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Tilahun A, Yimer M, Gelaye W, Tegegne B, Endalamaw D, Estifanos F, Abebaw A, Abere A. Comparison of malaria diagnostic methods for detection of asymptomatic Plasmodium infections among pregnant women in northwest Ethiopia. BMC Infect Dis 2024; 24:492. [PMID: 38745114 PMCID: PMC11092159 DOI: 10.1186/s12879-024-09369-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 04/30/2024] [Indexed: 05/16/2024] Open
Abstract
BACKGROUND Malaria in pregnancy remains a major public health problem in the globe, especially in sub-Saharan Africa. In malaria endemic areas, most pregnant women remain asymptomatic, but malaria could still cause complications on the mother and her offspring; as well as serve as reservoirs to transmit infection. Despite these effects, no attention is given to the diagnosis of asymptomatic Plasmodium infections (APIs) using highly sensitive and specific laboratory diagnostic tools in Ethiopia. Therefore, the goal of this study was to compare the performance of Rapid Diagnostic Test (RDT), microscopy and real-time polymerase chain reaction (RT-PCR) to detect APIs among pregnant women. METHODS A health facility based cross -sectional study was conducted among pregnant women attending antenatal care at Fendeka town health facilities Jawi district, northwest Ethiopia from February to March, 2019. A total of 166 participants were enrolled by using convenient sampling technique. Socio-demographic features were collected using a semi structured questionnaire. Dried blood spot (DBS) samples were collected for molecular analysis. Asymptomatic Plasmodium infection on pregnant women was diagnosed using RDT, microscopy and RT-PCR. Descriptive statistics were used to determine the prevalence of APIs. Method comparison was performed, and Cohen's kappa coefficient (k) was used to determine the degree of agreement among the diagnostic methods. Parasite densities were also calculated. RESULTS The prevalence of API was 9.6%, 11.4% and 18.7% using RDT, microscopy and RT-PCR, respectively. The overall proportion of API was 19.3%. Sensitivity of the RDT was 83.3% as compared with microscopy. Rapid Diagnostic Test and microscopy also showed sensitivity of 50% and 60%, respectively, as compared with RT-PCR. The mean parasite density was 3213 parasites/µl for P falciparum and 1140 parasites/µl of blood for P. vivax. CONCLUSION Prevalence of API in the study area was high. Both RDT and microscopy had lower sensitivity when compared with RT-PCR. Therefore, routine laboratory diagnosis of API among pregnant women should be given attention and done with better sensitive and specific laboratory diagnostic tools.
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Affiliation(s)
- Adane Tilahun
- Department of Medical Laboratory Science, College of Medicine and Health sciences, Debre Markos University, Debre Markos, Ethiopia.
| | - Mulat Yimer
- Department of Medical Laboratory Sciences, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Woynshet Gelaye
- Department of Medical Laboratory Sciences, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | | | | | | | - Abtie Abebaw
- Department of Medical Laboratory Science, College of Medicine and Health sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Aberham Abere
- School of Biomedical and Laboratory Sciences, College of Medicine and Health sciences, University of Gondar, Gondar, Ethiopia
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Zhang X, Jiang J, Sui Y, Yan H, Xia J, Liu Y, Sun L, Wang X, Marfurt J, Lu S, Li S, Ruan W, Wang D. Evaluation of performance for malaria diagnosis in health facilities by five provincial reference laboratories of China. Front Public Health 2023; 11:1243642. [PMID: 37841716 PMCID: PMC10569120 DOI: 10.3389/fpubh.2023.1243642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023] Open
Abstract
Introduction The provincial malaria diagnosis reference laboratories review and assess malaria cases diagnosed in health facilities for supporting the malaria elimination efforts and preventing re-transmission of imported malaria. The study aimed to evaluate the detection capability of malaria diagnosis in China from 2014 to 2021. Methods Data on malaria cases reported in the provincial-level administrative divisions (PLADs) of Anhui, Henan, Hubei, Guangxi, and Zhejiang from 2014 to 2021 were collected and analyzed. Results In total, 5,770 malaria cases were reported from 2014 to 2021, and 99.05% (5,715/5,770) were submitted to the provincial malaria diagnosis reference laboratories. The median time between malaria cases being reported and the samples being received by reference laboratories was 6 days (Interquartile range, IQR:3-12 days) from 2017 to 2021. Diagnosis of 5,680 samples in the laboratory were confirmed by provincial reference laboratories, including 3,970 cases of Plasmodium falciparum, 414 of P. vivax, 1,055 of P. ovale, 158 of P. malariae, 1 of P. knowlesi, and 82 of mixed infections. Plasmodium species of 5,141 confirmed cases were consistent with the initial diagnosis, with a species accuracy rate of 90.53% (5,141/5,679). The accuracy of P. falciparum diagnosis in health facilities was higher than that of non-falciparum species. The inconsistency between microscopy and nested polymerase chain reaction (nPCR) results of confirmatory diagnosis was mainly in malaria-positive versus malaria-negative cases, as well as in mixed versus single infection cases. Conclusion The provincial malaria diagnosis reference laboratories have played an important role in ensuring the accuracy and reliability of Plasmodium diagnosis in health facilities. However, the results of this study imply that capacity training for the identification of Plasmodium species in health facilities is warranted.
