1
|
Biggs J, Challenger JD, Hellewell J, Churcher TS, Cook J. A systematic review of sample size estimation accuracy on power in malaria cluster randomised trials measuring epidemiological outcomes. BMC Med Res Methodol 2024; 24:238. [PMID: 39407101 PMCID: PMC11476958 DOI: 10.1186/s12874-024-02361-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 10/01/2024] [Indexed: 10/20/2024] Open
Abstract
INTRODUCTION Cluster randomised trials (CRTs) are the gold standard for measuring the community-wide impacts of malaria control tools. CRTs rely on well-defined sample size estimations to detect statistically significant effects of trialled interventions, however these are often predicted poorly by triallists. Here, we review the accuracy of predicted parameters used in sample size calculations for malaria CRTs with epidemiological outcomes. METHODS We searched for published malaria CRTs using four online databases in March 2022. Eligible trials included those with malaria-specific epidemiological outcomes which randomised at least six geographical clusters to study arms. Predicted and observed sample size parameters were extracted by reviewers for each trial. Pair-wise Spearman's correlation coefficients (rs) were calculated to assess the correlation between predicted and observed control-arm outcome measures and effect sizes (relative percentage reductions) between arms. Among trials which retrospectively calculated an estimate of heterogeneity in cluster outcomes, we recalculated study power according to observed trial estimates. RESULTS Of the 1889 records identified and screened, 108 articles were eligible and comprised of 71 malaria CRTs. Among 91.5% (65/71) of trials that included sample size calculations, most estimated cluster heterogeneity using the coefficient of variation (k) (80%, 52/65) which were often predicted without using prior data (67.7%, 44/65). Predicted control-arm prevalence moderately correlated with observed control-arm prevalence (rs: 0.44, [95%CI: 0.12,0.68], p-value < 0.05], with 61.2% (19/31) of prevalence estimates overestimated. Among the minority of trials that retrospectively calculated cluster heterogeneity (20%, 13/65), empirical values contrasted with those used in sample size estimations and often compromised study power. Observed effect sizes were often smaller than had been predicted at the sample size stage (72.9%, 51/70) and were typically higher in the first, compared to the second, year of trials. Overall, effect sizes achieved by malaria interventions tested in trials decreased between 1995 and 2021. CONCLUSIONS Study findings reveal sample size parameters in malaria CRTs were often inaccurate and resulted in underpowered studies. Future trials must strive to obtain more representative epidemiological sample size inputs to ensure interventions against malaria are adequately evaluated. REGISTRATION This review is registered with PROSPERO (CRD42022315741).
Collapse
Affiliation(s)
- Joseph Biggs
- Medical Research Council (MRC) International Statistics and Epidemiology Group, Department of Infectious Disease Epidemiology and International Health, London School of Hygiene and Tropical Medicine, London, UK.
| | - Joseph D Challenger
- Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Joel Hellewell
- Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Thomas S Churcher
- Medical Research Council (MRC) Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, UK
| | - Jackie Cook
- Medical Research Council (MRC) International Statistics and Epidemiology Group, Department of Infectious Disease Epidemiology and International Health, London School of Hygiene and Tropical Medicine, London, UK
| |
Collapse
|
2
|
Tréhard H, Musset L, Lazrek Y, White M, Pelleau S, Mueller I, Djossou F, Sanna A, Landier J, Gaudart J, Mosnier E. Which diagnostic test to use for Testing and Treatment strategies in Plasmodium vivax low-transmission settings: a secondary analysis of a longitudinal interventional study. LANCET REGIONAL HEALTH. AMERICAS 2024; 38:100883. [PMID: 39319096 PMCID: PMC11420435 DOI: 10.1016/j.lana.2024.100883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 08/05/2024] [Accepted: 08/19/2024] [Indexed: 09/26/2024]
Abstract
Background The lack of sensitive field tests to diagnose blood stages and hypnozoite carriers prevents Testing and Treatment (TAT) strategies to achieve Plasmodium vivax elimination in low-transmission settings, but recent advances in Polymerase Chain Reaction (PCR) and serology position them as promising tools. This study describes a PCR-based TAT strategy (PCRTAT) implemented in Saint Georges (SGO), French Guiana, and explores alternative strategies (seroTAT and seroPCRTAT) to diagnose and treat P. vivax carriers. Methods The PALUSTOP cohort study implemented in SGO (September 2017 to December 2018) screened participants for P. vivax using PCR tests and treated positive cases. Serology was also performed. Passive detection of P. vivax infection occurred during follow-up. Participants were categorised into overlapping treatment groups based on 2017 PCR and serological results. Strategies were described in terms of participants targeted or missed, primaquine contraindications (pregnancy, G6PD severe or intermediate deficiency), and sociodemographic characteristics. Findings In 2017, 1567 inhabitants were included, aged 0-92 years. A total of 90 (6%) were P. vivax carriers and 390 seropositive (25%). PCRTAT missed 282 seropositive individuals while seroTAT would have missed 21 PCR-positive cases. Primaquine contraindications ranged from 12% to 17% across strategies. Interpretation Serology and PCR are promising tools for targeted treatment strategies in P. vivax low-transmission settings, when field compatible sensitive tests will be available. Both seem necessary to capture blood stages and potential hypnozoite carriers, while avoiding mass treatment. However, high primaquine contraindications rates need consideration for successful elimination. Funding Supported by European Funds for Regional Development, French Guiana Regional Health Agency, Pan American Health Organization, WHO, French Ministry for Research.
Collapse
Affiliation(s)
- Hélène Tréhard
- Aix Marseille Univ, INSERM, IRD, SESSTIM, Sciences Economiques & Sociales de la Santé & Traitement de l’Information Médicale, Aix Marseille Institute of Public Health ISSPAM, Marseille, France
| | - Lise Musset
- Laboratoire de parasitologie, World Health Organization Collaborating Center for Surveillance of Antimalarial Drug Resistance, Centre National de Référence du Paludisme, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Yassamine Lazrek
- Laboratoire de parasitologie, World Health Organization Collaborating Center for Surveillance of Antimalarial Drug Resistance, Centre National de Référence du Paludisme, Institut Pasteur de la Guyane, Cayenne, French Guiana
| | - Michael White
- Infectious Diseases Epidemiology and Analytics, Department of Global Health, Institut Pasteur, Université Paris Cité, Paris, France
| | - Stéphane Pelleau
- Infectious Diseases Epidemiology and Analytics, Department of Global Health, Institut Pasteur, Université Paris Cité, Paris, France
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Felix Djossou
- Unité des Maladies Infectieuses et Tropicales, Centre Hospitalier de Cayenne, French Guiana
| | - Alice Sanna
- Centre d’Investigation Clinique Antilles Guyane CIC, Centre Hospitalier de Cayenne, French Guiana
| | - Jordi Landier
- Aix Marseille Univ, INSERM, IRD, SESSTIM, Sciences Economiques & Sociales de la Santé & Traitement de l’Information Médicale, Aix Marseille Institute of Public Health ISSPAM, Marseille, France
| | - Jean Gaudart
- Aix Marseille Univ, INSERM, IRD, ISSPAM, SESSTIM, UMR1252, AP HM, Hop Timone, BioSTIC, Biostatistic & ICT, Marseille, France
| | - Emilie Mosnier
- Aix Marseille Univ, INSERM, IRD, SESSTIM, Sciences Economiques & Sociales de la Santé & Traitement de l’Information Médicale, Aix Marseille Institute of Public Health ISSPAM, Marseille, France
- Grant Management Office, University of Health Sciences, Phnom Penh, Cambodia
- French Agency for Research on AIDS, Viral Hepatitis and Emerging Infectious diseases (ANRS-MIE), Phnom Penh, Cambodia
| |
Collapse
|
3
|
Lu F, Xu J, Liu Y, Ren Z, Chen J, Gong W, Yin Y, Li Y, Qian L, He X, Han X, Lin Z, Lu J, Zhang W, Liu J, Menard D, Han ET, Cao J. Plasmodium vivax serological exposure markers: PvMSP1-42-induced humoral and memory B-cell response generates long-lived antibodies. PLoS Pathog 2024; 20:e1012334. [PMID: 38941356 PMCID: PMC11239109 DOI: 10.1371/journal.ppat.1012334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 07/11/2024] [Accepted: 06/10/2024] [Indexed: 06/30/2024] Open
Abstract
Plasmodium vivax serological exposure markers (SEMs) have emerged as promising tools for the actionable surveillance and implementation of targeted interventions to accelerate malaria elimination. To determine the dynamic profiles of SEMs in current and past P. vivax infections, we screened and selected 11 P. vivax proteins from 210 putative proteins using protein arrays, with a set of serum samples obtained from patients with acute P. vivax and documented past P. vivax infections. Then we used a murine protein immune model to initially investigate the humoral and memory B cell response involved in the generation of long-lived antibodies. We show that of the 11 proteins, especially C-terminal 42-kDa region of P. vivax merozoite surface protein 1 (PvMSP1-42) induced longer-lasting long-lived antibodies, as these antibodies were detected in individuals infected with P. vivax in the 1960-1970s who were not re-infected until 2012. In addition, we provide a potential mechanism for the maintenance of long-lived antibodies after the induction of PvMSP1-42. The results indicate that PvMSP1-42 induces more CD73+CD80+ memory B cells (MBCs) compared to P. vivax GPI-anchored micronemal antigen (PvGAMA), allowing IgG anti-PvMSP1-42 antibodies to be maintained for a long time.
