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Ursing J, Johns R, Aydin-Schmidt B, Calçada C, Kofoed PE, Ghanchi NK, Veiga MI, Rombo L. OUP accepted manuscript. J Antimicrob Chemother 2022; 77:1005-1011. [PMID: 35137072 PMCID: PMC8969533 DOI: 10.1093/jac/dkac008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/24/2021] [Indexed: 11/14/2022] Open
Abstract
Background Plasmodium falciparum strains that are resistant to standard-dose chloroquine can be treated by higher chloroquine concentrations maintained for a longer time in vivo. Objectives To determine the relative importance of chloroquine concentrations versus exposure time for elimination of chloroquine-susceptible and -resistant P. falciparum in vitro. Methods Chloroquine-susceptible (3D7) and -resistant (FCR3) strains were exposed in vitro to 1, 2, 4, 8, 16 or 32 times their respective 90% inhibitory chloroquine concentrations for 3, 5, 7 or 14 days and then followed until recrudescence, or not, by 42 days after the end of exposure. Results Exposure to chloroquine appeared to eliminate susceptible and resistant parasites, leaving small pyknotic apparently dead parasites. Chloroquine-susceptible and -resistant parasites recrudesced after 3 and 5 days of chloroquine exposure. Recrudescence occurred in one out of four 7 day exposure series but not after 14 days exposure. The median time to recrudescence was 13 to 28 days with a range of 8 to 41 days after the end of exposure. Time to recrudescence after the end of exposure increased with duration of exposure for susceptible and resistant strains (P < 0.001). Time to recrudescence did not correlate with concentrations greater than 1× IC90. Conclusions Chloroquine-susceptible and -resistant P. falciparum probably become dormant. Elimination of dormant parasites is primarily dependent upon the duration of chloroquine exposure. Exposure to effective drug concentrations for 7 days eliminates most parasites in vitro. The results support in vivo data indicating that elimination of chloroquine-resistant P. falciparum correlates with Day 7 chloroquine concentrations.
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Affiliation(s)
- Johan Ursing
- Projecto de Saúde de Bandim, Indepth Network, Bissau, Guinea-Bissau
- Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Danderyd Hospital, Stockholm, Sweden
- Corresponding author. E-mail:
| | - Rasmus Johns
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Carla Calçada
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Poul-Erik Kofoed
- Projecto de Saúde de Bandim, Indepth Network, Bissau, Guinea-Bissau
- Department of Paediatrics and Adolescent Medicine, Lillebaelt Hospital, University Hospital of Southern Denmark, Kolding, Denmark
| | - Najia Karim Ghanchi
- Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Maria Isabel Veiga
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Lars Rombo
- Centre for Clinical Research, Region Sörmland, Eskilstuna, Sweden
- Unit of infectious Diseases, Uppsala University, Uppsala, Sweden
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Holmström O, Stenman S, Suutala A, Moilanen H, Kücükel H, Ngasala B, Mårtensson A, Mhamilawa L, Aydin-Schmidt B, Lundin M, Diwan V, Linder N, Lundin J. A novel deep learning-based point-of-care diagnostic method for detecting Plasmodium falciparum with fluorescence digital microscopy. PLoS One 2020; 15:e0242355. [PMID: 33201905 PMCID: PMC7671488 DOI: 10.1371/journal.pone.0242355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/30/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Malaria remains a major global health problem with a need for improved field-usable diagnostic tests. We have developed a portable, low-cost digital microscope scanner, capable of both brightfield and fluorescence imaging. Here, we used the instrument to digitize blood smears, and applied deep learning (DL) algorithms to detect Plasmodium falciparum parasites. METHODS Thin blood smears (n = 125) were collected from patients with microscopy-confirmed P. falciparum infections in rural Tanzania, prior to and after initiation of artemisinin-based combination therapy. The samples were stained using the 4',6-diamidino-2-phenylindole fluorogen and digitized using the prototype microscope scanner. Two DL algorithms were trained to detect malaria parasites in the samples, and results compared to the visual assessment of both the digitized samples, and the Giemsa-stained thick smears. RESULTS Detection of P. falciparum parasites in the digitized thin blood smears was possible both by visual assessment and by DL-based analysis with a strong correlation in results (r = 0.99, p < 0.01). A moderately strong correlation was observed between the DL-based thin smear analysis and the visual thick smear-analysis (r = 0.74, p < 0.01). Low levels of parasites were detected by DL-based analysis on day three following treatment initiation, but a small number of fluorescent signals were detected also in microscopy-negative samples. CONCLUSION Quantification of P. falciparum parasites in DAPI-stained thin smears is feasible using DL-supported, point-of-care digital microscopy, with a high correlation to visual assessment of samples. Fluorescent signals from artefacts in samples with low infection levels represented the main challenge for the digital analysis, thus highlighting the importance of minimizing sample contaminations. The proposed method could support malaria diagnostics and monitoring of treatment response through automated quantification of parasitaemia and is likely to be applicable also for diagnostics of other Plasmodium species and other infectious diseases.