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Affiliation(s)
- Xuan Zhang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Jingjing Jiang
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Yuan Sui
- Brown School, Washington University, St. Louis, MO, United States
| | - Hui Yan
- Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention, Nanning, China
| | - Jing Xia
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, China
| | - Ying Liu
- Henan Provincial Center for Disease Control and Prevention, Zhengzhou, China
| | - Lingcong Sun
- Hubei Provincial Center for Disease Control and Prevention, Wuhan, China
| | - Xiaoxiao Wang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Jutta Marfurt
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- College of Medicine and Public Health, Flinders University, Darwin, NT, Australia
| | - Shenning Lu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Shizhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
| | - Wei Ruan
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Duoquan Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, China
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Yigezu E, Wondale B, Abebe D, Tamiru G, Eligo N, Lindtjørn B, Gadisa E, Tadesse FG, Massebo F. Malaria misdiagnosis in the routine health system in Arba Minch area district in southwest Ethiopia: an implication for malaria control and elimination. Malar J 2023; 22:273. [PMID: 37710252 PMCID: PMC10503053 DOI: 10.1186/s12936-023-04711-2] [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: 02/28/2023] [Accepted: 09/10/2023] [Indexed: 09/16/2023] Open
Abstract
BACKGROUND Plasmodium falciparum and Plasmodium vivax are coendemic in Ethiopia, with different proportion in different settings. Microscopy is the diagnostic tool in Ethiopian health centres. Accurate species-specific diagnosis is vital for appropriate treatment of cases to interrupt its transmission. Therefore, this study assessed the status of species-specific misdiagnosis by microscope compared with polymerase chain reaction (PCR). METHODS A health facility based cross-sectional study was conducted from November 2019 to January 2020 in Kolla Shelle Health centre, Arba Minch Zuria district. The study population were suspected malaria cases, who visited the health centre for a diagnosis and treatment. Consecutive microscopy positive cases as well as a sample of microscopically negative cases were included for molecular analysis by polymerase chain reaction (PCR). RESULTS 254 microscopically negative and 193 microscopically positive malaria suspects were included. Of the 193 malaria positive cases, 46.1% [95% confidence interval (CI) 38.9-53.4] (89/193) were P. falciparum infection, 52.3% (95% CI 45.0-59.5) (101/193) were P. vivax infection, and 1.6% (3/193) had mixed infection of P. falciparum and P. vivax. Of the microscopically positive cases of P. falciparum, 3.4% (3/89) were P. vivax and 11.2% (10/89) were mixed infections with P. falciparum and P. vivax and a single case was negative molecularly. Similarly, of the microscopically positive P. vivax cases, 5.9% (6/101) were P. falciparum and 1% (1/101) was mixed infection. Single case was negative by molecular technique. Of the 254 microscopically negative cases, 0.8% were tested positive for P. falciparum and 2% for P. vivax by PCR. Considering molecular technique as a reference, the sensitivity of microscopy for detecting P. falciparum was 89.2% and for P. vivax, it was 91.2%. The specificity of microscopy for detecting P. falciparum was 96.1% and for P. vivax, it was 97.7%. However, the sensitivity of microscopy in detecting mixed infection of P. falciparum and P. vivax was low (8.3%). CONCLUSION There were cases left untreated or inappropriately treated due to the species misidentification. Therefore, to minimize this problem, the gaps in the microscopic-based malaria diagnosis should be identified. It is recommended to regularly monitor the competency of malaria microscopists in the study area to improve species identification and diagnosis accuracy.