Collapse
Affiliation(s)
- Feng Lu
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Jiahui Xu
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Yaobao Liu
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Zhenyu Ren
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Junhu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
| | - Weijuan Gong
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Yi Yin
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Yinyue Li
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Li Qian
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Xinlong He
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Xiu Han
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Zhijie Lin
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Jingyuan Lu
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Wenwen Zhang
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Jiali Liu
- Department of Pathogenic Biology and Immunology, School of Medicine, Key laboratory of Jiangsu province university for Nucleic Acid & Cell Fate Manipulation, Affiliated Hospital of Yangzhou University, Yangzhou University, Yangzhou, China
| | - Didier Menard
- Institut Pasteur, Université Paris Cité, Malaria Parasite Biology and Vaccines Unit, Paris, France
- Université de Strasbourg, UR 3073—Pathogens Host Arthropods Vectors Interactions Unit, Malaria Genetics and Resistance Team (MEGATEAM), Strasbourg, France
- CHU Strasbourg, Laboratory of Parasitology and Medical Mycology, Strasbourg, France
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Jun Cao
- National Health Commission Key Laboratory of Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Provincial Medical Key Laboratory, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| |
Collapse
|
4
|
Bhamani B, Martí Coma-Cros E, Tusell M, Mithi V, Serra-Casas E, Williams NA, Lindblade KA, Allen KC. Targeted Testing and Treatment To Reduce Human Malaria Transmission in High-Risk Populations: A Systematic Review. Am J Trop Med Hyg 2024; 110:54-64. [PMID: 38471159 PMCID: PMC10993793 DOI: 10.4269/ajtmh.23-0097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 01/04/2024] [Indexed: 03/14/2024] Open
Abstract
As countries approach elimination of malaria, groups with increased exposure to malaria vectors or poor access to health services may serve as important human reservoirs of infection that help maintain transmission in the community. Parasitological testing and treatment targeted to these groups may reduce malaria transmission overall. This systematic review assessed the effectiveness of targeted testing and treatment (TTaT) to reduce malaria transmission, the contextual factors, and the results of modeling studies that estimated the intervention's potential impact. Bibliographic searches were conducted in March 2021 and updated in April 2022, and a total of 1,210 articles were identified. Three studies were included for outcome data: one factorial cluster randomized controlled trial (cRCT) in Kenya (5,233 participants), one cRCT in Ghana (3,046 participants), and one controlled before-and-after cohort study in schoolchildren in Malawi (786 participants). Nine reports were included for contextual factors, and two were included for mathematical modeling. Data on outcomes from the three studies suggested that at the community level, TTaT would result in little to no difference in the incidence of malaria infection (measured via active surveillance), adverse events, and severe AEs. In contrast, the effects of TTaT on prevalence (malaria parasitemia) among those targeted by the intervention were found to include a short-term impact on reducing transmission but little to no impact on transmission for extended periods. Future iterations of this review should ensure consideration for populations proven to host the vast majority of the reservoir of infection in lower-transmission settings to determine the effectiveness of the intervention.
Collapse
Affiliation(s)
- Beena Bhamani
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Elisabet Martí Coma-Cros
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Maria Tusell
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Vita Mithi
- Armref Data for Action in Public Health Research Consultancy, Mzuzu, Malawi
- Society for Research on Nicotine and Tobacco—Genetics and Omics Network, Madison, Wisconsin
- Leaders of Africa Institute, Baltimore, Maryland
| | - Elisa Serra-Casas
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Nana Aba Williams
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - Kim A. Lindblade
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Koya C. Allen
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic, University of Barcelona, Barcelona, Spain
| |
Collapse
|
5
|
Bhamani B, Martí Coma-Cros E, Tusell M, Mithi V, Serra-Casas E, Williams NA, Lindblade KA, Allen KC. Mass Testing and Treatment to Accelerate Malaria Elimination: A Systematic Review and Meta-Analysis. Am J Trop Med Hyg 2024; 110:44-53. [PMID: 38471168 PMCID: PMC10993795 DOI: 10.4269/ajtmh.23-0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 01/17/2024] [Indexed: 03/14/2024] Open
Abstract
In regions where malaria transmission persists, the implementation of approaches aimed at eliminating parasites from the population can effectively decrease both burden of disease and transmission of infection. Thus, mass strategies that target symptomatic and asymptomatic infections at the same time may help countries to reduce transmission. This systematic review assessed the potential benefits and harms of mass testing and treatment (MTaT) to reduce malaria transmission. Searches were conducted in March 2021 and updated in April 2022 and included cluster-randomized controlled trials (cRCTs) as well as nonrandomized studies (NRSs) using malaria infection incidence, clinical malaria incidence, or prevalence as outcomes. The risk of bias was assessed with Cochrane's risk of bias (RoB2) tool and Risk of Bias Tool in Nonrandomized Studies - of Interventions (ROBINS-I), and the certainty of evidence (CoE) was graded for each outcome. Of 4,462 citations identified, seven studies (four cRCTs and three NRSs) contributed outcome data. The analysis revealed that MTaT did not reduce the incidence (risk ratio [RR]: 0.95, 95% CI: 0.87-1.04; 1,181 participants; moderate CoE) or prevalence (RR: 0.83, 95% CI: 0.67-1.01; 7,522 participants; moderate CoE) of malaria infection but resulted in a small reduction in clinical malaria (RR: 0.82; 95% CI: 0.70-0.95; 334,944 participants; moderate CoE). Three studies contributing data on contextual factors concluded that MTaT is an acceptable, feasible, and cost-effective intervention. Mathematical modeling analyses (n = 10) suggested that MTaT effectiveness depends on the baseline transmission level, diagnostic test performance, number of rounds, and other co-interventions. Based on the limited evidence available, MTaT has little to no impact on reducing malaria transmission.
Collapse
Affiliation(s)
- Beena Bhamani
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic – Universitat de Barcelona, Barcelona, Spain
| | - Elisabet Martí Coma-Cros
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic – Universitat de Barcelona, Barcelona, Spain
| | - Maria Tusell
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic – Universitat de Barcelona, Barcelona, Spain
| | - Vita Mithi
- Armref Data for Action in Public Health Research Consultancy, Mzuzu, Malawi
- Society for Research on Nicotine and Tobacco-Genetics and Omics Network, Madison, Wisconsin
- Leaders of Africa Institute, Baltimore, Maryland
| | - Elisa Serra-Casas
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic – Universitat de Barcelona, Barcelona, Spain
| | - Nana Aba Williams
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic – Universitat de Barcelona, Barcelona, Spain
| | - Kim A. Lindblade
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | - Koya C. Allen
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic – Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
6
|
McCallum F, Mond K, Cheng Q, Furuya-Kanamori L, Auliff A, Kaminiel P. A Health Survey Revealing Prevalence of Vector-Borne Diseases and Tuberculosis in Papua New Guinea Defence Force Personnel and Families. Am J Trop Med Hyg 2023; 109:1086-1094. [PMID: 37748766 PMCID: PMC10622466 DOI: 10.4269/ajtmh.23-0341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/26/2023] [Indexed: 09/27/2023] Open
Abstract
The Papua New Guinean Defence Force (PNGDF) and the Australian Defence Force (ADF) work and train closely. Infectious diseases pose a health threat to both forces, but recent knowledge about the risk at military bases in Papua New Guinea is limited. To improve understanding, a collaborative cross-sectional survey was conducted (March-April 2019) at Lombrum Naval base (Manus province) and Moem Army barracks (Wewak, East Sepik province) plus its Vanimo outpost (Sandaun province). Clinical data, venous blood, and sputum were collected from PNGDF personnel (DF) from the three sites, with point-of-care testing conducted for malaria (microscopy and rapid diagnostic test [RDT]), lymphatic filariasis (RDT), glucose-6-phosphate-dehydrogenase (G6PD) deficiency (RDT), tuberculosis (GeneXpert), and hemoglobin level. Finger prick blood collected from family members residing at the Wewak base was tested for malaria and hemoglobin level. Overall, 235 DF and 793 family members completed the survey. Microscopy revealed malaria prevalence as 0.4% Plasmodium falciparum and 3.1% Plasmodium vivax among DF and 3.5% P. falciparum, 14.3% P. vivax, and 0.3% mixed P. falciparum/P. vivax among family members. Among DF, 3.9% were G6PD deficient and none tested positive for tuberculosis or for lymphatic filariasis antigen. Anemia was present in 6.5% of DF and 47.3% of family members, predominantly females. Results suggest ongoing exposure to malaria, particularly P. vivax, at study sites, whereas infections of lymphatic filariasis and tuberculosis were not detected. Survey results will inform the PNGDF and the ADF regarding vector-borne disease risk for future sustainable health and disease control interventions.
