Characterization Of Plasmodium Falciparum And Plasmodium Vivax Recent Exposure In An Area Of Significantly Decreased Transmission Intensity In Central Vietnam, Johanna Helena Kattenberg, Annette Erhart, Minh Hieu Truong, Eduard Rovira-Vallbona, Khac Anh Dung Vu, Thi Hong Ngoc Nguyen, Van Hong Nguyen, Van Van Nguyen, Melanie Bannister-Tyrrell, Michael Theisen, Adam Bennet, Andrew A. Lover, Thanh Duong Tran, Xuan Xa Nguyen, Anna Rosanas-Urgell
Dec 2017
Characterization Of Plasmodium Falciparum And Plasmodium Vivax Recent Exposure In An Area Of Significantly Decreased Transmission Intensity In Central Vietnam, Johanna Helena Kattenberg, Annette Erhart, Minh Hieu Truong, Eduard Rovira-Vallbona, Khac Anh Dung Vu, Thi Hong Ngoc Nguyen, Van Hong Nguyen, Van Van Nguyen, Melanie Bannister-Tyrrell, Michael Theisen, Adam Bennet, Andrew A. Lover, Thanh Duong Tran, Xuan Xa Nguyen, Anna Rosanas-Urgell
Andrew Lover
Background
In Vietnam, malaria transmission has been reduced to very low levels over the past 20 years, and as a consequence, the country aims to eliminate malaria by 2030. This study aimed to characterize the dynamics and extent of the parasite reservoir in Central Vietnam, in order to further target elimination strategies and surveillance.
Methods
A 1-year prospective cohort study (n = 429) was performed in three rural communities in Quang Nam province. Six malaria screenings were conducted between November 2014 and November 2015, including systematic clinical examination and blood sampling for malaria parasite identification, as well as molecular and serological …
Prevalence And Risk Factors For Asymptomatic Malaria And Genotyping Of Glucose 6-Phosphate (G6pd) Deficiencies In A Vivax-Predominant Setting, Lao Pdr: Implications For Sub-National Elimination Goals, Andrew A. Lover, Emily Dantzer, Bouasy Hongvanthong, Keobouphaphone Chindavongsa, Susie Welty, Tania Reza, Nimol Khim, Didier Menard, Adam Bennett
Dec 2017
Prevalence And Risk Factors For Asymptomatic Malaria And Genotyping Of Glucose 6-Phosphate (G6pd) Deficiencies In A Vivax-Predominant Setting, Lao Pdr: Implications For Sub-National Elimination Goals, Andrew A. Lover, Emily Dantzer, Bouasy Hongvanthong, Keobouphaphone Chindavongsa, Susie Welty, Tania Reza, Nimol Khim, Didier Menard, Adam Bennett
Andrew Lover
Background
Lao People Democratic Republic (PDR; Laos), a landlocked country in Southeast Asia, has made important progress in reducing malaria morbidity and mortality in the past 5–6 years, and the northern provinces have very low reported incidence. To support national progress towards elimination, it is critical to verify and understand these changes in disease burden.
Methods
A two-stage cluster cross-sectional survey was conducted in four districts within four northern provinces (Khua, Phongsaly Province; Paktha, Bokeo Province; Nambak, Luang Prabang, and Muang Et, Huaphanh Province). During September and October 2016, demographics and malaria risk factors were collected from a total of 1492 …
Malaria Elimination: Time To Target All Species, Andrew A. Lover, J. Kevin Baird, Roly Gosling, Ric N. Price
Dec 2017
Malaria Elimination: Time To Target All Species, Andrew A. Lover, J. Kevin Baird, Roly Gosling, Ric N. Price
Andrew Lover
Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again under discussion. If the ambitious goal of eradication is to be achieved by 2040, all species of Plasmodium infecting humans will need to be targeted with evidence-based and concerted interventions. In this perspective, the potential barriers to achieving global malaria elimination are discussed with respect to the related diversities in host, parasite, and vector populations. We argue that control strategies need to be reorientated from a sequential attack on each species, dominated by Plasmodium …
Regional Initiatives For Malaria Elimination: Building And Maintaining Partnerships, Andrew A. Lover, Kelly E. Harvard, Alistair E. Lindawson, Cara Smith Gueye, Rima Shretta, Roly Gosling, Richard Feachem
Dec 2016
Regional Initiatives For Malaria Elimination: Building And Maintaining Partnerships, Andrew A. Lover, Kelly E. Harvard, Alistair E. Lindawson, Cara Smith Gueye, Rima Shretta, Roly Gosling, Richard Feachem
Andrew Lover
- Country programs and international donors are increasingly focused on regional approaches to malaria elimination; regional initiatives have been established in southern Africa, the Arabian Peninsula, Asia Pacific, Eastern Europe, and Latin America. Despite this growing attention, there is limited information and guidance on both key activities and organizational components of regional initiatives.
