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Morales-Pérez A, Nava-Aguilera E, Hernández-Alvarez C, Alvarado-Castro VM, Arosteguí J, Legorreta-Soberanis J, Flores-Moreno M, Morales-Nava L, Harris E, Ledogar RJ, Andersson N, Cockcroft A. Utility of entomological indices for predicting transmission of dengue virus: secondary analysis of data from the Camino Verde trial in Mexico and Nicaragua. PLoS Negl Trop Dis 2020; 14:e0008768. [PMID: 33104693 PMCID: PMC7588090 DOI: 10.1371/journal.pntd.0008768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 08/31/2020] [Indexed: 12/22/2022] Open
Abstract
Dengue vector entomological indices are widely used to monitor vector density and disease control activities. But the value of these indices as predictors of dengue infection is not established. We used data from the impact assessment of a trial of community mobilization for dengue prevention (Camino Verde) to examine the associations between vector indices and evidence of dengue infection and their value for predicting dengue infection levels. In 150 clusters in Mexico and Nicaragua, two entomological surveys, three months apart, allowed calculation of the mean Container Index, Breteau index, Pupae per Household Index, and Pupae per Container Index across the two surveys. We measured recent dengue virus infection in children, indicated by a doubling of dengue antibodies in paired saliva samples over the three-month period. We examined the associations between each of the vector indices and evidence of dengue infection at household level and at cluster level, accounting for trial intervention status. To examine the predictive value for dengue infection, we constructed receiver operating characteristic (ROC) curves at household and cluster level, considering the four vector indices as continuous variables, and calculated the positive and negative likelihood ratios for different levels of the indices. None of the vector indices was associated with recent dengue infection at household level. The Breteau Index was associated with recent infection at cluster level (Odds ratio 1.36, 95% confidence interval 1.14–1.61). The ROC curve confirmed the weak predictive value for dengue infection of the Breteau Index at cluster level. Other indices showed no predictive value. Conventional vector indices were not useful in predicting dengue infection in Mexico and Nicaragua. The findings are compatible with the idea of sources of infection outside the household which were tackled by community action in the Camino Verde trial. Vector control is the basis of preventing dengue virus infection. Measurement of dengue vector indices is widely used to monitor dengue control activities, but their utility as predictors of dengue infection is not clear. We used data about vector indices and evidence of recent dengue virus infection from a trial of community mobilization for dengue prevention in Mexico and Nicaragua (Camino Verde), to examine how four standard vector indices could predict dengue infection. Only the Breteau index was associated with evidence of dengue infection, and that only at cluster level. Receiver operating characteristic (ROC) curves confirmed the Breteau Index was only a weak predictor of infection at cluster level; none of the other indices had predictive value. These findings indicate that the four entomological indices studied were not useful predictors of dengue infection. The results are compatible with the idea of sources of infection outside the household which were tackled by community action in the Camino Verde trial.