Collapse
Affiliation(s)
- Fiona McCallum
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Krond Mond
- Papua New Guinea Defence Force Health Services, Port Moresby, Papua New Guinea
| | - Qin Cheng
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Luis Furuya-Kanamori
- School of Public Health, Faculty of Medicine, The University of Queensland, Herston, Australia
| | - Alyson Auliff
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Peter Kaminiel
- Papua New Guinea Defence Force Health Services, Port Moresby, Papua New Guinea
| |
Collapse
|
7
|
Newby G, Cotter C, Roh ME, Harvard K, Bennett A, Hwang J, Chitnis N, Fine S, Stresman G, Chen I, Gosling R, Hsiang MS. Testing and treatment for malaria elimination: a systematic review. Malar J 2023; 22:254. [PMID: 37661286 PMCID: PMC10476355 DOI: 10.1186/s12936-023-04670-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/07/2023] [Indexed: 09/05/2023] Open
Abstract
BACKGROUND Global interest in malaria elimination has prompted research on active test and treat (TaT) strategies. METHODS A systematic review and meta-analysis were conducted to assess the effectiveness of TaT strategies to reduce malaria transmission. RESULTS A total of 72 empirical research and 24 modelling studies were identified, mainly focused on proactive mass TaT (MTaT) and reactive case detection (RACD) in higher and lower transmission settings, respectively. Ten intervention studies compared MTaT to no MTaT and the evidence for impact on malaria incidence was weak. No intervention studies compared RACD to no RACD. Compared to passive case detection (PCD) alone, PCD + RACD using standard diagnostics increased infection detection 52.7% and 11.3% in low and very low transmission settings, respectively. Using molecular methods increased this detection of infections by 1.4- and 1.1-fold, respectively. CONCLUSION Results suggest MTaT is not effective for reducing transmission. By increasing case detection, surveillance data provided by RACD may indirectly reduce transmission by informing coordinated responses of intervention targeting.
Collapse
Affiliation(s)
- Gretchen Newby
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
| | - Chris Cotter
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Michelle E Roh
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
- Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA
| | - Kelly Harvard
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
- Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA
- PATH, Seattle, WA, USA
| | - Jimee Hwang
- Malaria Branch, Centers for Disease Control and Prevention, U.S. President's Malaria Initiative, Atlanta, GA, USA
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Sydney Fine
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
| | - Gillian Stresman
- College of Public Health, University of South Florida, Tampa, FL, USA
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Ingrid Chen
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
- Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA
| | - Roly Gosling
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA
- Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California San Francisco (UCSF), 550 16th Street, San Francisco, CA, 94143, USA.
- Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA.
- Department of Pediatrics, UCSF, San Francisco, CA, USA.
| |
Collapse
|
8
|
Nekkab N, Obadia T, Monteiro WM, Lacerda MV, White M, Mueller I. Accelerating towards P. vivax elimination with a novel serological test-and-treat strategy: a modelling case study in Brazil. LANCET REGIONAL HEALTH. AMERICAS 2023; 22:100511. [PMID: 37250687 PMCID: PMC10209700 DOI: 10.1016/j.lana.2023.100511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/05/2023] [Accepted: 05/04/2023] [Indexed: 05/31/2023]
Abstract
Background Plasmodium vivax malaria is challenging to control and eliminate. Treatment with radical cure drugs fails to target the hidden asymptomatic and hypnozoite reservoirs in populations. PvSeroTAT, a novel serological test-and-treat intervention using a serological diagnostic to screen hypnozoite carriers for radical cure eligibility and treatment, could accelerate P. vivax elimination. Methods Using a previously developed mathematical model of P. vivax transmission adapted to the Brazilian context as a case study for implementation, we evaluate the public health impact of various deployment strategies of PvSeroTAT as a mass campaign. We compare relative reductions in prevalence, cases averted, glucose-6-phosphate dehydrogenase (G6PD) tests, and treatment doses of PvSeroTAT campaigns to strengthened case management alone or mass drug administration (MDA) campaigns across different settings. Findings Deploying a single round of PvSeroTAT with 80% coverage to treat cases with a high efficacy radical cure regimen with primaquine is predicted to reduce point population prevalence by 22.5% [95% UI: 20.2%-24.8%] in a peri-urban setting with high transmission and by 25.2% [95% UI: 9.6%-42.2%] in an occupational setting with moderate transmission. In the latter example, while a single PvSeroTAT achieves 9.2% less impact on prevalence and averts 300 less cases per 100,000 than a single MDA (25.2% [95% UI: 9.6%-42.2%] point prevalence reduction versus 34.4% [95% UI: 24.9%-44%]), PvSeroTAT requires 4.6 times less radical cure treatments and G6PD tests. Layering strengthened case management and deploying four rounds of PvSeroTAT six months apart is predicted to reduce point prevalence by a mean of 74.1% [95% UI: 61.3%-86.3%] or more in low transmission settings with less than 10 cases per 1000 population. Interpretation Modelling predicts that mass campaigns with PvSeroTAT are predicted to reduce P. vivax parasite prevalence across a range of transmission settings and require fewer resources than MDA. In combination with strengthened case management, mass campaigns of serological test-and-treat interventions can accelerate towards P. vivax elimination. Funding This project was funded in part by the Bill and Melinda Gates Foundation and the National Health and Medical Research Council.
Collapse
Affiliation(s)
- Narimane Nekkab
- Institut Pasteur, Université Paris Cité, G5 Épidémiologie et Analyse des Maladies Infectieuses, Paris, France
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Thomas Obadia
- Institut Pasteur, Université Paris Cité, G5 Épidémiologie et Analyse des Maladies Infectieuses, Paris, France
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Paris, France
| | - Wuelton M. Monteiro
- Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Marcus V.G. Lacerda
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
- Instituto Leônidas e Maria Deane, Fundação Oswaldo Cruz, Manaus, Brazil
| | - Michael White
- Institut Pasteur, Université Paris Cité, G5 Épidémiologie et Analyse des Maladies Infectieuses, Paris, France
| | - Ivo Mueller
- Population Health & Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| |
Collapse
|
9
|
Jorgensen SCJ, Miljanic S, Tabbara N, Somanader D, Leung F, De Castro C, Tse CLY, Law J, Fernandes V, Lapinsky SE, Malhamé I, Burry L. Inclusion of pregnant and breastfeeding women in nonobstetrical randomized controlled trials. Am J Obstet Gynecol MFM 2022; 4:100700. [PMID: 35914736 DOI: 10.1016/j.ajogmf.2022.100700] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND There is an urgent need to prioritize and expedite the inclusion of pregnant and breastfeeding women in research. Characterizing trials that have successfully included these populations could inform the design and execution of future studies. In addition, up-to-date data on their inclusion in clinical research could assist in setting benchmarks, establishing targets, and monitoring progress toward more equitable inclusion. OBJECTIVE This study aimed to characterize the eligibility and enrollment of pregnant and breastfeeding women in randomized controlled trials evaluating interventions for nonobstetrical conditions experienced by, but not limited to, these populations. STUDY DESIGN We developed a literature search in collaboration with an information specialist. We included randomized controlled trials published between 2017 and 2019 in the 5 highest-impact general medicine journals and the 3 highest-impact specialty journals in cardiovascular disease, critical care, general infectious diseases, HIV, and psychiatry. We included randomized controlled trials that evaluated screening, diagnosis, prevention, or treatment of nonobstetrical medical conditions. We excluded randomized controlled trials exclusively focused on males, pediatrics, geriatrics, oncology, or postmenopausal women, and publications reporting subgroup, pooled, or follow-up analyses of previously published randomized controlled trials. We screened titles and abstracts independently and in duplicate, with discrepancies resolved by a third reviewer. We entered data into a standardized electronic case report form. We reviewed study protocols, appendices, and trial registries for additional data. RESULTS Of the 1333 randomized controlled trials, pregnant and breastfeeding women were eligible for 13 (1.0%) and 6 (0.5%), respectively. Pregnancy and breastfeeding eligibility criteria were not addressed in 383 of 1333 (28.7%) and 710 of 1333 (53.3%) randomized controlled trials, respectively. In total, 102 of 937 (10.9%) and 33 of 617 (5.3%) randomized controlled trials that explicitly excluded pregnant and breastfeeding women documented the rationale. Most studies excluding pregnant women (542/937; 57.8%) required at least 1 method of contraception and/or pregnancy testing as part of trial participation for women with reproductive capacity. Among the 13 randomized controlled trials that allowed inclusion of pregnant women, 3 restricted eligibility to specific trimesters. Two randomized controlled trials enrolled pregnant women after the first year of the study following interim review of safety results in nonpregnant participants. Four randomized controlled trials reported the number of pregnant women enrolled, which ranged from 0.7% to 3.4% of the study population. None of the studies reported on pregnancy or perinatal outcomes. Compared with randomized controlled trials that excluded pregnant women, those including them more commonly had an infectious disease focus (12/13 [92.3%] vs 270/937 [28.8%]; p<.0001), including HIV (5/13 [38.5%] vs 96/937 [10.2%]; p=.0079), enrolled participants in sub-Saharan Africa (5/13 [38.5%] vs 111/937 [11.8%]; p=.0143), and had exclusively nonindustry sponsorship (13/13 [100%] vs 559/937 [59.7%]; p=.0025); inclusion varied by study phase, randomization level, and intervention type. CONCLUSION This study illustrates a major inequity in research involving pregnant and breastfeeding women. As new health challenges arise, including novel pandemics, and the research community mobilizes to develop therapies and innovate in patient care, it is crucial that pregnant and breastfeeding women not be left behind. Greater regulatory support, in the form of explicit requirements and incentives, will be needed to ensure these populations are integrated into the research agenda.