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Affiliation(s)
- Engida Yigezu
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Biniam Wondale
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Daniel Abebe
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Girum Tamiru
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Nigatu Eligo
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Bernt Lindtjørn
- Centre for International Health, University of Bergen, Bergen, Norway
| | | | | | - Fekadu Massebo
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
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van Loon W, Oliveira R, Bergmann C, Habarugira F, Tacoli C, Jäger J, Savelsberg D, Mbarushimana D, Ndoli JM, Sendegeya A, Bayingana C, Mockenhaupt FP. Plasmodium vivax Malaria in Duffy-Positive Patients in Rwanda. Am J Trop Med Hyg 2023; 109:621-623. [PMID: 37549894 PMCID: PMC10484245 DOI: 10.4269/ajtmh.23-0143] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/21/2023] [Indexed: 08/09/2023] Open
Abstract
Plasmodium vivax is the second-most common malaria pathogen globally, but is considered very rare in the predominantly Duffy-negative sub-Saharan African population. In 259 malaria patients from highland southern Rwanda, we assessed Plasmodium species and Duffy blood group status by polymerase chain reaction (PCR). Plasmodium falciparum, P. vivax, Plasmodium malariae, and Plasmodium ovale were seen in 90.7%, 8.1%, 11.6%, and 5.0%, respectively. Plasmodium vivax occurred more frequently as a monoinfection than in combination with P. falciparum. All P. vivax-infected individuals showed heterozygous Duffy positivity, whereas this was the case for only 3.1% of patients with P. falciparum monoinfection and malaria-negative control subjects (P < 0.01). Based on PCR diagnosis, P. vivax is not rare in southern Rwanda. All episodes of P. vivax were observed in heterozygous Duffy-positive patients, whereas elsewhere in Africa, P. vivax is also reported in Duffy-negative individuals. Refined mapping of Plasmodium species is required to establish control and elimination strategies including all malaria species.
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Affiliation(s)
- Welmoed van Loon
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Rafael Oliveira
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
- John Curtin School of Medical Research, Australian National University, Canberra, Australia
| | - Clara Bergmann
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Felix Habarugira
- Pathology Department, University Teaching Hospital of Butare, Huye, Rwanda
| | - Costanza Tacoli
- Malaria Molecular Epidemiology Unit Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Julia Jäger
- Associatid Group Immune Ontogeny and Viral Infections, Leibniz Institute of Virology, Hamburg, Germany
| | - Darius Savelsberg
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
| | | | - Jules M. Ndoli
- Clinical Education and Research Division, University Teaching Hospital of Butare, Huye, Rwanda
| | | | | | - Frank P. Mockenhaupt
- Institute of International Health, Center for Global Health, Charité–Universitätsmedizin Berlin, Berlin, Germany
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Cardona-Arias JA, Higuita Gutiérrez LF, Carmona-Fonseca J. Diagnostic Accuracy of a Thick Blood Smear Compared to qPCR for Malaria Associated with Pregnancy in Colombia. Trop Med Infect Dis 2023; 8:tropicalmed8020119. [PMID: 36828535 PMCID: PMC9959527 DOI: 10.3390/tropicalmed8020119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 02/17/2023] Open
Abstract
This study aimed to evaluate the accuracy of the thick blood smear (TBS) versus quantitative polymerase chain reaction (qPCR) for the diagnosis of malaria associated with pregnancy (MAP) caused by P. falciparum or P. vivax in Colombia in its gestational malaria (GM), placental malaria (PM), and congenital malaria (CM) forms as well as to compare its accuracy in different subgroups of pregnant women according to the presence of fever, anemia and a history of malaria. This was a diagnostic evaluation of 829 pregnant women, 579 placentas, 381 umbilical cord samples, and 221 neonatal peripheral blood samples. Accuracy was evaluated based on the parameters of sensitivity, specificity, predictive values, likelihood ratios, and validity index, with their 95% confidence intervals. The frequency of GM was 36% (n = 297/829), PM 27% (n = 159/579), and CM 16.5% (n = 63/381) in umbilical cord samples and 2% (n = 5/221) in neonatal peripheral blood samples. For GM, the sensitivity was 55%, with higher rates in those infected with P. vivax (68%), with a history of malaria (69%), and with fever (96%). These three subgroups presented the best results in terms of the negative likelihood ratio and validity index. For PM, sensitivity was 8%; in subgroup analyses in terms of species, symptomatology (anemia and fever), and history of malaria, it was 1-18%, and the negative likelihood ratio was >0.80 in all subgroups. No false positives were recorded in any of the subgroups. The TBS did not detect any cases of CM. This study found the TBS yielded satisfactory results in terms of diagnosing GM for P. vivax, pregnant women with previous malaria and febrile. It also showed that the TBS is not useful for diagnosing PM and CM. It is necessary to conduct surveillance of MAP with molecular methods in in groups where TBS is deficient (asymptomatic GM, P. falciparum, and pregnant women without history of malaria) to optimize the timely treatment of PM and CM, avoid the deleterious effects of MAP and achieve the malaria elimination goals in Colombia.