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Affiliation(s)
- Arcadio Morales-Pérez
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
| | - Elizabeth Nava-Aguilera
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
- * E-mail:
| | | | - Víctor Manuel Alvarado-Castro
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
| | | | - José Legorreta-Soberanis
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
| | - Miguel Flores-Moreno
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
| | - Liliana Morales-Nava
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, United States of America
| | | | - Neil Andersson
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, México
- Department of Family Medicine, McGill University, Montreal, Canada
| | - Anne Cockcroft
- Department of Family Medicine, McGill University, Montreal, Canada
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Nava-Aguilera E, Morales-Pérez A, Balanzar-Martínez A, Rodríguez-Ramírez O, Jiménez-Alejo A, Flores-Moreno M, Gasga-Salinas D, Legorreta-Soberanis J, Paredes-Solís S, Morales-Nava PA, de Lourdes Soto-Ríos M, Ledogar RJ, Coloma J, Harris E, Andersson N. Dengue occurrence relations and serology: cross-sectional analysis of results from the Guerrero State, Mexico, baseline for a cluster-randomised controlled trial of community mobilisation for dengue prevention. BMC Public Health 2017; 17:435. [PMID: 28699560 PMCID: PMC5506575 DOI: 10.1186/s12889-017-4291-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background The Mexican arm of the Camino Verde trial of community mobilisation for dengue prevention covered three coastal regions of Guerrero state: Acapulco, Costa Grande and Costa Chica. A baseline cross-sectional survey provided data for community mobilisation and for adapting the intervention design to concrete conditions in the intervention areas. Methods Trained field teams constructed community profiles in randomly selected clusters, based on observation and key informant interviews. In each household they carried out an entomological inspection of water containers, collected information on socio-demographic variables and cases of dengue illness among household members in the last year, and gathered paired saliva samples from children aged 3–9 years, which were subjected to ELISA testing to detect recent dengue infection. We examined associations with dengue illness and recent dengue infection in bivariate and then multivariate analysis. Results In 70/90 clusters, key informants were unable to identify any organized community groups. Some 1.9% (1029/55,723) of the household population reported dengue illness in the past year, with a higher rate in Acapulco region. Among children 3–9 years old, 6.1% (392/6382) had serological evidence of recent dengue infection. In all three regions, household use of anti-mosquito products, household heads working, and households having less than 5 members were associated with self-reported dengue illness. In Acapulco region, people aged less than 25 years, those with a more educated household head and those from urban sites were also more likely to report dengue illness, while in Costa Chica and Costa Grande, females were more likely to report dengue illness. Among children aged 3–9 years, those aged 3–4 years and those living in Acapulco were more likely to have evidence of recent dengue infection. Conclusions The evidence from the baseline survey provided important support for the design and implementation of the trial intervention. The weakness of community leadership and the relatively low rates of self-reported dengue illness were challenges that the Mexican intervention team had to overcome. The higher dengue illness occurrence among women in Costa Grande and Costa Chica may help explain why women participated more than men in activities during the Camino Verde trial.
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Affiliation(s)
- Elizabeth Nava-Aguilera
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico.
| | - Arcadio Morales-Pérez
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - Alejandro Balanzar-Martínez
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - Ofelia Rodríguez-Ramírez
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - Abel Jiménez-Alejo
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - Miguel Flores-Moreno
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - David Gasga-Salinas
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - José Legorreta-Soberanis
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | - Sergio Paredes-Solís
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico
| | | | | | | | - Joséfina Coloma
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, CA, USA
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, CA, USA
| | - Neil Andersson
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Guerrero, Mexico.,Department of Family Medicine, McGill University, Montreal, Canada
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Affiliation(s)
- Hildy Fong
- Center for Global Public Health and Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, CA, United States of America
| | - Eva Harris
- Center for Global Public Health and Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, CA, United States of America
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Gordon A, Kuan G, Aviles W, Sanchez N, Ojeda S, Lopez B, Gresh L, Balmaseda A, Harris E. The Nicaraguan pediatric influenza cohort study: design, methods, use of technology, and compliance. BMC Infect Dis 2015; 15:504. [PMID: 26553094 PMCID: PMC4640204 DOI: 10.1186/s12879-015-1256-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/30/2015] [Indexed: 12/03/2022] Open
Abstract
Background Influenza causes substantial morbidity and mortality worldwide, yet few data exist on influenza infection rates in tropical, developing countries. In 2011, we established the Nicaraguan Pediatric Influenza Cohort Study (NPICS) to study the burden and seasonality of influenza in Nicaraguan children. Here we describe the study design, methods, and participation data of the NPICS for 2011–2013. Methods/Design A total of 1532 children aged 0 to 12 years were enrolled into the study in 2011, and an additional 401 children were enrolled between 2012 and 2013. Children were provided with all of their medical care through the study, and data on medical visits were recorded systematically. A number of surveys were conducted together with a blood sample annually, including a height and weight measurement, a socio-economic status and risk factor survey, and a breastfeeding survey. Discussion Unique features of our study include the customized low-cost, open-source informatics system as well as the development of methods to leverage infrastructure and resources by conducting multiple studies in the same setting while maximizing protocol adherence and quality control. These methods should be useful to others conducting large cohort studies, particularly in low-resource settings. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1256-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aubree Gordon
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
| | - Guillermina Kuan
- Sócrates Flores Vivas Health Center, Ministry of Health, Managua, Nicaragua. @icsnicaragua.org
| | | | - Nery Sanchez
- Sustainable Sciences Institute, Managua, Nicaragua. @icsnicaragua.org
| | - Sergio Ojeda
- Sustainable Sciences Institute, Managua, Nicaragua. @icsnicaragua.org
| | - Brenda Lopez
- Sustainable Sciences Institute, Managua, Nicaragua. @icsnicaragua.org
| | - Lionel Gresh
- Sustainable Sciences Institute, Managua, Nicaragua. @icsnicaragua.org
| | - Angel Balmaseda
- Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua.