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Affiliation(s)
- Oscar Holmström
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Sebastian Stenman
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Antti Suutala
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Hannu Moilanen
- Center of Microscopy and Nanotechnology, University of Oulu, Oulu, Finland
| | - Hakan Kücükel
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Billy Ngasala
- Department of Women’s and Children’s Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
- Department of Medical Entomology and Parasitology, School of Public Health, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Andreas Mårtensson
- Department of Women’s and Children’s Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Lwidiko Mhamilawa
- Department of Women’s and Children’s Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
- Department of Medical Entomology and Parasitology, School of Public Health, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mikael Lundin
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Vinod Diwan
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | - Nina Linder
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Department of Women’s and Children’s Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Johan Lundin
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
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Khan AQ, Pernaute-Lau L, Khattak AA, Luijcx S, Aydin-Schmidt B, Hussain M, Khan TA, Mufti FU, Morris U. Surveillance of genetic markers associated with Plasmodium falciparum resistance to artemisinin-based combination therapy in Pakistan, 2018-2019. Malar J 2020; 19:206. [PMID: 32513171 PMCID: PMC7282094 DOI: 10.1186/s12936-020-03276-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/29/2020] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The spread of artemisinin resistance in the Greater Mekong Subregion of Southeast Asia poses a significant threat for current anti-malarial treatment guidelines globally. The aim of this study was to assess the current prevalence of molecular markers of drug resistance in Plasmodium falciparum in the four provinces with the highest malaria burden in Pakistan, after introducing artemether-lumefantrine as first-line treatment in 2017. METHODS Samples were collected during routine malaria surveillance in Punjab, Sindh, Baluchistan, and Khyber Pakhtunkhwa provinces of Pakistan between January 2018 and February 2019. Plasmodium falciparum infections were confirmed by rapid diagnostic test or microscopy. Plasmodium falciparum positive isolates (n = 179) were screened by Sanger sequencing for single nucleotide polymorphisms (SNPs) in the P. falciparum kelch 13 (pfk13) propeller domain and in P. falciparum coronin (pfcoronin). SNPs in P. falciparum multidrug resistance 1 (pfmdr1) N86Y, Y184F, D1246Y and P. falciparum chloroquine resistance transporter (pfcrt) K76T were genotyped by PCR-restriction fragment length polymorphism. RESULTS No artemisinin resistance associated SNPs were identified in the pfk13 propeller domain or in pfcoronin. The pfmdr1 N86, 184F, D1246 and pfcrt K76 alleles associated with reduced lumefantrine sensitivity were present in 83.8% (150/179), 16.9% (29/172), 100.0% (173/173), and 8.4% (15/179) of all infections, respectively. The chloroquine resistance associated pfcrt 76T allele was present in 98.3% (176/179) of infections. CONCLUSION This study provides an update on the current prevalence of molecular markers associated with reduced P. falciparum sensitivity to artemether and/or lumefantrine in Pakistan, including a first baseline assessment of polymorphisms in pfcoronin. No mutations associated with artemisinin resistance were observed in pfk13 or pfcoronin. However, the prevalence of the pfmdr1 N86 and D1246 alleles, that have been associated with decreased susceptibility to lumefantrine, remain high. Although clinical and molecular data suggest that the current malaria treatment guidelines for P. falciparum are presently effective in Pakistan, close monitoring for artemisinin and lumefantrine resistance will be critical to ensure early detection and enhanced containment of emerging ACT resistance spreading across from Southeast Asia.
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Affiliation(s)
- Abdul Qader Khan
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Leyre Pernaute-Lau
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Biosystems and Integrative Science Institute, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal
| | - Aamer Ali Khattak
- Department of Medical Lab Technology, The University of Haripur, Haripur, Pakistan
| | - Sanna Luijcx
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mubashir Hussain
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Taj Ali Khan
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Farees Uddin Mufti
- Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
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Mhamilawa LE, Aydin-Schmidt B, Mmbando BP, Ngasala B, Morris U. Detection of Plasmodium falciparum by Light Microscopy, Loop-Mediated Isothermal Amplification, and Polymerase Chain Reaction on Day 3 after Initiation of Artemether-Lumefantrine Treatment for Uncomplicated Malaria in Bagamoyo District, Tanzania: A Comparative Trial. Am J Trop Med Hyg 2020; 101:1144-1147. [PMID: 31549618 DOI: 10.4269/ajtmh.19-0298] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Microscopy-determined Plasmodium falciparum positivity rates exceeding 10% on day 3 after initiation of artemisinin-based combination therapy (ACT) is an important indicator of artemisinin resistance. However, microscopy does not detect low-density parasitemia, contrary to molecular tools such as loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR). We compared microscopy, LAMP, and PCR for detection of P. falciparum on day 3 after ACT in 256 patients with uncomplicated malaria in Bagamoyo District, Tanzania. Day 3 positivity rates were 0%, 84.8%, and 84.4% for each method, respectively. The sensitivity and specificity of LAMP against PCR was 100% (95% CI, 96.1-100) and 77.4% (95% CI, 58.9-90.4) when quantitative PCR-determined parasite densities were ≥ two parasites/µL. Loop-mediated isothermal amplification had comparable diagnostic accuracy to PCR and could potentially represent a field-friendly tool for determining day 3 positivity rates. However, what day 3 P. falciparum positivity determined using molecular methods represents needs to be further elucidated.
