevalence. RESULTS Only 6 of 1416 (0.42%) children had a positive dengue rapid test, while none of the RT-PCR results were positive. ELISA testing demonstrated reactive IgG antibodies in 28 (2.2%) participants with the highest prevalence seen at the urban site in Mbarara (19 of 392, 4.9%, p < 0.001). CONCLUSIONS Overall, these findings suggest that dengue, while present, is an uncommon cause of non-malarial, pediatric febrile illness in western Uganda. Further investigation into the eocological factors that sustain low-level transmission in urban settings are urgently needed to reduce the risk of epidemics.
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Affiliation(s)
- Ross M Boyce
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA. .,Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda.
| | - Matthew Collins
- Division of Infectious Diseases, Emory University, Atlanta, GA, 30322, USA
| | - Rabbison Muhindo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Regina Nakakande
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Emily J Ciccone
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Samantha Grounds
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA.,College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Daniel Espinoza
- Division of Infectious Diseases, Emory University, Atlanta, GA, 30322, USA
| | - Yerun Zhu
- Division of Infectious Diseases, Emory University, Atlanta, GA, 30322, USA
| | - Michael Matte
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Moses Ntaro
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
| | - Dan Nyehangane
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda.,Epicentre Mbarara Research Centre, Mbarara, Uganda
| | - Jonathan J Juliano
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Edgar M Mulogo
- Department of Community Health, Faculty of Medicine, Mbarara University of Science & Technology, Mbarara, Uganda
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Woon YL, Hor CP, Lee KY, Mohd Anuar SFZ, Mudin RN, Sheikh Ahmad MK, Komari S, Amin F, Jamal R, Chen WS, Goh PP, Yeap L, Lim ZR, Lim TO. Estimating dengue incidence and hospitalization in Malaysia, 2001 to 2013. BMC Public Health 2018; 18:946. [PMID: 30068318 PMCID: PMC6090758 DOI: 10.1186/s12889-018-5849-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 07/13/2018] [Indexed: 01/09/2023] Open
Abstract
Background Epidemiologic measures of the dengue burden such as prevalence and incidence are important for policy-making and monitoring the progress of disease control. It is a common practice where epidemiologic and economic research estimate dengue burden based on notification data. However, a basic challenge in estimating the incidence of dengue is that a significant proportion of infected population are asymptomatic. It can be overcome by using mathematical models that relate observed prevalence and mortality to incidence. In this study, we estimate the trend of dengue incidence and hospitalization in Malaysia. Methods This study is based entirely on the available secondary data sources on dengue in Malaysia. The age-specific incidence of dengue between 2001 and 2013 was estimated using the prevalence and mortality estimates in an incidence-prevalence-mortality (IPM) model. Data on dengue prevalence were extracted from six sero-surveys conducted in Malaysia between 2001 and 2013; while statistics on dengue notification and Case Fatality Rate were derived from National Dengue Surveillance System. Dengue hospitalization data for the years 2009 to 2013 were extracted from the Health Informatics Centre and the volumes of dengue hospitalization for hospitals with missing data were estimated with Poisson models. Results The dengue incidence in Malaysia varied from 69.9 to 93.4 per 1000 population (pkp) between 2001 and 2013.The temporal trend in incidence rate was decreasing since 2001. It has been reducing at an average rate of 2.57 pkp per year from 2001 to 2013 (p = 0.011). The age-specific incidence of dengue decreased steadily with dengue incidence reaching zero by age > 70 years. Dengue notification rate has remained stable since 2001 and the number of notified cases each year was only a small fraction of the incident cases (0.7 to 2.3%). Similarly, the dengue hospitalization was larger but still a small fraction of the incident cases (3.0 to 5.6%). Conclusion Dengue incidence can be estimated with the use of sero-prevalence surveys and mortality data. This study highlights a reducing trend of dengue incidence in Malaysia and demonstrates the discrepancy between true dengue disease burden and cases reported by national surveillance system. Sero-prevalence studies with representative samples should be conducted regularly to allow better estimation of dengue burden in Malaysia.
