1
|
Kang SY, Amratia P, Dunn J, Vilay P, Connell M, Symons T, Rumisha S, Zhang S, Ward A, Sichanthongthip O, Banouvong V, Shortus M, Reyburn R, Butphomvihane P, Phiphakavong V, Hahm M, Phongchantha V, Khamlome B, Chindavongsa K, Chanthavisouk C, Weiss DJ, Gething PW, Cameron E. Fine-scale maps of malaria incidence to inform risk stratification in Laos. Malar J 2024; 23:196. [PMID: 38918779 PMCID: PMC11202256 DOI: 10.1186/s12936-024-05007-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 06/01/2024] [Indexed: 06/27/2024] Open
Abstract
BACKGROUND Malaria risk maps are crucial for controlling and eliminating malaria by identifying areas of varying transmission risk. In the Greater Mekong Subregion, these maps guide interventions and resource allocation. This article focuses on analysing changes in malaria transmission and developing fine-scale risk maps using five years of routine surveillance data in Laos (2017-2021). The study employed data from 1160 geolocated health facilities in Laos, along with high-resolution environmental data. METHODS A Bayesian geostatistical framework incorporating population data and treatment-seeking propensity was developed. The models incorporated static and dynamic factors and accounted for spatial heterogeneity. RESULTS Results showed a significant decline in malaria cases in Laos over the five-year period and a shift in transmission patterns. While the north became malaria-free, the south experienced ongoing transmission with sporadic outbreaks. CONCLUSION The risk maps provided insights into changing transmission patterns and supported risk stratification. These risk maps are valuable tools for malaria control in Laos, aiding resource allocation, identifying intervention gaps, and raising public awareness. The study enhances understanding of malaria transmission dynamics and facilitates evidence-based decision-making for targeted interventions in high-risk areas.
Collapse
Affiliation(s)
- Su Yun Kang
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia.
| | - Punam Amratia
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia.
- Ifakara Health Institute, Dar es Salaam, Tanzania.
| | - Julia Dunn
- Clinton Health Access Initiative, Boston, USA
| | - Phoutnalong Vilay
- Centre of Malariology, Parasitology and Entomology, Vientiane, Lao PDR
| | - Mark Connell
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
| | - Tasmin Symons
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
- Curtin University, Perth, Australia
| | - Susan Rumisha
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
- Ifakara Health Institute, Dar es Salaam, Tanzania
| | - Song Zhang
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
| | | | | | | | | | | | | | | | - Mary Hahm
- Clinton Health Access Initiative, Boston, USA
| | | | - Boualam Khamlome
- Centre of Malariology, Parasitology and Entomology, Vientiane, Lao PDR
| | | | | | - Daniel J Weiss
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
- Curtin University, Perth, Australia
| | - Peter W Gething
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
- Curtin University, Perth, Australia
| | - Ewan Cameron
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
- Curtin University, Perth, Australia
| |
Collapse
|
2
|
Chaves LSM, Bergo ES, Bickersmith SA, Laporta GZ, Conn JE, Sallum MAM. Forest cover percentage drives the peak biting time of Nyssorhynchus darlingi (Diptera: Culicidae) in the Brazilian Amazon. Malar J 2024; 23:166. [PMID: 38807105 PMCID: PMC11131226 DOI: 10.1186/s12936-024-04984-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 05/14/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND Deforestation is an important driver of malaria dynamics, with a relevant impact on mosquito ecology, including larval habitat availability, blood-feeding behaviour, and peak biting time. The latter is one of several entomological metrics to evaluate vectorial capacity and effectiveness of disease control. This study aimed to test the effect of forest cover percentage on the peak biting time of Plasmodium-uninfected and infected Nyssorhynchus darlingi females. METHODS Mosquitoes were captured utilizing human landing catch (HLC) in the peridomestic habitat in field collections carried out in the wet, wet-dry transition, and dry seasons from 2014 to 2017 in areas with active malaria transmission in Amazonian Brazil. The study locations were in rural settlements in areas with the mean annual malaria parasite incidence (Annual Parasite Incidence, API ≥ 30). All Ny. darlingi females were tested for Plasmodium spp. infection using real time PCR technique. Forest cover percentage was calculated for each collection site using QGIS v. 2.8 and was categorized in three distinct deforestation scenarios: (1) degraded, < 30% forest cover, (2) intermediate, 30-70% forest cover, and (3) preserved, > 70% forest cover. RESULTS The highest number of uninfected female Ny. darlingi was found in degraded landscape-sites with forest cover < 30% in any peak biting time between 18:00 and 0:00. Partially degraded landscape-sites, with (30-70%) forest cover, showed the highest number of vivax-infected females, with a peak biting time of 21:00-23:00. The number of P. falciparum-infected mosquitoes was highest in preserved sites with > 70% forest cover, a peak biting at 19:00-20:00, and in sites with 30-70% forest cover at 22:00-23:00. CONCLUSIONS Results of this study show empirically that degraded landscapes favour uninfected Ny. darlingi with a peak biting time at dusk (18:00-19:00), whereas partially degraded landscapes affect the behaviour of Plasmodium-infected Ny. darlingi by shifting its peak biting time towards hours after dark (21:00-23:00). In preserved sites, Plasmodium-infected Ny. darlingi bite around dusk (18:00-19:00) and shortly after (19:00-20:00).
Collapse
Affiliation(s)
- Leonardo Suveges Moreira Chaves
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo, 715 - Pacaembu, CEP, 01246-904, São Paulo, SP, Brasil
| | | | | | - Gabriel Z Laporta
- Graduate Program in Health Sciences, FMABC Medical School University Center, Santo André, SP, Brazil
| | - Jan E Conn
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, NY, USA
| | - Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo, 715 - Pacaembu, CEP, 01246-904, São Paulo, SP, Brasil.
| |
Collapse
|
3
|
Endriyas M, Kassa M, Chisha Y, Mekonnen E, Misganaw T, Loha E, Astatkie A. Low long-lasting insecticidal net use in malaria elimination areas in Southern Ethiopia: results from community based cross-sectional study. Malar J 2024; 23:94. [PMID: 38575937 PMCID: PMC10996104 DOI: 10.1186/s12936-024-04909-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
BACKGROUND Despite remarkable progress in malaria burden reduction, malaria continues to be a major public health problem globally. Ethiopia has been distributing long-lasting insecticidal nets (LLINs) for free and nationwide distribution was completed in 2016. However, evidence suggests that the utilization of LLINs varies from setting to setting and from time to time due to different factors, and up-to-date evidence is required for LLIN related decision-making. Hence, this study was designed to assess LLIN utilization and its determinants in the Southern Nations, Nationalities, and People's Region (SNNPR) of Ethiopia. METHODS A community-based cross-sectional study was conducted in Southern Ethiopia in 2019. Using multi-stage sampling, a total of 2466 households were included. The region was stratified based on the annual malaria index as high, moderate, low, and free strata. Cluster sampling was then applied to select households from high, moderate, and low strata. Data on LLIN ownership, utilization and different determinant factors were collected using household questionnaire. SurveyCTO was used to collect data and data was managed using Stata 15. Descriptive statistics and multilevel mixed-effects logistic regression were performed to identify the determinants of utilization of LLINs. Effect measures were reported using adjusted odds ratio (AOR) with 95% CI. RESULTS From a total of 2466 households, 48.7% of households had at least one LLIN. LLIN adequacy based on family size was 23% while it was15.7% based on universal access and 29.2% based on sleeping space. From 1202 households that possessed LLIN(s), 66.0% of households reported that they slept under LLIN the night preceding the survey. However, when the total population in all surveyed households were considered, only 22.9% of household members slept under LLIN the night preceding the survey. Malaria endemicity, educational status, wealth status, and knowledge about malaria were associated with LLINs utilization. In addition, reasons for non-use included perceived absence of malaria, side effects of LLIN, conditions of LLINs, inconvenient space and low awareness. CONCLUSION Low LLIN coverage and low utilization were noted. A low level of utilization was associated with malaria endemicity, wealth status and level of awareness. Distribution of LLIN and continuous follow-up with community awareness creation activities are vital to improve coverage and utilization of LLINs, and to ensure the country's malaria elimination goal.
Collapse
Affiliation(s)
| | - Mekidim Kassa
- College of Medicine and Health Sciences, Arbaminch University, Arbaminch, Ethiopia
| | - Yilma Chisha
- College of Medicine and Health Sciences, Arbaminch University, Arbaminch, Ethiopia
| | | | | | - Eskindir Loha
- Centre for International Health, University of Bergen, Bergen, Norway
- Chr. Michelsen Institute, Bergen, Norway
| | - Ayalew Astatkie
- School of Public Health, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia
| |
Collapse
|
4
|
Champagne C, Gerhards M, Lana JT, Le Menach A, Pothin E. Quantifying the impact of interventions against Plasmodium vivax: A model for country-specific use. Epidemics 2024; 46:100747. [PMID: 38330786 PMCID: PMC10944169 DOI: 10.1016/j.epidem.2024.100747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 11/03/2023] [Accepted: 01/23/2024] [Indexed: 02/10/2024] Open
Abstract
In order to evaluate the impact of various intervention strategies on Plasmodium vivax dynamics in low endemicity settings without significant seasonal pattern, we introduce a simple mathematical model that can be easily adapted to reported case numbers similar to that collected by surveillance systems in various countries. The model includes case management, vector control, mass drug administration and reactive case detection interventions and is implemented in both deterministic and stochastic frameworks. It is available as an R package to enable users to calibrate and simulate it with their own data. Although we only illustrate its use on fictitious data, by simulating and comparing the impact of various intervention combinations on malaria risk and burden, this model could be a useful tool for strategic planning, implementation and resource mobilization.
Collapse
Affiliation(s)
- C Champagne
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
| | - M Gerhards
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - J T Lana
- Clinton Health Access Initiative, Boston, USA
| | - A Le Menach
- Clinton Health Access Initiative, Boston, USA
| | - E Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Clinton Health Access Initiative, Boston, USA
| |
Collapse
|
5
|
Nguyen M, Dzianach PA, Castle PECW, Rumisha SF, Rozier JA, Harris JR, Gibson HS, Twohig KA, Vargas-Ruiz CA, Bisanzio D, Cameron E, Weiss DJ, Bhatt S, Gething PW, Battle KE. Trends in treatment-seeking for fever in children under five years old in 151 countries from 1990 to 2020. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0002134. [PMID: 37611001 PMCID: PMC10446233 DOI: 10.1371/journal.pgph.0002134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 07/11/2023] [Indexed: 08/25/2023]
Abstract
Access to medical treatment for fever is essential to prevent morbidity and mortality in individuals and to prevent transmission of communicable febrile illness in communities. Quantification of the rates at which treatment is accessed is critical for health system planning and a prerequisite for disease burden estimates. In this study, national data on the proportion of children under five years old with fever who were taken for medical treatment were collected from all available countries in Africa, Latin America, and Asia (n = 91). We used generalised additive mixed models to estimate 30-year trends in the treatment-seeking rates across the majority of countries in these regions (n = 151). Our results show that the proportions of febrile children brought for medical treatment increased steadily over the last 30 years, with the greatest increases occurring in areas where rates had originally been lowest, which includes Latin America and Caribbean, North Africa and the Middle East (51 and 50% increase, respectively), and Sub-Saharan Africa (23% increase). Overall, the aggregated and population-weighted estimate of children with fever taken for treatment at any type of facility rose from 61% (59-64 95% CI) in 1990 to 71% (69-72 95% CI) in 2020. The overall population-weighted average for fraction of treatment in the public sector was largely unchanged during the study period: 49% (42-58 95% CI) sought care at public facilities in 1990 and 47% (44-52 95% CI) in 2020. Overall, the findings indicate that improvements in access to care have been made where they were most needed, but that despite rapid initial gains, progress can plateau without substantial investment. In 2020 there remained significant gaps in care utilisation that must be factored in when developing control strategies and deriving disease burden estimates.