Collapse
Affiliation(s)
- Sarah C J Jorgensen
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (Drs Jorgensen and Burry).
| | - Simona Miljanic
- Department of Pharmacy, Mount Sinai Hospital, Toronto, Ontario, Canada (Drs Miljanic, Tabbara, Law, Fernandes, and Burry)
| | - Najla Tabbara
- Department of Pharmacy, Mount Sinai Hospital, Toronto, Ontario, Canada (Drs Miljanic, Tabbara, Law, Fernandes, and Burry)
| | - Deborah Somanader
- Antimicrobial Stewardship Program, Sinai Health System-University Health Network, Toronto, Ontario, Canada (Ms Somanader)
| | - Felicia Leung
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada (Ms Leung and Drs Tse and Burry)
| | - Charmaine De Castro
- Library Services, Mount Sinai Hospital, Toronto, Ontario, Canada (Ms De Castro)
| | - Christopher L Y Tse
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada (Ms Leung and Drs Tse and Burry)
| | - Janice Law
- Department of Pharmacy, Mount Sinai Hospital, Toronto, Ontario, Canada (Drs Miljanic, Tabbara, Law, Fernandes, and Burry)
| | - Virginia Fernandes
- Department of Pharmacy, Mount Sinai Hospital, Toronto, Ontario, Canada (Drs Miljanic, Tabbara, Law, Fernandes, and Burry)
| | - Stephen E Lapinsky
- Division of Respirology, Mount Sinai Hospital, Toronto, Ontario, Canada (Mr Lapinsky); Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada (Mr Lapinsky and Dr Burry)
| | - Isabelle Malhamé
- Division of General Internal Medicine, Department of Medicine, McGill University Health Centre, Montreal, Canada (Dr Malhamé); Center for Outcomes Research and Evaluation, Research Institute of McGill University Health Centre, Montreal, Canada (Dr Malhamé)
| | - Lisa Burry
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (Drs Jorgensen and Burry); Department of Pharmacy, Mount Sinai Hospital, Toronto, Ontario, Canada (Drs Miljanic, Tabbara, Law, Fernandes, and Burry); Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada (Ms Leung and Drs Tse and Burry); Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada (Mr Lapinsky and Dr Burry)
| |
Collapse
|
10
|
The Impact of Submicroscopic Parasitemia on Malaria Rapid Diagnosis in Northeastern Tanzania, an Area with Diverse Transmission Patterns. Infect Dis Rep 2022; 14:798-809. [PMID: 36412740 PMCID: PMC9680434 DOI: 10.3390/idr14060082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/07/2022] [Accepted: 08/08/2022] [Indexed: 12/14/2022] Open
Abstract
Global malaria epidemiology has changed in the last decade with a substantial increase in cases and deaths being recorded. Tanzania accounts for about 4% of all cases and deaths reported in recent years. Several factors contribute to the resurgence of malaria, parasite resistance to antimalarials and mosquito resistance to insecticides being at the top of the list. The presence of sub-microscopic infections poses a significant challenge to malaria rapid diagnostic tests (mRDT). Our cross-sectional surveys in Handeni and Moshi, Tanzania assessed the effect of low parasite density on mRDT. Handeni had higher malaria prevalence by mRDT (39.6%), light microscopy (LM) (16.9%) and polymerase chain reaction (PCR) (18.5%), compared to Moshi with prevalence of 0.2%, 1.3% and 2.3%, respectively. A significant difference (p ˂ 0.001) in malaria prevalence by mRDT, LM and nested PCR was found among age groups. In comparison to all other groups, school-age children (5-15 years) had the highest prevalence of malaria. Our results show that mRDT may miss up to 6% of cases of malaria mainly due to low-density parasitemia when compared to LM and PCR. Routinely used mRDT will likely miss the sub-microscopic parasitemia which will ultimately contribute to the spread of malaria and hinder efforts of elimination.
Collapse
|
11
|
Tayipto Y, Rosado J, Gamboa D, White MT, Kiniboro B, Healer J, Opi DH, Beeson JG, Takashima E, Tsuboi T, Harbers M, Robinson L, Mueller I, Longley RJ. Assessment of IgG3 as a serological exposure marker for Plasmodium vivax in areas with moderate-high malaria transmission intensity. Front Cell Infect Microbiol 2022; 12:950909. [PMID: 36017364 PMCID: PMC9395743 DOI: 10.3389/fcimb.2022.950909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/15/2022] [Indexed: 02/01/2023] Open
Abstract
A more sensitive surveillance tool is needed to identify Plasmodium vivax infections for treatment and to accelerate malaria elimination efforts. To address this challenge, our laboratory has developed an eight-antigen panel that detects total IgG as serological markers of P. vivax exposure within the prior 9 months. The value of these markers has been established for use in areas with low transmission. In moderate-high transmission areas, there is evidence that total IgG is more long-lived than in areas with low transmission, resulting in poorer performance of these markers in these settings. Antibodies that are shorter-lived may be better markers of recent infection for use in moderate-high transmission areas. Using a multiplex assay, the antibody temporal kinetics of total IgG, IgG1, IgG3, and IgM against 29 P. vivax antigens were measured over 36 weeks following asymptomatic P. vivax infection in Papua New Guinean children (n = 31), from an area with moderate-high transmission intensity. IgG3 declined faster to background than total IgG, IgG1, and IgM. Based on these kinetics, IgG3 performance was then assessed for classifying recent exposure in a cohort of Peruvian individuals (n = 590; age 3-85 years) from an area of moderate transmission intensity. Using antibody responses against individual antigens, the highest performance of IgG3 in classifying recent P. vivax infections in the prior 9 months was to one of the Pv-fam-a proteins assessed (PVX_125728) (AUC = 0.764). Surprisingly, total IgG was overall a better marker of recent P. vivax infection, with the highest individual classification performance to RBP2b1986-2653 (PVX_094255) (AUC = 0.838). To understand the acquisition of IgG3 in this Peruvian cohort, relevant epidemiological factors were explored using a regression model. IgG3 levels were positively associated with increasing age, living in an area with (relatively) higher transmission intensity, and having three or more PCR-detected blood-stage P. vivax infections within the prior 13 months. Overall, we found that IgG3 did not have high accuracy for detecting recent exposure to P. vivax in the Peruvian cohort, with our data suggesting that this is due to the high levels of prior exposure required to acquire high IgG3 antibody levels.