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, CA, USA.
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Genome-wide patterns of intrahuman dengue virus diversity reveal associations with viral phylogenetic clade and interhost diversity. J Virol 2012; 86:8546-58. [PMID: 22647702 DOI: 10.1128/jvi.00736-12] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Analogous to observations in RNA viruses such as human immunodeficiency virus, genetic variation associated with intrahost dengue virus (DENV) populations has been postulated to influence viral fitness and disease pathogenesis. Previous attempts to investigate intrahost genetic variation in DENV characterized only a few viral genes or a limited number of full-length genomes. We developed a whole-genome amplification approach coupled with deep sequencing to capture intrahost diversity across the entire coding region of DENV-2. Using this approach, we sequenced DENV-2 genomes from the serum of 22 Nicaraguan individuals with secondary DENV infection and captured ∼75% of the DENV genome in each sample (range, 40 to 98%). We identified and quantified variants using a highly sensitive and specific method and determined that the extent of diversity was considerably lower than previous estimates. Significant differences in intrahost diversity were detected between genes and also between antigenically distinct domains of the Envelope gene. Interestingly, a strong association was discerned between the extent of intrahost diversity in a few genes and viral clade identity. Additionally, the abundance of viral variants within a host, as well as the impact of viral mutations on amino acid encoding and predicted protein function, determined whether intrahost variants were observed at the interhost level in circulating Nicaraguan DENV-2 populations, strongly suggestive of purifying selection across transmission events. Our data illustrate the value of high-coverage genome-wide analysis of intrahost diversity for high-resolution mapping of the relationship between intrahost diversity and clinical, epidemiological, and virological parameters of viral infection.
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OhAinle M, Balmaseda A, Macalalad AR, Tellez Y, Zody MC, Saborío S, Nuñez A, Lennon NJ, Birren BW, Gordon A, Henn MR, Harris E. Dynamics of dengue disease severity determined by the interplay between viral genetics and serotype-specific immunity. Sci Transl Med 2012; 3:114ra128. [PMID: 22190239 DOI: 10.1126/scitranslmed.3003084] [Citation(s) in RCA: 223] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The rapid spread of dengue is a worldwide public health problem. In two clinical studies of dengue in Managua, Nicaragua, we observed an abrupt increase in disease severity across several epidemic seasons of dengue virus serotype 2 (DENV-2) transmission. Waning DENV-1 immunity appeared to increase the risk of severe disease in subsequent DENV-2 infections after a period of cross-protection. The increase in severity coincided with replacement of the Asian/American DENV-2 NI-1 clade with a new virus clade, NI-2B. In vitro analyses of viral isolates from the two clades and analysis of viremia in patient blood samples support the emergence of a fitter virus in later, relative to earlier, epidemic seasons. In addition, the NI-1 clade of viruses was more virulent specifically in children who were immune to DENV-1, whereas DENV-3 immunity was associated with more severe disease among NI-2B infections. Our data demonstrate that the complex interaction between viral genetics and population dynamics of serotype-specific immunity contributes to the risk of severe dengue disease. Furthermore, this work provides insights into viral evolution and the interaction between viral and immunological determinants of viral fitness and virulence.