Collapse
Affiliation(s)
- Michele Nguyen
- Asian School of the Environment, Nanyang Technological University, Singapore, Singapore
| | | | | | - Susan F. Rumisha
- Child Health Analytics, Telethon Kids Institute, Nedlands, WA, Australia
| | - Jennifer A. Rozier
- Child Health Analytics, Telethon Kids Institute, Nedlands, WA, Australia
| | - Joseph R. Harris
- Child Health Analytics, Telethon Kids Institute, Nedlands, WA, Australia
| | | | - Katherine A. Twohig
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | | | - Donal Bisanzio
- RTI International, Washington, District of Columbia, United States of America
- Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Ewan Cameron
- Child Health Analytics, Telethon Kids Institute, Nedlands, WA, Australia
- Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
| | - Daniel J. Weiss
- Child Health Analytics, Telethon Kids Institute, Nedlands, WA, Australia
- Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
| | - Samir Bhatt
- Department of Infectious Disease Epidemiology, Imperial College, St Mary’s Hospital, London, United Kingdom
- Department of Public Health, Section of Epidemiology, University of Copenhagen, Copenhagen, Denmark
| | - Peter W. Gething
- Child Health Analytics, Telethon Kids Institute, Nedlands, WA, Australia
- Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
| | - Katherine E. Battle
- Institute for Disease Modeling, Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
| |
Collapse
|
6
|
Liu M, Liu Y, Po L, Xia S, Huy R, Zhou XN, Liu J. Assessing the spatiotemporal malaria transmission intensity with heterogeneous risk factors: A modeling study in Cambodia. Infect Dis Model 2023; 8:253-269. [PMID: 36844760 PMCID: PMC9944205 DOI: 10.1016/j.idm.2023.01.006] [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: 09/26/2022] [Revised: 01/08/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
Malaria control can significantly benefit from a holistic and precise way of quantitatively measuring the transmission intensity, which needs to incorporate spatiotemporally varying risk factors. In this study, we conduct a systematic investigation to characterize malaria transmission intensity by taking a spatiotemporal network perspective, where nodes capture the local transmission intensities resulting from dominant vector species, the population density, and land cover, and edges describe the cross-region human mobility patterns. The inferred network enables us to accurately assess the transmission intensity over time and space from available empirical observations. Our study focuses on malaria-severe districts in Cambodia. The malaria transmission intensities determined using our transmission network reveal both qualitatively and quantitatively their seasonal and geographical characteristics: the risks increase in the rainy season and decrease in the dry season; remote and sparsely populated areas generally show higher transmission intensities than other areas. Our findings suggest that: the human mobility (e.g., in planting/harvest seasons), environment (e.g., temperature), and contact risk (coexistences of human and vector occurrence) contribute to malaria transmission in spatiotemporally varying degrees; quantitative relationships between these influential factors and the resulting malaria transmission risk can inform evidence-based tailor-made responses at the right locations and times.
Collapse
Affiliation(s)
- Mutong Liu
- Department of Computer Science, Hong Kong Baptist University, Hong Kong Special administrative region of China
- HKBU-CSD & NIPD Joint Research Laboratory for Intelligent Disease Surveillance and Control, China
| | - Yang Liu
- Department of Computer Science, Hong Kong Baptist University, Hong Kong Special administrative region of China
- HKBU-CSD & NIPD Joint Research Laboratory for Intelligent Disease Surveillance and Control, China
- Corresponding author. Department of Computer Science, Hong Kong Baptist University, Hong Kong Special administrative region of China.
| | - Ly Po
- National Center for Parasitology, Entomology & Malaria Control (CNM), Ministry of Health, Phnom Penh, Cambodia
| | - Shang Xia
- HKBU-CSD & NIPD Joint Research Laboratory for Intelligent Disease Surveillance and Control, China
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, National Health and Commission of the People's Republic of China, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Rekol Huy
- National Center for Parasitology, Entomology & Malaria Control (CNM), Ministry of Health, Phnom Penh, Cambodia
| | - Xiao-Nong Zhou
- HKBU-CSD & NIPD Joint Research Laboratory for Intelligent Disease Surveillance and Control, China
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, National Health and Commission of the People's Republic of China, Shanghai, China
- WHO Collaborating Center for Tropical Diseases, Shanghai, China
| | - Jiming Liu
- Department of Computer Science, Hong Kong Baptist University, Hong Kong Special administrative region of China
- HKBU-CSD & NIPD Joint Research Laboratory for Intelligent Disease Surveillance and Control, China
- Corresponding author. Department of Computer Science, Hong Kong Baptist University, Hong Kong Special administrative region of China.
| |
Collapse
|
7
|
An Overview of Malaria Transmission Mechanisms, Control, and Modeling. Med Sci (Basel) 2022; 11:medsci11010003. [PMID: 36649040 PMCID: PMC9844307 DOI: 10.3390/medsci11010003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/11/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
In sub-Saharan Africa, malaria is a leading cause of mortality and morbidity. As a result of the interplay between many factors, the control of this disease can be challenging. However, few studies have demonstrated malaria's complexity, control, and modeling although this perspective could lead to effective policy recommendations. This paper aims to be a didactic material providing the reader with an overview of malaria. More importantly, using a system approach lens, we intend to highlight the debated topics and the multifaceted thematic aspects of malaria transmission mechanisms, while showing the control approaches used as well as the model supporting the dynamics of malaria. As there is a large amount of information on each subject, we have attempted to provide a basic understanding of malaria that needs to be further developed. Nevertheless, this study illustrates the importance of using a multidisciplinary approach to designing next-generation malaria control policies.
Collapse
|
8
|
Dlamini SN, Fall IS, Mabaso SD. Bayesian Geostatistical Modeling to Assess Malaria Seasonality and Monthly Incidence Risk in Eswatini. J Epidemiol Glob Health 2022; 12:340-361. [PMID: 35976542 PMCID: PMC9382628 DOI: 10.1007/s44197-022-00054-4] [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: 05/12/2022] [Accepted: 08/06/2022] [Indexed: 11/30/2022] Open
Abstract
Eswatini is on the brink of malaria elimination and had however, had to shift its target year to eliminate malaria on several occasions since 2015 as the country struggled to achieve its zero malaria goal. We conducted a Bayesian geostatistical modeling study using malaria case data. A Bayesian distributed lags model (DLM) was implemented to assess the effects of seasonality on cases. A second Bayesian model based on polynomial distributed lags was implemented on the dataset to improve understanding of the lag effect of environmental factors on cases. Results showed that malaria increased during the dry season with proportion 0.051 compared to the rainy season with proportion 0.047 while rainfall of the preceding month (Lag2) had negative effect on malaria as it decreased by proportion − 0.25 (BCI: − 0.46, − 0.05). Night temperatures of the preceding first and second month were significantly associated with increased malaria in the following proportions: at Lag1 0.53 (BCI: 0.23, 0.84) and at Lag2 0.26 (BCI: 0.01, 0.51). Seasonality was an important predictor of malaria with proportion 0.72 (BCI: 0.40, 0.98). High malaria rates were identified for the months of July to October, moderate rates in the months of November to February and low rates in the months of March to June. The maps produced support-targeted malaria control interventions. The Bayesian geostatistical models could be extended for short-term and long-term forecasting of malaria supporting-targeted response both in space and time for effective elimination.
Collapse
Affiliation(s)
- Sabelo Nick Dlamini
- Department of Geography, University of Eswatini, Kwaluseni, Manzini, M200, Eswatini. .,World Health Organization, 27 Geneva, Geneva, Switzerland.
| | | | - Sizwe Doctor Mabaso
- Department of Geography, University of Eswatini, Kwaluseni, Manzini, M200, Eswatini
| |
Collapse
|
9
|
Karim A, de Savigny D, Awor P, Cobos Muñoz D, Mäusezahl D, Kitoto Tshefu A, Ngaima JS, Enebeli U, Isiguzo C, Nsona H, Ogbonnaya I, Ngoy P, Alegbeleye A. The building blocks of community health systems: a systems framework for the design, implementation and evaluation of iCCM programs and community-based interventions. BMJ Glob Health 2022; 7:bmjgh-2022-008493. [PMID: 35772810 PMCID: PMC9247653 DOI: 10.1136/bmjgh-2022-008493] [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: 01/11/2022] [Accepted: 05/30/2022] [Indexed: 11/08/2022] Open
Abstract
Introduction Almost all sub-Saharan African countries have adopted some form of integrated community case management (iCCM) to reduce child mortality, a strategy targeting common childhood diseases in hard-to-reach communities. These programs are complex, maintain diverse implementation typologies and involve many components that can influence the potential success of a program or its ability to effectively perform at scale. While tools and methods exist to support the design and implementation of iCCM and measure its progress, these may not holistically consider some of its key components, which can include program structure, setting context and the interplay between community, human resources, program inputs and health system processes. Methods We propose a Global South-driven, systems-based framework that aims to capture these different elements and expand on the fundamental domains of iCCM program implementation. We conducted a content analysis developing a code frame based on iCCM literature, a review of policy documents and discussions with key informants. The framework development was guided by a combination of health systems conceptual frameworks and iCCM indices. Results The resulting framework yielded 10 thematic domains comprising 106 categories. These are complemented by a catalogue of critical questions that program designers, implementers and evaluators can ask at various stages of program development to stimulate meaningful discussion and explore the potential implications of implementation in decentralised settings. Conclusion The iCCM Systems Framework proposed here aims to complement existing intervention benchmarks and indicators by expanding the scope and depth of the thematic components that comprise it. Its elements can also be adapted for other complex community interventions. While not exhaustive, the framework is intended to highlight the many forces involved in iCCM to help managers better harmonise the organisation and evaluation of their programs and examine their interactions within the larger health system.
Collapse
Affiliation(s)
- Aliya Karim
- University of Basel, Basel, Switzerland .,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Don de Savigny
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Phyllis Awor
- Department of Community Health and Behavioural Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | - Daniel Cobos Muñoz
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Daniel Mäusezahl
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Jean Serge Ngaima
- School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Ugo Enebeli
- Department of Community Medicine, University of Port Harcourt, Choba, Rivers State, Nigeria
| | - Chinwoke Isiguzo
- School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Society for Family Health Nigeria, Abuja, Nigeria
| | - Humphreys Nsona
- IMCI, Malawi Ministry of Health, Lilongwe, Central Region, Malawi
| | - Ikechi Ogbonnaya
- Department of Health, Planning, Research & Statistics, Federal Ministry of Health, Abuja, Federal Capital Territory, Nigeria
| | - Pascal Ngoy
- PROSANI, USAID, Washington, District of Columbia, USA
| | | |
Collapse
|
10
|
Huber JH, Hsiang MS, Dlamini N, Murphy M, Vilakati S, Nhlabathi N, Lerch A, Nielsen R, Ntshalintshali N, Greenhouse B, Perkins TA. Inferring person-to-person networks of Plasmodium falciparum transmission: are analyses of routine surveillance data up to the task? Malar J 2022; 21:58. [PMID: 35189905 PMCID: PMC8860266 DOI: 10.1186/s12936-022-04072-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 01/31/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inference of person-to-person transmission networks using surveillance data is increasingly used to estimate spatiotemporal patterns of pathogen transmission. Several data types can be used to inform transmission network inferences, yet the sensitivity of those inferences to different data types is not routinely evaluated. METHODS The influence of different combinations of spatial, temporal, and travel-history data on transmission network inferences for Plasmodium falciparum malaria were evaluated. RESULTS The information content of these data types may be limited for inferring person-to-person transmission networks and may lead to an overestimate of transmission. Only when outbreaks were temporally focal or travel histories were accurate was the algorithm able to accurately estimate the reproduction number under control, Rc. Applying this approach to data from Eswatini indicated that inferences of Rc and spatiotemporal patterns therein depend upon the choice of data types and assumptions about travel-history data. CONCLUSIONS These results suggest that transmission network inferences made with routine malaria surveillance data should be interpreted with caution.
Collapse
Affiliation(s)
- John H Huber
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
| | - Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, CA, USA.,Department of Pediatrics, University of California, San Francisco,, CA, USA
| | - Nomcebo Dlamini
- National Malaria Elimination Programme, Ministry of Health, Manzini, Eswatini
| | - Maxwell Murphy
- Department of Medicine, University of California, San Francisco, CA, USA
| | | | - Nomcebo Nhlabathi
- National Malaria Elimination Programme, Ministry of Health, Manzini, Eswatini
| | - Anita Lerch
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Rasmus Nielsen
- Department of Integrative Biology and Statistics, University of California, Berkeley, CA, USA
| | | | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - T Alex Perkins
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
| |
Collapse
|
11
|
Amoah B, McCann RS, Kabaghe AN, Mburu M, Chipeta MG, Moraga P, Gowelo S, Tizifa T, van den Berg H, Mzilahowa T, Takken W, van Vugt M, Phiri KS, Diggle PJ, Terlouw DJ, Giorgi E. Identifying Plasmodium falciparum transmission patterns through parasite prevalence and entomological inoculation rate. eLife 2021; 10:65682. [PMID: 34672946 PMCID: PMC8530514 DOI: 10.7554/elife.65682] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Background Monitoring malaria transmission is a critical component of efforts to achieve targets for elimination and eradication. Two commonly monitored metrics of transmission intensity are parasite prevalence (PR) and the entomological inoculation rate (EIR). Comparing the spatial and temporal variations in the PR and EIR of a given geographical region and modelling the relationship between the two metrics may provide a fuller picture of the malaria epidemiology of the region to inform control activities. Methods Using geostatistical methods, we compare the spatial and temporal patterns of Plasmodium falciparum EIR and PR using data collected over 38 months in a rural area of Malawi. We then quantify the relationship between EIR and PR by using empirical and mechanistic statistical models. Results Hotspots identified through the EIR and PR partly overlapped during high transmission seasons but not during low transmission seasons. The estimated relationship showed a 1-month delayed effect of EIR on PR such that at lower levels of EIR, increases in EIR are associated with rapid rise in PR, whereas at higher levels of EIR, changes in EIR do not translate into notable changes in PR. Conclusions Our study emphasises the need for integrated malaria control strategies that combine vector and human host managements monitored by both entomological and parasitaemia indices. Funding This work was supported by Stichting Dioraphte grant number 13050800.