- In a review conducted for this policy forum, common characteristics across existing regional initiatives emerged: building a region-specific evidence base, leveraging expertise and resources, shifting commodities or pooling procurement, developing data-sharing systems, mobilizing resources, promoting high-level accountability, and strengthening advocacy.
- Regional initiatives share key structural elements: a strategic …
Malaria Risk Factors And Care-Seeking Behaviour Within The Private Sector Among High-Risk Populations In Vietnam: A Qualitative Study, Ingrid Chen, Huong Ngo Thi Thanh, Andrew A. Lover, Phung Thi Thao, Tang Viet Luu, Hoang Nghia Thang, Ngo Duc Thang, Josselyn Neukom, Adam Bennett
Dec 2016
Malaria Risk Factors And Care-Seeking Behaviour Within The Private Sector Among High-Risk Populations In Vietnam: A Qualitative Study, Ingrid Chen, Huong Ngo Thi Thanh, Andrew A. Lover, Phung Thi Thao, Tang Viet Luu, Hoang Nghia Thang, Ngo Duc Thang, Josselyn Neukom, Adam Bennett
Andrew Lover
Background
Vietnam has successfully reduced malaria incidence by more than 90% over the past 10 years, and is now preparing for malaria elimination. However, the remaining malaria burden resides in individuals that are hardest to reach, in highly remote areas, where many malaria cases are treated through the informal private sector and are not reported to public health systems. This qualitative study aimed to contextualize and characterize the role of private providers, care-seeking behaviour of individuals at high risk of malaria, as well as risk factors that should be addressed through malaria elimination programmes in Vietnam.
Methods
Semi-structured qualitative interviews were …
Early Diagnosis Of Dengue Disease Severity In A Resource-Limited Asian Country, Philippe Cavailler, Arnaud Tarantola, Yee Sin Leo, Andrew A. Lover, Anne Rachline, Duch Moniboth, Rekol Huy, Ai Li Quake, Kdan Yuvatha, Veasna Duong, Jeremy L. Brett, Philippe Buchy
Dec 2015
Early Diagnosis Of Dengue Disease Severity In A Resource-Limited Asian Country, Philippe Cavailler, Arnaud Tarantola, Yee Sin Leo, Andrew A. Lover, Anne Rachline, Duch Moniboth, Rekol Huy, Ai Li Quake, Kdan Yuvatha, Veasna Duong, Jeremy L. Brett, Philippe Buchy
Andrew Lover
Background: Dengue is endemic throughout Cambodia, a country faced with significant health and economic challenges. We undertook a clinical study at the National Paediatric Hospital in Phnom Penh to evaluate clinical diagnostic parameters for dengue and predictors of disease outcome. Methods: Between September 2011 and January 2013, all consecutive inpatients aged between 1 and 15 years and presenting with suspected dengue were enrolled. They were clinically assessed using both the 1997 and 2009 WHO dengue classifications. Specimens were collected upon admission and discharge and tested for dengue at Institut Pasteur in Cambodia. Results: A total of 701 patients were screened. …
Eliminate Now: Seven Critical Actions Required To Accelerate Elimination Of Plasmodium Falciparum Malaria In The Greater Mekong Subregion, Andrew A. Lover, Roly Gosling, Richard Feachem, Jim Tulloch
Dec 2015
Eliminate Now: Seven Critical Actions Required To Accelerate Elimination Of Plasmodium Falciparum Malaria In The Greater Mekong Subregion, Andrew A. Lover, Roly Gosling, Richard Feachem, Jim Tulloch
Andrew Lover
The emergence in 2009 of Plasmodium falciparum parasites resistant to the primary therapies currently in use (artemisinin-based combination therapy, ACT) in Southeast Asia threatens to set back decades of global progress in malaria control and elimination. Progress to date through multiple sets of initiatives and partners to contain or eliminate these parasites has been hampered due to a wide range of organizational, financial, and health systems-level challenges. In this commentary, a set of seven specific and concrete actions are proposed to directly address these issues and to accelerate P. falciparum elimination within the Greater Mekong Subregion to avert a wider …
Serological Evidence For Localized And Persistent Antibody Response In Zika Virus-Positive Neonates With Microcephaly (Brazil, 2015)- A Secondary Analysis, Andrew A. Lover
Dec 2015
Serological Evidence For Localized And Persistent Antibody Response In Zika Virus-Positive Neonates With Microcephaly (Brazil, 2015)- A Secondary Analysis, Andrew A. Lover
Andrew Lover
