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Poespoprodjo JR, Hafiidhaturrahmah, Sariyanti N, Indrawanti R, McLean ARD, Simpson JA, Kenangalem E, Burdam FH, Noviyanti R, Trianty L, Fadhilah C, Soenarto Y, Price RN. Intermittent screening and treatment for malaria complementary to routine immunisation in the first year of life in Papua, Indonesia: a cluster randomised superiority trial. BMC Med 2022; 20:190. [PMID: 35672703 PMCID: PMC9175359 DOI: 10.1186/s12916-022-02394-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 05/04/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In Papua (Indonesia), infants with P. falciparum and/or P. vivax malaria are at risk of severe anaemia and death. We hypothesized that in an area of high malaria transmission, intermittent screening and treatment of infants with malaria (ISTi) will reduce morbidity compared to passive case detection (PCDi). METHODS We conducted a cluster randomised, open label, superiority trial. A total of 21 clusters of village health posts (VHP) were randomised 1:1 to either IST for infants coinciding with 4 routine immunisation visits or PCDi. Healthy term infants born to consenting mothers enrolled into a maternal malaria cluster randomised trial were included in the study and followed for 12 months. Point of care malaria rapid diagnostic tests were used to detect peripheral parasitaemia at 2, 3, 4 and 9 months old in all infants in ISTi clusters and when symptomatic in PCDi clusters. Infants with detected peripheral parasitaemia were treated with dihydroartemisinin-piperaquine. The co-primary outcomes were the incidence rate of clinical malaria in the first year of life and the prevalence of parasitaemia at age 12 months. The incidence rate ratio and prevalence ratio between ISTi and PCDi were estimated using mixed-effects Poisson and log-binomial regression modelling (accounting for clustering at VHP level). RESULTS Between May 2014 and February 2017, 757 infants were enrolled into the study, 313 into 10 ISTi clusters, and 444 into 11 PCDi clusters. Overall, 132 episodes of parasitaemia were detected, of whom 17 (12.9%) were in symptomatic infants. Over 12 months, the incidence rate (IR) of clinical malaria was 24 [95% CI, 10-50] per 1000 children-years at risk in the ISTi arm and 19 [95% CI, 8,38] per 1000 children-years in the PCDi arm (adjusted incidence rate ratio [aIRR] 1.77 [95% CI, 0.62-5.01]; p = 0.280). The prevalence of parasitaemia at 12 months was 13% (33/254) in the IST clusters and 15% (57/379) in the PCD clusters (adjusted prevalence ratio (aPR) = 0.92 (95% CI, 0.70-1.21), p = 0.55). There was no difference in the risk of anaemia between treatment arms. CONCLUSIONS In high malaria transmission area outside of Africa, our study suggests that compared to PCDi, ISTi offers no significant benefit in reducing the risk of clinical malaria in infants born to women receiving effective protection from malaria during pregnancy. TRIAL REGISTRATION ClinicalTrials.gov NCT02001428 , registered on 20 Nov 2013.
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Affiliation(s)
- Jeanne Rini Poespoprodjo
- Centre for Child Health and Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Kesehatan no.1, Sekip, Yogyakarta, 55284, Indonesia. .,Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Jl. SP2-SP5, RSMM Area, Timika, Papua, 99910, Indonesia. .,Mimika District Hospital and District Health Authority, Jl. Yos Sudarso, Timika, Papua, 99910, Indonesia.
| | - Hafiidhaturrahmah
- Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Jl. SP2-SP5, RSMM Area, Timika, Papua, 99910, Indonesia
| | - Novita Sariyanti
- Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Jl. SP2-SP5, RSMM Area, Timika, Papua, 99910, Indonesia
| | - Ratni Indrawanti
- Centre for Child Health and Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Kesehatan no.1, Sekip, Yogyakarta, 55284, Indonesia
| | - Alistair R D McLean
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, VIC, 3010, Melbourne, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, 207 Bouverie Street, VIC, 3010, Melbourne, Australia
| | - Enny Kenangalem
- Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Jl. SP2-SP5, RSMM Area, Timika, Papua, 99910, Indonesia
| | - Faustina Helena Burdam
- Timika Malaria Research Facility, Papuan Health and Community Development Foundation, Jl. SP2-SP5, RSMM Area, Timika, Papua, 99910, Indonesia.,Mimika District Hospital and District Health Authority, Jl. Yos Sudarso, Timika, Papua, 99910, Indonesia
| | - Rintis Noviyanti
- Eijkman Institute for Molecular Biology, Jl. Diponegoro No.69, Jakarta, 10430, Indonesia
| | - Leily Trianty
- Eijkman Institute for Molecular Biology, Jl. Diponegoro No.69, Jakarta, 10430, Indonesia
| | - Chairunisa Fadhilah
- Eijkman Institute for Molecular Biology, Jl. Diponegoro No.69, Jakarta, 10430, Indonesia
| | - Yati Soenarto
- Centre for Child Health and Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jl. Kesehatan no.1, Sekip, Yogyakarta, 55284, Indonesia
| | - Ric N Price
- Global Health Division, Menzies School of Health Research and Charles Darwin University, PO Box 41096, Casuarina, Darwin, NT, 0811, Australia.,Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX37LJ, UK.,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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2
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Abstract
BACKGROUND Intermittent preventive treatment could help prevent malaria in infants (IPTi) living in areas of moderate to high malaria transmission in sub-Saharan Africa. The World Health Organization (WHO) policy recommended IPTi in 2010, but its adoption in countries has been limited. OBJECTIVES To evaluate the effects of intermittent preventive treatment (IPT) with antimalarial drugs to prevent malaria in infants living in malaria-endemic areas. SEARCH METHODS We searched the following sources up to 3 December 2018: the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library), MEDLINE (PubMed), Embase (OVID), LILACS (Bireme), and reference lists of articles. We also searched the metaRegister of Controlled Trials (mRCT) and the WHO International Clinical Trials Registry Platform (ICTRP) portal for ongoing trials up to 3 December 2018. SELECTION CRITERIA We included randomized controlled trials (RCTs) that compared IPT to placebo or no intervention in infants (defined as young children aged between 1 to 12 months) in malaria-endemic areas. DATA COLLECTION AND ANALYSIS The primary outcome was clinical malaria (fever plus asexual parasitaemia). Two review authors independently assessed trials for inclusion, evaluated the risk of bias, and extracted data. We summarized dichotomous outcomes and count data using risk ratios (RR) and rate ratios respectively, and presented all measures with 95% confidence intervals (CIs). We extracted protective efficacy values and their 95% CIs; when an included trial did not report this data, we calculated these values from the RR or rate ratio with its 95% CI. Where appropriate, we combined data in meta-analyses and assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS We included 12 trials that enrolled 19,098 infants; all were conducted in sub-Saharan Africa. Three trials were cluster-RCTs. IPTi with sulfadoxine-pyrimethamine (SP) was evaluated in 10 trials from 1999 to 2013 (n = 15,256). Trials evaluating ACTs included dihydroartemisinin-piperaquine (1 trial, 147 participants; year 2013), amodiaquine-artesunate (1 study, 684 participants; year 2008), and SP-artesunate (1 trial, 676 participants; year 2008). The earlier studies evaluated IPTi with SP, and were conducted in Tanzania (in 1999 and 2006), Mozambique (2004), Ghana (2004 to 2005), Gabon (2005), Kenya (2008), and Mali (2009). One trial evaluated IPTi with amodiaquine in Tanzania (2000). Later studies included three conducted in Kenya (2008), Tanzania (2008), and Uganda (2013), evaluating IPTi in multiple trial arms that included artemisinin-based combination therapy (ACT). Although the effect size varied over time and between drugs, overall IPTi impacts on the incidence of clinical malaria overall, with a 30% reduction (rate ratio 0.70, 0.62 to 0.80; 10 studies, 10,602 participants). The effect of SP appeared to attenuate over time, with trials conducted after 2009 showing little or no effect of the intervention. IPTi with SP probably resulted in fewer episodes of clinical malaria (rate ratio 0.78, 0.69 to 0.88; 8 trials, 8774 participants, moderate-certainty evidence), anaemia (rate ratio 0.82, 0.68 to 0.98; 6 trials, 7438 participants, moderate-certainty evidence), parasitaemia (rate ratio 0.66, 0.56 to 0.79; 1 trial, 1200 participants, moderate-certainty evidence), and fewer hospital admissions (rate ratio 0.85, 0.78 to 0.93; 7 trials, 7486 participants, moderate-certainty evidence). IPTi with SP probably made little or no difference to all-cause mortality (risk ratio 0.93, 0.74 to 1.15; 9 trials, 14,588 participants, moderate-certainty evidence). Since 2009, IPTi trials have evaluated ACTs and indicate impact on clinical malaria and parasitaemia. A small trial of DHAP in 2013 shows substantive effects on clinical malaria (RR 0.42, 0.33 to 0.54; 1 trial, 147 participants, moderate-certainty evidence) and parasitaemia (moderate-certainty evidence). AUTHORS' CONCLUSIONS In areas of sub-Saharan Africa, giving antimalarial drugs known to be effective against the malaria parasite at the time to infants as IPT probably reduces the risk of clinical malaria, anaemia, and hospital admission. Evidence from SP studies over a 19-year period shows declining efficacy, which may be due to increasing drug resistance. Combinations with ACTs appear promising as suitable alternatives for IPTi.
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Affiliation(s)
- Ekpereonne B Esu
- Department of Public Health, College of Medical Sciences, University of Calabar, Calabar, Nigeria
| | - Chioma Oringanje
- GIDP Entomology and Insect Science, University of Tucson, Tucson, Arizona, USA
| | - Martin M Meremikwu
- Department of Paediatrics, University of Calabar Teaching Hospital, Calabar, Nigeria
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Kattenberg JH, Razook Z, Keo R, Koepfli C, Jennison C, Lautu-Gumal D, Fola AA, Ome-Kaius M, Barnadas C, Siba P, Felger I, Kazura J, Mueller I, Robinson LJ, Barry AE. Monitoring Plasmodium falciparum and Plasmodium vivax using microsatellite markers indicates limited changes in population structure after substantial transmission decline in Papua New Guinea. Mol Ecol 2020; 29:4525-4541. [PMID: 32985031 PMCID: PMC10008436 DOI: 10.1111/mec.15654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 07/27/2020] [Indexed: 02/01/2023]
Abstract
Monitoring the genetic structure of pathogen populations may be an economical and sensitive approach to quantify the impact of control on transmission dynamics, highlighting the need for a better understanding of changes in population genetic parameters as transmission declines. Here we describe the first population genetic analysis of two major human malaria parasites, Plasmodium falciparum (Pf) and Plasmodium vivax (Pv), following nationwide distribution of long-lasting insecticide-treated nets (LLINs) in Papua New Guinea (PNG). Parasite isolates from pre- (2005-2006) and post-LLIN (2010-2014) were genotyped using microsatellite markers. Despite parasite prevalence declining substantially (East Sepik Province: Pf = 54.9%-8.5%, Pv = 35.7%-5.6%, Madang Province: Pf = 38.0%-9.0%, Pv: 31.8%-19.7%), genetically diverse and intermixing parasite populations remained. Pf diversity declined modestly post-LLIN relative to pre-LLIN (East Sepik: Rs = 7.1-6.4, HE = 0.77-0.71; Madang: Rs = 8.2-6.1, HE = 0.79-0.71). Unexpectedly, population structure present in pre-LLIN populations was lost post-LLIN, suggesting that more frequent human movement between provinces may have contributed to higher gene flow. Pv prevalence initially declined but increased again in one province, yet diversity remained high throughout the study period (East Sepik: Rs = 11.4-9.3, HE = 0.83-0.80; Madang: Rs = 12.2-14.5, HE = 0.85-0.88). Although genetic differentiation values increased between provinces over time, no significant population structure was observed at any time point. For both species, a decline in multiple infections and increasing clonal transmission and significant multilocus linkage disequilibrium post-LLIN were positive indicators of impact on the parasite population using microsatellite markers. These parameters may be useful adjuncts to traditional epidemiological tools in the early stages of transmission reduction.