Collapse
Affiliation(s)
- Benjamin Amoah
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - Robert S McCann
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.,Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, United States
| | - Alinune N Kabaghe
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Monicah Mburu
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.,Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Michael G Chipeta
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Malawi-Liverpool Wellcome Trust Research Programme, Blantyre, Malawi.,Big Data Institute, University of Oxford, Oxford, United Kingdom
| | - Paula Moraga
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom.,Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Steven Gowelo
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.,Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Tinashe Tizifa
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Henk van den Berg
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands
| | - Themba Mzilahowa
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands
| | - Michele van Vugt
- Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Kamija S Phiri
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Peter J Diggle
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - Dianne J Terlouw
- Department of Public Health, College of Medicine, University of Malawi, Blantyre, Malawi.,Malawi-Liverpool Wellcome Trust Research Programme, Blantyre, Malawi.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Emanuele Giorgi
- Centre for Health Informatics, Computing, and Statistics (CHICAS), Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| |
Collapse
|
12
|
Monteiro EF, Fernandez-Becerra C, Curado I, Wunderlich G, Hiyane MI, Kirchgatter K. Antibody Profile Comparison against MSP1 Antigens of Multiple Plasmodium Species in Human Serum Samples from Two Different Brazilian Populations Using a Multiplex Serological Assay. Pathogens 2021; 10:1138. [PMID: 34578170 PMCID: PMC8470980 DOI: 10.3390/pathogens10091138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmodium malariae has a wide geographic distribution, but mainly at very low parasitemias and in co-infections, leading to an underestimated prevalence of this species. Studies for the detection of antibodies against Plasmodium recombinant proteins are increasingly used to map geographical distributions, seroprevalence and transmission intensities of malaria infection. However, no seroepidemiological survey using recombinant P. malariae proteins has been conducted in Brazil. This work evaluated the antibody response in serum samples of individuals from endemic regions of Brazil (the Amazon region and Atlantic Forest) against five recombinant proteins of P. malariae merozoite surface protein 1 (MSP1), and the MSP1 C-terminal portions of P. vivax and P. falciparum, in a multiplex assay. The positivity was 69.5% of samples recognizing at least one MSP1 recombinant protein. The mean of the Reactivity Index for the C-terminal portion of the P. falciparum was significantly higher compared to the other recombinant proteins, followed by the C-terminal of P. vivax and the N-terminal of P. malariae. Among the recombinant P. malariae proteins, the N-terminal of P. malariae showed the highest Reactivity Index alone. This study validates the use of the multiplex assay to measure naturally acquired IgG antibodies against Plasmodium MSP1 proteins and demonstrate that these proteins are important tools for seroepidemiological surveys and could be used in malaria surveillance.
Collapse
Affiliation(s)
- Eliana Ferreira Monteiro
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, Brazil; (E.F.M.); (I.C.)
| | - Carmen Fernandez-Becerra
- ISGlobal, Hospital Clínic—Universitat de Barcelona, 08036 Barcelona, Spain;
- Germans Trias i Pujol Health Science Research Institute (IGTP), 08916 Badalona, Spain
| | - Izilda Curado
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, Brazil; (E.F.M.); (I.C.)
- Departamento de Laboratórios Especializados, Superintendência de Controle de Endemias, São Paulo 01027-000, Brazil
| | - Gerhard Wunderlich
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508-000, Brazil;
| | - Meire Ioshie Hiyane
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo 05508-900, Brazil;
| | - Karin Kirchgatter
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-000, Brazil; (E.F.M.); (I.C.)
- Departamento de Laboratórios Especializados, Superintendência de Controle de Endemias, São Paulo 01027-000, Brazil
| |
Collapse
|
13
|
McMahon A, Mihretie A, Ahmed AA, Lake M, Awoke W, Wimberly MC. Remote sensing of environmental risk factors for malaria in different geographic contexts. Int J Health Geogr 2021; 20:28. [PMID: 34120599 PMCID: PMC8201719 DOI: 10.1186/s12942-021-00282-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/03/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Despite global intervention efforts, malaria remains a major public health concern in many parts of the world. Understanding geographic variation in malaria patterns and their environmental determinants can support targeting of malaria control and development of elimination strategies. METHODS We used remotely sensed environmental data to analyze the influences of environmental risk factors on malaria cases caused by Plasmodium falciparum and Plasmodium vivax from 2014 to 2017 in two geographic settings in Ethiopia. Geospatial datasets were derived from multiple sources and characterized climate, vegetation, land use, topography, and surface water. All data were summarized annually at the sub-district (kebele) level for each of the two study areas. We analyzed the associations between environmental data and malaria cases with Boosted Regression Tree (BRT) models. RESULTS We found considerable spatial variation in malaria occurrence. Spectral indices related to land cover greenness (NDVI) and moisture (NDWI) showed negative associations with malaria, as the highest malaria rates were found in landscapes with low vegetation cover and moisture during the months that follow the rainy season. Climatic factors, including precipitation and land surface temperature, had positive associations with malaria. Settlement structure also played an important role, with different effects in the two study areas. Variables related to surface water, such as irrigated agriculture, wetlands, seasonally flooded waterbodies, and height above nearest drainage did not have strong influences on malaria. CONCLUSION We found different relationships between malaria and environmental conditions in two geographically distinctive areas. These results emphasize that studies of malaria-environmental relationships and predictive models of malaria occurrence should be context specific to account for such differences.
Collapse
Affiliation(s)
- Andrea McMahon
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, OK USA
| | - Abere Mihretie
- Health, Development, and Anti-Malaria Association, Addis Ababa, Ethiopia
| | - Adem Agmas Ahmed
- Malaria Control and Elimination Partnership in Africa, Bahir Dar, Ethiopia
| | | | - Worku Awoke
- School of Public Health, Bahir Dar University, Bahir Dar, Ethiopia
| | - Michael Charles Wimberly
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, OK USA
| |
Collapse
|
14
|
Lucas TCD, Nandi AK, Chestnutt EG, Twohig KA, Keddie SH, Collins EL, Howes RE, Nguyen M, Rumisha SF, Python A, Arambepola R, Bertozzi‐Villa A, Hancock P, Amratia P, Battle KE, Cameron E, Gething PW, Weiss DJ. Mapping malaria by sharing spatial information between incidence and prevalence data sets. J R Stat Soc Ser C Appl Stat 2021. [DOI: 10.1111/rssc.12484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Andre Python
- Big Data Institute University of Oxford Oxford UK
| | | | - Amelia Bertozzi‐Villa
- Big Data Institute University of Oxford Oxford UK
- Institute for Disease Modeling Bellevue Washington USA
| | | | | | | | - Ewan Cameron
- Big Data Institute University of Oxford Oxford UK
| | - Peter W. Gething
- Big Data Institute University of Oxford Oxford UK
- Telethon Kids Institute Perth Children's Hospital Perth Australia
- Curtin University Perth Australia
| | | |
Collapse
|
15
|
Oliveira TMP, Laporta GZ, Bergo ES, Chaves LSM, Antunes JLF, Bickersmith SA, Conn JE, Massad E, Sallum MAM. Vector role and human biting activity of Anophelinae mosquitoes in different landscapes in the Brazilian Amazon. Parasit Vectors 2021; 14:236. [PMID: 33957959 PMCID: PMC8101188 DOI: 10.1186/s13071-021-04725-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/16/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Environmental disturbance, deforestation and socioeconomic factors all affect malaria incidence in tropical and subtropical endemic areas. Deforestation is the major driver of habitat loss and fragmentation, which frequently leads to shifts in the composition, abundance and spatial distribution of vector species. The goals of the present study were to: (i) identify anophelines found naturally infected with Plasmodium; (ii) measure the effects of landscape on the number of Nyssorhynchus darlingi, presence of Plasmodium-infected Anophelinae, human biting rate (HBR) and malaria cases; and (iii) determine the frequency and peak biting time of Plasmodium-infected mosquitoes and Ny. darlingi. METHODS Anopheline mosquitoes were collected in peridomestic and forest edge habitats in seven municipalities in four Amazon Brazilian states. Females were identified to species and tested for Plasmodium by real-time PCR. Negative binomial regression was used to measure any association between deforestation and number of Ny. darlingi, number of Plasmodium-infected Anophelinae, HBR and malaria. Peak biting time of Ny. darlingi and Plasmodium-infected Anophelinae were determined in the 12-h collections. Binomial logistic regression measured the association between presence of Plasmodium-infected Anophelinae and landscape metrics and malaria cases. RESULTS Ninety-one females of Ny. darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B were found to be infected with Plasmodium. Analysis showed that the number of malaria cases and the number of Plasmodium-infected Anophelinae were more prevalent in sites with higher edge density and intermediate forest cover (30-70%). The distance of the drainage network to a dwelling was inversely correlated to malaria risk. The peak biting time of Plasmodium-infected Anophelinae was 00:00-03:00 h. The presence of Plasmodium-infected mosquitoes was higher in landscapes with > 13 malaria cases. CONCLUSIONS Nyssorhynchus darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B can be involved in malaria transmission in rural settlements. The highest fraction of Plasmodium-infected Anophelinae was caught from midnight to 03:00 h. In some Amazonian localities, the highest exposure to infectious bites occurs when residents are sleeping, but transmission can occur throughout the night. Forest fragmentation favors increases in both malaria and the occurrence of Plasmodium-infected mosquitoes in peridomestic habitat. The use of insecticide-impregnated mosquito nets can decrease human exposure to infectious Anophelinae and malaria transmission.
Collapse
Affiliation(s)
- Tatiane M P Oliveira
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo, 715, Cerqueira César, São Paulo, SP, 01246-904, Brazil.
| | - Gabriel Z Laporta
- Setor de Pós-Graduação, Pesquisa e Inovação, Centro Universitário Saúde ABC (FMABC), Fundação ABC, Santo André, SP, Brazil
| | - Eduardo S Bergo
- Superintendencia de Controle de Endemias, Secretaria de Estado da Saúde, Araraquara, SP, Brazil
| | - Leonardo Suveges Moreira Chaves
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo, 715, Cerqueira César, São Paulo, SP, 01246-904, Brazil
| | - José Leopoldo F Antunes
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo, 715, Cerqueira César, São Paulo, SP, 01246-904, Brazil
| | | | - Jan E Conn
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
- Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, NY, USA
| | - Eduardo Massad
- Escola de Matemática Aplicada, Fundação Getúlio Vargas, Rio de Janeiro, RJ, Brazil
| | - Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo, 715, Cerqueira César, São Paulo, SP, 01246-904, Brazil
| |
Collapse
|
16
|
Fornace KM, Diaz AV, Lines J, Drakeley CJ. Achieving global malaria eradication in changing landscapes. Malar J 2021; 20:69. [PMID: 33530995 PMCID: PMC7856737 DOI: 10.1186/s12936-021-03599-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/20/2021] [Indexed: 11/10/2022] Open
Abstract
Land use and land cover changes, such as deforestation, agricultural expansion and urbanization, are one of the largest anthropogenic environmental changes globally. Recent initiatives to evaluate the feasibility of malaria eradication have highlighted impacts of landscape changes on malaria transmission and the potential of these changes to undermine malaria control and elimination efforts. Multisectoral approaches are needed to detect and minimize negative impacts of land use and land cover changes on malaria transmission while supporting development aiding malaria control, elimination and ultimately eradication. Pathways through which land use and land cover changes disrupt social and ecological systems to increase or decrease malaria risks are outlined, identifying priorities and opportunities for a global malaria eradication campaign. The impacts of land use and land cover changes on malaria transmission are complex and highly context-specific, with effects changing over time and space. Landscape changes are only one element of a complex development process with wider economic and social dimensions affecting human health and wellbeing. While deforestation and other landscape changes threaten to undermine malaria control efforts and have driven the emergence of zoonotic malaria, most of the malaria elimination successes have been underpinned by agricultural development and land management. Malaria eradication is not feasible without addressing these changing risks while, conversely, consideration of malaria impacts in land management decisions has the potential to significantly accelerate progress towards eradication. Multisectoral cooperation and approaches to linking malaria control and environmental science, such as conducting locally relevant ecological monitoring, integrating landscape data into malaria surveillance systems and designing environmental management strategies to reduce malaria burdens, are essential to achieve malaria eradication.