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Affiliation(s)
- Yuan Liang Woon
- Clinical Research Centre, Ministry of Health Malaysia, c/o Third Floor, Dermatology Block, Hospital Kuala Lumpur, Jalan Pahang, 50586, Kuala Lumpur, Malaysia
| | - Chee Peng Hor
- Kepala Batas Hospital, Ministry of Health Malaysia, Jalan Bertam 2, 13200 Kepala Batas, Penang, Malaysia
| | - Keng Yee Lee
- Clinical Research Centre, Ministry of Health Malaysia, c/o Third Floor, Dermatology Block, Hospital Kuala Lumpur, Jalan Pahang, 50586, Kuala Lumpur, Malaysia
| | - Siti Fatimah Zahra Mohd Anuar
- Clinical Research Centre, Ministry of Health Malaysia, c/o Third Floor, Dermatology Block, Hospital Kuala Lumpur, Jalan Pahang, 50586, Kuala Lumpur, Malaysia
| | - Rose Nani Mudin
- Sector of Vector-Borne Disease, Disease Control Division, Ministry of Health Malaysia, 62590, Putrajaya, Malaysia
| | - Mohd Khadzir Sheikh Ahmad
- Health Informatic Centre, Planning Division, Ministry of Health Malaysia, 62590, Putrajaya, Malaysia
| | - Suhaya Komari
- Health Informatic Centre, Planning Division, Ministry of Health Malaysia, 62590, Putrajaya, Malaysia
| | - Faridah Amin
- National Public Health Laboratory, Lot 1853, Kg, Melayu, 47000, Sungai Buloh, Selangor, Malaysia
| | - Rahman Jamal
- UKM Medical Molecular Biology Institute, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Wei Seng Chen
- Klinik Alam Medic, 41, Jalan Perdana 3/4, Taman Puchong Perdana, 47100, Puchong, Selangor, Malaysia
| | - Pik Pin Goh
- Clinical Research Centre, Ministry of Health Malaysia, c/o Third Floor, Dermatology Block, Hospital Kuala Lumpur, Jalan Pahang, 50586, Kuala Lumpur, Malaysia
| | - Lena Yeap
- Stats Consulting Pte Ltd, D7-3-1, Block D7, Pusat Perdagangan Dana 1, Jalan PJU 1A/46, PJU 1A, 47301, Petaling Jaya, Selangor, Malaysia
| | - Zhuo Ren Lim
- Stats Consulting Pte Ltd, D7-3-1, Block D7, Pusat Perdagangan Dana 1, Jalan PJU 1A/46, PJU 1A, 47301, Petaling Jaya, Selangor, Malaysia
| | - Teck Onn Lim
- ClinResearch Pte Ltd, D7-3-1, Block D7, Pusat Perdagangan Dana 1, Jalan PJU 1A/46, PJU 1A, 47301, Petaling Jaya, Selangor, Malaysia.
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Agha SB, Tchouassi DP, Bastos ADS, Sang R. Dengue and yellow fever virus vectors: seasonal abundance, diversity and resting preferences in three Kenyan cities. Parasit Vectors 2017; 10:628. [PMID: 29284522 PMCID: PMC5747025 DOI: 10.1186/s13071-017-2598-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/17/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The transmission patterns of dengue (DENV) and yellow fever (YFV) viruses, especially in urban settings, are influenced by Aedes (Stegomyia) mosquito abundance and behavior. Despite recurrent dengue outbreaks on the Kenyan coast, these parameters remain poorly defined in this and other areas of contrasting dengue endemicity in Kenya. In assessing the transmission risk of DENV/YFV in three Kenyan cities, we determined adult abundance and resting habits of potential Aedes (Stegomyia) vectors in Kilifi (dengue-outbreak prone), and Nairobi and Kisumu (no dengue outbreaks reported). In addition, mosquito diversity, an important consideration for changing mosquito-borne disease dynamics, was compared. METHODS Between October 2014 and June 2016, host-seeking adult mosquitoes were sampled using CO2-baited BG-Sentinel traps (12 traps daily) placed in vegetation around homesteads, across study sites in the three major cities. Also, indoor and outdoor resting mosquitoes were sampled using Prokopack aspirators. Three samplings, each of five consecutive days, were conducted during the long-rains, short-rains and dry season for each city. Inter-city and seasonal variation in mosquito abundance and diversity was evaluated using general linear models while mosquito-resting preference (indoors vs outdoors) was compared using Chi-square test. RESULTS Aedes aegypti, which comprised 60% (n = 7772) of the total 12,937 host-seeking mosquitoes collected, had comparable numbers in Kisumu (45.2%, n = 3513) and Kilifi (37.7%, n = 2932), both being significantly higher than Nairobi (17.1%, n = 1327). Aedes aegypti abundance was significantly lower in the short-rains and dry season relative to the long-rains (P < 0.0001). Aedes bromeliae, which occurred in low numbers, did not differ significantly between seasons or cities. Mosquito diversity was highest during the long-rains and in Nairobi. Only 10% (n = 43) of the 450 houses aspirated were found positive for resting Ae. aegypti, with overall low captures in all areas. Aedes aegypti densities were comparable indoors/outdoors in Kilifi; but with higher densities outdoors than indoors in Kisumu and Nairobi. CONCLUSIONS The presence and abundance of Ae. aegypti near human habitations and dwellings, especially in Kilifi/Kisumu, is suggestive of increased DENV transmission risk due to higher prospects of human vector contact. Despite low abundance of Ae. bromeliae suggestive of low YFV transmission risk, its proximity to human habitation as well as the observed diversity of potential YFV vectors should be of public health concern and monitored closely for targeted control. The largely outdoor resting behavior for Ae. aegypti provides insights for targeted adult vector control especially during emergency outbreak situations.