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Affiliation(s)
- Johanna Helena Kattenberg
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea
| | - Zahra Razook
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Raksmei Keo
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Cristian Koepfli
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Charlie Jennison
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Dulcie Lautu-Gumal
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Abebe A Fola
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Maria Ome-Kaius
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Céline Barnadas
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - James Kazura
- Centre for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.,Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Leanne J Robinson
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Yagaum, Papua New Guinea.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.,Disease Elimination, Burnet Institute, Melbourne, VIC, Australia
| | - Alyssa E Barry
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
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4
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Jabbarzare M, Njie M, Jaworowski A, Umbers AJ, Ome-Kaius M, Hasang W, Randall LM, Kalionis B, Rogerson SJ. Innate immune responses to malaria-infected erythrocytes in pregnant women: Effects of gravidity, malaria infection, and geographic location. PLoS One 2020; 15:e0236375. [PMID: 32726331 PMCID: PMC7390391 DOI: 10.1371/journal.pone.0236375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/02/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Malaria in pregnancy causes maternal, fetal and neonatal morbidity and mortality, and maternal innate immune responses are implicated in pathogenesis of these complications. The effects of malaria exposure and obstetric and demographic factors on the early maternal immune response are poorly understood. METHODS Peripheral blood mononuclear cell responses to Plasmodium falciparum-infected erythrocytes and phytohemagglutinin were compared between pregnant women from Papua New Guinea (malaria-exposed) with and without current malaria infection and from Australia (unexposed). Elicited levels of inflammatory cytokines at 48 h and 24 h (interferon γ, IFN-γ only) and the cellular sources of IFN-γ were analysed. RESULTS Among Papua New Guinean women, microscopic malaria at enrolment did not alter peripheral blood mononuclear cell responses. Compared to samples from Australia, cells from Papua New Guinean women secreted more inflammatory cytokines tumor necrosis factor-α, interleukin 1β, interleukin 6 and IFN-γ; p<0.001 for all assays, and more natural killer cells produced IFN-γ in response to infected erythrocytes and phytohemagglutinin. In both populations, cytokine responses were not affected by gravidity, except that in the Papua New Guinean cohort multigravid women had higher IFN-γ secretion at 24 h (p = 0.029) and an increased proportion of IFN-γ+ Vδ2 γδ T cells (p = 0.003). Cytokine levels elicited by a pregnancy malaria-specific CSA binding parasite line, CS2, were broadly similar to those elicited by CD36-binding line P6A1. CONCLUSIONS Geographic location and, to some extent, gravidity influence maternal innate immunity to malaria.
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MESH Headings
- Adolescent
- Adult
- Australia/epidemiology
- CD36 Antigens/genetics
- Erythrocytes/immunology
- Erythrocytes/parasitology
- Erythrocytes/pathology
- Female
- Gravidity/immunology
- Humans
- Immunity, Innate/genetics
- Interferon-gamma/genetics
- Interferon-gamma/immunology
- Interleukin-6/genetics
- Killer Cells, Natural/immunology
- Killer Cells, Natural/parasitology
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/parasitology
- Leukocytes, Mononuclear/pathology
- Malaria, Falciparum/epidemiology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Middle Aged
- Papua New Guinea/epidemiology
- Plasmodium falciparum/immunology
- Plasmodium falciparum/pathogenicity
- Pregnancy
- Pregnancy Complications, Parasitic/immunology
- Pregnancy Complications, Parasitic/parasitology
- Pregnancy Complications, Parasitic/pathology
- T-Lymphocytes/immunology
- T-Lymphocytes/parasitology
- Young Adult
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Affiliation(s)
- Marzieh Jabbarzare
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, Australia
- * E-mail:
| | - Madi Njie
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, Australia
| | - Anthony Jaworowski
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria, Australia
| | - Alexandra J. Umbers
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Maria Ome-Kaius
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Wina Hasang
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, Australia
| | - Louise M. Randall
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, Australia
| | - Bill Kalionis
- Department of Maternal-Fetal Medicine, Pregnancy Research Centre, Royal Women’s Hospital Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Australia
| | - Stephen J. Rogerson
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, Australia
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5
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Abstract
BACKGROUND Intermittent preventive treatment could help prevent malaria in infants (IPTi) living in areas of moderate to high malaria transmission in sub-Saharan Africa. The World Health Organization (WHO) policy recommended IPTi in 2010, but its adoption in countries has been limited. OBJECTIVES To evaluate the effects of intermittent preventive treatment (IPT) with antimalarial drugs to prevent malaria in infants living in malaria-endemic areas. SEARCH METHODS We searched the following sources up to 3 December 2018: the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library), MEDLINE (PubMed), Embase (OVID), LILACS (Bireme), and reference lists of articles. We also searched the metaRegister of Controlled Trials (mRCT) and the WHO International Clinical Trials Registry Platform (ICTRP) portal for ongoing trials up to 3 December 2018. SELECTION CRITERIA We included randomized controlled trials (RCTs) that compared IPT to placebo or no intervention in infants (defined as young children aged between 1 to 12 months) in malaria-endemic areas. DATA COLLECTION AND ANALYSIS The primary outcome was clinical malaria (fever plus asexual parasitaemia). Two review authors independently assessed trials for inclusion, evaluated the risk of bias, and extracted data. We summarized dichotomous outcomes and count data using risk ratios (RR) and rate ratios respectively, and presented all measures with 95% confidence intervals (CIs). We extracted protective efficacy values and their 95% CIs; when an included trial did not report this data, we calculated these values from the RR or rate ratio with its 95% CI. Where appropriate, we combined data in meta-analyses and assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS We included 12 trials that enrolled 19,098 infants; all were conducted in sub-Saharan Africa. Three trials were cluster-RCTs. IPTi with sulfadoxine-pyrimethamine (SP) was evaluated in 10 trials from 1999 to 2013 (n = 15,256). Trials evaluating ACTs included dihydroartemisinin-piperaquine (1 trial, 147 participants; year 2013), amodiaquine-artesunate (1 study, 684 participants; year 2008), and SP-artesunate (1 trial, 676 participants; year 2008). The earlier studies evaluated IPTi with SP, and were conducted in Tanzania (in 1999 and 2006), Mozambique (2004), Ghana (2004 to 2005), Gabon (2005), Kenya (2008), and Mali (2009). One trial evaluated IPTi with amodiaquine in Tanzania (2000). Later studies included three conducted in Kenya (2008), Tanzania (2008), and Uganda (2013), evaluating IPTi in multiple trial arms that included artemisinin-based combination therapy (ACT). Although the effect size varied over time and between drugs, overall IPTi impacts on the incidence of clinical malaria overall, with a 27% reduction (rate ratio 0.73, 0.65 to 0.82; 10 studies, 10,602 participants). The effect of SP appeared to attenuate over time, with trials conducted after 2009 showing little or no effect of the intervention. IPTi with SP probably resulted in fewer episodes of clinical malaria (rate ratio 0.79, 0.74 to 0.85; 8 trials, 8774 participants, moderate-certainty evidence), anaemia (rate ratio 0.82, 0.68 to 0.98; 6 trials, 7438 participants, moderate-certainty evidence), parasitaemia (rate ratio 0.66, 0.56 to 0.79; 1 trial, 1200 participants, moderate-certainty evidence), and fewer hospital admissions (rate ratio 0.85, 0.78 to 0.93; 7 trials, 7486 participants, moderate-certainty evidence). IPTi with SP probably made little or no difference to all-cause mortality (risk ratio 0.93, 0.74 to 1.15; 9 trials, 14,588 participants, moderate-certainty evidence). Since 2009, IPTi trials have evaluated ACTs and indicate impact on clinical malaria and parasitaemia. A small trial of DHAP in 2013 shows substantive effects on clinical malaria (RR 0.42, 0.33 to 0.54; 1 trial, 147 participants, moderate-certainty evidence) and parasitaemia (moderate-certainty evidence). AUTHORS' CONCLUSIONS In areas of sub-Saharan Africa, giving antimalarial drugs known to be effective against the malaria parasite at the time to infants as IPT probably reduces the risk of clinical malaria, anaemia, and hospital admission. Evidence from SP studies over a 19-year period shows declining efficacy, which may be due to increasing drug resistance. Combinations with ACTs appear promising as suitable alternatives for IPTi. 2 December 2019 Up to date All studies incorporated from most recent search All eligible published studies found in the last search (3 Dec, 2018) were included.
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Affiliation(s)
- Ekpereonne B Esu
- College of Medical Sciences, University of CalabarDepartment of Public HealthCalabarCross River StateNigeria
| | - Chioma Oringanje
- University of TucsonGIDP Entomology and Insect ScienceTucsonArizonaUSA85721
| | - Martin M Meremikwu
- University of Calabar Teaching HospitalDepartment of PaediatricsPMB 1115CalabarCross River StateNigeria
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6
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Retrospective study on the usefulness of pulse oximetry for the identification of young children with severe illnesses and severe pneumonia in a rural outpatient clinic of Papua New Guinea. PLoS One 2019; 14:e0213937. [PMID: 30986206 PMCID: PMC6464326 DOI: 10.1371/journal.pone.0213937] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 03/04/2019] [Indexed: 11/19/2022] Open
Abstract
Objective This secondary analysis of data of a randomized controlled trial (RCT) retrospectively investigated the performance of pulse oximetry in identifying children with severe illnesses, with and without respiratory signs/symptoms, in a cohort of children followed for morbid episodes in an intervention trial assessing the efficacy of Intermittent Preventive Treatment for malaria in infants (IPTi) in Papua New Guinea (PNG) from June 2006 to May 2010. Setting The IPTi study was conducted in a paediatric population visiting two health centres on the north coast of PNG in the Mugil area of the Sumkar District. Participants A total of 669 children visited the clinic and a total of 1921 illness episodes were recorded. Inclusion criteria were: age between 3 and 27 months, full clinical record (signs/symptoms) and pulse oximetry used systematically to assess sick children at all visits. Children were excluded if they visited the clinic in the previous 14 days. Outcomes The outcome measures were severe illness, severe pneumonia, pneumonia, defined by the Integrated Management of Childhood Illness (IMCI) definitions, and hospitalization. Results Out of 1921 illness episodes, 1663 fulfilled the inclusion criteria. A total of 139 severe illnesses were identified, of which 93 were severe pneumonia. The ROC curves of pulse oximetry (continuous variable) showed an AUC of 0.63, 0.68 and 0.65 for prediction of severe illness, severe pneumonia and hospitalization, respectively. Pulse oximetry allowed better discrimination between severe and non-severe illness, severe and non-severe pneumonia, admitted and non-admitted patients, in children ≤12-months of age relative to older patients. For the threshold of peripheral arterial oxygen saturation ≤ 94% measured by pulse oximetry (SpO2), unadjusted odds ratios for severe illness, severe pneumonia and hospitalization were 6.1 (95% Confidence Interval (CI) 3.9–9.8), 8.5 (4.9–14.6) and 5.9 (3.4–10.3), respectively. Conclusion Pulse oximetry was helpful in identifying children with severe illness in outpatient facilities in PNG. A SpO2 of 94% seems the most discriminative threshold. Considering its affordability and ease of use, pulse oximetry could be a valuable additional tool assisting the decision to admit for treatment.