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Affiliation(s)
- Lwidiko E Mhamilawa
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Bruno P Mmbando
- Tanga Centre, National Institute for Medical Research, Tanga, Tanzania
| | - Billy Ngasala
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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Björkman A, Shakely D, Ali AS, Morris U, Mkali H, Abbas AK, Al-Mafazy AW, Haji KA, Mcha J, Omar R, Cook J, Elfving K, Petzold M, Sachs MC, Aydin-Schmidt B, Drakeley C, Msellem M, Mårtensson A. From high to low malaria transmission in Zanzibar-challenges and opportunities to achieve elimination. BMC Med 2019; 17:14. [PMID: 30665398 PMCID: PMC6341737 DOI: 10.1186/s12916-018-1243-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 12/17/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Substantial global progress in the control of malaria in recent years has led to increased commitment to its potential elimination. Whether this is possible in high transmission areas of sub-Saharan Africa remains unclear. Zanzibar represents a unique case study of such attempt, where modern tools and strategies for malaria treatment and vector control have been deployed since 2003. METHODS We have studied temporal trends of comprehensive malariometric indices in two districts with over 100,000 inhabitants each. The analyses included triangulation of data from annual community-based cross-sectional surveys, health management information systems, vital registry and entomological sentinel surveys. RESULTS The interventions, with sustained high-community uptake, were temporally associated with a major malaria decline, most pronounced between 2004 and 2007 and followed by a sustained state of low transmission. In 2015, the Plasmodium falciparum community prevalence of 0.43% (95% CI 0.23-0.73) by microscopy or rapid diagnostic test represented 96% reduction compared with that in 2003. The P. falciparum and P. malariae prevalence by PCR was 1.8% (95% CI 1.3-2.3), and the annual P. falciparum incidence was estimated to 8 infections including 2.8 clinical episodes per 1000 inhabitants. The total parasite load decreased over 1000-fold (99.9%) between 2003 and 2015. The incidence of symptomatic malaria at health facilities decreased by 94% with a trend towards relatively higher incidence in age groups > 5 years, a more pronounced seasonality and with reported travel history to/from Tanzania mainland as a higher risk factor. All-cause mortality among children < 5 years decreased by 72% between 2002 and 2007 mainly following the introduction of artemisinin-based combination therapies whereas the main reduction in malaria incidence followed upon the vector control interventions from 2006. Human biting rates decreased by 98% with a major shift towards outdoor biting by Anopheles arabiensis. CONCLUSIONS Zanzibar provides new evidence of the feasibility of reaching uniquely significant and sustainable malaria reduction (pre-elimination) in a previously high endemic region in sub-Saharan Africa. The data highlight constraints of optimistic prognostic modelling studies. New challenges, mainly with outdoor transmission, a large asymptomatic parasite reservoir and imported infections, require novel tools and reoriented strategies to prevent a rebound effect and achieve elimination.
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Affiliation(s)
- A Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.
| | - D Shakely
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.,Health Metrics at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - A S Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - U Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden
| | - H Mkali
- MEASURE Evaluation, Dar es Salaam, Tanzania
| | - A K Abbas
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - A-W Al-Mafazy
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - K A Haji
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - J Mcha
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - R Omar
- Zanzibar Malaria Elimination Programme, Zanzibar, Tanzania
| | - J Cook
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.,London School of Hygiene and Tropical Medicine, London, UK
| | - K Elfving
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden.,Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
| | - M Petzold
- Centre for Applied Biostatistics, University of Gothenburg, Gothenburg, Sweden
| | - M C Sachs
- Biostatistics Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - B Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solnavägen 9, SE-171 77, Stockholm, Sweden
| | - C Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - M Msellem
- Training and Research, Mnazi Mmoja Hospital, Zanzibar, Tanzania
| | - A Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
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Morris U, Msellem MI, Mkali H, Islam A, Aydin-Schmidt B, Jovel I, Shija SJ, Khamis M, Ali SM, Hodzic L, Magnusson E, Poirot E, Bennett A, Sachs MC, Tarning J, Mårtensson A, Ali AS, Björkman A. A cluster randomised controlled trial of two rounds of mass drug administration in Zanzibar, a malaria pre-elimination setting-high coverage and safety, but no significant impact on transmission. BMC Med 2018; 16:215. [PMID: 30526588 PMCID: PMC6287359 DOI: 10.1186/s12916-018-1202-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/29/2018] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Mass drug administration (MDA) has the potential to interrupt malaria transmission and has been suggested as a tool for malaria elimination in low-endemic settings. This study aimed to determine the effectiveness and safety of two rounds of MDA in Zanzibar, a pre-elimination setting. METHODS A cluster randomised controlled trial was conducted in 16 areas considered as malaria hotspots, with an annual parasite index of > 0.8%. The areas were randomised to eight intervention and eight control clusters. The intervention included two rounds of MDA with dihydroartemisinin-piperaquine and single low-dose primaquine 4 weeks apart in May-June 2016. Primary and secondary outcomes were cumulative confirmed malaria case incidences 6 months post-MDA and parasite prevalences determined by PCR 3 months post-MDA. Additional outcomes included intervention coverage, treatment adherence, occurrence of adverse events, and cumulative incidences 3, 12, and 16 months post-MDA. RESULTS Intervention coverage was 91.0% (9959/10944) and 87.7% (9355/10666) in the first and second rounds, respectively; self-reported adherence was 82.0% (881/1136) and 93.7% (985/1196). Adverse events were reported in 11.6% (147/1268) and 3.2% (37/1143) of post-MDA survey respondents after both rounds respectively. No serious adverse event was reported. No difference in cumulative malaria case incidence was observed between the control and intervention arms 6 months post-MDA (4.2 and 3.9 per 1000 population; p = 0.94). Neither was there a difference in PCR-determined parasite prevalences 3 months post-MDA (1.4% and 1.7%; OR = 1.0, p = 0.94), although having received at least the first MDA was associated with reduced odds of malaria infection (aOR = 0.35; p = 0.02). Among confirmed malaria cases at health facilities, 26.0% and 26.3% reported recent travel outside Zanzibar in the intervention and control shehias (aOR ≥ 85; p ≤ 0.001). CONCLUSIONS MDA was implemented with high coverage, adherence, and tolerability. Despite this, no significant impact on transmission was observed. The findings suggest that two rounds of MDA in a single year may not be sufficient for a sustained impact on transmission in a pre-elimination setting, especially when the MDA impact is restricted by imported malaria. Importantly, this study adds to the limited evidence for the use of MDA in low transmission settings in sub-Saharan Africa. TRIAL REGISTRATION ClinicalTrials.gov, NCT02721186 (registration date: March 29, 2016).