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Affiliation(s)
- Sheila B Agha
- International Centre of Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya. .,Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Hatfield, 0083, South Africa.
| | - David P Tchouassi
- International Centre of Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya
| | - Armanda D S Bastos
- Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Hatfield, 0083, South Africa
| | - Rosemary Sang
- International Centre of Insect Physiology and Ecology, P. O Box 30772-00100, Nairobi, Kenya.,Arbovirus/Viral Hemorrhagic Fever Laboratory, Centre for Virus Research, Kenya Medical Research Institute, P. O Box 54840-00200, Nairobi, Kenya
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Rural-urban comparisons of dengue seroprevalence in Malaysia. BMC Public Health 2016; 16:824. [PMID: 27538986 PMCID: PMC4991088 DOI: 10.1186/s12889-016-3496-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 08/12/2016] [Indexed: 12/16/2022] Open
Abstract
Background Each year an estimated 390 million dengue infections occur worldwide. In Malaysia, dengue is a growing public health concern but estimate of its disease burden remains uncertain. We compared the urban-rural difference of dengue seroprevalence and determined age-specific dengue seroprevalence in Malaysia. Methods We undertook analysis on 11,821 subjects from six seroprevalence surveys conducted in Malaysia between 2001 and 2013, which composed of five urban and two rural series. Results Prevalence of dengue increased with age in both urban and rural locations in Malaysia, which exceeded 90 % among those aged 70 years or beyond. The age-specific rates of the 5 urban surveys overlapped without clear separation among them, while prevalence was lower in younger subjects in rural series than in urban series, the trend reversed in older subjects. There were no differences in the seroprevalence by gender, ethnicity or region. Poisson regression model confirmed the prevalence have not changed in urban areas since 2001 but in rural areas, there was a significant positive time trend such that by year 2008, rural prevalence was as high as in urban areas. Conclusion Dengue seroprevalence has stabilized but persisted at a high level in urban areas since 2001, and is fast stabilizing in rural areas at the same high urban levels by 2008. The cumulative seroprevalence of dengue exceeds 90 % by the age of 70 years, which translates into 16.5 million people or 55 % of the total population in Malaysia, being infected by dengue by 2013.
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Atique S, Abdul SS, Hsu CY, Chuang TW. Meteorological influences on dengue transmission in Pakistan. ASIAN PAC J TROP MED 2016; 9:954-961. [PMID: 27794388 DOI: 10.1016/j.apjtm.2016.07.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/19/2016] [Accepted: 07/18/2016] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To identify the influences of local and regional climate phenomena on dengue transmission in Lahore District of Pakistan, from 2006 to 2014. METHODS Time-series models were applied to analyze associations between reported cases of dengue and climatic parameters. The coherence trend of regional climate phenomena (IOD and ENSO) was evaluated with wavelet analysis. RESULTS The minimum temperature 4 months before the dengue outbreak played the most important role in the Lahore District (P = 0.03). A NINO 3.4 index 9 months before the outbreaks exhibited a significant negative effect on dengue transmission (P = 0.02). The IOD exhibited a synchronized pattern with dengue outbreak from 2010 to 2012. The ENSO effect (NINO 3.4 index) might have played a more important role after 2012. CONCLUSIONS This study provides preliminary results of climate influences on dengue transmission in the Lahore District of Pakistan. An increasing dengue transmission risk accompanied by frequent climate changes should be noted. Integrating the influences of climate variability into disease prevention strategies should be considered by public health authorities.