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Affiliation(s)
- Molly OhAinle
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA 94720-7354, USA
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Thriemer K, Ley B, Ame SM, Puri MK, Hashim R, Chang NY, Salim LA, Ochiai RL, Wierzba TF, Clemens JD, von Seidlein L, Deen JL, Ali SM, Ali M. Replacing paper data collection forms with electronic data entry in the field: findings from a study of community-acquired bloodstream infections in Pemba, Zanzibar. BMC Res Notes 2012; 5:113. [PMID: 22353420 PMCID: PMC3392743 DOI: 10.1186/1756-0500-5-113] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 02/21/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Entering data on case report forms and subsequently digitizing them in electronic media is the traditional way to maintain a record keeping system in field studies. Direct data entry using an electronic device avoids this two-step process. It is gaining in popularity and has replaced the paper-based data entry system in many studies. We report our experiences with paper- and PDA-based data collection during a fever surveillance study in Pemba Island, Zanzibar, Tanzania. METHODS Data were collected on a 14-page case report paper form in the first period of the study. The case report paper forms were then replaced with handheld computers (personal digital assistants or PDAs). The PDAs were used for screening and clinical data collection, including a rapid assessment of patient eligibility, real time errors, and inconsistency checking. RESULTS A comparison of paper-based data collection with PDA data collection showed that direct data entry via PDA was faster and 25% cheaper. Data was more accurate (7% versus 1% erroneous data) and omission did not occur with electronic data collection. Delayed data turnaround times and late error detections in the paper-based system which made error corrections difficult were avoided using electronic data collection. CONCLUSIONS Electronic data collection offers direct data entry at the initial point of contact. It has numerous advantages and has the potential to replace paper-based data collection in the field. The availability of information and communication technologies for direct data transfer has the potential to improve the conduct of public health research in resource-poor settings.
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Affiliation(s)
- Kamala Thriemer
- International Vaccine Institute, SNU Research Park, San 4-8, Nakseongdae-dong, Gwanak-gu, Seoul, Republic of Korea 151-600.
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Liu F, Guo F, Zhou Y, He Z, Tian X, Guo C, Ning T, Pan Y, Cai H, Ke Y. The Anyang Esophageal Cancer Cohort Study: study design, implementation of fieldwork, and use of computer-aided survey system. PLoS One 2012; 7:e31602. [PMID: 22328939 PMCID: PMC3273470 DOI: 10.1371/journal.pone.0031602] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 01/10/2012] [Indexed: 12/19/2022] Open
Abstract
Background Human papillomavirus (HPV) has been observed repeatedly in esophageal squamous cell carcinoma (ESCC) tissues. However, the causal relationship between HPV infection and the onset of ESCC remains unknown. A large cohort study focusing on this topic is being carried out in rural Anyang, China. Methodology/Principal Findings The Anyang Esophageal Cancer Cohort Study (AECCS) is a population-based prospective endoscopic cohort study designed to investigate the association of HPV infection and ESCC. This paper provides information regarding the design and implementation of this study. In particular we describe the recruitment strategies and quality control procedures which have been put into place, and the custom designed computer-aided survey system (CASS) used for this project. This system integrates barcode technology and unique identification numbers, and has been developed to facilitate real-time data management throughout the workflow using a wireless local area network. A total of 8,112 (75.3%) of invited subjects participated in the baseline endoscopic examination; of those invited two years later to take part in the first cycle of follow-up, 91.9% have complied. Conclusions/Significance The AECCS study has high potential for evaluating the causal relationship between HPV infection and the occurrence of ESCC. The experience in setting up the AECCS may be beneficial for others planning to initiate similar epidemiological studies in developing countries.