A recent publication in The Lancet by Cordeiro and colleagues reported levels of IgM for Zika (ZIKV) and dengue (DENV) viruses in serum and cerebrospinal fluid (CSF) of 31 infants born with microcephaly in Brazil. 1 Their study suggests higher titers in CSF relative to serum in individual neonates, but no quantitative comparisons were reported. In this short report, the differences in antibody titers are quantified and compared between sample sources; across sampling periods; and between sample sources within individual neonates to more comprehensively understand these data to inform serological surveillance. These are statistically significant differences in ZIKV titers between …
Epidemiology Of Latency And Relapse In Plasmodium Vivax Malaria, Andrew A. Lover
Dec 2014
Epidemiology Of Latency And Relapse In Plasmodium Vivax Malaria, Andrew A. Lover
Andrew Lover
Malaria is a major contributor to health burdens throughout the regions where it is endemic. Historically, it was believed that there was limited morbidity and essentially no mortality associated with Plasmodium vivax; however, evidence from diverse settings now suggests that infections with P. vivax can be both severe and fatal. This awareness has highlighted a critical gap: the vast majority of research has been directed towards P. falciparum, leading to a decades-long neglect of epidemiological and clinical studies of P. vivax. There exists a large body of historical data on human experimental infections with P. vivax; these studies in controlled …
Considerations For Comprehensive Analyses Of Sporozoite-Based Controlled Human Malaria Infection Studies, Andrew A. Lover
Dec 2014
Considerations For Comprehensive Analyses Of Sporozoite-Based Controlled Human Malaria Infection Studies, Andrew A. Lover
Andrew Lover
There has been renewed interest in the use of sporozoite-based approaches for controlled human malaria infections (CHMIs), and several sets of human challenge studies have recently completed. A study undertaken in Tanzania and published in 2014 found dose dependence between 10,000 and 25,000 sporozoite doses, as well as divergent times-to-parasitemia relative to earlier studies in European volunteers, with important implications for planning future studies. Analysis of time-to-event data has had extensive development in recent years, but these methods have had limited exposure outside biostatistics. Expansion of the published analyses to include recent methodological approaches optimized for the types of data …
Short Report: Study Variability In Recent Human Challenge Experiments With Plasmodium Falciparum Sporozoites (Pfspz Challenge), Andrew A. Lover
Dec 2014
Short Report: Study Variability In Recent Human Challenge Experiments With Plasmodium Falciparum Sporozoites (Pfspz Challenge), Andrew A. Lover
Andrew Lover
There has been renewed interest in the use of sporozoite-based approaches for malaria vaccination and controlled human infections, and several sets of human challenge studies have recently completed. A study undertaken in Tanzania and published in 2014 found dose-dependence between 10,000 and 25,000 sporozoite doses, as well as divergent times-to-parasitemia relative to earlier studies in European volunteers. However, this analysis shows that these conclusions are based upon suboptimal analytical methods; with more optimal analysis, there is no evidence for dose-dependence within this dose range; and more importantly, no evidence for differences in event times between Dutch and Tanzanian study sites. …
Spatial Epidemiology And Climatic Predictors Of Paediatric Dengue Infections Captured Via Sentinel Site Surveillance, Phnom Penh Cambodia 2011–2012, Andrew A. Lover, Philippe Buchy, Anne Rachline, Duch Moniboth, Rekol Huy, Chour Y. Meng, Yee Sin Leo, Kdan Yuvatha, Ung Sophal, Ngan Chantha, Bunthin Y, Veasna Duong, Sophie Goyet, Jeremy Brett, Arnaud Tarantola, Philippe Cavailler
Dec 2013
Spatial Epidemiology And Climatic Predictors Of Paediatric Dengue Infections Captured Via Sentinel Site Surveillance, Phnom Penh Cambodia 2011–2012, Andrew A. Lover, Philippe Buchy, Anne Rachline, Duch Moniboth, Rekol Huy, Chour Y. Meng, Yee Sin Leo, Kdan Yuvatha, Ung Sophal, Ngan Chantha, Bunthin Y, Veasna Duong, Sophie Goyet, Jeremy Brett, Arnaud Tarantola, Philippe Cavailler
Andrew Lover
Background
Dengue is a major contributor to morbidity in children aged twelve and below throughout Cambodia; the 2012 epidemic season was the most severe in the country since 2007, with more than 42,000 reported (suspect or confirmed) cases.