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7
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Sottas O, Guidi M, Thieffry B, Schneider M, Décosterd L, Mueller I, Genton B, Csajka C, Senn N. Adherence to intermittent preventive treatment for malaria in Papua New Guinean infants: A pharmacological study alongside the randomized controlled trial. PLoS One 2019; 14:e0210789. [PMID: 30726224 PMCID: PMC6364960 DOI: 10.1371/journal.pone.0210789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 12/28/2018] [Indexed: 11/18/2022] Open
Abstract
Background The intermittent preventive treatment in infants (IPTi) trial that took place in Papua New Guinea showed an overall reduction of 29% of the risk of malaria when delivering single-dose sulfadoxine-pyrimethamine (SP) associated to 3 days of amodiaquine (AQ) every three months to children during the first year of life. The aim of the present study was to assess if the last two doses of AQ were truly administered as prescribed by the parents at home based on drug level measurement and PK modelling, which is a good proxy of medication adherence. It provides also important information to discuss the efficacy of the intervention and on feasibility of self-administered preventive malaria treatment. Methods and findings During the three-arm randomized double-blinded IPTi trial, each child was prescribed one dose of SP (day 0) and 3 doses of either AQ or artesunate (AS) at day 0, 1 & 2 adjusted to weight or placebo. Treatments were given at 3, 6, 9 and 12 months of age. The first day of treatment was delivered by nursing staff (initiation under directly observed treatment (DOT)) and the two last doses of AQ or AS by parents at home without supervision. For this cross-sectional study, 206 consecutive children already involved in the IPTi trial were enrolled over a 2-month period. At the time of the survey, allocation of the children to one of the three arms was not known. Blood samples for drug level measurement were collected from finger pricks one day after the planned last third dose intake. Only children allocated to the SP-AQ arm were included in the present analysis. Indeed, the half-life of AS is too short to assess if drugs were given on not. Because of the short half-life of AQ, desethyl-AQ (metabolite of AQ (DAQ)) measurements were used to investigate AQ medication adherence. Two PK (PK) models from previously published studies in paediatric populations were applied to the dataset using non-linear mixed effect modelling (NONMEM) to estimate the number of doses really given by the parents. The study nurse reported the administration time for the first AQ dose while it was estimated by the parents for the remaining two doses. Out of 206 children, 64 were in the SP-AQ arm. The adjusted dosing history for each individual was identified as the one with the lowest difference between observed and individual predicted concentrations estimated by the two PK models for all the possible adherence schemes. The median (range) blood concentration AQ in AQ arm was 9.3 ng/mL (0–1427.8 ng/mL), (Quartiles 1–3: 2.4 ng/mL -22.2 ng/mL). The median (range) for DAQ was 162.0 ng/mL (0–712 ng/mL), (Quartiles 1–3: 80.4 ng/mL-267.7 ng/mL). Under the assumption of full adherence for all participants, a marked underprediction of concentrations was observed using both PK models. Our results suggest that only 39–50% of children received the three scheduled doses of AQ as prescribed, 33–37% two doses and 17–24% received only the first dose administered by the study nurse. Both models were highly congruent to classify adherence patterns. Conclusions Considering the IPTi intervention, our results seem to indicate that medication adherence is low in the ideal trial research setting and is likely to be even lower if given in day-to-day practice, questioning the real impact that this intervention might have. More generally, the estimation of the number of doses truly administered, a proxy measure of adherence and an assessment of the feasibility of the mode of administration, should be more thoroughly studied when discussing the efficacy of the interventions in trials investigating self-administered malaria preventive treatments.
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Affiliation(s)
- Oriane Sottas
- Department of Ambulatory Care and Community Medicine, Lausanne, Switzerland
| | - Monia Guidi
- Service of Clinical Pharmacology, Lausanne University Hospital, Lausanne, Switzerland
- Clinical Pharmacy Sciences, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Benjamin Thieffry
- Service of Clinical Pharmacology, Lausanne University Hospital, Lausanne, Switzerland
| | - Marie Schneider
- Department of Ambulatory Care and Community Medicine, Lausanne, Switzerland
- Clinical Pharmacy Sciences, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Laurent Décosterd
- Service of Clinical Pharmacology, Lausanne University Hospital, Lausanne, Switzerland
| | - Ivo Mueller
- Walter and Eliza Hall Institute, Melbourne, Australia
- Papua New Guinea Institute of medical research (PNG IMR), Madang, Papua New Guinea
| | - Blaise Genton
- Department of Ambulatory Care and Community Medicine, Lausanne, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Chantal Csajka
- Service of Clinical Pharmacology, Lausanne University Hospital, Lausanne, Switzerland
- Clinical Pharmacy Sciences, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
| | - Nicolas Senn
- Department of Ambulatory Care and Community Medicine, Lausanne, Switzerland
- Papua New Guinea Institute of medical research (PNG IMR), Madang, Papua New Guinea
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- * E-mail:
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8
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Mita T, Hombhanje F, Takahashi N, Sekihara M, Yamauchi M, Tsukahara T, Kaneko A, Endo H, Ohashi J. Rapid selection of sulphadoxine-resistant Plasmodium falciparum and its effect on within-population genetic diversity in Papua New Guinea. Sci Rep 2018; 8:5565. [PMID: 29615786 PMCID: PMC5882878 DOI: 10.1038/s41598-018-23811-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/21/2018] [Indexed: 11/18/2022] Open
Abstract
The ability of the human malarial parasite Plasmodium falciparum to adapt to environmental changes depends considerably on its ability to maintain within-population genetic variation. Strong selection, consequent to widespread antimalarial drug usage, occasionally elicits a rapid expansion of drug-resistant isolates, which can act as founders. To investigate whether this phenomenon induces a loss of within-population genetic variation, we performed a population genetic analysis on 302 P. falciparum cases detected during two cross-sectional surveys in 2002/2003, just after the official introduction of sulphadoxine/pyrimethamine as a first-line treatment, and again in 2010/2011, in highly endemic areas in Papua New Guinea. We found that a single-origin sulphadoxine-resistant parasite isolate rapidly increased from 0% in 2002/2003 to 54% in 2010 and 84% in 2011. However, a considerable number of pairs exhibited random associations among 10 neutral microsatellite markers located in various chromosomes, suggesting that outcrossing effectively reduced non-random associations, albeit at a low average multiplicity of infection (1.35–1.52). Within-population genetic diversity was maintained throughout the study period. This indicates that the parasites maintained within-population variation, even after a clonal expansion of drug-resistant parasites. Outcrossing played a role in the preservation of within-population genetic diversity despite low levels of multiplicity of infection.
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Affiliation(s)
- Toshihiro Mita
- Department of Tropical Medicine and Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan.
| | - Francis Hombhanje
- Centre for Health Research & Diagnostics, Divine Word University, Nabasa Road, P.O. Box 483, Madang, Papua New Guinea
| | - Nobuyuki Takahashi
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Makoto Sekihara
- Department of Tropical Medicine and Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan
| | - Masato Yamauchi
- Department of Tropical Medicine and Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo, 113-8421, Japan
| | - Takahiro Tsukahara
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Akira Kaneko
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77, Stockholm, Sweden.,Department of Parasitology, Osaka City University Graduate School of Medicine, Asahi-cho 1-4-3, Abeno-ku, Osaka, 545-8585, Japan
| | - Hiroyoshi Endo
- Department of International Affairs and Tropical Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Jun Ohashi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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9
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Lombardo P, Vaucher P, Rarau P, Mueller I, Favrat B, Senn N. Hemoglobin Levels and the Risk of Malaria in Papua New Guinean Infants: A Nested Cohort Study. Am J Trop Med Hyg 2017; 97:1770-1776. [PMID: 29016324 DOI: 10.4269/ajtmh.17-0093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Studies are available that assess the risk of malaria in accordance to the body's iron store and the systematic iron supplementation of preschool children. However, only a few studies evaluated the temporal association between hemoglobin and malaria and their results are opposing. A total of 1,650 3-month-old Papua New Guinean infants were enrolled in this study and followed-up for 12 months. The risk of malaria was assessed in all children every 3 months and with each episode of fever. The incidence of clinical malaria between 3 and 15 months of age was 249 cases per 1,000 infants per year. After adjustment for potential confounding factors, a decrease of 1 g/dL of hemoglobin was associated with a nonsignificant increase of 11% for risk of malaria infection (hazard ratio, 1.11, 95% confidence interval; CI, 0.99-1.25, P = 0.076). Only children with severe anemia (hemoglobin < 8.0 g/dL) at baseline were at higher risk of malaria infection (hazard ratio, 1.72, 95% CI, 1.08-2.76, P = 0.023) during the follow-up year compared with the control group (Hemoglobin > 10.0 g/dL). This association was not statistically significant if only clinical malaria episodes were taken into account (hazard ratio, 1.42, 95% CI, 0.77-2.61, P = 0.26). Our study suggests that infants with lower hemoglobin levels are not protected against malaria infection. Further research that examines the risk of malaria in relation to both hemoglobin and iron store levels would be important to better understand this complex interaction.
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Affiliation(s)
- Patrick Lombardo
- Institute of Family Medicine, University of Lausanne, Lausanne, Switzerland
| | - Paul Vaucher
- University Center of Legal Medicine, University Hospital Lausanne (CHUV), Lausanne, Switzerland.,School of Health Sciences Fribourg, University of Applied Sciences Western Switzerland (HES-SO), Fribourg, Switzerland
| | - Patricia Rarau
- Papua New Guinea Institute of Medical Research, Vector Borne Diseases Unit, Madang, Papua New Guinea
| | - Ivo Mueller
- Division of Population Health and Immunity, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Bernard Favrat
- Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Senn
- Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland.,Institute of Family Medicine, University of Lausanne, Lausanne, Switzerland
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10
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Howes RE, Battle KE, Mendis KN, Smith DL, Cibulskis RE, Baird JK, Hay SI. Global Epidemiology of Plasmodium vivax. Am J Trop Med Hyg 2016; 95:15-34. [PMID: 27402513 PMCID: PMC5198891 DOI: 10.4269/ajtmh.16-0141] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/19/2016] [Indexed: 01/09/2023] Open
Abstract
Plasmodium vivax is the most widespread human malaria, putting 2.5 billion people at risk of infection. Its unique biological and epidemiological characteristics pose challenges to control strategies that have been principally targeted against Plasmodium falciparum Unlike P. falciparum, P. vivax infections have typically low blood-stage parasitemia with gametocytes emerging before illness manifests, and dormant liver stages causing relapses. These traits affect both its geographic distribution and transmission patterns. Asymptomatic infections, high-risk groups, and resulting case burdens are described in this review. Despite relatively low prevalence measurements and parasitemia levels, along with high proportions of asymptomatic cases, this parasite is not benign. Plasmodium vivax can be associated with severe and even fatal illness. Spreading resistance to chloroquine against the acute attack, and the operational inadequacy of primaquine against the multiple attacks of relapse, exacerbates the risk of poor outcomes among the tens of millions suffering from infection each year. Without strategies accounting for these P. vivax-specific characteristics, progress toward elimination of endemic malaria transmission will be substantially impeded.