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Affiliation(s)
- Fangfang Liu
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Fangcen Guo
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Yue Zhou
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
- National Research Institute for Family Planning, Beijing, People's Republic of China
| | - Zhonghu He
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Xiuyun Tian
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Chuanhai Guo
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Tao Ning
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Yaqi Pan
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Hong Cai
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
- * E-mail: (HC); (YK)
| | - Yang Ke
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China
- * E-mail: (HC); (YK)
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Olopade CO, Olugbile S, Olopade OI. Issues and Challenges for Clinical Research in International Settings. PRINCIPLES AND PRACTICE OF CLINICAL RESEARCH 2012. [PMCID: PMC7150258 DOI: 10.1016/b978-0-12-382167-6.00047-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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Ali M, Deen JL, Khatib A, Enwere G, von Seidlein L, Reyburn R, Ali SM, Chang NY, Perroud V, Marodon F, Saleh AA, Hashim R, Lopez AL, Beard J, Ley BN, Thriemer K, Puri MK, Sah B, Jiddawi MS, Clemens JD. Paperless registration during survey enumerations and large oral cholera mass vaccination in Zanzibar, the United Republic of Tanzania. Bull World Health Organ 2010; 88:556-9. [PMID: 20616976 DOI: 10.2471/blt.09.070334] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 10/07/2009] [Accepted: 10/22/2009] [Indexed: 11/27/2022] Open
Abstract
PROBLEM Field trials require extensive data preparation and complex logistics. The use of personal digital assistants (PDAs) can bypass many of the traditional steps that are necessary in a paper-based data entry system. APPROACH We programmed, designed and supervised the use of PDAs for a large survey enumeration and mass vaccination campaign. LOCAL SETTING The project was implemented in Zanzibar in the United Republic of Tanzania. Zanzibar is composed of two main islands, Unguja and Pemba, where outbreaks of cholera have been reported since the 1970s. RELEVANT CHANGES PDAs allowed us to digitize information at the initial point of contact with the respondents. Immediate response by the system in case of error helped ensure the quality and reliability of the data. PDAs provided quick data summaries that allowed subsequent research activities to be implemented in a timely fashion. LESSONS LEARNT Portability, immediate recording and linking of information enhanced structure data collection in our study. PDAs could be more useful than paper-based systems for data collection in the field, especially in impoverished settings in developing countries.
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Affiliation(s)
- Mohammad Ali
- International Vaccine Institute, Kwanak PO Box-14, Seoul, 151-600, Republic of Korea.
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Balmaseda A, Standish K, Mercado JC, Matute JC, Tellez Y, Saborío S, Hammond SN, Nuñez A, Avilés W, Henn MR, Holmes EC, Gordon A, Coloma J, Kuan G, Harris E. Trends in patterns of dengue transmission over 4 years in a pediatric cohort study in Nicaragua. J Infect Dis 2010; 201:5-14. [PMID: 19929380 PMCID: PMC3724236 DOI: 10.1086/648592] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Dengue is the most prevalent mosquito-borne viral disease in humans and a major urban public health problem worldwide. METHODS A prospective cohort study of approximately 3800 children initially aged 2-9 years was established in Managua, Nicaragua, in 2004 to study the natural history of dengue transmission in an urban pediatric population. Blood samples from healthy subjects were collected annually prior to the dengue season, and identification of dengue cases occurred via enhanced passive surveillance at the study health center. RESULTS Over the first four years of the study, seroprevalence of anti-dengue virus (DENV) antibodies increased from 22%-40% in the 2-year-old cohort and 90%-95% in the 9-year-old cohort. The incidence of symptomatic dengue cases and the ratio of inapparent to symptomatic DENV infection varied substantially from year to year. The switch in dominant transmission from DENV-1 to DENV-2 was accompanied by an increase in disease severity but, paradoxically, a decrease in transmission. Phylogeographic analysis of full-length DENV-2 sequences revealed strong geographic clustering of dengue cases. CONCLUSIONS This large-scale cohort study of dengue in the Americas demonstrates year-to-year variation of dengue within a pediatric population, revealing expected patterns in transmission while highlighting the impact of interventions, climate, and viral evolution.