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Affiliation(s)
- Suleman Atique
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Shabbir Syed Abdul
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Chien-Yeh Hsu
- Master Program in Global Health and Development, Taipei Medical University, Taipei, Taiwan; Department of Information Management, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
| | - Ting-Wu Chuang
- Department of Molecular Parasitology and Tropical Diseases, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Messina JP, Pigott DM, Golding N, Duda KA, Brownstein JS, Weiss DJ, Gibson H, Robinson TP, Gilbert M, William Wint GR, Nuttall PA, Gething PW, Myers MF, George DB, Hay SI. The global distribution of Crimean-Congo hemorrhagic fever. Trans R Soc Trop Med Hyg 2015; 109:503-13. [PMID: 26142451 PMCID: PMC4501401 DOI: 10.1093/trstmh/trv050] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne infection caused by a virus (CCHFV) from the Bunyaviridae family. Domestic and wild vertebrates are asymptomatic reservoirs for the virus, putting animal handlers, slaughter-house workers and agricultural labourers at highest risk in endemic areas, with secondary transmission possible through contact with infected blood and other bodily fluids. Human infection is characterized by severe symptoms that often result in death. While it is known that CCHFV transmission is limited to Africa, Asia and Europe, definitive global extents and risk patterns within these limits have not been well described. METHODS We used an exhaustive database of human CCHF occurrence records and a niche modeling framework to map the global distribution of risk for human CCHF occurrence. RESULTS A greater proportion of shrub or grass land cover was the most important contributor to our model, which predicts highest levels of risk around the Black Sea, Turkey, and some parts of central Asia. Sub-Saharan Africa shows more focalized areas of risk throughout the Sahel and the Cape region. CONCLUSIONS These new risk maps provide a valuable starting point for understanding the zoonotic niche of CCHF, its extent and the risk it poses to humans.
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Affiliation(s)
| | | | - Nick Golding
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - John S Brownstein
- Department of Pediatrics, Harvard Medical School and Children's Hospital Informatics Program, Boston Children's Hospital, Boston, MA, USA
| | | | - Harry Gibson
- Department of Zoology, University of Oxford, Oxford, UK
| | - Timothy P Robinson
- Livestock Systems and Environment (LSE), International Livestock Research Institute (ILRI),Nairobi, Kenya
| | - Marius Gilbert
- Biological Control and Spatial Ecology, Université Libre de Bruxelles, Brussels, Belgium Fonds National de la Recherche Scientifique, Brussels, Belgium
| | | | | | | | | | - Dylan B George
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Simon I Hay
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK Fogarty International Center, National Institutes of Health, Bethesda, MD, USA Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
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11
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Limper M, Thai KTD, Gerstenbluth I, Osterhaus ADME, Duits AJ, van Gorp ECM. Climate Factors as Important Determinants of Dengue Incidence in Curaçao. Zoonoses Public Health 2015; 63:129-37. [PMID: 26122819 DOI: 10.1111/zph.12213] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Indexed: 11/28/2022]
Abstract
Macro- and microclimates may have variable impact on dengue incidence in different settings. We estimated the short-term impact and delayed effects of climate variables on dengue morbidity in Curaçao. Monthly dengue incidence data from 1999 to 2009 were included to estimate the short-term influences of climate variables by employing wavelet analysis, generalized additive models (GAM) and distributed lag nonlinear models (DLNM) on rainfall, temperature and relative humidity in relation to dengue incidence. Dengue incidence showed a significant irregular 4-year multi-annual cycle associated with climate variables. Based on GAM, temperature showed a U-shape, while humidity and rainfall exhibited a dome-shaped association, suggesting that deviation from mean temperature increases and deviation from mean humidity and rainfall decreases dengue incidence, respectively. Rainfall was associated with an immediate increase in dengue incidence of 4.1% (95% CI: 2.2-8.1%) after a 10-mm increase, with a maximum increase of 6.5% (95% CI: 3.2-10.0%) after 1.5 month lag. A 1 °C decrease of mean temperature was associated with a RR of 17.4% (95% CI: 11.2-27.0%); the effect was inversed for a 1°C increase of mean temperature (RR= 0.457, 95% CI: 0.278-0.752). Climate variables are important determinants of dengue incidence and provide insight into its short-term effects. An increase in mean temperature was associated with lower dengue incidence, whereas lower temperatures were associated with higher dengue incidence.