Collapse
Affiliation(s)
- Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. .,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK.
| | - Adriana V Diaz
- Pathology and Population Sciences, Royal Veterinary College, Hatfield, UK
| | - Jo Lines
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| |
Collapse
|
17
|
Host feeding patterns of Nyssorhynchus darlingi (Diptera: Culicidae) in the Brazilian Amazon. Acta Trop 2021; 213:105751. [PMID: 33166514 DOI: 10.1016/j.actatropica.2020.105751] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 10/31/2020] [Indexed: 12/12/2022]
Abstract
Nyssorhynchus darlingi (Root) is the dominant malaria vector in the Brazilian Amazon River basin, with additional Anophelinae Grassi species involved in local and regional transmission. Mosquito blood-feeding behavior is an essential component to define the mosquito-human contact rate and shape the transmission cycle of vector-borne diseases. However, there is little information on the host preferences and blood-feeding behavior of Anophelinae vectors in rural Amazonian landscapes. The barrier screen sampling (BSS) method was employed to sample females from 34 peridomestic habitats in 27 rural communities from 11 municipalities in the Brazilian Amazon states of Acre, Amazonas, Pará and Rondônia, from August 2015 to November 2017. Nyssorhynchus darlingi comprised 97.94% of the females collected resting on barrier screens, and DNA sequence comparison detected 9 vertebrate hosts species. The HBI index ranged from 0.03-1.00. Results revealed the plasticity of Ny. darlingi in blood-feeding on a wide range of mainly mammalian hosts. In addition, the identification of blood meal sources using silica-dried females is appropriate for studies of human malaria vectors in remote locations.
Collapse
|
18
|
Chipoya MN, Shimaponda-Mataa NM. Prevalence, characteristics and risk factors of imported and local malaria cases in North-Western Province, Zambia: a cross-sectional study. Malar J 2020; 19:430. [PMID: 33228684 PMCID: PMC7686676 DOI: 10.1186/s12936-020-03504-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Imported malaria is a major challenge for countries that are in malaria elimination stage such as Zambia. Legitimate cross-border activities add to the risk of transmission, necessitating determination of prevalence, characteristics and risk factors of imported and local malaria. METHODS This cross-sectional study was conducted in 103 consented child and adult patients with clinical malaria symptoms, from selected health facilities in north-western Zambia. Patient demographic data and blood samples for malaria microscopy and full blood count were obtained. Chi-square and penalized logistic regression were performed to describe the characteristics and assess the risk factors of imported and local malaria in North-Western Province. RESULTS Overall, malaria prevalence was 78.6% with 93.8% Plasmodium falciparum and 6.2% other species. The local cases were 72 (88.9%) while the imported were 9 (11.1%) out of the 81 positive participants. About 98.6% of the local cases were P. falciparum compared to 55.6% (χ2 = 52.4; p < 0.01) P. falciparum among the imported cases. Among the imported cases, 44% were species other than P. falciparum (χ2 = 48; p < 0.01) while among the local cases only 1.4% were. Gametocytes were present in 44% of the imported malaria cases and only in 2.8% of the local cases (χ2 = 48; p < 0.01). About 48.6% of local participants had severe anaemia compared to 33.3% of participants from the two neighbouring countries who had (χ2 = 4.9; p = 0.03). In the final model, only country of residence related positively to presence of species other than P. falciparum (OR = 39.0, CI [5.9, 445.9]; p < 0.01) and presence of gametocytes (OR = 23.1, CI [4.2, 161.6]; p < 0.01). CONCLUSION Malaria prevalence in North-Western Province is high, with P. falciparum as the predominant species although importation of Plasmodium ovale and Plasmodium malariae is happening as well. Country of residence of patients is a major risk factor for malaria species and gametocyte presence. The need for enhanced malaria control with specific focus on border controls to detect and treat, for specific diagnosis and treatment according to species obtaining, for further research in the role of species and gametocytaemia in imported malaria, cannot be overemphasized.
Collapse
Affiliation(s)
- Maureen N Chipoya
- Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Ridgeway Campus, Lusaka, Zambia
| | - Nzooma M Shimaponda-Mataa
- Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Ridgeway Campus, Lusaka, Zambia.
| |
Collapse
|
19
|
Sallum MAM, Obando RG, Carrejo N, Wilkerson RC. Identification keys to the Anopheles mosquitoes of South America (Diptera: Culicidae). II. Fourth-instar larvae. Parasit Vectors 2020; 13:582. [PMID: 33208185 PMCID: PMC7672918 DOI: 10.1186/s13071-020-04299-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 08/08/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Accurate species identification of South American anophelines using morphological characters of the fourth-instar larva is problematic, because of the lack of up-to-date identification keys. In addition, taxonomic studies, employing scanning electron microscopy of the eggs and DNA sequence data, have uncovered multiple complexes of morphologically similar species, and resulted in the resurrection of other species from synonymy, mainly in the subgenus Nyssorhynchus. Consequently, the identification keys urgently need to be updated to provide accurate morphological tools to identify fourth-instar larvae of all valid species and species complexes. METHODS Morphological characters of the fourth-instar larvae of South American species of the genus Anopheles were examined and employed to elaborate a fully illustrated identification key. For species for which no specimens were available, illustrations were based on published literature records. RESULTS A fully illustrated key to the fourth-instar larvae of South American species of the genus Anopheles (Diptera: Culicidae) is presented. Definitions of the morphological terms used in the key are provided and illustrated. CONCLUSIONS Morphological identification of South American Anopheles species based on the fourth-instar larvae has been updated. Characters of the spiracular apparatus were determined useful for the identification of morphologically similar species, in the Strodei Group and some taxa in the Myzorhynchella Section. The single versus branched abdominal seta 6-IV used to differentiate Myzorhynchella species from other Nyssorhynchus species was shown to be variable in Myzorhynchella species. Also, the abdominal setae 1-IV,V of Anopheles atacamensis and Anopheles pictipennis were shown to be slightly serrate at the edges. Recognition of this character is important to avoid inaccurate identification of these species as members of the subgenus Anopheles.
Collapse
Affiliation(s)
- Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Avenida Doutor Arnaldo 715, São Paulo, São Paulo CEP01246-904 Brazil
| | | | - Nancy Carrejo
- Departamento de Biología, Universidad del Valle, A.A 25360 Cali, Colombia
| | - Richard C. Wilkerson
- Department of Entomology, Smithsonian Institution, National Museum of Natural History (NMNH), Washington, DC 20560 USA
- Walter Reed Biosystematics Unit, Smithsonian Institution Museum Support Center, 4210 Silver Hill Rd., Suitland, MD 20746 USA
- Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
| |
Collapse
|
20
|
Ghilardi L, Okello G, Nyondo-Mipando L, Chirambo CM, Malongo F, Hoyt J, Lee J, Sedekia Y, Parkhurst J, Lines J, Snow RW, Lynch CA, Webster J. How useful are malaria risk maps at the country level? Perceptions of decision-makers in Kenya, Malawi and the Democratic Republic of Congo. Malar J 2020; 19:353. [PMID: 33008465 PMCID: PMC7530951 DOI: 10.1186/s12936-020-03425-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/23/2020] [Indexed: 11/24/2022] Open
Abstract
Background Declining malaria prevalence and pressure on external funding have increased the need for efficiency in malaria control in sub-Saharan Africa (SSA). Modelled Plasmodium falciparum parasite rate (PfPR) maps are increasingly becoming available and provide information on the epidemiological situation of countries. However, how these maps are understood or used for national malaria planning is rarely explored. In this study, the practices and perceptions of national decision-makers on the utility of malaria risk maps, showing prevalence of parasitaemia or incidence of illness, was investigated. Methods A document review of recent National Malaria Strategic Plans was combined with 64 in-depth interviews with stakeholders in Kenya, Malawi and the Democratic Republic of Congo (DRC). The document review focused on the type of epidemiological maps included and their use in prioritising and targeting interventions. Interviews (14 Kenya, 17 Malawi, 27 DRC, 6 global level) explored drivers of stakeholder perceptions of the utility, value and limitations of malaria risk maps. Results Three different types of maps were used to show malaria epidemiological strata: malaria prevalence using a PfPR modelled map (Kenya); malaria incidence using routine health system data (Malawi); and malaria prevalence using data from the most recent Demographic and Health Survey (DRC). In Kenya the map was used to target preventative interventions, including long-lasting insecticide-treated nets (LLINs) and intermittent preventive treatment in pregnancy (IPTp), whilst in Malawi and DRC the maps were used to target in-door residual spraying (IRS) and LLINs distributions in schools. Maps were also used for operational planning, supply quantification, financial justification and advocacy. Findings from the interviews suggested that decision-makers lacked trust in the modelled PfPR maps when based on only a few empirical data points (Malawi and DRC). Conclusions Maps were generally used to identify areas with high prevalence in order to implement specific interventions. Despite the availability of national level modelled PfPR maps in all three countries, they were only used in one country. Perceived utility of malaria risk maps was associated with the epidemiological structure of the country and use was driven by perceived need, understanding (quality and relevance), ownership and trust in the data used to develop the maps.
Collapse
Affiliation(s)
- Ludovica Ghilardi
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
| | - George Okello
- Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya
| | - Linda Nyondo-Mipando
- Department of Health Systems and Policy, College of Medicine, University of Malawi, Blantyre, Malawi
| | | | - Fathy Malongo
- Kinshasa School of Public Health, University of Kinshasa, Mont Amba/Lemba, BP 11850 Kin I, Kinshasa, Democratic Republic of Congo
| | - Jenna Hoyt
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Jieun Lee
- World Vision UK, 1rb, 11 Belgrave Rd, Pimlico, London, SW1V 1RB, UK
| | - Yovitha Sedekia
- Mwanza Intervention Trials Unit (MITU)/ National Institute for Medical Research (NIMR)- Mwanza Research Centre, P.O BOX 11936, Isamilo road, Mwanza, Tanzania
| | - Justin Parkhurst
- London School of Economics and Political Science, Houghton Street, London, WC2A 2AE, UK
| | - Jo Lines
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Robert W Snow
- Kenya Medical Research Institute-Wellcome Trust Research Programme, P.O. Box 43640-00100, Nairobi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, OX3 7LJ, Oxford, UK
| | - Caroline A Lynch
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Jayne Webster
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| |
Collapse
|
21
|
Massad E, Laporta GZ, Conn JE, Chaves LS, Bergo ES, Figueira EAG, Bezerra Coutinho FA, Lopez LF, Struchiner C, Sallum MAM. The risk of malaria infection for travelers visiting the Brazilian Amazonian region: A mathematical modeling approach. Travel Med Infect Dis 2020; 37:101792. [PMID: 32771653 DOI: 10.1016/j.tmaid.2020.101792] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 05/30/2020] [Accepted: 06/15/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Human mobility between malaria endemic and malaria-free areas can hinder control and elimination efforts in the Amazon basin, maintaining Plasmodium circulation and introduction to new areas. METHODS The analysis begins by estimating the incidence of malaria in areas of interest. Then, the risk of infection as a function of the duration of stay after t0 was calculated as the number of infected travelers over the number of arrived travelers. Differential equations were employed to estimate the risk of nonimmune travelers acquiring malaria in Amazonian municipalities. Risk was calculated as a result of the force of the infection in terms of local dynamics per time of arrival and duration of visit. RESULTS Maximum risk occurred at the peak or at the end of the rainy season and it was nonlinearly (exponentially) correlated with the fraction of infected mosquitoes. Relationship between the risk of malaria and duration of visit was linear and positively correlated. Relationship between the risk of malaria and the time of arrival in the municipality was dependent on local effects of seasonality. CONCLUSIONS The risk of nonimmune travelers acquiring malaria is not negligible and can maintain regional circulation of parasites, propagating introductions in areas where malaria has been eliminated.