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Affiliation(s)
- Ulrika Morris
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I. Msellem
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Humphrey Mkali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Atiqul Islam
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Irina Jovel
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Shija Joseph Shija
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Mwinyi Khamis
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Safia Mohammed Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Lamija Hodzic
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Ellinor Magnusson
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Eugenie Poirot
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, USA
| | - Michael C. Sachs
- Biostatistics Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Bangkok, Thailand
- Nuffield Department of Clinical Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, UK
| | - Andreas Mårtensson
- Department of Women’s and Children’s Health, International Maternal and Child Health, Uppsala University, Uppsala, Sweden
| | - Abdullah S. Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Anders Björkman
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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Inoue J, Jovel I, Morris U, Aydin-Schmidt B, Islam A, Segurado AC, Björkman A, Di Santi S, Mårtensson A. Absence of Plasmodium falciparum K13 Propeller Domain Polymorphisms among Field Isolates Collected from the Brazilian Amazon Basin between 1984 and 2011. Am J Trop Med Hyg 2018; 99:1504-1507. [PMID: 30277206 DOI: 10.4269/ajtmh.18-0554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Artemisinin resistance, presently confined to Southeast Asia and associated with mutations in the Plasmodium falciparum K13 (PfK13) propeller domain, represents a serious threat to global malaria control. This study aimed to provide baseline information for future artemisinin resistance surveillance, by analyzing the PfK13 propeller domain in P. falciparum field isolates collected from the Brazilian Amazon Basin between 1984 and 2011. A total of 152 P. falciparum mono-infections were assessed, of which 118 (78%) were collected before and 34 (22%) after the introduction of artemisinin-based combination therapy (ACT) in 2006. An 849-base pair fragment encoding the PfK13 propeller was amplified by nested polymerase chain reaction and sequenced in both directions. The sequences were compared with the reference sequence of P. falciparum 3D7. All samples showed wild-type sequences, thus, no mutations were observed. The results are in agreement with other recent reports and do not provide evidence for presence of PfK13 propeller domain polymorphisms associated with artemisinin resistance among P. falciparum field isolates in the Brazilian Amazon Basin neither before nor after the implementation of ACT.
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Affiliation(s)
- Juliana Inoue
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Irina Jovel
- Department of Microbiology, Tumor and Cell Biology, Centre for Malaria Research, Karolinska Institutet, Stockholm, Sweden
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Centre for Malaria Research, Karolinska Institutet, Stockholm, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Centre for Malaria Research, Karolinska Institutet, Stockholm, Sweden
| | - Atiqul Islam
- Department of Microbiology, Tumor and Cell Biology, Centre for Malaria Research, Karolinska Institutet, Stockholm, Sweden
| | - Aluisio Cotrim Segurado
- Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Centre for Malaria Research, Karolinska Institutet, Stockholm, Sweden
| | - Silvia Di Santi
- Núcleo de Estudos em Malária, Superintendência de Controle de Endemias, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil.,Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
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Aydin-Schmidt B, Morris U, Ding XC, Jovel I, Msellem MI, Bergman D, Islam A, Ali AS, Polley S, Gonzalez IJ, Mårtensson A, Björkman A. Field Evaluation of a High Throughput Loop Mediated Isothermal Amplification Test for the Detection of Asymptomatic Plasmodium Infections in Zanzibar. PLoS One 2017; 12:e0169037. [PMID: 28095434 PMCID: PMC5240913 DOI: 10.1371/journal.pone.0169037] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/10/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND New field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar. METHODS HTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a community-based survey in 2015. RESULTS The PCR and HTP-LAMP determined malaria prevalences were 1.6% (95%CI 1.3-2.4) and 0.7% (95%CI 0.4-1.1), respectively. The sensitivity of HTP-LAMP compared to PCR was 40.8% (CI95% 27.0-55.8) and the specificity was 99.9% (CI95% 99.8-100). For the PCR positive samples, there was no statistically significant difference between the geometric mean parasite densities among the HTP-LAMP positive (2.5 p/μL, range 0.2-770) and HTP-LAMP negative (1.4 p/μL, range 0.1-7) samples (p = 0.088). Two lab technicians analysed up to 282 samples per day and the HTP-LAMP method was experienced as user friendly. CONCLUSIONS Although field applicable, this high throughput format of LAMP as used here was not sensitive enough to be recommended for detection of asymptomatic low-density infections in areas like Zanzibar, approaching malaria elimination.