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Affiliation(s)
- M Limper
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - K T D Thai
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - I Gerstenbluth
- Epidemiology and Research Unit, Medical & Public Health Service (GGD) of Curaçao, Willemstad, Curaçao
| | - A D M E Osterhaus
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - A J Duits
- Red Cross Blood Bank Foundation Curaçao, Willemstad, Curaçao
| | - E C M van Gorp
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands.,Department of Viroscience, Erasmus University Medical Center, Rotterdam, the Netherlands
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12
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Jaenisch T, Junghanss T, Wills B, Brady OJ, Eckerle I, Farlow A, Hay SI, McCall PJ, Messina JP, Ofula V, Sall AA, Sakuntabhai A, Velayudhan R, Wint GRW, Zeller H, Margolis HS, Sankoh O. Dengue expansion in Africa-not recognized or not happening? Emerg Infect Dis 2015; 20. [PMID: 25271370 PMCID: PMC4193177 DOI: 10.3201/eid2010.140487] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Addressing this expansion is essential before control and prevention of dengue are implemented. An expert conference on Dengue in Africa was held in Accra, Ghana, in February 2013 to consider key questions regarding the possible expansion of dengue in Africa. Four key action points were highlighted to advance our understanding of the epidemiology of dengue in Africa. First, dengue diagnostic tools must be made more widely available in the healthcare setting in Africa. Second, representative data need to be collected across Africa to uncover the true burden of dengue. Third, established networks should collaborate to produce these types of data. Fourth, policy needs to be informed so the necessary steps can be taken to provide dengue vector control and health services.
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13
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Tran TT, Olsen A, Viennet E, Sleigh A. Social sustainability of Mesocyclops biological control for dengue in South Vietnam. Acta Trop 2015; 141:54-9. [PMID: 25312335 DOI: 10.1016/j.actatropica.2014.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 10/02/2014] [Accepted: 10/05/2014] [Indexed: 11/17/2022]
Abstract
Copepod Mesocyclops as biological control agents for dengue was previously proven to be effective and sustainable in the Northern and Central provinces of Vietnam. We aim to study social sustainability of Mesocyclops intervention in south Vietnam. Both quantitative and qualitative approaches were used. An entomological survey was carried out in 100 random households of Chanh An commune, Vinh Long Province. Aedes larval indices and Mesocyclops prevalence were compared with historical pre- and post-intervention values. In the same commune, using purposeful sampling, sixteen semi-structured interviews (1 villager leader, 1 local doctor, 10 villagers, 2 teachers, 2 entomology officials), and a focus group discussion (6 Mesocyclops program collaborators) explored water storage habits, beliefs about dengue prevention and behaviour related to Mesocyclops. Thematic analysis was conducted to interpret the qualitative findings. Aedes abundance increased after responsibility for Mesocyclops intervention moved from government to community in 2010, with post-transfer surges in Breteau Index, Container Index, and Larval Density Index. Larval increments coincided with decrease in Mesocyclops prevalence. Villagers had some knowledge of dengue but it was conflated with other mosquito borne diseases and understanding of Mesocyclops was incomplete. Program adoption among the villagers was limited. With reduced government support program collaborators reported limited capacity to conduct population monitoring, and instead targeted 'problem' households. Although the Mesocyclops program was highly sustainable in northern and central provinces of Vietnam, the intervention has not been consistently adopted by southern households in Chanh An commune. Limited education, household monitoring and government support are affecting sustainability. Findings were based on a small household sample visited over a short time period, so other evaluations are needed. However, our results suggest that government support for the Mesocyclops program is still required in this part of Vietnam.
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Affiliation(s)
- Thanh Tam Tran
- National Centre for Epidemiology and Population Health, Research School of Population Health, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia.