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Affiliation(s)
- Rosalind E. Howes
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Katherine E. Battle
- Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Kamini N. Mendis
- Global Malaria Program, World Health Organization, Geneva, Switzerland
| | - David L. Smith
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland
- Sanaria Institute for Global Health and Tropical Medicine, Rockville, Maryland
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | | | - J. Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Simon I. Hay
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
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11
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Burdam FH, Hakimi M, Thio F, Kenangalem E, Indrawanti R, Noviyanti R, Trianty L, Marfurt J, Handayuni I, Soenarto Y, Douglas NM, Anstey NM, Price RN, Poespoprodjo JR. Asymptomatic Vivax and Falciparum Parasitaemia with Helminth Co-Infection: Major Risk Factors for Anaemia in Early Life. PLoS One 2016; 11:e0160917. [PMID: 27504828 PMCID: PMC4978495 DOI: 10.1371/journal.pone.0160917] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/27/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Anaemia in children under five years old is associated with poor health, growth and developmental outcomes. In Papua, Indonesia, where the burden of anaemia in infants is high, we conducted a community survey to assess the association between Plasmodium infection, helminth carriage and the risk of anaemia. METHODS A cross sectional household survey was carried out between April and July 2013 in 16 villages in the District of Mimika using a multistage sampling procedure. A total of 629 children aged 1-59 months from 800 households were included in the study. Demographic, symptom and anthropometry data were recorded using a standardized questionnaire. Blood and stool samples were collected for examination. RESULTS Of the 533 children with blood film examination, 8.8% (47) had P. vivax parasitaemia and 3.9% (21) had P. falciparum; the majority of children with malaria were asymptomatic (94.4%, 68/72). Soil transmitted helminth (STH) infection was present in 43% (105/269) of children assessed; those with STH were at significantly greater risk of P. vivax parasitaemia compared to those without STH (OR = 3.7 [95%CI 1.5-9.2], p = 0.004). Anaemia (Hb<10 g/dl) was present in 24.5% (122/497) of children and associated with P. vivax parasitaemia (OR = 2.9 [95%CI, 1.7-4.9], p = 0.001), P. falciparum parasitaemia (OR = 4.3 [95%CI, 2.0-9.4], p<0.001), hookworm carriage (OR = 2.6 [95%CI, 1.2-5.8], p = 0.026), Plasmodium-helminth coinfection (OR 4.0 [95%CI, 1.4-11.3], p = 0.008) and severe stunting (OR = 1.9 ([95%CI, 1.1-3.3], p = 0.012). CONCLUSIONS Asymptomatic P. vivax and P. falciparum infections and hookworm all contribute to risk of paediatric anaemia in coendemic areas and should be targeted with prevention and treatment programs. The relationship between helminth infections and the increased risk of P. vivax parasitaemia should be explored prospectively.
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Affiliation(s)
- Faustina Helena Burdam
- Mimika District Health Authority, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
- Maternal and Child Health and Reproductive Health, Department of Public Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Mohammad Hakimi
- Maternal and Child Health and Reproductive Health, Department of Public Health, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Franciscus Thio
- Mimika District Hospital, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
| | - Enny Kenangalem
- Mimika District Health Authority, Timika, Papua, Indonesia
- Mimika District Hospital, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
| | - Ratni Indrawanti
- Department of Child Health, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, Indonesia
| | | | - Leily Trianty
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Jutta Marfurt
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Irene Handayuni
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Yati Soenarto
- Department of Child Health, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, Indonesia
| | - Nicholas M. Douglas
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Jeanne Rini Poespoprodjo
- Mimika District Hospital, Timika, Papua, Indonesia
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Timika, Papua, Indonesia
- Department of Child Health, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, Indonesia
- * E-mail:
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12
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Olotu A, Fegan G, Wambua J, Nyangweso G, Leach A, Lievens M, Kaslow DC, Njuguna P, Marsh K, Bejon P. Seven-Year Efficacy of RTS,S/AS01 Malaria Vaccine among Young African Children. N Engl J Med 2016; 374:2519-29. [PMID: 27355532 PMCID: PMC4962898 DOI: 10.1056/nejmoa1515257] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The candidate malaria vaccine RTS,S/AS01 is being evaluated in order to inform a decision regarding its inclusion in routine vaccination schedules. METHODS We conducted 7 years of follow-up in children who had been randomly assigned, at 5 to 17 months of age, to receive three doses of either the RTS,S/AS01 vaccine or a rabies (control) vaccine. The end point was clinical malaria (temperature of ≥37.5°C and infection with Plasmodium falciparum of >2500 parasites per cubic millimeter). In an analysis that was not prespecified, the malaria exposure of each child was estimated with the use of information on the prevalence of malaria among residents within a 1-km radius of the child's home. Vaccine efficacy was defined as 1 minus the hazard ratio or the incidence-rate ratio, multiplied by 100, in the RTS,S/AS01 group versus the control group. RESULTS Over 7 years of follow-up, we identified 1002 episodes of clinical malaria among 223 children randomly assigned to the RTS,S/AS01 group and 992 episodes among 224 children randomly assigned to the control group. The vaccine efficacy, as assessed by negative binomial regression, was 4.4% (95% confidence interval [CI], -17.0 to 21.9; P=0.66) in the intention-to-treat analysis and 7.0% (95% CI, -14.5 to 24.6; P=0.52) in the per-protocol analysis. Vaccine efficacy waned over time (P=0.006 for the interaction between vaccination and time), including negative efficacy during the fifth year among children with higher-than-average exposure to malaria parasites (intention-to-treat analysis: -43.5%; 95% CI, -100.3 to -2.8 [P=0.03]; per-protocol analysis: -56.8%; 95% CI, -118.7 to -12.3 [P=0.008]). CONCLUSIONS A three-dose vaccination with RTS,S/AS01 was initially protective against clinical malaria, but this result was offset by rebound in later years in areas with higher-than-average exposure to malaria parasites. (Funded by the PATH Malaria Vaccine Initiative and others; ClinicalTrials.gov number, NCT00872963.).
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Affiliation(s)
- Ally Olotu
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Gregory Fegan
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Juliana Wambua
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - George Nyangweso
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Amanda Leach
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Marc Lievens
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - David C Kaslow
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Patricia Njuguna
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Kevin Marsh
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
| | - Philip Bejon
- From the Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya (A.O., G.F., J.W., G.N., P.N., K.M., P.B.); Ifakara Health Institute, Bagamoyo, Tanzania (A.O.); the Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom (G.F., K.M., P.B.); GlaxoSmithKline Vaccines, Wavre, Belgium (A.L., M.L.); and PATH, Seattle (D.C.K.)
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13
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Atwell JE, Thumar B, Robinson LJ, Tobby R, Yambo P, Ome-Kaius M, Siba PM, Unger HW, Rogerson SJ, King CL, Karron RA. Impact of Placental Malaria and Hypergammaglobulinemia on Transplacental Transfer of Respiratory Syncytial Virus Antibody in Papua New Guinea. J Infect Dis 2016; 213:423-31. [PMID: 26238686 PMCID: PMC4704666 DOI: 10.1093/infdis/jiv401] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/20/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Passively acquired respiratory syncytial virus (RSV) neutralizing antibody protects against RSV-associated lower respiratory infections, but placental malaria (PM) and maternal hypergammaglobulinemia might interfere with transplacental immunoglobulin transport. METHODS We measured RSV plaque-reduction neutralization (PRN) antibody in 300 full-term maternal/cord serum pairs in 2 cohorts in malaria-endemic Papua New Guinea: Alexishafen (2005-2008) and the Fetal Immunity Study (FIS) (2011-2013). We defined impaired transport as a cord-to-maternal titer ratio <1.0 and a protective RSV PRN titer (PRNT) ≥1:200. RESULTS PM and hypergammaglobulinemia occurred in 60% and 54% of Alexishafen mothers versus 8% and 9% of FIS mothers, respectively. 34% of Alexishafen and 32% of FIS pairs demonstrated impaired transport. Multivariate modeling revealed significant associations between increasing maternal IgG (log2) and impaired transport (adjusted OR, Alexishafen: 2.68 [1.17-6.14], FIS: 6.94 [1.94-24.8]) but no association with PM. 34% of Alexishafen and 31% of FIS cord PRNTs were <1:200. CONCLUSIONS Impaired RSV antibody transport was observed in approximately one-third of maternal/cord pairs. Hypergammaglobulinemia, but not PM, was associated with impaired transport, particularly among women with low RSV PRNT. Detection of RSV PRNT <1:200 in one-third of cord sera confirms the need to increase levels of RSV neutralizing antibody in pregnant women through maternal immunization.
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Affiliation(s)
- Jessica E Atwell
- Department of International Health, Center for Immunization Research, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Bhagvanji Thumar
- Department of International Health, Center for Immunization Research, Johns Hopkins School of Public Health, Baltimore, Maryland
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Madang & Goroka Walter and Eliza Hall Institute Department of Medical Biology, The University of Melbourne, Parkville, Victoria
| | - Roselyn Tobby
- Papua New Guinea Institute of Medical Research, Madang & Goroka
| | - Phantica Yambo
- Papua New Guinea Institute of Medical Research, Madang & Goroka
| | - Maria Ome-Kaius
- Papua New Guinea Institute of Medical Research, Madang & Goroka
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Madang & Goroka Division of Tropical Health and Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville City, Queensland
| | - Holger W Unger
- Department of Medicine, The University of Melbourne, Australia
| | | | - Christopher L King
- Center for Global Health and Disease, Case Western Reserve University and Veterans Affairs Medical Center, Cleveland, Ohio
| | - Ruth A Karron
- Department of International Health, Center for Immunization Research, Johns Hopkins School of Public Health, Baltimore, Maryland
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14
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Abstract
Malaria is one of the most serious infectious diseases with most of the severe disease
caused by Plasmodium falciparum (Pf). Naturally acquired immunity
develops over time after repeated infections and the development of antimalarial
antibodies is thought to play a crucial role. Neonates and young infants are relatively
protected from symptomatic malaria through mechanisms that are poorly understood. The
prevailing paradigm is that maternal antimalarial antibodies transferred to the fetus in
the last trimester of pregnancy protect the infant from early infections. These
antimalarial antibodies wane by approximately 6 months of age leaving the infant
vulnerable to malaria, however direct evidence supporting this epidemiologically based
paradigm is lacking. As infants are the target population for future malaria vaccines,
understanding how they begin to develop immunity to malaria and the gaps in their
responses is key. This review summarizes the antimalarial antibody responses detected in
infants and how they change over time. We focus primarily on Pf antibody responses and
will briefly mention Plasmodium vivax responses in infants.