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Affiliation(s)
- Berit Aydin-Schmidt
- Centre for Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Unit of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Ulrika Morris
- Centre for Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Xavier C Ding
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Irina Jovel
- Centre for Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I Msellem
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Daniel Bergman
- Centre for Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Atiqul Islam
- Centre for Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme, Ministry of Health, Zanzibar, Tanzania
| | - Spencer Polley
- Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals, NHS Foundation Trust, London, United Kingdom
| | - Iveth J Gonzalez
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Anders Björkman
- Centre for Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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Mwaiswelo R, Ngasala B, Jovel I, Aydin-Schmidt B, Gosling R, Premji Z, Mmbando B, Björkman A, Mårtensson A. Adding a single low-dose of primaquine (0.25 mg/kg) to artemether-lumefantrine did not compromise treatment outcome of uncomplicated Plasmodium falciparum malaria in Tanzania: a randomized, single-blinded clinical trial. Malar J 2016; 15:435. [PMID: 27565897 PMCID: PMC5002101 DOI: 10.1186/s12936-016-1430-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/05/2016] [Indexed: 01/26/2023] Open
Abstract
Background The World Health Organization (WHO) recently recommended the addition of a single low-dose of the gametocytocidal drug primaquine (PQ) to artemisinin-based combination therapy (ACT) in low transmission settings as a component of pre-elimination or elimination programmes. However, it is unclear whether that influences the ACT cure rate. The study assessed treatment outcome of artemether-lumefantrine (AL) plus a single PQ dose (0.25 mg/kg) versus standard AL regimen for treatment of acute uncomplicated Plasmodium falciparum malaria in Tanzania. Methods A randomized, single-blinded, clinical trial was conducted in Yombo, Bagamoyo district, Tanzania. Acute uncomplicated P. falciparum malaria patients aged ≥1 year, with the exception of pregnant and lactating women, were enrolled and treated with AL plus a single PQ dose (0.25 mg/kg) or AL alone under supervision. PQ was administered together with the first AL dose. Clinical and laboratory assessments were performed at 0, 8, 24, 36, 48, 60, and 72 h and on days 7, 14, 21, and 28. The primary end-point was a polymerase chain reaction (PCR)-adjusted adequate clinical and parasitological response (ACPR) on day 28. Secondary outcomes included: fever and asexual parasitaemia clearance, proportion of patients with PCR-determined parasitaemia on day 3, and proportion of patients with Pfmdr1 N86Y and Pfcrt K76T on days 0, 3 and day of recurrent infection. Results Overall 220 patients were enrolled, 110 were allocated AL + PQ and AL, respectively. Parasite clearance by microscopy was fast, but PCR detectable parasitaemia on day 3 was 31/109 (28.4 %) and 29/108 (26.9 %) in patients treated with AL + PQ and AL, respectively (p = 0.79). Day 28 PCR-adjusted ACPR and re-infection rate was 105/105 (100 %) and 101/102 (99 %) (p = 0.31), and 5/107 (4.7 %) and 5/8 (4.8 %) (p = 0.95), in AL + PQ and AL arm, respectively. There was neither any statistically significant difference in the proportion of Pfmdr1 N86Y or Pfcrt K76T between treatment arms on days 0, 3 and day of recurrent infection, nor within treatment arms between days 0 and 3 or day 0 and day of recurrent infection. Conclusion The new WHO recommendation of adding a single low-dose of PQ to AL did not compromise treatment outcome of uncomplicated P. falciparum malaria in Tanzania. Trial registration number NCT02090036 Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1430-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard Mwaiswelo
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar Es Salaam, Tanzania
| | - Billy Ngasala
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar Es Salaam, Tanzania.
| | - Irina Jovel
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Berit Aydin-Schmidt
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Roland Gosling
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.,Global Health Group, University of California San Francisco, San Francisco, CA, USA
| | - Zul Premji
- Aga Khan University Hospital, Nairobi, Kenya
| | - Bruno Mmbando
- Tanga Centre, National Institute for Medical Research, Tanga, Tanzania
| | - Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
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10
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Morris U, Khamis M, Aydin-Schmidt B, Abass AK, Msellem MI, Nassor MH, González IJ, Mårtensson A, Ali AS, Björkman A, Cook J. Field deployment of loop-mediated isothermal amplification for centralized mass-screening of asymptomatic malaria in Zanzibar: a pre-elimination setting. Malar J 2015; 14:205. [PMID: 25982190 PMCID: PMC4440539 DOI: 10.1186/s12936-015-0731-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/08/2015] [Indexed: 12/14/2022] Open
Abstract
Background Molecular tools for detection of low-density asymptomatic Plasmodium infections are needed in malaria elimination efforts. This study reports results from the hitherto largest implementation of loop-mediated isothermal amplification (LAMP) for centralized mass screening of asymptomatic malaria in Zanzibar. Methods Healthy individuals present and willing to participate in randomly selected households in 60 villages throughout Zanzibar were screened for malaria by rapid diagnostic tests (RDT). In 50 % of the study households, participants were asked to provide 60 μL of finger-prick blood for additional LAMP screening. LAMP was conducted in two centralized laboratories in Zanzibar, by trained technicians with limited or no previous experience of molecular methods. The LAMP assay was performed with LoopampTM MALARIA Pan/Pf Detection Kit (Eiken Chemical Company, Japan). Samples positive for Plasmodium genus (Pan)-LAMP were re-tested using Plasmodium falciparum-specific LAMP kits. Results Paired RDT and LAMP samples were available from 3983 individuals. The prevalence of asymptomatic malaria was 0.5 % (CI 95 % 0.1-0.8) and 1.6 % (CI 95 % 1.1-2.2) by RDT and Pan-LAMP, respectively. LAMP detected 3.4 (CI 95 % 2.2-5.2) times more Plasmodium positive samples than RDT. DNA contamination was experienced, but solved by repetitive decontamination of all equipment and reagents. Conclusions LAMP is a simple and sensitive molecular tool, and has potential in active surveillance and mass-screening programmes for detection of low-density asymptomatic malaria in pre-elimination settings. However, in order to deploy LAMP more effectively in field settings, protocols may need to be adapted for processing larger numbers of samples. A higher throughput, affordable closed system would be ideal to avoid contamination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0731-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ulrika Morris
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden.