Methods
We report basic epidemiological characteristics in a series of 701 patients at the National Paediatric Hospital in Cambodia, recruited during a prospective clinical study (2011–2012). To more fully explore this cohort, we examined climatic factors using multivariate negative binomial models and spatial clustering of cases using spatial scan statistics to place the clinical study within a larger epidemiological framework.
Results
We …
Retention And Risk Factors For Attrition In A Large Public Health Art Program In Myanmar: A Retrospective Cohort Analysis, Aye Thida, Sai Thein Than Tun, Sai Ko Ko Zaw, Andrew A. Lover, Philippe Cavailler, Jennifer Chunn, Mar Mar Aye, Par Par, Kyaw Win Naing, Kaung Nyunt Zan, Myint Shwe Shwe, Thar Tun Kyaw, Zaw Htoon Waing, Philippe Clevenbergh
Dec 2013
Retention And Risk Factors For Attrition In A Large Public Health Art Program In Myanmar: A Retrospective Cohort Analysis, Aye Thida, Sai Thein Than Tun, Sai Ko Ko Zaw, Andrew A. Lover, Philippe Cavailler, Jennifer Chunn, Mar Mar Aye, Par Par, Kyaw Win Naing, Kaung Nyunt Zan, Myint Shwe Shwe, Thar Tun Kyaw, Zaw Htoon Waing, Philippe Clevenbergh
Andrew Lover
Background
The outcomes from an antiretroviral treatment (ART) program within the public sector in Myanmar have not been reported. This study documents retention and the risk factors for attrition in a large ART public health program in Myanmar.
Methods
A retrospective analysis of a cohort of adult patients enrolled in the Integrated HIV Care (IHC) Program between June 2005 and October 2011 and followed up until April 2012 is presented. The primary outcome was attrition (death or loss-follow up); a total of 10,223 patients were included in the 5-year cumulative survival analysis. Overall 5,718 patients were analyzed for the risk …
Note On The Origin Of The Madagascar Strain Of Plasmodium Vivax, Andrew A. Lover
Dec 2013
Note On The Origin Of The Madagascar Strain Of Plasmodium Vivax, Andrew A. Lover
Andrew Lover
Dear Sir:
Recent studies have established the potential for strains of
Plasmodium vivax in Madagascar to infect Duffy-negative populations,
1 and polymerase chain reaction (PCR)-based screening suggests a previously unrecognized burden of this parasite in sub-Saharan Africa.
2There is a dearth of data concerning any
P. vivax parasites from Africa; however, one of the most widely studied strains used during the malariotherapy era was the Madagascar strain, used at the Horton Hospital research site in the UK from 1923 to ca. 1970. This isolate has been the subject of extensive studies,
3,4 but there has been considerable …
Demographic And Spatial Predictors Of Anemia In Women Of Reproductive Age In Timor-Leste: Implications For Health Program Prioritization, Andrew A. Lover, Mikael Hartman, Kee Seng Chia, David L. Heymann
Dec 2013
Demographic And Spatial Predictors Of Anemia In Women Of Reproductive Age In Timor-Leste: Implications For Health Program Prioritization, Andrew A. Lover, Mikael Hartman, Kee Seng Chia, David L. Heymann
Andrew Lover
Anemia is a significant risk factor for poor health outcomes for both the mother and neonate; however, the determinants of anemia in many epidemiological settings are poorly understood. Using a subset of a nationally representative cluster survey (2010 Demographic and Health Survey) in combination with other non-contemporaneous survey data, the epidemiology of anemia among women of reproductive age in Timor-Leste has been explored. Logistic regression was used to identify risk factors, population-level impacts were estimated as population attributable fractions and spatial analytics were used to identify regions of highest risk. The DHS survey found that ∼21% of adult women in …
The Distribution Of Incubation And Relapse Times In Experimental Human Infections With The Malaria Parasite Plasmodium Vivax, Andrew A. Lover, Xiahong Zhao, Zheng Gao, Richard J. Coker, Alex R. Cook
Dec 2013
The Distribution Of Incubation And Relapse Times In Experimental Human Infections With The Malaria Parasite Plasmodium Vivax, Andrew A. Lover, Xiahong Zhao, Zheng Gao, Richard J. Coker, Alex R. Cook
Andrew Lover
Background
The distributions of incubation and relapse periods are key components of infectious disease models for the malaria parasite Plasmodium vivax; however, detailed distributions based upon experimental data are lacking.