Collapse
Affiliation(s)
- Yanie Tayipto
- 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
| | - Jason Rosado
- Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Dionicia Gamboa
- Laboratorio International Centers of Excellence for Malaria Research (ICEMR)-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Michael T. White
- Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Benson Kiniboro
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Julie Healer
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - D. Herbert Opi
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia,Department of Immunology and Pathology, Monash University, Melbourne, VIC, Australia,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - James G. Beeson
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia,Department of Immunology and Pathology, Monash University, Melbourne, VIC, Australia,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia,Department of Microbiology and Central Clinical School, Monash University, Clayton, VIC, Australia
| | - Eizo Takashima
- Proteo-Science Center, Ehime University, Matsuyama, Japan
| | | | - Matthias Harbers
- CellFree Sciences Co., Ltd., Yokohama, Japan,RIKEN Centre for Integrative Medical Sciences, Yokohama, Japan
| | - Leanne Robinson
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia,Life Sciences, Burnet Institute, Melbourne, VIC, Australia
| | - 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
| | - Rhea J. Longley
- 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,*Correspondence: Rhea J. Longley,
| |
Collapse
|
12
|
Obadia T, Nekkab N, Robinson LJ, Drakeley C, Mueller I, White MT. Developing sero-diagnostic tests to facilitate Plasmodium vivax Serological Test-and-Treat approaches: modeling the balance between public health impact and overtreatment. BMC Med 2022; 20:98. [PMID: 35300700 PMCID: PMC8932240 DOI: 10.1186/s12916-022-02285-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/07/2022] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Eliminating Plasmodium vivax will require targeting the hidden liver-stage reservoir of hypnozoites. This necessitates new interventions balancing the benefit of reducing vivax transmission against the risk of over-treating some individuals with drugs which may induce haemolysis. By measuring antibodies to a panel of vivax antigens, a strategy of serological-testing-and-treatment (PvSeroTAT) can identify individuals with recent blood-stage infections who are likely to carry hypnozoites and target them for radical cure. This provides a potential solution to selectively treat the vivax reservoir with 8-aminoquinolines. METHODS PvSeroTAT can identify likely hypnozoite carriers with ~80% sensitivity and specificity. Diagnostic test sensitivities and specificities ranging 50-100% were incorporated into a mathematical model of vivax transmission to explore how they affect the risks and benefits of different PvSeroTAT strategies involving hypnozoiticidal regimens. Risk was measured as the rate of overtreatment and benefit as reduction of community-level vivax transmission. RESULTS Across a wide range of combinations of diagnostic sensitivity and specificity, PvSeroTAT was substantially more effective than bloodstage mass screen and treat strategies and only marginally less effective than mass drug administration. The key test characteristic determining of the benefit of PvSeroTAT strategies is diagnostic sensitivity, with higher values leading to more hypnozoite carriers effectively treated and greater reductions in vivax transmission. The key determinant of risk is diagnostic specificity: higher specificity ensures that a lower proportion of uninfected individuals are unnecessarily treated with primaquine. These relationships are maintained in both moderate and low transmission settings (qPCR prevalence 10% and 2%). Increased treatment efficacy and adherence can partially compensate for lower test performance. Multiple rounds of PvSeroTAT with a lower performing test may lead to similar or higher reductions in vivax transmission than fewer rounds with a higher performing test, albeit with higher rate of overtreatment. CONCLUSIONS At current performance, PvSeroTAT is predicted to be a safe and efficacious option for targeting the hypnozoite reservoir towards vivax elimination. P. vivax sero-diagnostic tests should aim for both high performance and ease of use in the field. The target product profiles informing such development should thus reflect the trade-offs between impact, overtreatment, and ease of programmatic implementation.
Collapse
Affiliation(s)
- Thomas Obadia
- G5 Épidémiologie et Analyse des Maladies Infectieuses, Département de Santé Globale, Institut Pasteur, F-75015, Paris, France.
- Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes vecteurs, Institut Pasteur, F-75015, Paris, France.
- Hub de Bioinformatique et Biostatistique, Département de Biologie Computationnelle, Institut Pasteur, F-75015, Paris, France.
| | - Narimane Nekkab
- G5 Épidémiologie et Analyse des Maladies Infectieuses, Département de Santé Globale, Institut Pasteur, F-75015, Paris, France
- Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes vecteurs, Institut Pasteur, F-75015, Paris, France
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Leanne J Robinson
- Population Health & Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
- Burnet Institute, Melbourne, Victoria, Australia
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Ivo Mueller
- Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes vecteurs, Institut Pasteur, F-75015, Paris, France
- Population Health & Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Michael T White
- G5 Épidémiologie et Analyse des Maladies Infectieuses, Département de Santé Globale, Institut Pasteur, F-75015, Paris, France
- Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes vecteurs, Institut Pasteur, F-75015, Paris, France
| |
Collapse
|
13
|
Cintyamena U, Murhandarwati EEH, Elyazar I, Probandari A, Ahmad RA. Identifying forms of interventions towards cross border malaria in the Asia-Pacific region: a scoping review protocol. BMJ Open 2022; 12:e056265. [PMID: 35168980 PMCID: PMC8852765 DOI: 10.1136/bmjopen-2021-056265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
INTRODUCTION An ambitious epidemiology strategy has been set by the WHO, targeting malaria elimination for at least 35 countries in 2030. Challenges in preventing malaria cross borders require greater attention to achieve the elimination target. This scoping review aims to identify successful forms of interventions to control malaria transmission across national borders in the Asia-Pacific region. METHODS AND ANALYSIS This scoping review will search four electronic databases (PubMed, ScienceDirect, EBSCOhost and ProQuest) limiting the time of publication to the last 10 years. Two independent reviewers will screen all titles and abstracts during the second stage. Study characteristics will be recorded; qualitative data will be extracted and evaluated, while quantitative data will be extracted and summarised. Overall, we will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. ETHICS AND DISSEMINATION This scoping review has received ethical approval from the Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada. The results will be disseminated through peer-reviewed publications, conference presentations and policy briefs.
Collapse
Affiliation(s)
- Utsamani Cintyamena
- Center for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - E Elsa Herdiana Murhandarwati
- Center for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Iqbal Elyazar
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jakarta Pusat, DKI Jakarta, Indonesia
| | - Ari Probandari
- Center for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
- Department of Public Health, Faculty of Medicine, Universitas Sebelas Maret, Surakarta, Indonesia
| | - Riris Andono Ahmad
- Center for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
- Department of Biostatistics, Epidemiology and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| |
Collapse
|
14
|
Angrisano F, Robinson LJ. Plasmodium vivax - How hidden reservoirs hinder global malaria elimination. Parasitol Int 2021; 87:102526. [PMID: 34896312 DOI: 10.1016/j.parint.2021.102526] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 01/23/2023]
Abstract
Plasmodium vivax is the most geographically widespread human malaria parasite. Global malaria efforts have been less successful at reducing the burden of P. vivax compared to P. falciparum, owing to the unique biology and related treatment complexity of P. vivax. As a result, P. vivax is now the dominant malaria parasite throughout the Asia-Pacific and South America causing up to 14 million clinical cases every year and is considered a major obstacle to malaria elimination. Key features circumventing existing malaria control tools are the transmissibility of asymptomatic, low-density circulating infections and reservoirs of persistent dormant liver stages (hypnozoites) that are undetectable but reactivate to cause relapsing infections and sustain transmission. In this review we summarise the new knowledge shaping our understanding of the global epidemiology of P. vivax infections, highlighting the challenges for elimination and the tools that will be required achieve this.
Collapse
|
15
|
Characterizing the inclusion of pregnant and breastfeeding people in infectious diseases randomized controlled trials: a targeted literature review. Clin Microbiol Infect 2021; 28:801-811. [PMID: 34768020 DOI: 10.1016/j.cmi.2021.10.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/04/2021] [Accepted: 10/30/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Severe complications of infectious diseases can occur during pregnancy. Evidence-based prevention and treatment strategies are critical to improve maternal and neonatal health outcomes. Despite this medical need, pregnant and breastfeeding people have been systematically excluded from biomedical research. The objective of this study was to characterize representation of pregnant and breastfeeding people in randomized controlled trials (RCTs) evaluating a broad range of interventions for infectious diseases. METHODS Pregnancy and breastfeeding inclusion criteria were examined in infectious diseases RCTs published between 1 January 2017, and 31 December 2019, in the top five highest impact general medicine and the top three highest impact infectious diseases and HIV journals. RESULTS Of 376 RCTs, 5.3% and 1.9% included pregnant and breastfeeding people, respectively. Justification for exclusion was documented in 36/271 (13.3%) studies that explicitly excluded pregnant people. Most studies excluding pregnant people (177/271, 65.3%) required at least one form of contraception, abstinence and/or negative pregnancy test(s) as part of participation. Only 11/271 (4.1%) studies excluding pregnant people allowed participants to continue the intervention if unintended pregnancy occurred during the study. When both pregnant and non-pregnant people were eligible, pregnant people made up <3% of participants. Only 2/48 (4.2%) vaccine studies included pregnant people; 13/234 (5.5%) drug studies included pregnant people. All studies of procedures, devices, behaviour/education and supplements/vitamins explicitly excluded or did not address pregnancy eligibility criteria. Only 2/20 (10.0%) RCTs including pregnant people collected pharmacokinetic data. DISCUSSION This study demonstrates widespread exclusion of pregnant and breastfeeding people from infectious disease RCTs.