| | - Mwinyi Khamis
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Berit Aydin-Schmidt
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden.
| | - Ali K Abass
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania
| | - Mwinyi I Msellem
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Majda H Nassor
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Iveth J González
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland.
| | - Andreas Mårtensson
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden. .,Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden. .,Centre for Clinical Research Sörmland, Uppsala University, Uppsala, Sweden.
| | - Abdullah S Ali
- Zanzibar Malaria Elimination Programme (ZAMEP), Ministry of Health, Zanzibar, Tanzania.
| | - Anders Björkman
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden.
| | - Jackie Cook
- Malaria Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsväg 16, 171 77, Stockholm, Sweden. .,London School of Hygiene and Tropical Medicine, London, UK.
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Aydin-Schmidt B, Xu W, González IJ, Polley SD, Bell D, Shakely D, Msellem MI, Björkman A, Mårtensson A. Loop mediated isothermal amplification (LAMP) accurately detects malaria DNA from filter paper blood samples of low density parasitaemias. PLoS One 2014; 9:e103905. [PMID: 25105591 PMCID: PMC4126669 DOI: 10.1371/journal.pone.0103905] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/03/2014] [Indexed: 11/18/2022] Open
Abstract
Background Loop mediated isothermal amplification (LAMP) provides an opportunity for improved, field-friendly detection of malaria infections in endemic areas. However data on the diagnostic accuracy of LAMP for active case detection, particularly low-density parasitaemias, are lacking. We therefore evaluated the performance of a new LAMP kit compared with PCR using DNA from filter paper blood spots. Methods and Findings Samples from 865 fever patients and 465 asymptomatic individuals collected in Zanzibar were analysed for Pan (all species) and Pf (P. falciparum) DNA with the Loopamp MALARIA Pan/Pf kit. Samples were amplified at 65°C for 40 minutes in a real-time turbidimeter and results were compared with nested PCR. Samples with discordant results between LAMP and nested PCR were analysed with real-time PCR. The real-time PCR corrected nested PCR result was defined as gold standard. Among the 117 (13.5%) PCR detected P. falciparum infections from fever patients (mean parasite density 7491/µL, range 6–782,400) 115, 115 and 111 were positive by Pan-LAMP, Pf-LAMP and nested PCR, respectively. The sensitivities were 98.3% (95%CI 94–99.8) for both Pan and Pf-LAMP. Among the 54 (11.6%) PCR positive samples from asymptomatic individuals (mean parasite density 10/µL, range 0–4972) Pf-LAMP had a sensitivity of 92.7% (95%CI 80.1–98.5) for detection of the 41 P. falciparum infections. Pan-LAMP had sensitivities of 97% (95%CI 84.2–99.9) and 76.9% (95%CI 46.2–95) for detection of P. falciparum and P. malariae, respectively. The specificities for both Pan and Pf-LAMP were 100% (95%CI 99.1–100) in both study groups. Conclusion Both components of the Loopamp MALARIA Pan/Pf detection kit revealed high diagnostic accuracy for parasite detection among fever patients and importantly also among asymptomatic individuals of low parasite densities from minute blood volumes preserved on filter paper. These data support LAMPs potential role for improved detection of low-density malaria infections in pre-elimination settings.