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15
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Robinson LJ, Wampfler R, Betuela I, Karl S, White MT, Li Wai Suen CSN, Hofmann NE, Kinboro B, Waltmann A, Brewster J, Lorry L, Tarongka N, Samol L, Silkey M, Bassat Q, Siba PM, Schofield L, Felger I, Mueller I. Strategies for understanding and reducing the Plasmodium vivax and Plasmodium ovale hypnozoite reservoir in Papua New Guinean children: a randomised placebo-controlled trial and mathematical model. PLoS Med 2015; 12:e1001891. [PMID: 26505753 PMCID: PMC4624431 DOI: 10.1371/journal.pmed.1001891] [Citation(s) in RCA: 194] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 09/17/2015] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The undetectable hypnozoite reservoir for relapsing Plasmodium vivax and P. ovale malarias presents a major challenge for malaria control and elimination in endemic countries. This study aims to directly determine the contribution of relapses to the burden of P. vivax and P. ovale infection, illness, and transmission in Papua New Guinean children. METHODS AND FINDINGS From 17 August 2009 to 20 May 2010, 524 children aged 5-10 y from East Sepik Province in Papua New Guinea (PNG) participated in a randomised double-blind placebo-controlled trial of blood- plus liver-stage drugs (chloroquine [CQ], 3 d; artemether-lumefantrine [AL], 3 d; and primaquine [PQ], 20 d, 10 mg/kg total dose) (261 children) or blood-stage drugs only (CQ, 3 d; AL, 3 d; and placebo [PL], 20 d) (263 children). Participants, study staff, and investigators were blinded to the treatment allocation. Twenty children were excluded during the treatment phase (PQ arm: 14, PL arm: 6), and 504 were followed actively for 9 mo. During the follow-up time, 18 children (PQ arm: 7, PL arm: 11) were lost to follow-up. Main primary and secondary outcome measures were time to first P. vivax infection (by qPCR), time to first clinical episode, force of infection, gametocyte positivity, and time to first P. ovale infection (by PCR). A basic stochastic transmission model was developed to estimate the potential effect of mass drug administration (MDA) for the prevention of recurrent P. vivax infections. Targeting hypnozoites through PQ treatment reduced the risk of having at least one qPCR-detectable P. vivax or P. ovale infection during 8 mo of follow-up (P. vivax: PQ arm 0.63/y versus PL arm 2.62/y, HR = 0.18 [95% CI 0.14, 0.25], p < 0.001; P. ovale: 0.06 versus 0.14, HR = 0.31 [95% CI 0.13, 0.77], p = 0.011) and the risk of having at least one clinical P. vivax episode (HR = 0.25 [95% CI 0.11, 0.61], p = 0.002). PQ also reduced the molecular force of P. vivax blood-stage infection in the first 3 mo of follow-up (PQ arm 1.90/y versus PL arm 7.75/y, incidence rate ratio [IRR] = 0.21 [95% CI 0.15, 0.28], p < 0.001). Children who received PQ were less likely to carry P. vivax gametocytes (IRR = 0.27 [95% CI 0.19, 0.38], p < 0.001). PQ had a comparable effect irrespective of the presence of P. vivax blood-stage infection at the time of treatment (p = 0.14). Modelling revealed that mass screening and treatment with highly sensitive quantitative real-time PCR, or MDA with blood-stage treatment alone, would have only a transient effect on P. vivax transmission levels, while MDA that includes liver-stage treatment is predicted to be a highly effective strategy for P. vivax elimination. The inclusion of a directly observed 20-d treatment regime maximises the efficiency of hypnozoite clearance but limits the generalisability of results to real-world MDA programmes. CONCLUSIONS These results suggest that relapses cause approximately four of every five P. vivax infections and at least three of every five P. ovale infections in PNG children and are important in sustaining transmission. MDA campaigns combining blood- and liver-stage treatment are predicted to be a highly efficacious intervention for reducing P. vivax and P. ovale transmission. TRIAL REGISTRATION ClinicalTrials.gov NCT02143934.
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Affiliation(s)
- Leanne J. Robinson
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Rahel Wampfler
- Molecular Diagnostics Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Inoni Betuela
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
| | - Stephan Karl
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Michael T. White
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, United Kingdom
| | - Connie S. N. Li Wai Suen
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Natalie E. Hofmann
- Molecular Diagnostics Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Benson Kinboro
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
| | - Andreea Waltmann
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Jessica Brewster
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Lina Lorry
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
| | - Nandao Tarongka
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
| | - Lornah Samol
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
| | - Mariabeth Silkey
- Molecular Diagnostics Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Quique Bassat
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Peter M. Siba
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang and Maprik, Papua New Guinea
- School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland, Australia
| | - Louis Schofield
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Ingrid Felger
- Molecular Diagnostics Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic–University of Barcelona, Barcelona, Spain
- * E-mail:
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16
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Glinz D, Hurrell RF, Ouattara M, Zimmermann MB, Brittenham GM, Adiossan LG, Righetti AA, Seifert B, Diakité VG, Utzinger J, N'Goran EK, Wegmüller R. The effect of iron-fortified complementary food and intermittent preventive treatment of malaria on anaemia in 12- to 36-month-old children: a cluster-randomised controlled trial. Malar J 2015; 14:347. [PMID: 26377199 PMCID: PMC4573684 DOI: 10.1186/s12936-015-0872-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/25/2015] [Indexed: 11/29/2022] Open
Abstract
Background Iron deficiency (ID) and malaria co-exist in tropical regions and both contribute to high rates of anaemia in young children. It is unclear whether iron fortification combined with intermittent preventive treatment (IPT) of malaria would be an efficacious strategy for reducing anaemia in young children. Methods A 9-month cluster-randomised, single-blinded, placebo-controlled intervention trial was carried out in children aged 12–36 months in south-central Côte d’Ivoire, an area of intense and perennial malaria transmission. The study groups were: group 1: normal diet and IPT-placebo (n = 125); group 2: consumption of porridge, an iron-fortified complementary food (CF) with optimised composition providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferrous fumarate 6 days per week (CF-FeFum) and IPT-placebo (n = 126); group 3: IPT of malaria at 3-month intervals, using sulfadoxine-pyrimethamine and amodiaquine and no dietary intervention (n = 127); group 4: both CF-FeFum and IPT (n = 124); and group 5: consumption of porridge, an iron-fortified CF with the composition currently on the Ivorian market providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferric pyrophosphate 6 days per week (CF-FePP) and IPT-placebo (n = 127). The primary outcome was haemoglobin (Hb) concentration. Linear and logistic regression mixed-effect models were used for the comparison of the five study groups, and a 2 × 2 factorial analysis was used to assess treatment interactions of CF-FeFum and IPT (study groups 1–4). Results After 9 months, the Hb concentration increased in all groups to a similar extent with no statistically significant difference between groups. In the 2 × 2 factorial analysis after 9 months, no treatment interaction was found on Hb (P = 0.89). The adjusted differences in Hb were 0.24 g/dl (95 % CI −0.10 to 0.59; P = 0.16) in children receiving IPT and −0.08 g/dl (95 % CI −0.42 to 0.26; P = 0.65) in children receiving CF-FeFum. At baseline, anaemia (Hb <11.0 g/dl) was 82.1 %. After 9 months, IPT decreased the odds of anaemia (odds ratio [OR], 0.46 [95 % CI 0.23–0.91]; P = 0.023), whereas iron-fortified CF did not (OR, 0.85 [95 % CI 0.43–1.68]; P = 0.68), although ID (plasma ferritin <30 μg/l) was decreased markedly in children receiving iron fortified CF (OR, 0.19 [95 % CI 0.09–0.40]; P < 0.001). Conclusions IPT alone only modestly decreased anaemia, but neither IPT nor iron fortified CF significantly improved Hb concentration after 9 months. Additionally, IPT did not augment the effect of the iron fortified CF. CF fortified with highly bioavailable iron improved iron status but not Hb concentration, despite three-monthly IPT of malaria. Thus, further research is necessary to develop effective combination strategies to prevent and treat anaemia in malaria endemic regions. Trial registration: http://www.clinicaltrials.gov; identifier NCT01634945; registered on July 3, 2012. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0872-3) contains supplementary material, which is available to authorised users.
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Affiliation(s)
- Dominik Glinz
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
| | - Richard F Hurrell
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
| | - Mamadou Ouattara
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire.
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
| | - Gary M Brittenham
- Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, USA.
| | | | - Aurélie A Righetti
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Burkhardt Seifert
- Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.
| | | | - Jürg Utzinger
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Eliézer K N'Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire. .,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire.
| | - Rita Wegmüller
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
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17
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Koleala T, Karl S, Laman M, Moore BR, Benjamin J, Barnadas C, Robinson LJ, Kattenberg JH, Javati S, Wong RPM, Rosanas-Urgell A, Betuela I, Siba PM, Mueller I, Davis TME. Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea. Malar J 2015; 14:37. [PMID: 25626445 PMCID: PMC4335551 DOI: 10.1186/s12936-015-0560-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/13/2015] [Indexed: 01/19/2023] Open
Abstract
Background In northern Papua New Guinea (PNG), most Plasmodium falciparum isolates proved resistant to chloroquine (CQ) in vitro between 2005 and 2007, and there was near-fixation of pfcrt K76T, pfdhfr C59R/S108N and pfmdr1 N86Y. To determine whether the subsequent introduction of artemisinin combination therapy (ACT) and reduced CQ-sulphadoxine-pyrimethamine pressure had attenuated parasite drug susceptibility and resistance-associated mutations, these parameters were re-assessed between 2011 and 2013. Methods A validated fluorescence-based assay was used to assess growth inhibition of 52 P. falciparum isolates from children in a clinical trial in Madang Province. Responses to CQ, lumefantrine, piperaquine, naphthoquine, pyronaridine, artesunate, dihydroartemisinin, artemether were assessed. Molecular resistance markers were detected using a multiplex PCR ligase detection reaction fluorescent microsphere assay. Results CQ resistance (in vitro concentration required for 50% parasite growth inhibition (IC50) >100 nM) was present in 19% of isolates. All piperaquine and naphthoquine IC50s were <100 nM and those for lumefantrine, pyronaridine and the artemisinin derivatives were in low nM ranges. Factor analysis of IC50s showed three groupings (lumefantrine; CQ, piperaquine, naphthoquine; pyronaridine, dihydroartemisinin, artemether, artesunate). Most isolates (96%) were monoclonal pfcrt K76T (SVMNT) mutants and most (86%) contained pfmdr1 N86Y (YYSND). No wild-type pfdhfr was found but most isolates contained wild-type (SAKAA) pfdhps. Compared with 2005–2007, the geometric mean (95% CI) CQ IC50 was lower (87 (71–107) vs 167 (141–197) nM) and there had been no change in the prevalence of pfcrt K76T or pfmdr1 mutations. There were fewer isolates of the pfdhps (SAKAA) wild-type (60 vs 100%) and pfdhfr mutations persisted. Conclusions Reflecting less drug pressure, in vitro CQ sensitivity appears to be improving in Madang Province despite continued near-fixation of pfcrt K76T and pfmdr1 mutations. Temporal changes in IC50s for other anti-malarial drugs were inconsistent but susceptibility was preserved. Retention or increases in pfdhfr and pfdhps mutations reflect continued use of sulphadoxine-pyrimethamine in the study area including through paediatric intermittent preventive treatment. The susceptibility of local isolates to lumefantrine may be unrelated to those of other ACT partner drugs. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12610000913077.
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Affiliation(s)
- Tamarah Koleala
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Stephan Karl
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - Brioni R Moore
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - John Benjamin
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Celine Barnadas
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Leanne J Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
| | - Johanna H Kattenberg
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia.
| | - Sarah Javati
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Rina P M Wong
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
| | - Anna Rosanas-Urgell
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea. .,Institute of Tropical Medicine, Antwerp, Belgium.
| | - Inoni Betuela
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
| | - Ivo Mueller
- Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia. .,Center de Recerca en Salut Internacional de Barcelona (CRESIB), Barcelona, Spain.
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle, 6959, WA, Australia.