Collapse
|
16
|
Tayipto Y, Liu Z, Mueller I, Longley RJ. Serology for Plasmodium vivax surveillance: A novel approach to accelerate towards elimination. Parasitol Int 2021; 87:102492. [PMID: 34728377 DOI: 10.1016/j.parint.2021.102492] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/30/2021] [Accepted: 10/28/2021] [Indexed: 01/13/2023]
Abstract
Plasmodium vivax is the most widespread causative agent of human malaria in the world. Despite the ongoing implementation of malaria control programs, the rate of case reduction has declined over the last 5 years. Hence, surveillance of malaria transmission should be in place to identify and monitor areas that require intensified malaria control interventions. Serological tools may offer additional insights into transmission intensity over parasite and entomological measures, especially as transmission levels decline. Antibodies can be detected in the host system for months to even years after parasite infections have been cleared from the blood, enabling malaria exposure history to be captured. Because the Plasmodium parasite expresses more than 5000 proteins, it is important to a) understand antibody longevity following infection and b) measure antibodies to more than one antigen in order to accurately inform on the exposure and/or immune status of populations. This review summarises current practices for surveillance of P. vivax malaria, the current state of research into serological exposure markers and their potential role for accelerating malaria elimination, and discusses further studies that need to be undertaken to see such technology implemented in malaria-endemic areas.
Collapse
Affiliation(s)
- Yanie Tayipto
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Zoe Liu
- The Institute for Mental and Physical Health and Clinical Translation, Barwon Health, Deakin University, Geelong, Victoria, Australia; School of Medicine, Centre for Molecular and Medical Research, Deakin University, Geelong, Australia
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Rhea J Longley
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia.
| |
Collapse
|
17
|
Abstract
J. Kevin Baird and colleagues, examine and discuss the estimated global burden of vivax malaria and it's biological, clinical, and public health complexity.
Collapse
Affiliation(s)
- Katherine E. Battle
- Institute for Disease Modeling, Seattle, Washington, United States of America
| | - J. Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Jakarta, Indonesia
- Nuffield Department of Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| |
Collapse
|
18
|
Baird JK. Basic Research of Plasmodium vivax Biology Enabling Its Management as a Clinical and Public Health Problem. Front Cell Infect Microbiol 2021; 11:696598. [PMID: 34540716 PMCID: PMC8447957 DOI: 10.3389/fcimb.2021.696598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/22/2021] [Indexed: 12/20/2022] Open
Abstract
The emerging understanding of Plasmodium vivax as an infection seated in extravascular spaces of its human host carries fundamentally important implications for its management as a complex clinical and public health problem. This progress begins to reverse decades of neglected research borne of the false dogma of P. vivax as an intrinsically benign and inconsequential parasite. This Review provides real world context for the on-going laboratory explorations of the molecular and cellular events in the life of this parasite. Chemotherapies against the latent reservoir impose extraordinarily complex and difficult problems of science and medicine, but great strides in studies of the biology of hepatic P. vivax promise solutions. Fundamental assumptions regarding the interpretation of parasitaemia in epidemiology, clinical medicine, and public health are being revisited and reassessed in light of new studies of P. vivax cellular/molecular biology and pathogenesis. By examining these long overlooked complexities of P. vivax malaria, we open multiple new avenues to vaccination, chemoprevention, countermeasures against transmission, epidemiology, diagnosis, chemotherapy, and clinical management. This Review expresses how clarity of vision of biology and pathogenesis may rationally and radically transform the multiple means by which we may combat this insidiously harmful infection.
Collapse
Affiliation(s)
- J Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Jakarta, Indonesia.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
19
|
Koepfli C, Nguitragool W, de Almeida ACG, Kuehn A, Waltmann A, Kattenberg E, Ome-Kaius M, Rarau P, Obadia T, Kazura J, Monteiro W, Darcy AW, Wini L, Bassat Q, Felger I, Sattabongkot J, Robinson LJ, Lacerda M, Mueller I. Identification of the asymptomatic Plasmodium falciparum and Plasmodium vivax gametocyte reservoir under different transmission intensities. PLoS Negl Trop Dis 2021; 15:e0009672. [PMID: 34449764 PMCID: PMC8428688 DOI: 10.1371/journal.pntd.0009672] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 09/09/2021] [Accepted: 07/21/2021] [Indexed: 11/25/2022] Open
Abstract
Background Understanding epidemiological variables affecting gametocyte carriage and density is essential to design interventions that most effectively reduce malaria human-to-mosquito transmission. Methodology/Principal findings Plasmodium falciparum and P. vivax parasites and gametocytes were quantified by qPCR and RT-qPCR assays using the same methodologies in 5 cross-sectional surveys involving 16,493 individuals in Brazil, Thailand, Papua New Guinea, and Solomon Islands. The proportion of infections with detectable gametocytes per survey ranged from 44–94% for P. falciparum and from 23–72% for P. vivax. Blood-stage parasite density was the most important predictor of the probability to detect gametocytes. In moderate transmission settings (prevalence by qPCR>5%), parasite density decreased with age and the majority of gametocyte carriers were children. In low transmission settings (prevalence<5%), >65% of gametocyte carriers were adults. Per survey, 37–100% of all individuals positive for gametocytes by RT-qPCR were positive by light microscopy for asexual stages or gametocytes (overall: P. falciparum 178/348, P. vivax 235/398). Conclusions/Significance Interventions to reduce human-to-mosquito malaria transmission in moderate-high endemicity settings will have the greatest impact when children are targeted. In contrast, all age groups need to be included in control activities in low endemicity settings to achieve elimination. Detection of infections by light microscopy is a valuable tool to identify asymptomatic blood stage infections that likely contribute most to ongoing transmission at the time of sampling. Plasmodium vivax and Plasmodium falciparum cause the vast majority of all human malaria cases. Across all transmission settings, a large proportion of infections of the two species remain asymptomatic. These infections are not diagnosed and treated by control programs focusing on clinical cases. They can carry gametocytes, the sexual stage of the parasite that establishes infections in mosquitos, thus asymptomatic infections contribute to transmission. In order to determine who is likely to contribute to transmission, gametocyte densities were measured by sensitive molecular methods in afebrile individuals in four countries. The proportion of infections with gametocytes varied greatly among surveys, and was higher in regions that had experienced low transmission for extended periods of time. In moderate-high transmission settings, gametocyte densities were particularly high in children below six years, highlighting the importance that interventions to reduce transmission include this age group. The majority of gametocyte carriers was positive by light microscopy. The comprehensive data on gametocyte carriage presented here lays the foundation for the development of more effective screen and treat activities to reduce malaria transmission.
Collapse
Affiliation(s)
- Cristian Koepfli
- Population Health & Immunity Division, Walter & Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- University of Notre Dame, Eck Institute for Global Health, Department of Biological Sciences, Notre Dame, Indiana, United States of America
- * E-mail:
| | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Anne Cristine Gomes de Almeida
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Andrea Kuehn
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Andreea Waltmann
- Population Health & Immunity Division, Walter & Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Eline Kattenberg
- Population Health & Immunity Division, Walter & Eliza Hall Institute, Parkville, Australia
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Maria Ome-Kaius
- Population Health & Immunity Division, Walter & Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Patricia Rarau
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Thomas Obadia
- Hub de Bioinformatique et Biostatistique, Département Biologie Computationnelle, Institut Pasteur, Paris, France
- Unité Malaria: parasites et Hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - James Kazura
- Centre for Global Health & Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Wuelton Monteiro
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, Brazil
- Universidade do Estado do Amazonas, Manaus, Brazil
| | - Andrew W. Darcy
- National Health Training and Research Institute, Ministry of Health, Honiara, Solomon Islands
| | - Lyndes Wini
- Vector Borne Diseases Program, Ministry of Health, Honiara, Solomon Islands
| | - Quique Bassat
- ISGlobal, Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- ICREA, Barcelona, Spain
- Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu (University of Barcelona), Barcelona, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Leanne J. Robinson
- Population Health & Immunity Division, Walter & Eliza Hall Institute, Parkville, Australia
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Marcus Lacerda
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, Brazil
| | - Ivo Mueller
- Population Health & Immunity Division, Walter & Eliza Hall Institute, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
- Unité Malaria: parasites et Hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| |
Collapse
|
20
|
Clustering of subpatent infections in households with asymptomatic rapid diagnostic test-positive cases in Bioko Island, Equatorial Guinea independent of travel to regions of higher malaria endemicity: a cross-sectional study. Malar J 2021; 20:313. [PMID: 34247643 PMCID: PMC8274032 DOI: 10.1186/s12936-021-03844-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/03/2021] [Indexed: 11/27/2022] Open
Abstract
Background Prevalence of falciparum malaria on Bioko Island remains high despite sustained, intensive control. Progress may be hindered by high proportions of subpatent infections that are not detected by rapid diagnostic tests (RDT) but contribute to onward transmission, and by imported infections. Better understanding of the relationship between subpatent infections and RDT-detected infections, and whether this relationship is different from imported versus locally acquired infections, is imperative to better understand the sources of infection and mechanisms of transmission to tailor more effective interventions. Methods Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was performed on a sub-set of samples from the 2015 Malaria Indicator Survey to identify subpatent infections. Households with RDT(+) individuals were matched 1:4 with households with no RDT(+) individuals. The association between living in a household with an RDT(+) individual and having a subpatent infection was evaluated using multivariate hierarchical logistic regression models with inverse probability weights for selection. To evaluate possible modification of the association by potential importation of the RDT(+) case, the analysis was repeated among strata of matched sets based on the reported eight-week travel history of the RDT(+) individual(s). Results There were 142 subpatent infections detected in 1,400 individuals (10.0%). The prevalence of subpatent infections was higher in households with versus without an RDT(+) individual (15.0 vs 9.1%). The adjusted prevalence odds of subpatent infection were 2.59-fold greater (95% CI: 1.31, 5.09) for those in a household with an RDT(+) individual compared to individuals in a household without RDT(+) individuals. When stratifying by travel history of the RDT(+) individual, the association between subpatent infections and RDT(+) infections was stronger in the strata in which the RDT(+) individual(s) had not recently travelled (adjusted prevalence odds ratio (aPOR) 2.95; 95% CI:1.17, 7.41), and attenuated in the strata in which recent travel was reported (aPOR 1.76; 95% CI: 0.54, 5.67). Conclusions There is clustering of subpatent infections around RDT(+) individual(s) when both imported and local infection are suspected. Future control strategies that aim to treat whole households in which an RDT(+) individual is found may target a substantial portion of infections that would otherwise not be detected. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03844-6.