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Affiliation(s)
| | - Luis Felipe Higuita Gutiérrez
- Escuela de Microbiología, Universidad de Antioquia, Medellín 050010, Colombia
- Facultad de Medicina, Universidad Cooperativa de Colombia, Medellín 050010, Colombia
| | - Jaime Carmona-Fonseca
- Grupo Salud y Comunidad César Uribe Piedrahíta, Facultad de Medicina, Universidad de Antioquia, Medellín 050010, Colombia
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Yon JLT, Htet NH, Naing C, Tung WS, Aung HH, Mak JW. Loop-mediated isothermal amplification (LAMP) test in the detection of uncomplicated malaria in pregnancy: a meta-analysis of diagnostic accuracy. Malar J 2022; 21:391. [PMID: 36550507 PMCID: PMC9783437 DOI: 10.1186/s12936-022-04419-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Due to relatively low malaria parasitaemia in pregnancy, an appropriate field test that can adequately detect infections in pregnant women presenting with illness or for malaria screening during antenatal care is crucially important. The objective was to evaluate the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for the detection of uncomplicated malaria in pregnancy. METHODS This was a meta-analysis of diagnostic accuracy. Relevant studies that assessed the diagnostic performance of LAMP for the detection of malaria in pregnancy were searched in health-related electronic databases including PubMed, Ovid, and Google Scholar. The methodological quality of the studies included was evaluated using the QUADAS-2 tool. RESULTS Of the 372 studies identified, eight studies involving 2999 pregnant women in five endemic countries that assessed the accuracy of LAMP were identified. With three types of PCR as reference tests, the pooled sensitivity of LAMP was 91% (95%CI 67-98%) and pooled specificity was 99% (95%CI 83-100%, 4 studies), and the negative likelihood ratio was 9% (2-40%). Caution is needed in the interpretation as there was substantial between-study heterogeneity (I2: 80%), and a low probability that a person without infection is tested negative. With microscopy as a reference, the pooled sensitivity of LAMP was 95% (95%CI 26-100%) and pooled specificity was 100% (95%CI 94-100%, 4 studies). There was a wide range of sensitivity and substantial between-study heterogeneity (I2: 83.5-98.4%). To investigate the source of heterogeneity, a meta-regression analysis was performed with covariates. Of these potential confounding factors, reference test (p: 0.03) and study design (p:0.03) had affected the diagnostic accuracy of LAMP in malaria in pregnancy. Overall, there was a low certainty of the evidence in accuracy estimates. CONCLUSION The findings suggest that LAMP is more sensitive than traditional tests used at facilities, but the utility of detecting and treating these low-density infections is not well understood. Due to the limited number of studies with bias in their methodological quality, variation in the study design, and different types of reference tests further research is likely to change the estimate. Well-conceived large prospective studies with blinding of the index test results are recommenced.