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Affiliation(s)
- Berit Aydin-Schmidt
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
- Unit of infectious diseases, Karolinska University Hospital, Stockholm, Sweden
- * E-mail:
| | - Weiping Xu
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - Iveth J. González
- Department of Clinical Parasitology, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Spencer D. Polley
- Hospital for Tropical Diseases, University College London Hospitals, London, United Kingdom
- NIHR Biomedical Research Centre at University College London Hospitals NHS Foundation Trust and University College, London, United Kingdom
| | - David Bell
- Global Good Fund, Bellevue, Washington, United States of America
| | - Delér Shakely
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I. Msellem
- Zanzibar Malaria Elimination Program, Ministry of Health, Zanzibar, Tanzania
| | - Anders Björkman
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Malaria Research, Department of Microbiology, Tumor and Cellbiology, Karolinska Institutet, Stockholm, Sweden
- Global Health, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
- Center for Clinical Research, Sörmland County Council, Sörmland, Sweden
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12
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Aydin-Schmidt B, Mubi M, Morris U, Petzold M, Ngasala BE, Premji Z, Björkman A, Mårtensson A. Usefulness of Plasmodium falciparum-specific rapid diagnostic tests for assessment of parasite clearance and detection of recurrent infections after artemisinin-based combination therapy. Malar J 2013; 12:349. [PMID: 24079306 PMCID: PMC3849780 DOI: 10.1186/1475-2875-12-349] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 09/20/2013] [Indexed: 11/24/2022] Open
Abstract
Background Rapid diagnostic test (RDT) is an important tool for parasite-based malaria diagnosis. High specificity of RDTs to distinguish an active Plasmodium falciparum infection from residual antigens from a previous infection is crucial in endemic areas where residents are repeatedly exposed to malaria. The efficiency of two RDTs based on histidine-rich protein 2 (HRP2) and lactate dehydrogenase (LDH) antigens were studied and compared with two microscopy techniques (Giemsa and acridine orange-stained blood smears) and real-time polymerase chain reaction (PCR) for assessment of initial clearance and detection of recurrent P. falciparum infections after artemisinin-based combination therapy (ACT) in a moderately high endemic area of rural Tanzania. Methods In this exploratory study 53 children < five years with uncomplicated P. falciparum malaria infection were followed up on nine occasions, i.e., day 1, 2, 3, 7, 14, 21, 28, 35 and 42, after initiation of artemether-lumefantrine treatment. At each visit capillary blood samples was collected for the HRP2 and LDH-based RDTs, Giemsa and acridine orange-stained blood smears for microscopy and real-time PCR. Assessment of clearance times and detection of recurrent P. falciparum infections were done for all diagnostic methods. Results The median clearance times were 28 (range seven to >42) and seven (two to 14) days for HRP2 and LDH-based RDTs, two (one to seven) and two (one to 14) days for Giemsa and acridine orange-stained blood smear and two (one to 28) days for real-time PCR. RDT specificity against Giemsa-stained blood smear microscopy was 21% for HRP2 on day 14, reaching 87% on day 42, and ≥96% from day 14 to 42 for LDH. There was no significant correlation between parasite density at enrolment and duration of HRP2 positivity (r = 0.13, p = 0.34). Recurrent malaria infections occurred in ten (19%) children. The HRP2 and LDH-based RDTs did not detect eight and two of the recurrent infections, respectively. Conclusion The LDH-based RDT was superior to HRP2-based for monitoring of treatment outcome and detection of recurrent infections after ACT in this moderately high transmission setting. The results may have implications for the choice of RDT devices in similar transmission settings for improved malaria case management. Trial registration Clinicaltrials.gov, NCT01843764
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Affiliation(s)
- Berit Aydin-Schmidt
- Malaria Research, Department of Medicine-Solna, Karolinska University Hospital/Karolinska Institutet, Stockholm, Sweden.
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Shakely D, Elfving K, Aydin-Schmidt B, Msellem MI, Morris U, Omar R, Weiping X, Petzold M, Greenhouse B, Baltzell KA, Ali AS, Björkman A, Mårtensson A. The usefulness of rapid diagnostic tests in the new context of low malaria transmission in Zanzibar. PLoS One 2013; 8:e72912. [PMID: 24023791 PMCID: PMC3762850 DOI: 10.1371/journal.pone.0072912] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/12/2013] [Indexed: 11/19/2022] Open
Abstract
Background We assessed if histidine-rich-protein-2 (HRP2) based rapid diagnostic test (RDT) remains an efficient tool for Plasmodium falciparum case detection among fever patients in Zanzibar and if primary health care workers continue to adhere to RDT results in the new epidemiological context of low malaria transmission. Further, we evaluated the performance of RDT within the newly adopted integrated management of childhood illness (IMCI) algorithm in Zanzibar. Methods and Findings We enrolled 3890 patients aged ≥2 months with uncomplicated febrile illness in this health facility based observational study conducted in 12 primary health care facilities in Zanzibar, between May-July 2010. One patient had an inconclusive RDT result. Overall 121/3889 (3.1%) patients were RDT positive. The highest RDT positivity rate, 32/528 (6.1%), was found in children aged 5–14 years. RDT sensitivity and specificity against PCR was 76.5% (95% CI 69.0–83.9%) and 99.9% (95% CI 99.7–100%), and against blood smear microscopy 78.6% (95% CI 70.8–85.1%) and 99.7% (95% CI 99.6–99.9%), respectively. All RDT positive, but only 3/3768 RDT negative patients received anti-malarial treatment. Adherence to RDT results was thus 3887/3889 (99.9%). RDT performed well in the IMCI algorithm with equally high adherence among children <5 years as compared with other age groups. Conclusions The sensitivity of HRP-2 based RDT in the hands of health care workers compared with both PCR and microscopy for P. falciparum case detection was relatively low, whereas adherence to test results with anti-malarial treatment was excellent. Moreover, the results provide evidence that RDT can be reliably integrated in IMCI as a tool for improved childhood fever management. However, the relatively low RDT sensitivity highlights the need for improved quality control of RDT use in primary health care facilities, but also for more sensitive point-of-care malaria diagnostic tools in the new epidemiological context of low malaria transmission in Zanzibar. Trial registration ClinicalTrials.gov NCT01002066