Collapse
Affiliation(s)
- Eduardo Massad
- Escola de Matemática Aplicada, Fundação Getúlio Vargas, Rio de Janeiro, Brazil
| | - Gabriel Zorello Laporta
- Setor de Pós-graduação, Pesquisa e Inovação, Centro Universitário Saúde ABC, Fundação do ABC, Santo André, SP, Brazil
| | - Jan Evelyn Conn
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Leonardo Suveges Chaves
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Eduardo Sterlino Bergo
- Superintendência de Controle de Endemias, Secretaria de Estado da Saúde de São Paulo, Araraquara, SP, Brazil
| | | | | | | | - Claudio Struchiner
- Escola de Matemática Aplicada, Fundação Getúlio Vargas, Rio de Janeiro, Brazil
| | - Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil.
| |
Collapse
|
22
|
Daniels RF, Schaffner SF, Dieye Y, Dieng G, Hainsworth M, Fall FB, Diouf CN, Ndiop M, Cisse M, Gueye AB, Sarr O, Guinot P, Deme AB, Bei AK, Sy M, Thwing J, MacInnis B, Earle D, Guinovart C, Sene D, Hartl DL, Ndiaye D, Steketee RW, Wirth DF, Volkman SK. Genetic evidence for imported malaria and local transmission in Richard Toll, Senegal. Malar J 2020; 19:276. [PMID: 32746830 PMCID: PMC7397603 DOI: 10.1186/s12936-020-03346-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 07/25/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Malaria elimination efforts can be undermined by imported malaria infections. Imported infections are classified based on travel history. METHODS A genetic strategy was applied to better understand the contribution of imported infections and to test for local transmission in the very low prevalence region of Richard Toll, Senegal. RESULTS Genetic relatedness analysis, based upon molecular barcode genotyping data derived from diagnostic material, provided evidence for both imported infections and ongoing local transmission in Richard Toll. Evidence for imported malaria included finding that a large proportion of Richard Toll parasites were genetically related to parasites from Thiès, Senegal, a region of moderate transmission with extensive available genotyping data. Evidence for ongoing local transmission included finding parasites of identical genotype that persisted across multiple transmission seasons as well as enrichment of highly related infections within the households of non-travellers compared to travellers. CONCLUSIONS These data indicate that, while a large number of infections may have been imported, there remains ongoing local malaria transmission in Richard Toll. These proof-of-concept findings underscore the value of genetic data to identify parasite relatedness and patterns of transmission to inform optimal intervention selection and placement.
Collapse
Affiliation(s)
- Rachel F. Daniels
- grid.38142.3c000000041936754XHarvard T.H. Chan School of Public Health, Boston, MA USA ,grid.66859.34Broad Institute, Cambridge, MA USA
| | | | | | | | | | - Fatou B. Fall
- Senegal National Malaria Control Programme, Dakar, Senegal
| | | | - Medoune Ndiop
- Senegal National Malaria Control Programme, Dakar, Senegal
| | | | | | - Oumar Sarr
- Senegal National Malaria Control Programme, Dakar, Senegal
| | | | - Awa B. Deme
- Dantec Teaching and Research Hospital, Dakar, Senegal
| | - Amy K. Bei
- grid.38142.3c000000041936754XHarvard T.H. Chan School of Public Health, Boston, MA USA
| | - Mouhamad Sy
- Dantec Teaching and Research Hospital, Dakar, Senegal
| | - Julie Thwing
- grid.416738.f0000 0001 2163 0069Centers for Disease Control and Prevention, Atlanta, GA USA
| | | | | | | | - Doudou Sene
- Senegal National Malaria Control Programme, Dakar, Senegal
| | - Daniel L. Hartl
- grid.38142.3c000000041936754XHarvard University, Cambridge, MA USA
| | - Daouda Ndiaye
- grid.8191.10000 0001 2186 9619Cheikh Anta Diop University, Dakar, Senegal
| | | | - Dyann F. Wirth
- grid.38142.3c000000041936754XHarvard T.H. Chan School of Public Health, Boston, MA USA ,grid.66859.34Broad Institute, Cambridge, MA USA
| | - Sarah K. Volkman
- grid.38142.3c000000041936754XHarvard T.H. Chan School of Public Health, Boston, MA USA ,grid.66859.34Broad Institute, Cambridge, MA USA ,grid.28203.3b0000 0004 0378 6053Simmons University, Boston, MA USA
| |
Collapse
|
23
|
Knudson A, González-Casabianca F, Feged-Rivadeneira A, Pedreros MF, Aponte S, Olaya A, Castillo CF, Mancilla E, Piamba-Dorado A, Sanchez-Pedraza R, Salazar-Terreros MJ, Lucchi N, Udhayakumar V, Jacob C, Pance A, Carrasquilla M, Apráez G, Angel JA, Rayner JC, Corredor V. Spatio-temporal dynamics of Plasmodium falciparum transmission within a spatial unit on the Colombian Pacific Coast. Sci Rep 2020; 10:3756. [PMID: 32111872 PMCID: PMC7048816 DOI: 10.1038/s41598-020-60676-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 01/29/2020] [Indexed: 02/07/2023] Open
Abstract
As malaria control programmes concentrate their efforts towards malaria elimination a better understanding of malaria transmission patterns at fine spatial resolution units becomes necessary. Defining spatial units that consider transmission heterogeneity, human movement and migration will help to set up achievable malaria elimination milestones and guide the creation of efficient operational administrative control units. Using a combination of genetic and epidemiological data we defined a malaria transmission unit as the area contributing 95% of malaria cases diagnosed at the catchment facility located in the town of Guapi in the South Pacific Coast of Colombia. We provide data showing that P. falciparum malaria transmission is heterogeneous in time and space and analysed, using topological data analysis, the spatial connectivity, at the micro epidemiological level, between parasite populations circulating within the unit. To illustrate the necessity to evaluate the efficacy of malaria control measures within the transmission unit in order to increase the efficiency of the malaria control effort, we provide information on the size of the asymptomatic reservoir, the nature of parasite genotypes associated with drug resistance as well as the frequency of the Pfhrp2/3 deletion associated with false negatives when using Rapid Diagnostic Tests.
Collapse
Affiliation(s)
- Angélica Knudson
- Departamento de Microbiología, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Felipe González-Casabianca
- Departamento de Matemáticas, Facultad de Ciencias, Universidad de Los Andes, Bogotá, Colombia.,Gestión y desarrollo urbanos, Facultad de Ciencia Política, Universidad del Rosario, Bogotá, Colombia
| | | | - Maria Fernanda Pedreros
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Samanda Aponte
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Adriana Olaya
- Secretaría Departamental de Salud del Cauca, Popayán, Colombia
| | | | - Elvira Mancilla
- Secretaría Departamental de Salud del Cauca, Popayán, Colombia
| | | | - Ricardo Sanchez-Pedraza
- Departamento de Psiquiatria, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Myriam Janeth Salazar-Terreros
- Post-doctoral fellow, Centro de Hematologia e Hemoterapia (HEMOCENTRO), Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
| | - Naomi Lucchi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Global Health, Centers for Disease Control and Prevention, Atlanta, 30030, GA, United States of America
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Global Health, Centers for Disease Control and Prevention, Atlanta, 30030, GA, United States of America
| | - Chris Jacob
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, CB10 1SA, United Kingdom
| | - Alena Pance
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, CB10 1SA, United Kingdom
| | - Manuela Carrasquilla
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, 02115, USA
| | - Giovanni Apráez
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia.,Secretaría Departamental de Salud del Cauca, Popayán, Colombia
| | - Jairo Andrés Angel
- Departamento de Matemáticas, Facultad de Ciencias, Universidad de Los Andes, Bogotá, Colombia.,Department of Mathematics and Statistics, Universidad del Norte, Barranquilla, Colombia
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, United Kingdom.
| | - Vladimir Corredor
- Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia.
| |
Collapse
|
24
|
Runge M, Snow RW, Molteni F, Thawer S, Mohamed A, Mandike R, Giorgi E, Macharia PM, Smith TA, Lengeler C, Pothin E. Simulating the council-specific impact of anti-malaria interventions: A tool to support malaria strategic planning in Tanzania. PLoS One 2020; 15:e0228469. [PMID: 32074112 PMCID: PMC7029840 DOI: 10.1371/journal.pone.0228469] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/16/2020] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION The decision-making process for malaria control and elimination strategies has become more challenging. Interventions need to be targeted at council level to allow for changing malaria epidemiology and an increase in the number of possible interventions. Models of malaria dynamics can support this process by simulating potential impacts of multiple interventions in different settings and determining appropriate packages of interventions for meeting specific expected targets. METHODS The OpenMalaria model of malaria dynamics was calibrated for all 184 councils in mainland Tanzania using data from malaria indicator surveys, school parasitaemia surveys, entomological surveillance, and vector control deployment data. The simulations were run for different transmission intensities per region and five interventions, currently or potentially included in the National Malaria Strategic Plan, individually and in combination. The simulated prevalences were fitted to council specific prevalences derived from geostatistical models to obtain council specific predictions of the prevalence and number of cases between 2017 and 2020. The predictions were used to evaluate in silico the feasibility of the national target of reaching a prevalence of below 1% by 2020, and to suggest alternative intervention stratifications for the country. RESULTS The historical prevalence trend was fitted for each council with an agreement of 87% in 2016 (95%CI: 0.84-0.90) and an agreement of 90% for the historical trend (2003-2016) (95%CI: 0.87-0.93) The current national malaria strategy was expected to reduce the malaria prevalence between 2016 and 2020 on average by 23.8% (95% CI: 19.7%-27.9%) if current case management levels were maintained, and by 52.1% (95% CI: 48.8%-55.3%) if the case management were improved. Insecticide treated nets and case management were the most cost-effective interventions, expected to reduce the prevalence by 25.0% (95% CI: 19.7%-30.2) and to avert 37 million cases between 2017 and 2020. Mass drug administration was included in most councils in the stratification selected for meeting the national target at minimal costs, expected to reduce the prevalence by 77.5% (95%CI: 70.5%-84.5%) and to avert 102 million cases, with almost twice higher costs than those of the current national strategy. In summary, the model suggested that current interventions are not sufficient to reach the national aim of a prevalence of less than 1% by 2020 and a revised strategic plan needs to consider additional, more effective interventions, especially in high transmission areas and that the targets need to be revisited. CONCLUSION The methodology reported here is based on intensive interactions with the NMCP and provides a helpful tool for assessing the feasibility of country specific targets and for determining which intervention stratifications at sub-national level will have most impact. This country-led application could support strategic planning of malaria control in many other malaria endemic countries.
Collapse
Affiliation(s)
- Manuela Runge
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Robert W. Snow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, England, United Kingodm
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Sumaiyya Thawer
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Ally Mohamed
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Renata Mandike
- National Malaria Control Programme (NMCP), Dar es Salaam, Tanzania
| | - Emanuele Giorgi
- CHICAS, Lancaster Medical School, Lancaster University, Lancaster, England, United Kingodm
| | - Peter M. Macharia
- Population Health Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - Thomas A. Smith
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Christian Lengeler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Emilie Pothin
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Clinton Health Access Initiative, Boston, Massachusetts, United States of America
| |
Collapse
|
25
|
Effect of Free Healthcare Policy for Children under Five Years Old on the Incidence of Reported Malaria Cases in Burkina Faso by Bayesian Modelling: "Not only the Ears but also the Head of the Hippopotamus". INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17020417. [PMID: 31936308 PMCID: PMC7014427 DOI: 10.3390/ijerph17020417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 12/24/2019] [Accepted: 01/03/2020] [Indexed: 02/02/2023]
Abstract
Burkina Faso has recently implemented an additional strategy, the free healthcare policy, to further improve maternal and child health. This policy targets children under five who bear the brunt of the malaria scourge. The effects of the free-of-charge healthcare were previously assessed in women but not in children. The present study aims at filling this gap by assessing the effect of this policy in children under five with a focus on the induced spatial and temporal changes in malaria morbidity. We used a Bayesian spatiotemporal negative binomial model to investigate the space–time variation in malaria incidence in relation to the implementation of the policy. The analysis relied on malaria routine surveillance data extracted from the national health data repository and spanning the period from January 2013 to December 2018. The model was adjusted for meteorological and contextual confounders. We found that the number of presumed and confirmed malaria cases per 1000 children per month increased between 2013 and 2018. We further found that the implementation of the free healthcare policy was significantly associated with a two-fold increase in the number of tested and confirmed malaria cases compared with the period before the policy rollout. This effect was, however, heterogeneous across the health districts. We attributed the rise in malaria incidence following the policy rollout to an increased use of health services combined with an increased availability of rapid tests and a higher compliance to the “test and treat” policy. The observed heterogeneity in the policy effect was attributed to parallel control interventions, some of which were rolled out at different paces and scales. Our findings call for a sustained and reinforced effort to test all suspected cases so that, alongside an improved case treatment, the true picture of the malaria scourge in children under five emerges clearly (see the hippopotamus almost entirely).