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Affiliation(s)
- Joseph Lee Teck Yon
- grid.411729.80000 0000 8946 5787School of Medicine, International Medical University, Kuala Lumpur, Malaysia ,grid.4305.20000 0004 1936 7988University of Edinburgh, Old College, Edinburgh, EH8 9YL UK
| | - Norah Htet Htet
- grid.411729.80000 0000 8946 5787School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Cho Naing
- grid.1011.10000 0004 0474 1797Division of Tropical Health and Medicine, James Cook University, Townsville, QLD Australia
| | - Wong Siew Tung
- grid.411729.80000 0000 8946 5787School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Htar Htar Aung
- grid.411729.80000 0000 8946 5787School of Medicine, International Medical University, Kuala Lumpur, Malaysia
| | - Joon Wah Mak
- grid.411729.80000 0000 8946 5787Institute of Research, Development and Innovation (IRDI), International Medical University, Kuala Lumpur, Malaysia
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Malaria Microscopy Competency in the Subnational Verification, China: Implications for Malaria Elimination and the Prevention of Malaria Reestablishment. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2022; 2022:8003845. [PMID: 36349187 PMCID: PMC9637463 DOI: 10.1155/2022/8003845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/15/2022] [Accepted: 10/19/2022] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Qualified microscopy competency is a key indicator for certification of malaria elimination. To better prepare the country certification and identify the priorities that need improvement to prevent malaria reestablishment, microscopy competency at different levels were assessed in subnational verification of malaria elimination in China. Methodology. Microscopist representatives from centers for disease control and prevention (CDC)/institutes of parasitic diseases (IPD) and medical institutes for malaria diagnosis at the provincial and county levels in the subnational verification were analyzed. Specifically, five provincial microscopist representatives and ten county-level representatives were assessed in each of previously endemic provinces on qualitative identification (Plasmodium positive or negative) and Plasmodium species identification using standard slides from the National Malaria Diagnosis Reference Laboratory. RESULTS A total of 100 provincial-level representatives (60 from 42 CDCs/IPDs and 40 from 34 medical institutes) and 200 county-level representatives (61 from 41 CDCs and 139 from 118 medical institutes) were included. The qualitative accuracy was higher than 90% each (P = 0.137), but slides with low parasite density were easy to be misdiagnosed as negative. Furthermore, the accuracy of species identification was 80.0% and 83.6% in medical institutes and centers for disease control and prevention (CDCs) at the provincial level (P = 0.407) with relatively high misdiagnosis of P. vivax as P. ovale in the latter (16.2%) and 82.0% and 85.0% in medical institutes and CDCs at the county level (P = 0.330) for the identification of P. falciparum and non-P. falciparum with higher false-negative in medical institutions (P < 0.001). CONCLUSIONS In conclusion, competent microscopy in subnational verification supported the quality in eliminating malaria in China, while the accurate identification of malaria parasites, especially slides with low parasite density still need to be improved through continuous diagnostic platform construction, continuous technological innovation, and targeted training to prevent reestablishment of malaria transmission.
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Tan AF, Sakam SSB, Rajahram G, William T, Abd Rachman Isnadi M, Daim S, Barber B, Kho S, Sutherland CJ, Anstey NM, Yerlikaya S, van Schalkwyk DA, Grigg MJ. Diagnostic accuracy and limit of detection of ten malaria parasite lactate dehydrogenase-based rapid tests for Plasmodium knowlesi and P. falciparum. Front Cell Infect Microbiol 2022; 12:1023219. [PMID: 36325471 PMCID: PMC9618705 DOI: 10.3389/fcimb.2022.1023219] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 09/26/2022] [Indexed: 11/21/2022] Open
Abstract
Background Plasmodium knowlesi causes zoonotic malaria across Southeast Asia. First-line diagnostic microscopy cannot reliably differentiate P. knowlesi from other human malaria species. Rapid diagnostic tests (RDTs) designed for P. falciparum and P. vivax are used routinely in P. knowlesi co-endemic areas despite potential cross-reactivity for species-specific antibody targets. Methods Ten RDTs were evaluated: nine to detect clinical P. knowlesi infections from Malaysia, and nine assessing limit of detection (LoD) for P. knowlesi (PkA1-H.1) and P. falciparum (Pf3D7) cultures. Targets included Plasmodium-genus parasite lactate dehydrogenase (pan-pLDH) and P. vivax (Pv)-pLDH. Results Samples were collected prior to antimalarial treatment from 127 patients with microscopy-positive PCR-confirmed P. knowlesi mono-infections. Median parasitaemia was 788/µL (IQR 247-5,565/µL). Pan-pLDH sensitivities ranged from 