| | - Anna Olsen
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Elvina Viennet
- National Centre for Epidemiology and Population Health, Research School of Population Health, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia
| | - Adrian Sleigh
- National Centre for Epidemiology and Population Health, Research School of Population Health, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia
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14
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Shepard DS, Undurraga EA, Betancourt-Cravioto M, Guzmán MG, Halstead SB, Harris E, Mudin RN, Murray KO, Tapia-Conyer R, Gubler DJ. Approaches to refining estimates of global burden and economics of dengue. PLoS Negl Trop Dis 2014; 8:e3306. [PMID: 25412506 PMCID: PMC4238988 DOI: 10.1371/journal.pntd.0003306] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 10/01/2014] [Indexed: 11/24/2022] Open
Abstract
Dengue presents a formidable and growing global economic and disease burden, with around half the world's population estimated to be at risk of infection. There is wide variation and substantial uncertainty in current estimates of dengue disease burden and, consequently, on economic burden estimates. Dengue disease varies across time, geography and persons affected. Variations in the transmission of four different viruses and interactions among vector density and host's immune status, age, pre-existing medical conditions, all contribute to the disease's complexity. This systematic review aims to identify and examine estimates of dengue disease burden and costs, discuss major sources of uncertainty, and suggest next steps to improve estimates. Economic analysis of dengue is mainly concerned with costs of illness, particularly in estimating total episodes of symptomatic dengue. However, national dengue disease reporting systems show a great diversity in design and implementation, hindering accurate global estimates of dengue episodes and country comparisons. A combination of immediate, short-, and long-term strategies could substantially improve estimates of disease and, consequently, of economic burden of dengue. Suggestions for immediate implementation include refining analysis of currently available data to adjust reported episodes and expanding data collection in empirical studies, such as documenting the number of ambulatory visits before and after hospitalization and including breakdowns by age. Short-term recommendations include merging multiple data sources, such as cohort and surveillance data to evaluate the accuracy of reporting rates (by health sector, treatment, severity, etc.), and using covariates to extrapolate dengue incidence to locations with no or limited reporting. Long-term efforts aim at strengthening capacity to document dengue transmission using serological methods to systematically analyze and relate to epidemiologic data. As promising tools for diagnosis, vaccination, vector control, and treatment are being developed, these recommended steps should improve objective, systematic measures of dengue burden to strengthen health policy decisions.
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Affiliation(s)
- Donald S. Shepard
- Schneider Institutes for Health Policy, Heller School, Brandeis University, Waltham, Massachusetts, United States of America
| | - Eduardo A. Undurraga
- Schneider Institutes for Health Policy, Heller School, Brandeis University, Waltham, Massachusetts, United States of America
| | | | | | - Scott B. Halstead
- Dengue Vaccine Initiative, Rockville, Maryland, United States of America
| | - Eva Harris
- University of California, Berkeley, California, United States of America
| | | | - Kristy O. Murray
- Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, United States of America
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15
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Advances in the understanding, management, and prevention of dengue. J Clin Virol 2014; 64:153-9. [PMID: 25453329 DOI: 10.1016/j.jcv.2014.08.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 08/25/2014] [Indexed: 01/09/2023]
Abstract
Dengue causes more human morbidity globally than any other vector-borne viral disease. Recent research has led to improved epidemiological methods that predict disease burden and factors involved in transmission, a better understanding of immune responses in infection, and enhanced animal models. In addition, a number of control measures, including preventative vaccines, are in clinical trials. However, significant gaps remain, including the need for better surveillance in large parts of the world, methods to predict which individuals will develop severe disease, and immunologic correlates of protection against dengue illness. During the next decade, dengue will likely expand its geographic reach and become an increasing burden on health resources in affected areas. Licensed vaccines and antiviral agents are needed in order to effectively control dengue and limit disease.
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16
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Abstract
Dengue is a mosquito-borne viral disease of expanding geographical range and increasing incidence. The vast majority of dengue cases are children less than 15 years of age. Dengue causes a spectrum of illness from mild fever to severe disease with plasma leakage and shock. Infants and children with secondary heterologous dengue infections are most at risk for severe dengue disease. Laboratory diagnosis of dengue can be established within five days of disease onset by direct detection of viral components in serum. After day five, serologic diagnosis provides indirect evidence of dengue. Currently, no effective antiviral agents are available to treat dengue infection. Therefore, treatment remains supportive, with emphasis on close hematological monitoring, recognition of warning signs of severe disease and fluid-replacement therapy and/or blood transfusions when required. Development of a dengue vaccine is considered a high public health priority. A safe and efficacious dengue vaccine would also be important for travelers. This review highlights the current understanding of dengue in children, including its clinical manifestations, pathogenesis, diagnostic tests, management and prevention.