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Affiliation(s)
- Angel Balmaseda
- Departamento de Virología, Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
| | | | - Juan Carlos Mercado
- Departamento de Virología, Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
| | - Juan Carlos Matute
- Departamento de Virología, Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
| | - Yolanda Tellez
- Departamento de Virología, Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
| | - Saira Saborío
- Departamento de Virología, Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
| | | | - Andrea Nuñez
- Departamento de Virología, Centro Nacional de Diagnóstico y Referencia, Ministry of Health, Managua, Nicaragua
| | | | | | - Edward C. Holmes
- Center for Infectious Disease Dynamics, Department of Biology, The Pennsylvania State University, University Park, PA
- Fogarty International Center, National Institutes of Health, Bethesda, MD
| | - Aubree Gordon
- Division of Infectious Diseases, School of Public Health, University of California, Berkeley, CA
| | - Josefina Coloma
- Division of Infectious Diseases, School of Public Health, University of California, Berkeley, CA
| | | | - Eva Harris
- Division of Infectious Diseases, School of Public Health, University of California, Berkeley, CA
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Coloma J, Harris E. From construction workers to architects: developing scientific research capacity in low-income countries. PLoS Biol 2009; 7:e1000156. [PMID: 19621063 PMCID: PMC2704958 DOI: 10.1371/journal.pbio.1000156] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Solving global health challenges in a sustainable manner depends on explicitly addressing scientific capacity-building needs, as well as establishing long-term, meaningful partnerships with colleagues in the developing world.
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Affiliation(s)
- Josefina Coloma
- Sustainable Sciences Institute, San Francisco, California, United States of America
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
| | - Eva Harris
- Sustainable Sciences Institute, San Francisco, California, United States of America
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
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Kuan G, Gordon A, Avilés W, Ortega O, Hammond SN, Elizondo D, Nuñez A, Coloma J, Balmaseda A, Harris E. The Nicaraguan pediatric dengue cohort study: study design, methods, use of information technology, and extension to other infectious diseases. Am J Epidemiol 2009; 170:120-9. [PMID: 19435864 PMCID: PMC2700880 DOI: 10.1093/aje/kwp092] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Dengue is a mosquito-borne viral disease that is a major public health problem worldwide. In 2004, the Pediatric Dengue Cohort Study was established in Managua, Nicaragua, to study the natural history and transmission of dengue in children. Here, the authors describe the study design, methods, and results from 2004 to 2008. Initially, 3,721 children 2–9 years of age were recruited through door-to-door visits. Each year, new children aged 2 years are enrolled in the study to maintain the age structure. Children are provided with medical care through the study, and data from each medical visit are recorded on systematic study forms. All participants presenting with suspected dengue or undifferentiated fever are tested for dengue by virologic, serologic, and molecular biologic assays. Yearly blood samples are collected to detect inapparent dengue virus infections. Numerous information and communications technologies are used to manage study data, track samples, and maintain quality control, including personal data assistants, barcodes, global information systems, and fingerprint scans. Close collaboration with the Nicaraguan Ministry of Health and use of almost entirely local staff are essential components for success. This study is providing critical data on the epidemiology and transmission of dengue in the Americas needed for future vaccine trials.
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Affiliation(s)
- Guillermina Kuan
- Centro de Salud Sócrates Flores Vivas, Barrio Monseñor Lezcano, Managua, Nicaragua
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Rajapakse M, Kanagasabai R, Ang WT, Veeramani A, Schreiber MJ, Baker CJ. Ontology-centric integration and navigation of the dengue literature. J Biomed Inform 2008; 41:806-15. [DOI: 10.1016/j.jbi.2008.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 03/30/2008] [Accepted: 04/05/2008] [Indexed: 11/30/2022]
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Coloma J, Harris E. Sustainable transfer of biotechnology to developing countries: fighting poverty by bringing scientific tools to developing-country partners. Ann N Y Acad Sci 2007; 1136:358-68. [PMID: 17954678 DOI: 10.1196/annals.1425.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Poverty and social inequalities have powerfully sculpted not only the distribution of infectious and other diseases but also the course of disease in those affected. The lack of proper diagnosis and access to adequate health services only compounds the problem. In low-resource settings, the burden of disease can be reduced if the basic human and material resources exist to support the use of low-cost interventions by appropriately trained personnel. For 20 years, the Sustainable Sciences Institute has built scientific capacity in developing countries to recognize, prevent, and respond to the threats posed by disease.
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Affiliation(s)
- Josefina Coloma
- Division of Infectious Diseases, School of Public Health, University of California, Berkeley, 1 Barker Hall #422, Berkeley, CA 94720-7354, USA
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