Collapse
|
21
|
Longley RJ, White MT, Brewster J, Liu ZSJ, Bourke C, Takashima E, Harbers M, Tham WH, Healer J, Chitnis CE, Monteiro W, Lacerda M, Sattabongkot J, Tsuboi T, Mueller I. IgG Antibody Responses Are Preferential Compared With IgM for Use as Serological Markers for Detecting Recent Exposure to Plasmodium vivax Infection. Open Forum Infect Dis 2021; 8:ofab228. [PMID: 34159216 PMCID: PMC8214013 DOI: 10.1093/ofid/ofab228] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/19/2021] [Indexed: 11/13/2022] Open
Abstract
To achieve malaria elimination, new tools are required to explicitly target Plasmodium vivax. Recently, a novel panel of P. vivax proteins were identified and validated as serological markers for detecting recent exposure to P. vivax within the last 9 months. In order to improve the sensitivity and specificity of these markers, immunoglobulin M (IgM) in addition to immunoglobulin G (IgG) antibody responses were compared with a down-selected panel of 20 P. vivax proteins. IgM was tested using archival plasma samples from observational cohort studies conducted in malaria-endemic regions of Thailand and Brazil. IgM responses to these proteins generally had poorer classification performance than IgG.
Collapse
Affiliation(s)
- Rhea J Longley
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Michael T White
- Malaria Parasites and Hosts Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Jessica Brewster
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Zoe S J Liu
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Caitlin Bourke
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Matthias Harbers
- CellFree Sciences Co., Ltd, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Wai-Hong Tham
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Infection and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Julie Healer
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Infection and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Chetan E Chitnis
- Malaria Parasite Biology and Vaccines, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Wuelton Monteiro
- Fundacão de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil.,Universidade do Estado do Amazonas, Manaus, Brazil
| | - Marcus Lacerda
- Instituto Leônicas & Maria Deane (Fiocruz), Manaus, Brazil
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Ivo Mueller
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia.,Malaria Parasites and Hosts Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| |
Collapse
|
22
|
Vekemans J, Schellenberg D, Benns S, O'Brien K, Alonso P. Meeting report: WHO consultation on malaria vaccine development, Geneva, 15-16 July 2019. Vaccine 2021; 39:2907-2916. [PMID: 33931251 DOI: 10.1016/j.vaccine.2021.03.093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 01/25/2023]
Abstract
Considerable progress has been made in malaria control in the last two decades, but progress has stalled in the last few years. New tools are needed to achieve public health goals in malaria control and elimination. A first generation vaccine, RTS,S/AS01, is currently being evaluated as it undergoes pilot implementation through routine health systems in parts of three African countries. The development of this vaccine took over 30 years and has been full of uncertainties. Even now, important unknowns remain as to its future role in public health. Lessons need to be learnt for second generation and future vaccines, including how to facilitate early planning of investments, streamlining of development, regulatory and policy pathways. A number of candidate vaccines populate the current development pipeline, some of which have the potential to contribute to burden reduction if efficacy is confirmed in conditions of natural exposure, and if they are amenable to affordable supply and programmatic implementation. New, innovative technologies will be needed if future malaria vaccines are to overcome important scientific hurdles and induce durable, high level protection. WHO convened a stakeholder consultation on the status of malaria vaccine research and development to inform the recently reconstituted Malaria Vaccine Advisory Committee (MALVAC) which will assist WHO in updating its current guidance and recommendations about priorities and product preferences for malaria vaccines.
Collapse
Affiliation(s)
- Johan Vekemans
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| | | | | | - Kate O'Brien
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| | - Pedro Alonso
- World Health Organization, 20 Av Appia, 1211 Geneva 27, Switzerland
| |
Collapse
|
23
|
Kosasih A, Koepfli C, Dahlan MS, Hawley WA, Baird JK, Mueller I, Lobo NF, Sutanto I. Gametocyte carriage of Plasmodium falciparum (pfs25) and Plasmodium vivax (pvs25) during mass screening and treatment in West Timor, Indonesia: a longitudinal prospective study. Malar J 2021; 20:177. [PMID: 33836772 PMCID: PMC8034167 DOI: 10.1186/s12936-021-03709-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 03/23/2021] [Indexed: 11/21/2022] Open
Abstract
Background A goal of malaria epidemiological interventions is the detection and treatment of parasite reservoirs in endemic areas—an activity that is expected to reduce local transmission. Since the gametocyte is the only transmissible stage from human host to mosquito vector, this study evaluated the pre and post presence of gametocytes during a mass screening and treatment (MST) intervention conducted during 2013 in East Nusa Tenggara, Indonesia. Methods RT-qPCR targeting pfs25 and pvs25 transcripts—gametocyte molecular markers for Plasmodium falciparum and Plasmodium vivax, respectively, was performed to detect and quantify gametocytes in blood samples of P. falciparum and P. vivax-infected subjects over the course of the MST study. The presence of both asexual and sexual parasites in microscopic and submicroscopic infections was compared from the start and end of the MST, using proportion tests as well as parametric and non-parametric tests. Results Parasite prevalence remained unchanged for P. falciparum (6% = 52/811 versus 7% = 50/740, p = 0.838), and decreased slightly for P. vivax (24% = 192/811 versus 19% = 142/740, p = 0.035) between the MST baseline and endpoint. No significant difference was observed in gametocyte prevalence for either P. falciparum (2% = 19/803 versus 3% = 23/729, p = 0.353, OR = 1.34, 95%CI = 0.69–2.63), or P. vivax (7% = 49/744 versus 5% = 39/704, p = 0.442, OR = 0.83, 95%CI = 0.52–1.31). Even though there was an insignificant difference between the two time points, the majority of parasite positive subjects at the endpoint had been negative at baseline (P. falciparum: 66% = 29/44, P. vivax: 60% = 80/134). This was similarly demonstrated for the transmissible stage—where the majority of gametocyte positive subjects at the endpoint were negative at baseline (P. falciparum: 95% = 20/21, P. vivax: 94% = 30/32). These results were independent of treatment provided during MST activities. No difference was demonstrated in parasite and gametocyte density between both time points either in P. falciparum or P. vivax. Conclusion In this study area, similar prevalence rates of P. falciparum and P. vivax parasites and gametocytes before and after MST, although in different individuals, points to a negligible impact on the parasite reservoir. Treatment administration based on parasite positivity as implemented in the MST should be reevaluated for the elimination strategy in the community. Trial registration Clinical trials registration NCT01878357. Registered 14 June 2013, https://www.clinicaltrials.gov/ct2/show/NCT01878357. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03709-y.