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Affiliation(s)
- Lilly M Verhagen
- Department of Pediatrics, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
| | - Ronald de Groot
- Department of Pediatrics, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
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17
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Guerra CA, Reiner RC, Perkins TA, Lindsay SW, Midega JT, Brady OJ, Barker CM, Reisen WK, Harrington LC, Takken W, Kitron U, Lloyd AL, Hay SI, Scott TW, Smith DL. A global assembly of adult female mosquito mark-release-recapture data to inform the control of mosquito-borne pathogens. Parasit Vectors 2014; 7:276. [PMID: 24946878 PMCID: PMC4067626 DOI: 10.1186/1756-3305-7-276] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/11/2014] [Indexed: 11/26/2022] Open
Abstract
Background Pathogen transmission by mosquitos is known to be highly sensitive to mosquito bionomic parameters. Mosquito mark-release-recapture (MMRR) experiments are a standard method for estimating such parameters including dispersal, population size and density, survival, blood feeding frequency and blood meal host preferences. Methods We assembled a comprehensive database describing adult female MMRR experiments. Bibliographic searches were used to build a digital library of MMRR studies and selected data describing the reported outcomes were extracted. Results The resulting database contained 774 unique adult female MMRR experiments involving 58 vector mosquito species from the three main genera of importance to human health: Aedes, Anopheles and Culex. Crude examination of these data revealed patterns associated with geography as well as mosquito genus, consistent with bionomics varying by species-specific life history and ecological context. Recapture success varied considerably and was significantly different amongst genera, with 8, 4 and 1% of adult females recaptured for Aedes, Anopheles and Culex species, respectively. A large proportion of experiments (59%) investigated dispersal and survival and many allowed disaggregation of the release and recapture data. Geographic coverage was limited to just 143 localities around the world. Conclusions This MMRR database is a substantial contribution to the compilation of global data that can be used to better inform basic research and public health interventions, to identify and fill knowledge gaps and to enrich theory and evidence-based ecological and epidemiological studies of mosquito vectors, pathogen transmission and disease prevention. The database revealed limited geographic coverage and a relative scarcity of information for vector species of substantial public health relevance. It represents, however, a wealth of entomological information not previously compiled and of particular interest for mosquito-borne pathogen transmission models.
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Affiliation(s)
- Carlos A Guerra
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
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18
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Stoler J, Al Dashti R, Anto F, Fobil JN, Awandare GA. Deconstructing "malaria": West Africa as the next front for dengue fever surveillance and control. Acta Trop 2014; 134:58-65. [PMID: 24613157 DOI: 10.1016/j.actatropica.2014.02.017] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/19/2014] [Accepted: 02/23/2014] [Indexed: 11/15/2022]
Abstract
Presumptive treatment of febrile illness patients for malaria remains the norm in endemic areas of West Africa, and "malaria" remains the top source of health facility outpatient visits in many West African nations. Many other febrile illnesses, including bacterial, viral, and fungal infections, share a similar symptomatology as malaria and are routinely misdiagnosed as such; yet growing evidence suggests that much of the burden of febrile illness is often not attributable to malaria. Dengue fever is one of several viral diseases with symptoms similar to malaria, and the combination of rapid globalization, the long-standing presence of Aedes mosquitoes, case reports from travelers, and recent seroprevalence surveys all implicate West Africa as an emerging front for dengue surveillance and control. This paper integrates recent vector ecology, public health, and clinical medicine literature about dengue in West Africa across community, regional, and global geographic scales. We present a holistic argument for greater attention to dengue fever surveillance in West Africa and renew the call for improving differential diagnosis of febrile illness patients in the region.
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Affiliation(s)
- Justin Stoler
- Department of Geography and Regional Studies, University of Miami, 1300 Campo Sano Avenue, Coral Gables, FL, USA; Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, USA.
| | - Rawan Al Dashti
- Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, USA.
| | - Francis Anto
- Department of Epidemiology and Disease Control, University of Ghana, Legon, Ghana.
| | - Julius N Fobil
- Department of Biological, Environmental & Occupational Health Sciences, University of Ghana, Legon, Ghana.
| | - Gordon A Awandare
- Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Ghana.
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19
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Dammert AC, Galdo JC, Galdo V. Preventing dengue through mobile phones: evidence from a field experiment in Peru. JOURNAL OF HEALTH ECONOMICS 2014; 35:147-161. [PMID: 24681813 DOI: 10.1016/j.jhealeco.2014.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 02/07/2014] [Accepted: 02/07/2014] [Indexed: 06/03/2023]
Abstract
Dengue is the most rapidly spreading mosquito-borne viral disease in the world (WHO, 2009). During the last two decades, the dramatic rise in the number of dengue infections has been particularly evident in Latin American and the Caribbean countries. This paper examines the experimental evidence of the effectiveness of mobile phone technology in improving households' health preventive behavior in dengue-endemic areas. The main results suggest that repeated exposure to health information encourages households' uptake of preventive measures against dengue. As a result, the Breteau Index in treatment households, an objective measure of dengue risk transmission, is 0.10 standard deviations below the mean of the control group, which shows a reduction in the number of containers per household that test positive for dengue larvae. The estimates also show marginally significant effects of the intervention on self-reported dengue symptoms. Moreover, we use a multiple treatment framework that randomly assigns households to one of the four treatment groups in order to analyze the impacts of framing on health behavior. Different variants emphasized information on monetary and non-monetary benefits and costs. The main results show no statistical differences among treatment groups.