50.6% (95% CI 39.6–61.5) (SD BIOLINE) to 87.0% (95% CI 75.1–94.6) (First Response® and CareStart™ PAN) compared to reference PCR. Pv-pLDH RDTs detected P. knowlesi with up to 92.0% (95% CI 84.3-96.7%) sensitivity (Biocredit™). For parasite counts ≥200/µL, pan-pLDH (Standard Q) and Pv-pLDH RDTs exceeded 95% sensitivity. Specificity of RDTs against 26 PCR-confirmed negative controls was 100%. Sensitivity of six highest performing RDTs were not significantly different when comparing samples taken before and after (median 3 hours) antimalarial treatment. Parasite ring stages were present in 30% of pre-treatment samples, with ring stage proportions (mean 1.9%) demonstrating inverse correlation with test positivity of Biocredit™ and two CareStart™ RDTs. For cultured P. knowlesi, CareStart™ PAN demonstrated the lowest LoD at 25 parasites/µL; LoDs of other pan-pLDH ranged from 98 to >2000 parasites/µL. Pv-pLDH LoD for P. knowlesi was 49 parasites/µL. No false-positive results were observed in either P. falciparum-pLDH or histidine-rich-protein-2 channels. Conclusion Selected RDTs demonstrate sufficient performance for detection of major human malaria species including P. knowlesi in co-endemic areas where microscopy is not available, particularly for higher parasite counts, although cannot reliably differentiate among non-falciparum malaria.
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Affiliation(s)
- Angelica F. Tan
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, N T, Australia
- Infectious Diseases Society Kota Kinabalu Sabah – Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- *Correspondence: Angelica F. Tan, ; Matthew J. Grigg,
| | - Sitti Saimah binti Sakam
- Infectious Diseases Society Kota Kinabalu Sabah – Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Giri S. Rajahram
- Infectious Diseases Society Kota Kinabalu Sabah – Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Ministry of Health, Kota Kinabalu, Sabah, Malaysia
- Department of Medicine, Queen Elizabeth Hospital II, Kota Kinabalu, Sabah, Malaysia
| | - Timothy William
- Infectious Diseases Society Kota Kinabalu Sabah – Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Ministry of Health, Kota Kinabalu, Sabah, Malaysia
| | | | - Sylvia Daim
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Bridget E. Barber
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, N T, Australia
- Clinical Malaria, Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Steven Kho
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, N T, Australia
| | - Colin J. Sutherland
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, N T, Australia
- Infectious Diseases Society Kota Kinabalu Sabah – Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Seda Yerlikaya
- Malaria and Fever, Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Donelly A. van Schalkwyk
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Matthew J. Grigg
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, N T, Australia
- Infectious Diseases Society Kota Kinabalu Sabah – Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- *Correspondence: Angelica F. Tan, ; Matthew J. Grigg,
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Kho S, Anstey NM, Barber BE, Piera K, William T, Kenangalem E, McCarthy JS, Jang IK, Domingo GJ, Britton S, Grigg MJ. Diagnostic performance of a 5-plex malaria immunoassay in regions co-endemic for Plasmodium falciparum, P. vivax, P. knowlesi, P. malariae and P. ovale. Sci Rep 2022; 12:7286. [PMID: 35508558 PMCID: PMC9068623 DOI: 10.1038/s41598-022-11042-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
Commercial point-of-care tests remain insufficient for accurately detecting and differentiating low-level malaria infections in regions co-endemic with multiple non-falciparum species, including zoonotic Plasmodium knowlesi (Pk). A 5-plex chemiluminescent assay simultaneously measures pan-Plasmodium lactate dehydrogenase (pLDH), P. falciparum (Pf)-LDH, P. vivax (Pv)-LDH, Pf-histidine-rich protein-2 (HRP2), and C-reactive protein. We assessed its diagnostic performance on whole blood (WB) samples from 102 healthy controls and 306 PCR-confirmed clinical cases of Pf, Pv, Pk, P. malariae (Pm) and P. ovale (Po) mono-infections from Southeast-Asia. We confirm its excellent HRP2-based detection of Pf. Cross-reactivity of Pf-LDH with all non-falciparum species tested was observed (specificity 57.3%). Pv-LDH performance was suboptimal for Pv (93.9% sensitivity and 73.9% specificity). Poor specificity was driven by strong Pk cross-reactivity, with Pv-LDH detecting 93.9% of Pk infections. The pan-LDH-to-Pf-LDH ratio was capable of discerning Pv from Pk, and robustly differentiated Pf from Pm or Po infection, useful in regions with hrp2/3 deletions. We tested the platform's performance in plasma for the first time, with WB outperforming plasma for all analytes except Pv-LDH for Pk. The platform is a promising tool for WB malaria diagnosis, although further development is warranted to improve its utility in regions co-endemic for multiple non-falciparum species.