Collapse
|
26
|
Demari-Silva B, Laporta GZ, Oliveira T, Sallum M. Plasmodium infection in Kerteszia cruzii (Diptera: Culicidae) in the Atlantic tropical rain forest, southeastern Brazil. INFECTION GENETICS AND EVOLUTION 2019; 78:104061. [PMID: 31683005 DOI: 10.1016/j.meegid.2019.104061] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/28/2019] [Accepted: 10/02/2019] [Indexed: 01/19/2023]
Abstract
In Southeastern Brazil, Kerteszia cruzii (former Anopheles cruzii), a bromeliad mosquito species, is considered an efficient human Plasmodium spp. vector. In this region, recent studies showed asymptomatic or sub-patent Plasmodium falciparum infection. In areas of the Atlantic coast in Rio de Janeiro, Plasmodium simium infection was recently reported in both human and howler monkey. Considering that (1) few malaria cases are reported each year in areas across the tropical Atlantic rain forest in southeastern Brazil; (2) malaria elimination in Atlantic forest is challenged by circulation of P. falciparum and P. simium in humans; (3) the complexity of malaria epidemiology in this region; and (4) the public health importance of Kerteszia cruzii as a sylvatic vector; the major goal of this study is to evaluate Plasmodium infection in Ke. cruzii. Mosquito sampling collections were conducted in Esteiro do Morro and Sítio Itapuan, in Cananeia municipality, and Tapiraí municipality in Ribeira Valley, southeastern São Paulo state, Brazil. Influence of climate and landscape factors in Plasmodium infection in Ke. cruzii was addressed. Among the 1719 mosquitoes tested, 3 females collected in Sítio Itapuan and three from Tapiraí were found infected with either P. vivax or P. simium. Results of statistical analyses did not demonstrate association between Plasmodium infection in mosquito and the landscape. Mosquito infection was found in two landscape clusters, with Plasmodium detected in forest fringe mosquitoes. This finding shows that Ke. cruzii can facilitate transmission among human and non-human primates. Plasmodium falciparum was not identified in the samples analyzed. Spatiotemporal variation in local malaria incidence, low prevalence of Plasmodium, variations in humidity and temperature can explain the absence of mosquitoes infected with P. falciparum in the study.
Collapse
Affiliation(s)
- B Demari-Silva
- Faculdade de Saúde Pública, Departamento de Epidemiologia. Av. Dr. Arnaldo - 715, São Paulo, SP, CEP 01246-904, Brazil.
| | - G Z Laporta
- Centro Universitário Saúde ABC da Fundação ABC, Setor de Pós-graduação, Pesquisa e Inovação. Av. Lauro Gomes, 2000, Santo André, SP, CEP, 09060-870, Brazil.
| | - Tmp Oliveira
- Faculdade de Saúde Pública, Departamento de Epidemiologia. Av. Dr. Arnaldo - 715, São Paulo, SP, CEP 01246-904, Brazil.
| | - Mam Sallum
- Faculdade de Saúde Pública, Departamento de Epidemiologia. Av. Dr. Arnaldo - 715, São Paulo, SP, CEP 01246-904, Brazil.
| |
Collapse
|
27
|
Howes RE, Franchard T, Rakotomanga TA, Ramiranirina B, Zikursh M, Cramer EY, Tisch DJ, Kang SY, Ramboarina S, Ratsimbasoa A, Zimmerman PA. Risk Factors for Malaria Infection in Central Madagascar: Insights from a Cross-Sectional Population Survey. Am J Trop Med Hyg 2019; 99:995-1002. [PMID: 30182923 DOI: 10.4269/ajtmh.18-0417] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Community prevalence of infection is a widely used, standardized metric for evaluating malaria endemicity. Conventional methods for measuring prevalence include light microscopy and rapid diagnostic tests (RDTs), but their detection thresholds are inadequate for diagnosing low-density infections. The significance of submicroscopic malaria infections is poorly understood in Madagascar, a country of heterogeneous malaria epidemiology. A cross-sectional community survey in the western foothills of Madagascar during the March 2014 transmission season found malaria infection to be predominantly submicroscopic and asymptomatic. Prevalence of Plasmodium infection diagnosed by microscopy, RDT, and molecular diagnosis was 2.4%, 4.1%, and 13.8%, respectively. This diagnostic discordance was greatest for Plasmodium vivax infection, which was 98.5% submicroscopic. Village location, insecticide-treated bednet ownership, and fever were significantly associated with infection outcomes, as was presence of another infected individual in the household. Duffy-negative individuals were diagnosed with P. vivax, but with reduced odds relative to Duffy-positive hosts. The observation of high proportions of submicroscopic infections calls for a wider assessment of the parasite reservoir in other regions of the island, particularly given the country's current focus on malaria elimination and the poorly documented distribution of the non-P. falciparum parasite species.
Collapse
Affiliation(s)
- Rosalind E Howes
- Malaria Atlas Project, Nuffield Department of Medicine, Oxford Big Data Institute, University of Oxford, Oxford, United Kingdom.,The Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Thierry Franchard
- National Malaria Control Programme of Madagascar, Ministry of Health, Antananarivo, Madagascar
| | | | - Brune Ramiranirina
- National Malaria Control Programme of Madagascar, Ministry of Health, Antananarivo, Madagascar
| | - Melinda Zikursh
- The Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Estee Y Cramer
- The Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Daniel J Tisch
- The Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Su Y Kang
- Malaria Atlas Project, Nuffield Department of Medicine, Oxford Big Data Institute, University of Oxford, Oxford, United Kingdom
| | - Stéphanie Ramboarina
- National Malaria Control Programme of Madagascar, Ministry of Health, Antananarivo, Madagascar.,The Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Arsène Ratsimbasoa
- Faculty of Sciences, University of Antananarivo, Antananarivo, Madagascar.,Faculty of Medicine, University of Antananarivo, Antananarivo, Madagascar.,National Malaria Control Programme of Madagascar, Ministry of Health, Antananarivo, Madagascar
| | - Peter A Zimmerman
- The Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
28
|
Stresman G, Bousema T, Cook J. Malaria Hotspots: Is There Epidemiological Evidence for Fine-Scale Spatial Targeting of Interventions? Trends Parasitol 2019; 35:822-834. [PMID: 31474558 DOI: 10.1016/j.pt.2019.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/29/2019] [Accepted: 07/29/2019] [Indexed: 12/20/2022]
Abstract
As data at progressively granular spatial scales become available, the temptation is to target interventions to areas with higher malaria transmission - so-called hotspots - with the aim of reducing transmission in the wider community. This paper reviews literature to determine if hotspots are an intrinsic feature of malaria epidemiology and whether current evidence supports hotspot-targeted interventions. Hotspots are a consistent feature of malaria transmission at all endemicities. The smallest spatial unit capable of supporting transmission is the household, where peri-domestic transmission occurs. Whilst the value of focusing interventions to high-burden areas is evident, there is currently limited evidence that local-scale hotspots fuel transmission. As boundaries are often uncertain, there is no conclusive evidence that hotspot-targeted interventions accelerate malaria elimination.
Collapse
Affiliation(s)
- Gillian Stresman
- Infection Biology Department, London School of Hygiene and Tropical Medicine, London, UK.
| | - Teun Bousema
- Radboud University Medical Centre, Department of Microbiology, HB Nijmegen, The Netherlands.
| | - Jackie Cook
- Medical Research Council (MRC) Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| |
Collapse
|
29
|
Eisele TP. Mass drug administration can be a valuable addition to the malaria elimination toolbox. Malar J 2019; 18:281. [PMID: 31438950 PMCID: PMC6704699 DOI: 10.1186/s12936-019-2906-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/07/2019] [Indexed: 12/28/2022] Open
Abstract
The Global Technical Strategy 2016-2030 of the World Health Organization (WHO) has the ambitious goal of malaria being eliminated from at least 35 countries by 2030. However, in areas with once-stable malaria transmission, the reservoir of human infection may be intermittently symptomatic or fully silent yet still lead to transmission, posing a serious challenge to elimination. Mass drug administration (MDA), defined as the provision of a therapeutic dose of an effective anti-malarial drug to the entire target population, irrespective of infection status or symptoms, is one strategy to combat the silent human reservoir of infection. MDA is currently recommended by the WHO as a potential strategy for the elimination of Plasmodium falciparum malaria in areas approaching interruption of transmission, given the prerequisites of good access to case management, effective vector control and surveillance, and limited potential for reintroduction. Recent community randomized controlled trials of MDA with dihydroartemisinin-piperaquine, implemented as part of a comprehensive package of interventions, have shown this strategy to be safe and effective in significantly lowering the malaria burden in pre-elimination settings. Here it is argued that effectively implemented MDA should be kept in the elimination toolbox as a potential strategy for P. falciparum elimination in a variety of settings, including islands, appropriate low transmission settings, and in epidemics and complex emergencies. Effectively implemented MDA using an ACT has been shown to be safe, unrelated to the emergence of drug resistance, and may play an important role in sufficiently lowering the malaria burden to allow malaria transmission foci to be more easily identified, and to allow elimination programmes to more feasibly implement case-based surveillance and follow-up activities. To be most impactful and guard against drug resistance, MDA should use an ACT, achieve high programmatic coverage and adherence, be implemented when transmission is lowest in areas of limited risk of immediate parasite reintroduction, and must always be implemented only once good access to case management, high coverage of effective vector control, and strong surveillance have been achieved. If these considerations are taken into account, MDA should prove to be a valuable tool for the malaria elimination toolbox.
Collapse
Affiliation(s)
- Thomas P Eisele
- Department of Tropical Medicine, Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA.
| |
Collapse
|
30
|
Sallum MAM, Conn JE, Bergo ES, Laporta GZ, Chaves LSM, Bickersmith SA, de Oliveira TMP, Figueira EAG, Moresco G, Olívêr L, Struchiner CJ, Yakob L, Massad E. Vector competence, vectorial capacity of Nyssorhynchus darlingi and the basic reproduction number of Plasmodium vivax in agricultural settlements in the Amazonian Region of Brazil. Malar J 2019; 18:117. [PMID: 30947726 PMCID: PMC6449965 DOI: 10.1186/s12936-019-2753-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/28/2019] [Indexed: 11/10/2022] Open
Abstract
Background Brazilian malaria control programmes successfully reduced the incidence and mortality rates from 2005 to 2016. Since 2017, increased malaria has been reported across the Amazon. Few field studies focus on the primary malaria vector in high to moderate endemic areas, Nyssorhynchus darlingi, as the key entomological component of malaria risk, and on the metrics of Plasmodium vivax propagation in Amazonian rural communities. Methods Human landing catch collections were carried out in 36 houses of 26 communities in five municipalities in the Brazilian states of Acre, Amazonas and Rondônia states, with API (> 30). In addition, data on the number of locally acquired symptomatic infections were employed in mathematical modelling analyses carried out to determine Ny. darlingi vector competence and vectorial capacity to P. vivax; and to calculate the basic reproduction number for P. vivax. Results Entomological indices and malaria metrics ranged among localities: prevalence of P. vivax infection in Ny. darlingi, from 0.243% in Mâncio Lima, Acre to 3.96% in Machadinho D’Oeste, Rondônia; daily human-biting rate per person from 23 ± 1.18 in Cruzeiro do Sul, Acre, to 66 ± 2.41 in Lábrea, Amazonas; vector competence from 0.00456 in São Gabriel da Cachoeira, Amazonas to 0.04764 in Mâncio Lima, Acre; vectorial capacity from 0.0836 in Mâncio Lima, to 1.5 in Machadinho D’Oeste. The estimated R0 for P. vivax (PvR0) was 3.3 in Mâncio Lima, 7.0 in Lábrea, 16.8 in Cruzeiro do Sul, 55.5 in São Gabriel da Cachoeira, and 58.7 in Machadinho D’Oeste. Correlation between P. vivax prevalence in Ny. darlingi and vector competence was non-linear whereas association between prevalence of P. vivax in mosquitoes, vectorial capacity and R0 was linear and positive. Conclusions In spite of low vector competence of Ny. darlingi to P. vivax, parasite propagation in the human population is enhanced by the high human-biting rate, and relatively high vectorial capacity. The high PvR0 values suggest hyperendemicity in Machadinho D’Oeste and São Gabriel da Cachoeira at levels similar to those found for P. falciparum in sub-Saharan Africa regions. Mass screening for parasite reservoirs, effective anti-malarial drugs and vector control interventions will be necessary to shrinking transmission in Amazonian rural communities, Brazil. Electronic supplementary material The online version of this article (10.1186/s12936-019-2753-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Maria Anice M Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil.