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18
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Plasmodium falciparum and Plasmodium vivax genotypes and efficacy of intermittent preventive treatment in Papua New Guinea. Antimicrob Agents Chemother 2014; 58:6958-61. [PMID: 25155586 DOI: 10.1128/aac.03323-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intermittent preventive treatment of infants (IPTi) reduces early childhood malaria-related morbidity. While genotypic drug resistance markers have proven useful in predicting the efficacy of antimalarial drugs in case management, there are few equivalent data relating to their protective efficacy when used as IPTi. The present data from an IPTi trial in Papua New Guinea demonstrate how these markers can predict protective efficacy of IPTi for both Plasmodium falciparum and Plasmodium vivax.
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19
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Bigira V, Kapisi J, Clark TD, Kinara S, Mwangwa F, Muhindo MK, Osterbauer B, Aweeka FT, Huang L, Achan J, Havlir DV, Rosenthal PJ, Kamya MR, Dorsey G. Protective efficacy and safety of three antimalarial regimens for the prevention of malaria in young Ugandan children: a randomized controlled trial. PLoS Med 2014; 11:e1001689. [PMID: 25093754 PMCID: PMC4122345 DOI: 10.1371/journal.pmed.1001689] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 06/26/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Chemoprevention offers a promising strategy for prevention of malaria in African children. However, the optimal chemoprevention drug and dosing strategy is unclear in areas of year-round transmission and resistance to many antimalarial drugs. To compare three available regimens, we conducted an open-label randomized controlled trial of chemoprevention in Ugandan children. METHODS AND FINDINGS This study was conducted between June 28, 2010, and September 25, 2013. 400 infants were enrolled and 393 randomized at 6 mo of age to no chemoprevention, monthly sulfadoxine-pyrimethamine (SP), daily trimethoprim-sulfamethoxazole (TS), or monthly dihydroartemisinin-piperaquine (DP). Study drugs were administered at home without supervision. Piperaquine (PQ) levels were used as a measure of compliance in the DP arm. Participants were given insecticide-treated bednets, and caregivers were encouraged to bring their child to a study clinic whenever they were ill. Chemoprevention was stopped at 24 mo of age, and participants followed-up an additional year. Primary outcome was the incidence of malaria during the intervention period. During the intervention, the incidence of malaria in the no chemoprevention arm was 6.95 episodes per person-year at risk. Protective efficacy was 58% (95% CI, 45%-67%, p<0.001) for DP, 28% (95% CI, 7%-44%, p = 0.01) for TS, and 7% for SP (95% CI, -19% to 28%, p = 0.57). PQ levels were below the detection limit 52% of the time when malaria was diagnosed in the DP arm, suggesting non-adherence. There were no differences between the study arms in the incidence of serious adverse events during the intervention and the incidence of malaria during the 1-y period after the intervention was stopped. CONCLUSIONS For preventing malaria in children living in an area of high transmission intensity, monthly DP was the most efficacious and safe, although adherence may pose a problem. Monthly SP and daily TS may not be appropriate in areas with high transmission intensity and frequent resistance to antifolates. TRIAL REGISTRATION www.ClinicalTrials.gov NCT00948896 Please see later in the article for the Editors' Summary.
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Affiliation(s)
- Victor Bigira
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - James Kapisi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Tamara D. Clark
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
| | - Stephen Kinara
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Beth Osterbauer
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
| | - Francesca T. Aweeka
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
| | - Liusheng Huang
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
| | - Jane Achan
- Department of Pediatrics, Makerere University College of Health Sciences, Kampala, Uganda
| | - Diane V. Havlir
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
| | - Philip J. Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
| | - Moses R. Kamya
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, United States of America
- * E-mail:
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20
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Biochemical and functional characterization of Plasmodium falciparum GTP cyclohydrolase I. Malar J 2014; 13:150. [PMID: 24745605 PMCID: PMC4005822 DOI: 10.1186/1475-2875-13-150] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/17/2013] [Indexed: 12/12/2022] Open
Abstract
Background Antifolates are currently in clinical use for malaria preventive therapy and treatment. The drugs kill the parasites by targeting the enzymes in the de novo folate pathway. The use of antifolates has now been limited by the spread of drug-resistant mutations. GTP cyclohydrolase I (GCH1) is the first and the rate-limiting enzyme in the folate pathway. The amplification of the gch1 gene found in certain Plasmodium falciparum isolates can cause antifolate resistance and influence the course of antifolate resistance evolution. These findings showed the importance of P. falciparum GCH1 in drug resistance intervention. However, little is known about P. falciparum GCH1 in terms of kinetic parameters and functional assays, precluding the opportunity to obtain the key information on its catalytic reaction and to eventually develop this enzyme as a drug target. Methods Plasmodium falciparum GCH1 was cloned and expressed in bacteria. Enzymatic activity was determined by the measurement of fluorescent converted neopterin with assay validation by using mutant and GTP analogue. The genetic complementation study was performed in ∆folE bacteria to functionally identify the residues and domains of P. falciparum GCH1 required for its enzymatic activity. Plasmodial GCH1 sequences were aligned and structurally modeled to reveal conserved catalytic residues. Results Kinetic parameters and optimal conditions for enzymatic reactions were determined by the fluorescence-based assay. The inhibitor test against P. falciparum GCH1 is now possible as indicated by the inhibitory effect by 8-oxo-GTP. Genetic complementation was proven to be a convenient method to study the function of P. falciparum GCH1. A series of domain truncations revealed that the conserved core domain of GCH1 is responsible for its enzymatic activity. Homology modelling fits P. falciparum GCH1 into the classic Tunnelling-fold structure with well-conserved catalytic residues at the active site. Conclusions Functional assays for P. falciparum GCH1 based on enzymatic activity and genetic complementation were successfully developed. The assays in combination with a homology model characterized the enzymatic activity of P. falciparum GCH1 and the importance of its key amino acid residues. The potential to use the assay for inhibitor screening was validated by 8-oxo-GTP, a known GTP analogue inhibitor.
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21
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Laman M, Moore BR, Benjamin J, Padapu N, Tarongka N, Siba P, Betuela I, Mueller I, Robinson LJ, Davis TME. Comparison of an assumed versus measured leucocyte count in parasite density calculations in Papua New Guinean children with uncomplicated malaria. Malar J 2014; 13:145. [PMID: 24739250 PMCID: PMC3991873 DOI: 10.1186/1475-2875-13-145] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 04/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The accuracy of the World Health Organization method of estimating malaria parasite density from thick blood smears by assuming a white blood cell (WBC) count of 8,000/μL has been questioned in several studies. Since epidemiological investigations, anti-malarial efficacy trials and routine laboratory reporting in Papua New Guinea (PNG) have all relied on this approach, its validity was assessed as part of a trial of artemisinin-based combination therapy, which included blood smear microscopy and automated measurement of leucocyte densities on Days 0, 3 and 7. RESULTS 168 children with uncomplicated malaria (median (inter-quartile range) age 44 (39-47) months) were enrolled, 80.3% with Plasmodium falciparum monoinfection, 14.9% with Plasmodium vivax monoinfection, and 4.8% with mixed P. falciparum/P. vivax infection. All responded to allocated therapy and none had a malaria-positive slide on Day 3. Consistent with a median baseline WBC density of 7.3 (6.5-7.8) × 10(9)/L, there was no significant difference in baseline parasite density between the two methods regardless of Plasmodium species. Bland Altman plots showed that, for both species, the mean difference between paired parasite densities calculated from assumed and measured WBC densities was close to zero. At parasite densities <10,000/μL by measured WBC, almost all between-method differences were within the 95% limits of agreement. Above this range, there was increasing scatter but no systematic bias. CONCLUSIONS Diagnostic thresholds and parasite clearance assessment in most PNG children with uncomplicated malaria are relatively robust, but accurate estimates of a higher parasitaemia, as a prognostic index, requires formal WBC measurement.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, PO Box 480, Fremantle 6959, Western Australia, Australia.
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Senn N, Rarau P, Salib M, Manong D, Siba P, Rogerson S, Mueller I, Genton B. Use of antibiotics within the IMCI guidelines in outpatient settings in Papua New Guinean children: an observational and effectiveness study. PLoS One 2014; 9:e90990. [PMID: 24626194 PMCID: PMC3953204 DOI: 10.1371/journal.pone.0090990] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 02/06/2014] [Indexed: 12/24/2022] Open
Abstract
Introduction There is a need to investigate the effectiveness and appropriateness of antibiotics prescription within the Integrated Management of Childhood Illness (IMCI) strategy in the context of routine outpatient clinics. Methods Making use of a passive case detection system established for a malaria prevention trial in outpatient clinics in Papua New Guinea, the appropriateness and effectiveness of the use of antibiotics within the IMCI was assessed in 1605 young children. Main outcomes were prescription of antibiotics and re-attendances within 14 days for mild pneumonia, mild diarrhoea and uncomplicated malaria whether they were managed with or without antibiotics (proxy of effectiveness). Appropriateness was assessed for both mild and severe cases, while effectiveness was assessed only for mild diseases. Results A total of 6975 illness episodes out of 8944 fulfilled inclusion criteria (no previous attendance <14 days+full medical records). Clinical incidence rates (episodes/child/year; 95% CI) were 0.85 (0.81–0.90) for pneumonia, 0.62 (0.58–0.66) for malaria and 0.72 (0.65–0.93) for diarrhoea. Fifty three percent of 6975 sick children were treated with antibiotics, 11% were not treated with antibiotics when they should have been and in 29% antibiotics were prescribed when they should not have been. Re-attendance rates within 14 days following clinical diagnosis of mild pneumonia were 9% (126/1401) when managed with antibiotics compared to 8% (56/701) when managed without (adjusted Hazard Ratio (aHR) = 1.00 (0.57–1.76), p = 0.98). Rates for mild diarrhoea were 8% (73/874) and 9% (79/866) respectively (aHR = 0.8 (0.42–1.57), p = 0.53). Conclusion Non-adherence to IMCI recommendations for prescription of antibiotics is common in routine settings in Papua New Guinea. Although recommended, the use of antibiotics in young children with mild pneumonia as defined by IMCI criteria did not impact on their outcome. Better tools and new strategies for the identification of bacterial infections that require antibiotics are urgently needed.