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20
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Bowman LR, Runge-Ranzinger S, McCall PJ. Assessing the relationship between vector indices and dengue transmission: a systematic review of the evidence. PLoS Negl Trop Dis 2014; 8:e2848. [PMID: 24810901 PMCID: PMC4014441 DOI: 10.1371/journal.pntd.0002848] [Citation(s) in RCA: 201] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/27/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Despite doubts about methods used and the association between vector density and dengue transmission, routine sampling of mosquito vector populations is common in dengue-endemic countries worldwide. This study examined the evidence from published studies for the existence of any quantitative relationship between vector indices and dengue cases. METHODOLOGY/PRINCIPAL FINDINGS From a total of 1205 papers identified in database searches following Cochrane and PRISMA Group guidelines, 18 were included for review. Eligibility criteria included 3-month study duration and dengue case confirmation by WHO case definition and/or serology. A range of designs were seen, particularly in spatial sampling and analyses, and all but 3 were classed as weak study designs. Eleven of eighteen studies generated Stegomyia indices from combined larval and pupal data. Adult vector data were reported in only three studies. Of thirteen studies that investigated associations between vector indices and dengue cases, 4 reported positive correlations, 4 found no correlation and 5 reported ambiguous or inconclusive associations. Six out of 7 studies that measured Breteau Indices reported dengue transmission at levels below the currently accepted threshold of 5. CONCLUSIONS/SIGNIFICANCE There was little evidence of quantifiable associations between vector indices and dengue transmission that could reliably be used for outbreak prediction. This review highlighted the need for standardized sampling protocols that adequately consider dengue spatial heterogeneity. Recommendations for more appropriately designed studies include: standardized study design to elucidate the relationship between vector abundance and dengue transmission; adult mosquito sampling should be routine; single values of Breteau or other indices are not reliable universal dengue transmission thresholds; better knowledge of vector ecology is required.
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Affiliation(s)
- Leigh R. Bowman
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Silvia Runge-Ranzinger
- The Special Programme for Research and Training in Tropical Diseases of the World Health Organization (WHO/TDR), Geneva, Switzerland
| | - P. J. McCall
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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21
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Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, Drake JM, Brownstein JS, Hoen AG, Sankoh O, Myers MF, George DB, Jaenisch T, Wint GRW, Simmons CP, Scott TW, Farrar JJ, Hay SI. The global distribution and burden of dengue. Nature 2013; 496:504-7. [PMID: 23563266 PMCID: PMC3651993 DOI: 10.1038/nature12060] [Citation(s) in RCA: 5733] [Impact Index Per Article: 521.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 03/07/2013] [Indexed: 02/07/2023]
Abstract
Dengue is a systemic viral infection transmitted between humans by Aedes mosquitoes. For some patients, dengue is a life-threatening illness. There are currently no licensed vaccines or specific therapeutics, and substantial vector control efforts have not stopped its rapid emergence and global spread. The contemporary worldwide distribution of the risk of dengue virus infection and its public health burden are poorly known. Here we undertake an exhaustive assembly of known records of dengue occurrence worldwide, and use a formal modelling framework to map the global distribution of dengue risk. We then pair the resulting risk map with detailed longitudinal information from dengue cohort studies and population surfaces to infer the public health burden of dengue in 2010. We predict dengue to be ubiquitous throughout the tropics, with local spatial variations in risk influenced strongly by rainfall, temperature and the degree of urbanization. Using cartographic approaches, we estimate there to be 390 million (95% credible interval 284-528) dengue infections per year, of which 96 million (67-136) manifest apparently (any level of disease severity). This infection total is more than three times the dengue burden estimate of the World Health Organization. Stratification of our estimates by country allows comparison with national dengue reporting, after taking into account the probability of an apparent infection being formally reported. The most notable differences are discussed. These new risk maps and infection estimates provide novel insights into the global, regional and national public health burden imposed by dengue. We anticipate that they will provide a starting point for a wider discussion about the global impact of this disease and will help to guide improvements in disease control strategies using vaccine, drug and vector control methods, and in their economic evaluation.
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Affiliation(s)
- Samir Bhatt
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
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22
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Arya SC, Agarwal N. Apropos "Preliminary study of dengue virus infection in Iran". Travel Med Infect Dis 2013; 11:200. [PMID: 23499195 DOI: 10.1016/j.tmaid.2013.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Accepted: 02/08/2013] [Indexed: 10/27/2022]
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