| | - Jan E Conn
- Wadsworth Center, New York State Department of Health, Albany, NY, USA.,Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, NY, USA
| | - Eduardo S Bergo
- Superintendência de Controle de Endemias, Secretaria de Estado da Saúde de São Paulo, Araraquara, SP, Brazil
| | - Gabriel Z Laporta
- Setor de Pós-graduação, Pesquisa e Inovação, Faculdade de Medicina do ABC, Santo André, SP, Brazil
| | - Leonardo S M Chaves
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Tatiane M P de Oliveira
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Gilberto Moresco
- Secretaria de Vigilância em Saúde, Departamento de Vigilância das Doenças Transmissíveis, Ministério da Saúde, Brasília, DF, Brazil
| | - Lêuda Olívêr
- Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Claudio J Struchiner
- Departamento de Doenças Endêmicas Samuel Pessoa, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Laith Yakob
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Eduardo Massad
- Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.,Escola de Matemática Aplicada, Fundação Getúlio Vargas, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
31
|
Howes RE, Hawa K, Andriamamonjy VF, Franchard T, Miarimbola R, Mioramalala SA, Rafamatanantsoa JF, Rahantamalala MAM, Rajaobary SH, Rajaonera HDG, Rakotonindrainy AP, Rakotoson Andrianjatonavalona C, Randriamiarinjatovo DNAL, Randrianasolo FM, Ramasy Razafindratovo RM, Ravaoarimanga M, Ye M, Gething PW, Taylor CA. A stakeholder workshop about modelled maps of key malaria indicator survey indicators in Madagascar. Malar J 2019; 18:90. [PMID: 30902070 PMCID: PMC6431047 DOI: 10.1186/s12936-019-2729-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 03/14/2019] [Indexed: 11/29/2022] Open
Abstract
The Demographic and Health Surveys (DHS) Program has supported three household Malaria Indicator Surveys (MIS) in Madagascar. The results of 13 key malaria indicators from these surveys have been mapped as continuous surfaces using model-based geostatistical methods. The opportunities and limitations of these mapped outputs were discussed during a workshop in Antananarivo, Madagascar in July 2018, attended by 15 representatives from various implementation, policy and research stakeholder institutions in Madagascar. Participants evaluated the findings from the maps, using these to develop figures and narratives to support their work in the control of malaria in Madagascar.
Collapse
Affiliation(s)
- Rosalind E Howes
- Malaria Atlas Project, Nuffield Department of Medicine, Big Data Institute, University of Oxford, Oxford, UK.
| | - Kaleem Hawa
- Malaria Atlas Project, Nuffield Department of Medicine, Big Data Institute, University of Oxford, Oxford, UK
| | | | - Thierry Franchard
- Ministry of Health, Antananarivo, Madagascar.,Faculty of Science, University of Antananarivo, Antananarivo, Madagascar
| | - Raharizo Miarimbola
- Ministry of Health, Antananarivo, Madagascar.,Department of Public Health, Faculty of Medicine, University of Antananarivo, Antananarivo, Madagascar
| | - Sedera Aurélien Mioramalala
- Ministry of Health, Antananarivo, Madagascar.,Department of Public Health, Faculty of Medicine, University of Antananarivo, Antananarivo, Madagascar
| | | | - Mirana Ando Mbolatiana Rahantamalala
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar.,Department of Public Health, Faculty of Medicine, University of Antananarivo, Antananarivo, Madagascar
| | | | | | | | | | | | | | | | | | - Maurice Ye
- MEASURE-Evaluation, ICF, Antananarivo, Madagascar
| | - Peter W Gething
- Malaria Atlas Project, Nuffield Department of Medicine, Big Data Institute, University of Oxford, Oxford, UK
| | | |
Collapse
|
32
|
Dhiman S. Are malaria elimination efforts on right track? An analysis of gains achieved and challenges ahead. Infect Dis Poverty 2019; 8:14. [PMID: 30760324 PMCID: PMC6375178 DOI: 10.1186/s40249-019-0524-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 01/31/2019] [Indexed: 01/30/2023] Open
Abstract
Background Malaria causes significant morbidity and mortality each year. In the past few years, the global malaria cases have been declining and many endemic countries are heading towards malaria elimination. Nevertheless, reducing the number of cases seems to be easy than sustained elimination. Therefore to achieve the objective of complete elimination and maintaining the elimination status, it is necessary to assess the gains made during the recent years. Main text With inclining global support and World Health Organisation (WHO) efforts, the control programmes have been implemented effectively in many endemic countries. Given the aroused interest and investments into malaria elimination programmes at global level, the ambitious goal of elimination appears feasible. Sustainable interventions have played a pivotal role in malaria contraction, however drug and insecticide resistance, social, demographic, cultural and behavioural beliefs and practices, and unreformed health infrastructure could drift back the progress attained so far. Ignoring such impeding factors coupled with certain region specific factors may jeopardise our ability to abide righteous track to achieve global elimination of malaria parasite. Although support beyond the territories is important, but well managed integrated vector management approach at regional and country level using scrupulously selected area specific interventions targeting both vector and parasite along with the community involvement is necessary. A brief incline in malaria during 2016 has raised fresh perturbation on whether elimination could be achieved on time or not. Conclusions The intervention tools available currently can most likely reduce transmission but clearing of malaria epicentres from where the disease can flare up any time, is not possible without involving local population. Nevertheless maintaining zero malaria transmission and checks on malaria import in declared malaria free countries, and further speeding up of interventions to stop transmission in elimination countries is most desirable. Strong collaboration backed by adequate political and financial support among the countries with a common objective to eliminate malaria must be on top priority. The present review attempts to assess the progress gained in malaria elimination during the past few years and highlights some issues that could be important in successful malaria elimination. Electronic supplementary material The online version of this article (10.1186/s40249-019-0524-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sunil Dhiman
- Vector Management Division, Defence Research and Development Establishment, Gwalior, Madhya Pradesh, 474002, India.
| |
Collapse
|
33
|
Greenhouse B, Daily J, Guinovart C, Goncalves B, Beeson J, Bell D, Chang MA, Cohen JM, Ding X, Domingo G, Eisele TP, Lammie PJ, Mayor A, Merienne N, Monteiro W, Painter J, Rodriguez I, White M, Drakeley C, Mueller I. Priority use cases for antibody-detecting assays of recent malaria exposure as tools to achieve and sustain malaria elimination. Gates Open Res 2019; 3:131. [PMID: 31172051 PMCID: PMC6545519 DOI: 10.12688/gatesopenres.12897.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2019] [Indexed: 01/12/2023] Open
Abstract
Measurement of malaria specific antibody responses represents a practical and informative method for malaria control programs to assess recent exposure to infection. Technical advances in recombinant antigen production, serological screening platforms, and analytical methods have enabled the identification of several target antigens for laboratory based and point-of-contact tests. Questions remain as to how these serological assays can best be integrated into malaria surveillance activities to inform programmatic decision-making. This report synthesizes discussions from a convening at Institut Pasteur in Paris in June 2017 aimed at defining practical and informative use cases for serology applications and highlights five programmatic uses for serological assays including: documenting the absence of transmission; stratification of transmission; measuring the effect of interventions; informing a decentralized immediate response; and testing and treating P. vivax hypnozoite carriers.
Collapse
Affiliation(s)
- Bryan Greenhouse
- Department of Medicine,, University of California San Francisco, San Francisco, CA, USA
| | | | - Caterina Guinovart
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- PATH, Seattle, WA, USA
| | | | | | - David Bell
- Intellectual Ventures, Bellevue, WA, USA
| | | | | | | | | | - Thomas P. Eisele
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | | | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | - Wuelto Monteiro
- Tropical Medicine Foundation Dr. Heitor Viera Dourado, Manaus, Amazonas, Brazil
| | - John Painter
- Centers of Disease Control and Prevention, Atlanta, GA, USA
| | - Isabel Rodriguez
- Department of Medicine,, University of California San Francisco, San Francisco, CA, USA
| | | | - Chris Drakeley
- London School of Tropical Medicine & Hygiene, London, UK
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - The Malaria Serology Convening
- Department of Medicine,, University of California San Francisco, San Francisco, CA, USA
- Consultant to UNITAID, Denver, CO, USA
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- PATH, Seattle, WA, USA
- London School of Tropical Medicine & Hygiene, London, UK
- The Burnet Institute, Melbourne, Australia
- Intellectual Ventures, Bellevue, WA, USA
- Centers of Disease Control and Prevention, Atlanta, GA, USA
- Clinton Health Access Initiative (CHAI), Boston, MA, USA
- FIND, Geneva, Switzerland
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
- Institut Pasteur, Paris, France
- Tropical Medicine Foundation Dr. Heitor Viera Dourado, Manaus, Amazonas, Brazil
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| |
Collapse
|
34
|
Operational Performance of a Plasmodium falciparum Ultrasensitive Rapid Diagnostic Test for Detection of Asymptomatic Infections in Eastern Myanmar. J Clin Microbiol 2018; 56:JCM.00565-18. [PMID: 29898998 PMCID: PMC6062819 DOI: 10.1128/jcm.00565-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/05/2018] [Indexed: 11/21/2022] Open
Abstract
In the Greater Mekong Subregion in Southeast Asia, malaria elimination strategies need to target all Plasmodium falciparum parasites, including those carried asymptomatically. More than 70% of asymptomatic carriers are not detected by current rapid diagnostic tests (RDTs) or microscopy. In the Greater Mekong Subregion in Southeast Asia, malaria elimination strategies need to target all Plasmodium falciparum parasites, including those carried asymptomatically. More than 70% of asymptomatic carriers are not detected by current rapid diagnostic tests (RDTs) or microscopy. An HRP2-based ultrasensitive RDT (uRDT) developed to improve the detection of low-density infections was evaluated during prevalence surveys within a malaria elimination program in a low-transmission area of eastern Myanmar. Surveys were conducted to identify high-prevalence villages. Two-milliliter venous blood samples were collected from asymptomatic adult volunteers and transported to the laboratory. Plasmodium parasites were detected by RDT, uRDT, microscopy, ultrasensitive qPCR (uPCR), and multiplex enzyme-linked immunosorbent assay (ELISA). The sensitivity, specificity, and predictive positive and negative values of RDT and uRDT were calculated compared to uPCR and ELISA. Parasite and antigen concentrations detected by each test were defined using uPCR and ELISA, respectively. A total of 1,509 samples, including 208 P. falciparum-positive samples were analyzed with all tests. The sensitivity of the uRDT was twofold higher than that of RDT, 51.4% versus 25.2%, with minor specificity loss, 99.5% versus 99.9%, against the combined reference (uPCR plus ELISA). The geometric mean parasitemia detected by uRDT in P. falciparum monospecific infections was 3,019 parasites per ml (95% confidence interval [95% CI], 1,790 to 5,094; n = 79) compared to 11,352 parasites per ml (95% CI, 5,643 to 22,837; n = 38) by RDT. The sensitivities of uRDT and RDT dropped to 34.6% and 15.1%, respectively, for the matched tests performed in the field. The uRDT performed consistently better than RDT and microscopy at low parasitemias. It shows promising characteristics for the identification of high-prevalence communities and warrants further evaluation in mass screening and treatment interventions.
Collapse
|
35
|
Umer MF, Zofeen S, Majeed A, Hu W, Qi X, Zhuang G. Spatiotemporal Clustering Analysis of Malaria Infection in Pakistan. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E1202. [PMID: 29880778 PMCID: PMC6025434 DOI: 10.3390/ijerph15061202] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/24/2018] [Accepted: 06/04/2018] [Indexed: 11/21/2022]
Abstract
Despite tremendous progress, malaria remains a serious public health problem in Pakistan. Very few studies have been done on spatiotemporal evaluation of malaria infection in Pakistan. The study aimed to detect the spatiotemporal pattern of malaria infection at the district level in Pakistan, and to identify the clusters of high-risk disease areas in the country. Annual data on malaria for two dominant species (Plasmodium falciparum, Plasmodium vivax) and mixed infections from 2011 to 2016 were obtained from the Directorate of Malaria Control Program, Pakistan. Population data were collected from the Pakistan Bureau of Statistics. A geographical information system was used to display the spatial distribution of malaria at the district level throughout Pakistan. Purely spatiotemporal clustering analysis was performed to identify the high-risk areas of malaria infection in Pakistan. A total of 1,593,409 positive cases were included in this study over a period of 6 years (2011⁻2016). The maximum number of P. vivax cases (474,478) were reported in Khyber Pakhtunkhwa (KPK). The highest burden of P. falciparum (145,445) was in Balochistan, while the highest counts of mixed Plasmodium cases were reported in Sindh (22,421) and Balochistan (22,229), respectively. In Balochistan, incidence of all three types of malaria was very high. Cluster analysis showed that primary clusters of P. vivax malaria were in the same districts in 2014, 2015 and 2016 (total 24 districts, 12 in Federally Administered Tribal Areas (FATA), 9 in KPK, 2 in Punjab and 1 in Balochistan); those of P. falciparum malaria were unchanged in 2012 and 2013 (total 18 districts, all in Balochistan), and mixed infections remained the same in 2014 and 2015 (total 7 districts, 6 in Balochistan and 1 in FATA). This study indicated that the transmission cycles of malaria infection vary in different spatiotemporal settings in Pakistan. Efforts in controlling P. vivax malaria in particular need to be enhanced in high-risk areas. Based on these findings, further research is needed to investigate the impact of risk factors on transmission of malaria in Pakistan.