Collapse
Affiliation(s)
- Ayleen Kosasih
- PhD Programme in Biomedical Sciences, Medical Faculty, Universitas Indonesia, Jakarta, Indonesia.,Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia.,Indonesian Medical Education and Research Institute, Jakarta, Indonesia
| | - Cristian Koepfli
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA.,Infection & Immunity Division, Walter & Eliza Hall Institute, Melbourne, Australia
| | | | | | - J Kevin Baird
- Center for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ivo Mueller
- Infection & Immunity Division, Walter & Eliza Hall Institute, Melbourne, Australia
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Inge Sutanto
- Indonesian Medical Education and Research Institute, Jakarta, Indonesia. .,Department of Parasitology, Medical Faculty, Universitas Indonesia, Jakarta, Indonesia.
| |
Collapse
|
24
|
Longley RJ, White MT, Takashima E, Brewster J, Morita M, Harbers M, Obadia T, Robinson LJ, Matsuura F, Liu ZSJ, Li-Wai-Suen CSN, Tham WH, Healer J, Huon C, Chitnis CE, Nguitragool W, Monteiro W, Proietti C, Doolan DL, Siqueira AM, Ding XC, Gonzalez IJ, Kazura J, Lacerda M, Sattabongkot J, Tsuboi T, Mueller I. Development and validation of serological markers for detecting recent Plasmodium vivax infection. Nat Med 2020; 26:741-749. [DOI: 10.1038/s41591-020-0841-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 03/18/2020] [Indexed: 11/09/2022]
|
25
|
Grossenbacher B, Holzschuh A, Hofmann NE, Omar KA, Stuck L, Fakih BS, Ali A, Yukich J, Hetzel MW, Felger I. Molecular methods for tracking residual Plasmodium falciparum transmission in a close-to-elimination setting in Zanzibar. Malar J 2020; 19:50. [PMID: 31996210 PMCID: PMC6988349 DOI: 10.1186/s12936-020-3127-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/16/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Molecular detection of low-density Plasmodium falciparum infections is essential for surveillance studies conducted to inform malaria control strategies in close-to-elimination settings. Molecular monitoring of residual malaria infections usually requires a large study size, therefore sampling and diagnostic processes need to be economical and optimized for high-throughput. A method comparison was undertaken to identify the most efficient diagnostic procedure for processing large collections of community samples with optimal test sensitivity, simplicity, and minimal costs. METHODS In a reactive case detection study conducted on Zanzibar, parasitaemia of 4590 individuals of all ages was investigated by a highly sensitive quantitative (q) PCR that targets multiple var gene copies per parasite genome. To reduce cost, a first round of positivity screening was performed on pools of dried blood spots from five individuals. Ten cycles of a pre-PCR were performed directly on the filter paper punches, followed by qPCR. In a second round, samples of positive pools were individually analysed by pre-PCR and qPCR. RESULTS Prevalence in household members and neighbors of index cases was 1.7% (78/4590) with a geometric mean parasite density of 58 parasites/µl blood. Using qPCR as gold standard, diagnostic sensitivity of rapid diagnostic tests (RDTs) was 37% (29/78). Infections positive by qPCR but negative by RDT had mean densities of 15 parasites/µl blood. CONCLUSION The approach of pre-screening reactive case detection samples in pools of five was ideal for a low prevalence setting such as in Zanzibar. Performing direct PCR on filter paper punches saves substantial time and justifies the higher cost for a polymerase suitable for amplifying DNA directly from whole blood. Molecular monitoring in community samples provided a more accurate picture of infection prevalence, as it identified a potential reservoir of infection that was largely missed by RDT. The developed qPCR-based methodology for screening large sample sets represents primarily a research tool that should inform the design of malaria elimination strategies. It may also prove beneficial for diagnostic tasks in surveillance-response activities.
Collapse
Affiliation(s)
- Benjamin Grossenbacher
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Aurel Holzschuh
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Natalie E Hofmann
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Kali Abdullah Omar
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Logan Stuck
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA
| | | | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Joshua Yukich
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Ingrid Felger
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| |
Collapse
|
26
|
Cheaveau J, Mogollon DC, Mohon MAN, Golassa L, Yewhalaw D, Pillai DR. Asymptomatic malaria in the clinical and public health context. Expert Rev Anti Infect Ther 2019; 17:997-1010. [PMID: 31718324 DOI: 10.1080/14787210.2019.1693259] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Introduction: Historically, the global community has focused on the control of symptomatic malaria. However, interest in asymptomatic malaria has been growing, particularly in the context of malaria elimination.Areas covered: We undertook a comprehensive PubMed literature review on asymptomatic malaria as it relates to detection and elimination with emphasis between 2014 and 2019. Diagnostic tools with a low limit of detection (LOD) have allowed us to develop a more detailed understanding of asymptomatic malaria and its impact. These highly sensitive diagnostics have demonstrated that the prevalence of asymptomatic malaria is greater than previously thought. In addition, it is now possible to detect the malaria reservoir in the community, something that was previously not feasible. Asymptomatic malaria has previously not been treated, but research has begun to examine whether treating individuals with asymptomatic malaria may lead to health benefits. Finally, we have begun to understand the importance of asymptomatic malaria in ongoing transmission.Expert opinion: Therefore, with malaria elimination back on the agenda, asymptomatic malaria can no longer be ignored, especially in light of new ultra-sensitive diagnostic tools.
Collapse
Affiliation(s)
- James Cheaveau
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Canada, AB, Canada
| | - Daniel Castaneda Mogollon
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Canada, AB, Canada
| | - Md Abu Naser Mohon
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Canada, AB, Canada
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Dylan R Pillai
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Canada, AB, Canada.,Department of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
27
|
Greenhouse B, Daily J, Guinovart C, Goncalves B, Beeson J, Bell D, Chang MA, Cohen JM, Ding X, Domingo G, Eisele TP, Lammie PJ, Mayor A, Merienne N, Monteiro W, Painter J, Rodriguez I, White M, Drakeley C, Mueller I. Priority use cases for antibody-detecting assays of recent malaria exposure as tools to achieve and sustain malaria elimination. Gates Open Res 2019; 3:131. [PMID: 31172051 PMCID: PMC6545519 DOI: 10.12688/gatesopenres.12897.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2019] [Indexed: 01/12/2023] Open
Abstract
Measurement of malaria specific antibody responses represents a practical and informative method for malaria control programs to assess recent exposure to infection. Technical advances in recombinant antigen production, serological screening platforms, and analytical methods have enabled the identification of several target antigens for laboratory based and point-of-contact tests. Questions remain as to how these serological assays can best be integrated into malaria surveillance activities to inform programmatic decision-making. This report synthesizes discussions from a convening at Institut Pasteur in Paris in June 2017 aimed at defining practical and informative use cases for serology applications and highlights five programmatic uses for serological assays including: documenting the absence of transmission; stratification of transmission; measuring the effect of interventions; informing a decentralized immediate response; and testing and treating P. vivax hypnozoite carriers.
Collapse
Affiliation(s)
- Bryan Greenhouse
- Department of Medicine,, University of California San Francisco, San Francisco, CA, USA
| | | | - Caterina Guinovart
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- PATH, Seattle, WA, USA
| | | | | | - David Bell
- Intellectual Ventures, Bellevue, WA, USA
| | | | | | | | | | - Thomas P. Eisele
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
| | | | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | - Wuelto Monteiro
- Tropical Medicine Foundation Dr. Heitor Viera Dourado, Manaus, Amazonas, Brazil
| | - John Painter
- Centers of Disease Control and Prevention, Atlanta, GA, USA
| | - Isabel Rodriguez
- Department of Medicine,, University of California San Francisco, San Francisco, CA, USA
| | | | - Chris Drakeley
- London School of Tropical Medicine & Hygiene, London, UK
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - The Malaria Serology Convening
- Department of Medicine,, University of California San Francisco, San Francisco, CA, USA
- Consultant to UNITAID, Denver, CO, USA
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- PATH, Seattle, WA, USA
- London School of Tropical Medicine & Hygiene, London, UK
- The Burnet Institute, Melbourne, Australia
- Intellectual Ventures, Bellevue, WA, USA
- Centers of Disease Control and Prevention, Atlanta, GA, USA
- Clinton Health Access Initiative (CHAI), Boston, MA, USA
- FIND, Geneva, Switzerland
- Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, New Orleans, LA, USA
- Institut Pasteur, Paris, France
- Tropical Medicine Foundation Dr. Heitor Viera Dourado, Manaus, Amazonas, Brazil
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| |
Collapse
|
28
|
Antimalarial Transmission-Blocking Interventions: Past, Present, and Future. Trends Parasitol 2018; 34:735-746. [PMID: 30082147 DOI: 10.1016/j.pt.2018.07.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/14/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022]
Abstract
Malaria remains a major global health challenge. Appropriate use of current antimalarial tools has reduced the disease burden, but morbidity and mortality remain unacceptably high. It is widely accepted that, to achieve long-term control/eradication, it will be necessary to use interventions that inhibit the transmission of parasites to mosquitoes - these tools are termed transmission-blocking interventions (TBIs). This article aims to outline the rationale for the development of TBIs, with a focus on transmission-blocking drugs and (parasite-derived) transmission-blocking vaccines. We describe and summarise the current status of each of these intervention classes and attempt to identify future requirements in development, with a focus on the challenges of establishing each method within an integrated malarial control programme in the future.
Collapse
|