Methods
Using a range of historical, experimental mosquito-transmitted human infections, Bayesian estimation with non-informative priors was used to determine parametric distributions that can be readily implemented for the incubation period and time-to-first relapse in P. vivax infections, including global subregions by parasite source. These analyses were complemented with a pooled analysis of observational human infection data with infections that included malaria chemoprophylaxis and long-latencies. The epidemiological impact of these …
Progression From New Methicillin-Resistant Staphylococcus Aureus Colonisation To Infection: An Observational Study In A Hospital Cohort, Michelle Nd Balm, Andrew A. Lover, Sharon Salmon, Paul A. Tambyah, Dale A. Fisher
Dec 2012
Progression From New Methicillin-Resistant Staphylococcus Aureus Colonisation To Infection: An Observational Study In A Hospital Cohort, Michelle Nd Balm, Andrew A. Lover, Sharon Salmon, Paul A. Tambyah, Dale A. Fisher
Andrew Lover
Background
Patients newly colonised with methicillin-resistant Staphylococcus aureus (MRSA) are at higher risk of clinical MRSA infection. At present, there are limited data on the duration or magnitude of this risk in a hospital population with a known time of MRSA acquisition.
Methods
A retrospective cohort study of 909 adult patients known to have newly identified MRSA colonisation during admission to National University Hospital, Singapore between 1 July 2007 and 30 June 2011 was undertaken. Patients were excluded if they had history of previous MRSA colonisation or infection, or if they had been a hospital inpatient in the preceding 12 …
Quantifying Effect Of Geographic Location On Epidemiology Of Plasmodium Vivax Malaria, Andrew A. Lover, Richard J. Coker
Dec 2012
Quantifying Effect Of Geographic Location On Epidemiology Of Plasmodium Vivax Malaria, Andrew A. Lover, Richard J. Coker
Andrew Lover
Recent autochthonous transmission of Plasmodium vivax malaria in previously malaria-free temperate regions has generated renewed interest in the epidemiology of this disease. Accurate estimates of the incubation period and time to relapse are required for effective malaria surveillance; however, this information is currently lacking. By using historical data from experimental human infections with diverse P. vivax strains, survival analysis models were used to obtain quantitative estimates of the incubation period and time to first relapse for P. vivax malaria in broad geographic regions. Results show that Eurasian strains from temperate regions have longer incubation periods, and Western Hemisphere strains from …
An Exploratory Study Of Treated-Bed Nets In Timor-Leste: Patterns Of Intended And Alternative Usage, Andrew A. Lover, Brett A. Sutton, Angelina J. Asy, Annelies Wilder-Smith
Dec 2010
An Exploratory Study Of Treated-Bed Nets In Timor-Leste: Patterns Of Intended And Alternative Usage, Andrew A. Lover, Brett A. Sutton, Angelina J. Asy, Annelies Wilder-Smith
Andrew Lover
Background
The Timor-Leste Ministry of Health has recently finalized the National Malaria Control Strategy for 2010-2020. A key component of this roadmap is to provide universal national coverage with long-lasting insecticide-treated nets (LLINs) in support of achieving the primary goal of reducing both morbidity and mortality from malaria by 30% in the first three years, followed by a further reduction of 20% by end of the programme cycle in 2020 [
1]. The strategic plan calls for this target to be supported by a comprehensive information, education and communication (IEC) programme; however, there is limited prior research into household …