Collapse
Affiliation(s)
- Muhammad Farooq Umer
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
| | - Shumaila Zofeen
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
| | - Abdul Majeed
- Directorate of Malaria Control Program, Islamabad 44000, Pakistan.
| | - Wenbiao Hu
- School of Public Health and Social Work, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia.
| | - Xin Qi
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
- Global Health Institute, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
| | - Guihua Zhuang
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
| |
Collapse
|
36
|
Affiliation(s)
- Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, San Francisco, California
| | - Jennifer L Smith
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, San Francisco, California
| |
Collapse
|
37
|
Kang SY, Battle KE, Gibson HS, Ratsimbasoa A, Randrianarivelojosia M, Ramboarina S, Zimmerman PA, Weiss DJ, Cameron E, Gething PW, Howes RE. Spatio-temporal mapping of Madagascar's Malaria Indicator Survey results to assess Plasmodium falciparum endemicity trends between 2011 and 2016. BMC Med 2018; 16:71. [PMID: 29788968 PMCID: PMC5964908 DOI: 10.1186/s12916-018-1060-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/24/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Reliable measures of disease burden over time are necessary to evaluate the impact of interventions and assess sub-national trends in the distribution of infection. Three Malaria Indicator Surveys (MISs) have been conducted in Madagascar since 2011. They provide a valuable resource to assess changes in burden that is complementary to the country's routine case reporting system. METHODS A Bayesian geostatistical spatio-temporal model was developed in an integrated nested Laplace approximation framework to map the prevalence of Plasmodium falciparum malaria infection among children from 6 to 59 months in age across Madagascar for 2011, 2013 and 2016 based on the MIS datasets. The model was informed by a suite of environmental and socio-demographic covariates known to influence infection prevalence. Spatio-temporal trends were quantified across the country. RESULTS Despite a relatively small decrease between 2013 and 2016, the prevalence of malaria infection has increased substantially in all areas of Madagascar since 2011. In 2011, almost half (42.3%) of the country's population lived in areas of very low malaria risk (<1% parasite prevalence), but by 2016, this had dropped to only 26.7% of the population. Meanwhile, the population in high transmission areas (prevalence >20%) increased from only 2.2% in 2011 to 9.2% in 2016. A comparison of the model-based estimates with the raw MIS results indicates there was an underestimation of the situation in 2016, since the raw figures likely associated with survey timings were delayed until after the peak transmission season. CONCLUSIONS Malaria remains an important health problem in Madagascar. The monthly and annual prevalence maps developed here provide a way to evaluate the magnitude of change over time, taking into account variability in survey input data. These methods can contribute to monitoring sub-national trends of malaria prevalence in Madagascar as the country aims for geographically progressive elimination.
Collapse
Affiliation(s)
- Su Yun Kang
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Katherine E Battle
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Harry S Gibson
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arsène Ratsimbasoa
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar.,University of Antananarivo, Antananarivo, Madagascar
| | - Milijaona Randrianarivelojosia
- Institut Pasteur de Madagascar, Antananarivo, Madagascar.,Faculté des Sciences, Université de Toliara, Toliara, Madagascar
| | - Stéphanie Ramboarina
- National Malaria Control Programme, Ministry of Health, Antananarivo, Madagascar.,University of Antananarivo, Antananarivo, Madagascar.,Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Peter A Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Daniel J Weiss
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ewan Cameron
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Peter W Gething
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rosalind E Howes
- Malaria Atlas Project, Oxford Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
38
|
Briand D, Roux E, Desconnets JC, Gervet C, Barcellos C. From global action against malaria to local issues: state of the art and perspectives of web platforms dealing with malaria information. Malar J 2018; 17:122. [PMID: 29562918 PMCID: PMC5863370 DOI: 10.1186/s12936-018-2270-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 03/13/2018] [Indexed: 11/30/2022] Open
Abstract
Background Since prehistory to present times and despite a rough combat against it, malaria remains a concern for human beings. While evolutions of science and technology through times allowed for some infectious diseases eradication in the 20th century, malaria resists. Objectives This review aims at assessing how Internet and web technologies are used in fighting malaria. Precisely, how do malaria fighting actors profit from these developments, how do they deal with ensuing phenomena, such as the increase of data volume, and did these technologies bring new opportunities for fighting malaria? Methods Eleven web platforms linked to spatio-temporal malaria information are reviewed, focusing on data, metadata, web services and categories of users. Results Though the web platforms are highly heterogeneous the review reveals that the latest advances in web technologies are underused. Information are rarely updated dynamically, metadata catalogues are absent, web services are more and more used, but rarely standardized, and websites are mainly dedicated to scientific communities, essentially researchers. Conclusion Improvement of systems interoperability, through standardization, is an opportunity to be seized in order to allow real time information exchange and online multisource data analysis. To facilitate multidisciplinary/multiscale studies, the web of linked data and the semantic web innovations can be used in order to formalize the different view points of actors involved in the combat against malaria. By doing so, new malaria fighting strategies could take place, to tackle the bottlenecks listed in the United Nation Millennium Development Goals reports, but also specific issues highlighted by the World Health Organization such as malaria elimination in international borders. Electronic supplementary material The online version of this article (10.1186/s12936-018-2270-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Dominique Briand
- FIOCRUZ, LIS Laboratory, Avenida Brasil, 4365, Pavilhão Haity Moussatché, Rio de Janeiro, Brazil. .,IRD, UMR ESPACE-DEV, Maison de la télédétection, 500 rue Jean François Breton, 34090, Montpelllier, France.
| | - Emmanuel Roux
- IRD, UMR ESPACE-DEV, Maison de la télédétection, 500 rue Jean François Breton, 34090, Montpelllier, France
| | - Jean Christophe Desconnets
- IRD, UMR ESPACE-DEV, Maison de la télédétection, 500 rue Jean François Breton, 34090, Montpelllier, France
| | - Carmen Gervet
- Université de Montpellier, UMR ESPACE-DEV, Maison de la télédétection, 500 rue Jean François Breton, 34090, Montpellier, France
| | - Christovam Barcellos
- FIOCRUZ, LIS Laboratory, Avenida Brasil, 4365, Pavilhão Haity Moussatché, Rio de Janeiro, Brazil
| |
Collapse
|
39
|
Catry T, Li Z, Roux E, Herbreteau V, Gurgel H, Mangeas M, Seyler F, Dessay N. Wetlands and Malaria in the Amazon: Guidelines for the Use of Synthetic Aperture Radar Remote-Sensing. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E468. [PMID: 29518988 PMCID: PMC5877013 DOI: 10.3390/ijerph15030468] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 11/16/2022]
Abstract
The prevention and control of mosquito-borne diseases, such as malaria, are important health issues in tropical areas. Malaria transmission is a multi-scale process strongly controlled by environmental factors, and the use of remote-sensing data is suitable for the characterization of its spatial and temporal dynamics. Synthetic aperture radar (SAR) is well-adapted to tropical areas, since it is capable of imaging independent of light and weather conditions. In this study, we highlight the contribution of SAR sensors in the assessment of the relationship between vectors, malaria and the environment in the Amazon region. More specifically, we focus on the SAR-based characterization of potential breeding sites of mosquito larvae, such as man-made water collections and natural wetlands, providing guidelines for the use of SAR capabilities and techniques in order to optimize vector control and malaria surveillance. In light of these guidelines, we propose a framework for the production of spatialized indicators and malaria risk maps based on the combination of SAR, entomological and epidemiological data to support malaria risk prevention and control actions in the field.
Collapse
Affiliation(s)
- Thibault Catry
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), 34093 Montpellier, France.
| | - Zhichao Li
- Ministry of Education, Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China.
| | - Emmanuel Roux
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), 34093 Montpellier, France.
| | - Vincent Herbreteau
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), 34093 Montpellier, France.
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), SEAS-OI, 97410 La Réunion, France.
| | - Helen Gurgel
- Department of Geography (GEA), University of Brasília (UnB), Brasília 70910-900, Brazil.
| | - Morgan Mangeas
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), 98848 Nouvelle-Calédonie, France.
| | - Frédérique Seyler
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), 34093 Montpellier, France.
| | - Nadine Dessay
- ESPACE-DEV, UMR 228 IRD/UM/UR/UG/UA, Institut de Recherche pour le Développement (IRD), 34093 Montpellier, France.
| |
Collapse
|
40
|
Kraemer MUG, Bisanzio D, Reiner RC, Zakar R, Hawkins JB, Freifeld CC, Smith DL, Hay SI, Brownstein JS, Perkins TA. Inferences about spatiotemporal variation in dengue virus transmission are sensitive to assumptions about human mobility: a case study using geolocated tweets from Lahore, Pakistan. EPJ DATA SCIENCE 2018; 7:16. [PMID: 30854281 PMCID: PMC6404370 DOI: 10.1140/epjds/s13688-018-0144-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/31/2018] [Indexed: 05/14/2023]
Abstract
UNLABELLED Billions of users of mobile phones, social media platforms, and other technologies generate an increasingly large volume of data that has the potential to be leveraged towards solving public health challenges. These and other big data resources tend to be most successful in epidemiological applications when utilized within an appropriate conceptual framework. Here, we demonstrate the importance of assumptions about host mobility in a framework for dynamic modeling of infectious disease spread among districts within a large urban area. Our analysis focused on spatial and temporal variation in the transmission of dengue virus (DENV) during a series of large seasonal epidemics in Lahore, Pakistan during 2011-2014. Similar to many directly transmitted diseases, DENV transmission occurs primarily where people spend time during daytime hours, given that DENV is transmitted by a day-biting mosquito. We inferred spatiotemporal variation in DENV transmission under five different assumptions about mobility patterns among ten districts of Lahore: no movement among districts, movement following patterns of geo-located tweets, movement proportional to district population size, and movement following the commonly used gravity and radiation models. Overall, we found that inferences about spatiotemporal variation in DENV transmission were highly sensitive to this range of assumptions about intra-urban human mobility patterns, although the three assumptions that allowed for a modest degree of intra-urban mobility all performed similarly in key respects. Differing inferences about transmission patterns based on our analysis are significant from an epidemiological perspective, as they have different implications for where control efforts should be targeted and whether conditions for transmission became more or less favorable over time. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (10.1140/epjds/s13688-018-0144-x) contains supplementary material.
Collapse
Affiliation(s)
- Moritz U. G. Kraemer
- Department of Pediatrics, Harvard Medical School, Boston, USA
- Computational Epidemiology Lab, Boston Children’s Hospital, Boston, USA
- Department of Zoology, University of Oxford, Oxford, UK
| | - D. Bisanzio
- RTI International, Washington, USA
- Center for Tropical Diseases, Sacro Cuore-Don Calabria Hospital, Negrar, Italy
| | - R. C. Reiner
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA
| | - R. Zakar
- Department of Public Health, University of Punjab, Lahore, Pakistan
| | - J. B. Hawkins
- Department of Pediatrics, Harvard Medical School, Boston, USA
- Computational Epidemiology Lab, Boston Children’s Hospital, Boston, USA
| | - C. C. Freifeld
- Computational Epidemiology Lab, Boston Children’s Hospital, Boston, USA
- College of Computer and Information Science, Northeastern University, Boston, USA
| | - D. L. Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, USA
| | - S. I. Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, USA
| | - J. S. Brownstein
- Department of Pediatrics, Harvard Medical School, Boston, USA
- Computational Epidemiology Lab, Boston Children’s Hospital, Boston, USA
| | - T. Alex Perkins
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA
| |
Collapse
|