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Affiliation(s)
- Delér Shakely
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Department of Medicine, Kungälv Hospital, Kungälv, Sweden
- * E-mail:
| | - Kristina Elfving
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Berit Aydin-Schmidt
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Mwinyi I. Msellem
- Zanzibar Malaria Control Programme, Ministry of Health, Zanzibar, Tanzania
| | - Ulrika Morris
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Rahila Omar
- Zanzibar Malaria Control Programme, Ministry of Health, Zanzibar, Tanzania
| | - Xu Weiping
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Max Petzold
- Centre for Applied Biostatistics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Kimberly A. Baltzell
- Department of Family Health Care Nursing, University of California San Francisco, San Francisco, California, United States of America
| | - Abdullah S. Ali
- Zanzibar Malaria Control Programme, Ministry of Health, Zanzibar, Tanzania
| | - Anders Björkman
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Division of Global Health (IHCAR), Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
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Morris U, Aydin-Schmidt B, Shakely D, Mårtensson A, Jörnhagen L, Ali AS, Msellem MI, Petzold M, Gil JP, Ferreira PE, Björkman A. Rapid diagnostic tests for molecular surveillance of Plasmodium falciparum malaria -assessment of DNA extraction methods and field applicability. Malar J 2013; 12:106. [PMID: 23510231 PMCID: PMC3605315 DOI: 10.1186/1475-2875-12-106] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 03/10/2013] [Indexed: 11/20/2022] Open
Abstract
Background The need for new malaria surveillance tools and strategies is critical, given improved global malaria control and regional elimination efforts. High quality Plasmodium falciparum DNA can reliably be extracted from malaria rapid diagnostic tests (RDTs). Together with highly sensitive molecular assays, wide scale collection of used RDTs may serve as a modern tool for improved malaria case detection and drug resistance surveillance. However, comparative studies of DNA extraction efficiency from RDTs and the field applicability are lacking. The aim of this study was to compare and evaluate different methods of DNA extraction from RDTs and to test the field applicability for the purpose of molecular epidemiological investigations. Methods DNA was extracted from two RDT devices (Paracheck-Pf® and SD Bioline Malaria Pf/Pan®), seeded in vitro with 10-fold dilutions of cultured 3D7 P. falciparum parasites diluted in malaria negative whole blood. The level of P. falciparum detection was determined for each extraction method and RDT device with multiple nested-PCR and real-time PCR assays. The field applicability was tested on 855 paired RDT (Paracheck-Pf) and filter paper (Whatman® 3MM) blood samples (734 RDT negative and 121 RDT positive samples) collected from febrile patients in Zanzibar 2010. RDT positive samples were genotyped at four key single nucleotide polymorphisms (SNPs) in pfmdr1 and pfcrt as well as for pfmdr1 copy number, all associated with anti-malarial drug resistance. Results The P. falciparum DNA detection limit varied with RDT device and extraction method. Chelex-100 extraction performed best for all extraction matrixes. There was no statistically significant difference in PCR detection rates in DNA extracted from RDTs and filter paper field samples. Similarly there were no significant differences in the PCR success rates and genotyping outcomes for the respective SNPs in the 121 RDT positive samples. Conclusions The results support RDTs as a valuable source of parasite DNA and provide evidence for RDT-DNA extraction for improved malaria case detection, molecular drug resistance surveillance, and RDT quality control.
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Affiliation(s)
- Ulrika Morris
- Malaria Research, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
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Baltzell KA, Shakely D, Hsiang M, Kemere J, Ali AS, Björkman A, Mårtensson A, Omar R, Elfving K, Msellem M, Aydin-Schmidt B, Rosenthal PJ, Greenhouse B. Prevalence of PCR detectable malaria infection among febrile patients with a negative Plasmodium falciparum specific rapid diagnostic test in Zanzibar. Am J Trop Med Hyg 2012; 88:289-91. [PMID: 23249688 DOI: 10.4269/ajtmh.2012.12-0095] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We screened for malaria in 594 blood samples from febrile patients who tested negative by a Plasmodium falciparum-specific histidine-rich protein-2-based rapid diagnostic test at 12 health facilities in Zanzibar districts North A and Micheweni, from May to August 2010. Screening was with microscopy, polymerase chain reaction (PCR) targeting the cytochrome b gene (cytbPCR) of the four major human malaria species, and quantitative PCR (qPCR). The prevalence of cytbPCR-detectable malaria infection was 2% (12 of 594), including 8 P. falciparum, 3 Plasmodium malariae, and 1 Plasmodium vivax infections. Microscopy identified 4 of 8 P. falciparum infections. Parasite density as estimated by microscopy or qPCR was > 4,000 parasites/μL in 5 of 8 cytbPCR-detectable P. falciparum infections. The infections that were missed by the rapid diagnostic test represent a particular challenge in malaria elimination settings and highlight the need for more sensitive point-of-care diagnostic tools to improve case detection of all human malaria species in febrile patients.
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Affiliation(s)
- Kimberly A Baltzell
- Department of Family Health Care Nursing, University of California, San Francisco, San Francisco, CA 94143, USA.
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