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Affiliation(s)
- Nicolas Senn
- Vector Born Unit, PNG Institute of Medical Research, Madang (MAD), Papua New Guinea; Health Intervention Unit, Swiss Tropical and Public Health Institute, Basel (BS), Switzerland; University of Basel, Basel (BS), Switzerland; Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Patricia Rarau
- Vector Born Unit, PNG Institute of Medical Research, Madang (MAD), Papua New Guinea
| | - Mary Salib
- Vector Born Unit, PNG Institute of Medical Research, Madang (MAD), Papua New Guinea
| | - Doris Manong
- Vector Born Unit, PNG Institute of Medical Research, Madang (MAD), Papua New Guinea
| | - Peter Siba
- Vector Born Unit, PNG Institute of Medical Research, Madang (MAD), Papua New Guinea
| | - Stephen Rogerson
- Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Ivo Mueller
- Vector Born Unit, PNG Institute of Medical Research, Madang (MAD), Papua New Guinea; Dept. of Infections & Immunity, Walter & Eliza Hall Institute of Medical Research, Melbourne, Australia; Centre de Recerca en Salut Internacional de Barcelona (CRESIB), Barcelona, Spain
| | - Blaise Genton
- Health Intervention Unit, Swiss Tropical and Public Health Institute, Basel (BS), Switzerland; University of Basel, Basel (BS), Switzerland
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Ludlow LE, Hasang W, Umbers AJ, Forbes EK, Ome M, Unger HW, Mueller I, Siba PM, Jaworowski A, Rogerson SJ. Peripheral blood mononuclear cells derived from grand multigravidae display a distinct cytokine profile in response to P. falciparum infected erythrocytes. PLoS One 2014; 9:e86160. [PMID: 24465935 PMCID: PMC3899203 DOI: 10.1371/journal.pone.0086160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/06/2013] [Indexed: 12/02/2022] Open
Abstract
Immunopathology of placental malaria is most significant in women in their first pregnancy especially in endemic areas, due to a lack of protective immunity to Plasmodium falciparum, which is acquired in successive pregnancies. In some studies (but not all), grand multigravidae (defined as 5 or more pregnancies, G5–7) are more susceptible to poor birth outcomes associated with malaria compared to earlier gravidities. By comparing peripheral cellular responses in primigravidae (G1), women in their second to fourth pregnancy (G2–4) and grand multigravidae we sought to identify key components of the dysregulated immune response. PBMC were exposed to CS2-infected erythrocytes (IE) opsonised with autologous plasma or unopsonised IE, and cytokine and chemokine secretion was measured. Higher levels of opsonising antibody were present in plasma derived from multigravid compared to primigravid women. Significant differences in the levels of cytokines and chemokines secreted in response to IE were observed. Less IL-10, IL-1β, IL-6 and TNF but more CXCL8, CCL8, IFNγ and CXCL10 were detected in G5–7 compared to G2–4 women. Our study provides fresh insight into the modulation of peripheral blood cell function and effects on the balance between host protection and immunopathology during placental malaria infection.
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Affiliation(s)
- Louise E Ludlow
- Department of Medicine (RMH), University of Melbourne, Post Office Royal Melbourne Hospital, Melbourne, Victoria, Australia ; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, Australia
| | - Wina Hasang
- Department of Medicine (RMH), University of Melbourne, Post Office Royal Melbourne Hospital, Melbourne, Victoria, Australia ; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, Australia
| | - Alexandra J Umbers
- Department of Medicine (RMH), University of Melbourne, Post Office Royal Melbourne Hospital, Melbourne, Victoria, Australia ; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, Australia ; Papua New Guinea Institute of Medical Research, Vector Borne Disease Unit, Madang, PNG
| | - Emily K Forbes
- Department of Medicine (RMH), University of Melbourne, Post Office Royal Melbourne Hospital, Melbourne, Victoria, Australia ; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, Australia
| | - Maria Ome
- Papua New Guinea Institute of Medical Research, Vector Borne Disease Unit, Madang, PNG
| | - Holger W Unger
- Department of Medicine (RMH), University of Melbourne, Post Office Royal Melbourne Hospital, Melbourne, Victoria, Australia ; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, Australia ; Papua New Guinea Institute of Medical Research, Vector Borne Disease Unit, Madang, PNG
| | - Ivo Mueller
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia ; Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Vector Borne Disease Unit, Madang, PNG
| | - Anthony Jaworowski
- Centre for Biomedical Research, Burnet Institute, Melbourne, Victoria, Australia ; Department of Infectious Diseases, Monash University, Victoria, Australia ; Department of Immunology, Monash University, Victoria, Australia
| | - Stephen J Rogerson
- Department of Medicine (RMH), University of Melbourne, Post Office Royal Melbourne Hospital, Melbourne, Victoria, Australia ; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria, Australia
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Abstract
In a linked Perspective, Roly Gosling and Michelle Hsiang discuss the importance of non-falciparum malaria species to regional and global health. Please see later in the article for the Editors' Summary
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Affiliation(s)
- Roly D. Gosling
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, San Francisco, California, United States of America
| | - Michelle S. Hsiang
- Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, San Francisco, California, United States of America
- Department of Pediatrics, UCSF Benioff Children's Hospital, University of California, San Francisco, San Francisco, California, United States of America
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Selective intermittent preventive treatment of vivax malaria: reduction of malaria incidence in an open cohort study in brazilian Amazon. Malar Res Treat 2013; 2013:310246. [PMID: 23577276 PMCID: PMC3618938 DOI: 10.1155/2013/310246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 02/11/2013] [Accepted: 02/19/2013] [Indexed: 11/17/2022] Open
Abstract
In children, the Intermittent Preventive Treatment (IPTc), currently called Seasonal Malaria Chemoprevention (SMC), was considered effective on malaria control due to the reduction of its incidence in Papua New Guinea and in some areas with seasonal malaria in Africa. However, the IPT has not been indicated because of its association with drug resistance and for hindering natural immunity development. Thus, we evaluated the alternative IPT impact on malaria incidence in three riverside communities on Madeira River, in the municipality of Porto Velho, RO. We denominate this scheme Selective Intermittent Preventive Treatment (SIPT). The SIPT consists in a weekly dose of two 150 mg chloroquine tablets for 12 weeks, for adults, and an equivalent dose for children, after complete supervised treatment for P. vivax infection. This scheme is recommend by Brazilian Health Ministry to avoid frequent relapses. The clinic parasitological and epidemiological surveillance showed a significant reduction on vivax malaria incidence. The results showed a reduction on relapses and recurrence of malaria after SIPT implementation. The SIPT can be effective on vivax malaria control in localities with high transmission risk in the Brazilian Amazon.
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Barry AE, Schultz L, Senn N, Nale J, Kiniboro B, Siba PM, Mueller I, Reeder JC. High levels of genetic diversity of Plasmodium falciparum populations in Papua New Guinea despite variable infection prevalence. Am J Trop Med Hyg 2013; 88:718-25. [PMID: 23400571 PMCID: PMC3617858 DOI: 10.4269/ajtmh.12-0056] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 11/30/2012] [Indexed: 11/07/2022] Open
Abstract
High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malaria-endemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity.
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Affiliation(s)
- Alyssa E Barry
- Centre for Population Health, Burnet Institute, Melbourne, Australia.
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Mueller I, Galinski MR, Tsuboi T, Arevalo-Herrera M, Collins WE, King CL. Natural acquisition of immunity to Plasmodium vivax: epidemiological observations and potential targets. ADVANCES IN PARASITOLOGY 2013; 81:77-131. [PMID: 23384622 DOI: 10.1016/b978-0-12-407826-0.00003-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Population studies show that individuals acquire immunity to Plasmodium vivax more quickly than Plasmodium falciparum irrespective of overall transmission intensity, resulting in the peak burden of P. vivax malaria in younger age groups. Similarly, actively induced P. vivax infections in malaria therapy patients resulted in faster and generally more strain-transcending acquisition of immunity than P. falciparum infections. The mechanisms behind the more rapid acquisition of immunity to P. vivax are poorly understood. Natural acquired immune responses to P. vivax target both pre-erythrocytic and blood-stage antigens and include humoral and cellular components. To date, only a few studies have investigated the association of these immune responses with protection, with most studies focussing on a few merozoite antigens (such as the Pv Duffy binding protein (PvDBP), the Pv reticulocyte binding proteins (PvRBPs), or the Pv merozoite surface proteins (PvMSP1, 3 & 9)) or the circumsporozoite protein (PvCSP). Naturally acquired transmission-blocking (TB) immunity (TBI) was also found in several populations. Although limited, these data support the premise that developing a multi-stage P. vivax vaccine may be feasible and is worth pursuing.
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Affiliation(s)
- Ivo Mueller
- Walter + Eliza Hall Institute, Infection & Immunity Division, Parkville, Victoria, Australia
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28
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Senn N, Rarau P, Manong D, Salib M, Siba P, Reeder JC, Rogerson SJ, Genton B, Mueller I. Effectiveness of Artemether/Lumefantrine for the Treatment of Uncomplicated Plasmodium vivax and P. falciparum Malaria in Young Children in Papua New Guinea. Clin Infect Dis 2013; 56:1413-20. [DOI: 10.1093/cid/cit068] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Douglas NM, John GK, von Seidlein L, Anstey NM, Price RN. Chemotherapeutic strategies for reducing transmission of Plasmodium vivax malaria. ADVANCES IN PARASITOLOGY 2013. [PMID: 23199490 DOI: 10.1016/b978-0-12-397900-1.00005-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Effective use of anti-malarial drugs is key to reducing the transmission potential of Plasmodium vivax. In patients presenting with symptomatic disease, treatment with potent and relatively slowly eliminated blood schizontocidal regimens administered concurrently with a supervised course of 7 mg/kg primaquine over 7-14 days has potential to exert the greatest transmission-blocking benefit. Given the spread of chloroquine-resistant P. vivax strains, the artemisinin combination therapies dihydroartemisinin + piperaquine and artesunate + mefloquine are currently the most assured means of preventing P. vivax recrudescence. Preliminary evidence suggests that, like chloroquine, these combinations potentiate the hypnozoitocidal effect of primaquine, but further supportive evidence is required. In view of the high rate of P. vivax relapse following falciparum infections in co-endemic regions, there is a strong argument for broadening current radical cure policy to include the administration of hypnozoitocidal doses of primaquine to patients with Plasmodium falciparum malaria. The most important reservoir for P. vivax transmission is likely to be very low-density, asymptomatic infections, the majority of which will arise from liver-stage relapses. Therefore, judicious mass administration of hypnozoitocidal therapy will reduce transmission of P. vivax to a greater extent than strategies focused on treatment of symptomatic patients. An efficacious hypnozoitocidal agent with a short curative treatment course would be particularly useful in mass drug administration campaigns.
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Affiliation(s)
- Nicholas M Douglas
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
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Manning L, Laman M, Rosanas-Urgell A, Michon P, Aipit S, Bona C, Siba P, Mueller I, Davis TME. Severe anemia in Papua New Guinean children from a malaria-endemic area: a case-control etiologic study. PLoS Negl Trop Dis 2012; 6:e1972. [PMID: 23272266 PMCID: PMC3521670 DOI: 10.1371/journal.pntd.0001972] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 11/02/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND There are few detailed etiologic studies of severe anemia in children from malaria-endemic areas and none in those countries with holoendemic transmission of multiple Plasmodium species. METHODOLOGY/PRINCIPAL FINDINGS We examined associates of severe anemia in 143 well-characterized Papua New Guinean (PNG) children aged 0.5-10 years with hemoglobin concentration <50 g/L (median [inter-quartile range] 39 [33]-[44] g/L) and 120 matched healthy children (113 [107-119] g/L) in a case-control cross-sectional study. A range of socio-demographic, behavioural, anthropometric, clinical and laboratory (including genetic) variables were incorporated in multivariate models with severe anemia as dependent variable. Consistent with a likely trophic effect of chloroquine or amodiaquine on parvovirus B19 (B19V) replication, B19V PCR/IgM positivity had the highest odds ratio (95% confidence interval) of 75.8 (15.4-526), followed by P. falciparum infection (19.4 (6.7-62.6)), vitamin A deficiency (13.5 (5.4-37.7)), body mass index-for-age z-score <2.0 (8.4 (2.7-27.0)) and incomplete vaccination (2.94 (1.3-7.2)). P. vivax infection was inversely associated (0.12 (0.02-0.47), reflecting early acquisition of immunity and/or a lack of reticulocytes for parasite invasion. After imputation of missing data, iron deficiency was a weak positive predictor (6.4% of population attributable risk). CONCLUSIONS/SIGNIFICANCE These data show that severe anemia is multifactorial in PNG children, strongly associated with under-nutrition and certain common infections, and potentially preventable through vitamin A supplementation and improved nutrition, completion of vaccination schedules, and intermittent preventive antimalarial treatment using non-chloroquine/amodiaquine-based regimens.
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Affiliation(s)
- Laurens Manning
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia
| | - Moses Laman
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | | | - Pascal Michon
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Faculty of Health Sciences, Divine Word University, Madang, Madang Province, Papua New Guinea
| | - Susan Aipit
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Cathy Bona
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Peter Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Ivo Mueller
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Infection and Immunity Division, Walter and Eliza Hall Institute, Parkville, Victoria, Australia
- Center de Recerca en Salut Internacional de Barcelona (CRESIB), Barcelona, Spain
| | - Timothy M. E. Davis
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia
- * E-mail:
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Rosanas-Urgell A, Senn N, Rarau P, Aponte JJ, Reeder JC, Siba PM, Michon P, Mueller I. Lack of associations of α(+)-thalassemia with the risk of Plasmodium falciparum and Plasmodium vivax infection and disease in a cohort of children aged 3-21 months from Papua New Guinea. Int J Parasitol 2012; 42:1107-13. [PMID: 23085147 DOI: 10.1016/j.ijpara.2012.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 10/01/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
Abstract
Despite consistent evidence of a protective effect of α(+)-thalassemia against severe Plasmodium falciparum disease, the mechanisms underlying this protection remain unknown. An increase in risk of Plasmodium vivax malaria in early childhood resulting in a cross-species protection against severe P. falciparum malaria has been proposed as a possible mechanism in Melanesian children. The association of α(+)-thalassemia genotypes with a risk of P. falciparum and P. vivax infection and uncomplicated illness was reassessed in a cohort of 1,112 Papua New Guinean children, followed from 3 to 21 months of age. Three hundred and eighty-nine (35.0%) children were homozygous for α(+)-thalassemia (-α/-α), 506 (45.5%) heterozygous (αα/-α) and 217 (19.5%) homozygous for the wild-type allele. No significant differences in the incidence of P. falciparum (Pf) or P. vivax (Pv) malaria were observed between α(+)-thalassemia homozygote (Pf: incidence rate ratio (IRR)=1.13, CI(95) (0.82, 1.56), P=0.45, Pv: IRR=1.15, CI(95) (0.88, 1.50), P=0.31), heterozygote (Pf: IRR=0.98, CI(95) (0.71, 1.34), P=0.93, Pv: IRR=1.14, CI(95) (0.88, 1.48), P=0.33) and wild-type children. The prevalence of infection with either species did not differ between α(+)-thalassemia genotypes, although densities of P. vivax (but not of P. falciparum) infections were significantly higher in α(+)-thalassemia homozygote and heterozygote children. An excessive risk of moderate-to-severe anemia (Hb<8 g/dl) was observed in α(+)-thalassemia homozygote children (IRR=1.54, CI(95) (1.12, 2.11), P=0.008). This study therefore failed to confirm an increased risk of P. vivax or P. falciparum malaria in very young, α(+)-thalassemic children without significant levels of acquired immunity. This confirms the lack of protection by α(+)-thalassemia against uncomplicated P. falciparum and challenges the hypothesis of immunological cross-protection between P. falciparum and P. vivax as a mechanism underlying α(+)-thalassemia protection against severe P. falciparum disease in Melanesian children.
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Betuela I, Rosanas-Urgell A, Kiniboro B, Stanisic DI, Samol L, de Lazzari E, Del Portillo HA, Siba P, Alonso PL, Bassat Q, Mueller I. Relapses contribute significantly to the risk of Plasmodium vivax infection and disease in Papua New Guinean children 1-5 years of age. J Infect Dis 2012; 206:1771-80. [PMID: 22966124 DOI: 10.1093/infdis/jis580] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Plasmodium vivax forms long-lasting hypnozoites in the liver. How much they contribute to the burden of P. vivax malaria in children living in highly endemic areas is unknown. METHODS In this study, 433 Papua New Guinean children aged 1-5 years were Randomized to receive artesunate (7 days) plus primaquine (14 days), artesunate alone or no treatment and followed up actively for recurrent Plasmodium infections and disease for 40 weeks. RESULTS Treatment with artesunate-primaquine reduced the risk of P. vivax episodes by 28% (P = .042) and 33% (P = .015) compared with the artesunate and control arms, respectively. A significant reduction was observed only in the first 3 months of follow-up (artesunate-primaquine vs control, -58% [P = .004]; artesunate-primaquine vs artesunate, -49% [P = .031]) with little difference thereafter. Primaquine treatment also reduced the risk of quantitative real-time polymerase chain reaction- and light microscopy-positive P. vivax reinfections by 44% (P < .001) and 67% (P < .001), respectively. Whereas primaquine treatment did not change the risk of reinfection with Plasmodium falciparum, fewer P. falciparum clinical episodes were observed in the artesunate-primaquine arm. CONCLUSIONS Hypnozoites are an important source of P. vivax infection and contribute substantially to the high burden of P. vivax disease observed in young Papua New Guinean children. Even in highly endemic areas with a high risk of reinfection, antihypnozoite treatment should be given to all cases with parasitologically confirmed P. vivax infections.
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Affiliation(s)
- Inoni Betuela
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
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Bardají A, Bassat Q, Alonso PL, Menéndez C. Intermittent preventive treatment of malaria in pregnant women and infants: making best use of the available evidence. Expert Opin Pharmacother 2012; 13:1719-36. [PMID: 22775553 DOI: 10.1517/14656566.2012.703651] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Malaria continues to represent a huge global health burden on the most vulnerable populations. The Intermittent Preventive Treatment (IPT) strategy has been shown to be an efficacious intervention in preventing most of the deleterious effects of malaria in pregnant women and infants. Yet, the effectiveness of the IPT strategy may be impaired by the increasing resistance to sulfadoxine-pyrimethamine (SP), and the scarcity of alternative antimalarial drugs. AREAS COVERED This review examines all the available information on IPT, in an aim to provide the scientific community with a framework to understand the benefits and limitations of this malaria control strategy. It includes the understanding of the historical background of the IPT strategy, the drug's mechanisms of actions, updated information on current available evidence, the implications of drug resistance and choice of alternative drugs, and a comprehensive discussion on the perspectives of IPT for malaria control in pregnant women and infants. EXPERT OPINION IPT in pregnancy and infants is a cost-effective strategy that can contribute significantly to the control of malaria in endemic areas. Monitoring its effectiveness will allow tracking of progress, evaluation of the adequacy of currently used drugs and will highlight the eventual need for new therapies or alternative interventions.
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Affiliation(s)
- Azucena Bardají
- University of Barcelona, Hospital Clínic, Barcelona Centre for International Health Research, Roselló, 132, 08036, Barcelona, Spain.
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Rosanas-Urgell A, Lin E, Manning L, Rarau P, Laman M, Senn N, Grimberg BT, Tavul L, Stanisic DI, Robinson LJ, Aponte JJ, Dabod E, Reeder JC, Siba P, Zimmerman PA, Davis TME, King CL, Michon P, Mueller I. Reduced risk of Plasmodium vivax malaria in Papua New Guinean children with Southeast Asian ovalocytosis in two cohorts and a case-control study. PLoS Med 2012; 9:e1001305. [PMID: 22973182 PMCID: PMC3433408 DOI: 10.1371/journal.pmed.1001305] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 07/23/2012] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The erythrocyte polymorphism, Southeast Asian ovalocytosis (SAO) (which results from a 27-base pair deletion in the erythrocyte band 3 gene, SLC4A1Δ27) protects against cerebral malaria caused by Plasmodium falciparum; however, it is unknown whether this polymorphism also protects against P. vivax infection and disease. METHODS AND FINDINGS The association between SAO and P. vivax infection was examined through genotyping of 1,975 children enrolled in three independent epidemiological studies conducted in the Madang area of Papua New Guinea. SAO was associated with a statistically significant 46% reduction in the incidence of clinical P. vivax episodes (adjusted incidence rate ratio [IRR] = 0.54, 95% CI 0.40-0.72, p<0.0001) in a cohort of infants aged 3-21 months and a significant 52% reduction in P. vivax (blood-stage) reinfection diagnosed by PCR (95% CI 22-71, p = 0.003) and 55% by light microscopy (95% CI 13-77, p = 0.014), respectively, in a cohort of children aged 5-14 years. SAO was also associated with a reduction in risk of P. vivax parasitaemia in children 3-21 months (1,111/µl versus 636/µl, p = 0.011) and prevalence of P. vivax infections in children 15-21 months (odds ratio [OR] = 0.39, 95% CI 0.23-0.67, p = 0.001). In a case-control study of children aged 0.5-10 years, no child with SAO was found among 27 cases with severe P. vivax or mixed P. falciparum/P. vivax malaria (OR = 0, 95% CI 0-1.56, p = 0.11). SAO was associated with protection against severe P. falciparum malaria (OR = 0.38, 95% CI 0.15-0.87, p = 0.014) but no effect was seen on either the risk of acquiring blood-stage infections or uncomplicated episodes with P. falciparum. Although Duffy antigen receptor expression and function were not affected on SAO erythrocytes compared to non-SAO children, high level (>90% binding inhibition) P. vivax Duffy binding protein-specific binding inhibitory antibodies were observed significantly more often in sera from SAO than non-SAO children (SAO, 22.2%; non-SAO, 6.7%; p = 0.008). CONCLUSIONS In three independent studies, we observed strong associations between SAO and protection against P. vivax malaria by a mechanism that is independent of the Duffy antigen. P. vivax malaria may have contributed to shaping the unique host genetic adaptations to malaria in Asian and Oceanic populations. Please see later in the article for the Editors' Summary.
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Affiliation(s)
| | - Enmoore Lin
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Laurens Manning
- Department of Medicine & Pharmacology, University of Western Australia, Perth, Australia
| | - Patricia Rarau
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Moses Laman
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Nicolas Senn
- PNG Institute of Medical Research, Madang, Papua New Guinea
- Swiss Tropical & Public Health Institute, Basel, Switzerland
| | - Brian T. Grimberg
- Center of Global Health & Diseases (CGHD), Case Western Reserve University, Cleveland, Ohio, United States of America
| | | | - Danielle I. Stanisic
- PNG Institute of Medical Research, Madang, Papua New Guinea
- Infection & Immunity Division, Walter+Eliza Hall Institute, Parkville, Victoria, Australia
| | - Leanne J. Robinson
- PNG Institute of Medical Research, Madang, Papua New Guinea
- Infection & Immunity Division, Walter+Eliza Hall Institute, Parkville, Victoria, Australia
| | - John J. Aponte
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
| | - Elijah Dabod
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | | | - Peter Siba
- PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Peter A. Zimmerman
- Center of Global Health & Diseases (CGHD), Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Timothy M. E. Davis
- Department of Medicine & Pharmacology, University of Western Australia, Perth, Australia
| | - Christopher L. King
- Center of Global Health & Diseases (CGHD), Case Western Reserve University, Cleveland, Ohio, United States of America
- Veterans Affairs Medical Center, Cleveland, Ohio, United States of America
| | - Pascal Michon
- PNG Institute of Medical Research, Madang, Papua New Guinea
- Faculty of Health Sciences, Divine Word University, Madang, Papua New Guinea
| | - Ivo Mueller
- PNG Institute of Medical Research, Madang, Papua New Guinea
- Infection & Immunity Division, Walter+Eliza Hall Institute, Parkville, Victoria, Australia
- Barcelona Centre for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- * E-mail:
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