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Affiliation(s)
- Steven Kho
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia.
| | - Nicholas M Anstey
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Bridget E Barber
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
- QIMR-Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Kim Piera
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Timothy William
- Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Enny Kenangalem
- Papuan Health and Community Development Foundation, Timika, Indonesia
| | - James S McCarthy
- The Peter Doherty Institute for Infection and Immunity, University of Melbourne and Royal Melbourne Hospital, Melbourne, VIC, Australia
| | | | | | - Sumudu Britton
- QIMR-Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Matthew J Grigg
- Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
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10
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Melese Y, Alemu M, Yimer M, Tegegne B, Tadele T. Asymptomatic Malaria in Households and Neighbors of Laboratory Confirmed Cases in Raya Kobo District, Northeast Ethiopia. Ethiop J Health Sci 2022; 32:623-630. [PMID: 35813680 PMCID: PMC9214748 DOI: 10.4314/ejhs.v32i3.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/13/2022] [Indexed: 11/17/2022] Open
Abstract
Background Malaria is the leading vector-borne parasitic disease that is causing high morbidity and mortality worldwide. So far huge efforts to control and eliminate malaria are hindered by the occurrence of asymptomatic carriers that are a potential source of infection. Yet, there is a scarcity of data nationally and in the current study area as well. Therefore, this study was aimed to assess the prevalence of asymptomatic malaria in Northeast Ethiopia. Methods A community-based cross-sectional study was conducted in 2019 involving a total of 270 study participants recruited via purposive non-probability sampling technique. A structured questionnaire was used to collect data on sociodemographic characteristics, individual and household factors related to asymptomatic malaria. Data were entered in Epi Data 3.1 version and analyzed by using SPSS version 20, and p< 0.05 was considered statistically significant. Results The overall prevalence of asymptomatic malaria was 7.0%, with 3.0%, 5.2%, and 12.0%, respectively by Rapid diagnostic tests (RDT), Microscopy and Polymerase chain reaction (PCR). The majority of infections (73.7%) were identified from index households. Previous malaria history (AOR: 4.030, 95% CI: 1.021-15.903), living with index cases (AOR: 3.880, 95% CI: 1.275-11.806) and family size > 6 members (AOR: 4.820, 95% CI: 1.260-18.437) were significant predictors of asymptomatic malaria. Conclusion Reactive case detection had identified considerably higher asymptomatic malaria cases in the community. Therefore, active case investigation should be established in the community by tracking the symptomatic cases at the health facilities.
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Affiliation(s)
| | - Megbaru Alemu
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia
| | - Mulat Yimer
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia
| | | | - Tigist Tadele
- Department of Biomedical Sciences, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia
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11
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Tenfold difference in DNA recovery rate: systematic comparison of whole blood vs. dried blood spot sample collection for malaria molecular surveillance. Malar J 2022; 21:88. [PMID: 35292038 PMCID: PMC8922754 DOI: 10.1186/s12936-022-04122-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/07/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Molecular and genomic surveillance is becoming increasingly used to track malaria control and elimination efforts. Blood samples can be collected as whole blood and stored at - 20 °C until DNA extraction, or as dried blood spots (DBS), circumventing the need for a cold chain. Despite the wide use of either method, systematic comparisons of how the method of blood sample preservation affects the limit of detection (LOD) of molecular diagnosis and the proportion of DNA recovered for downstream applications are lacking. METHODS Extractions based on spin columns, magnetic beads, Tween-Chelex, and direct PCR without prior extraction were compared for whole blood and dried blood spots (DBS) using dilution series of Plasmodium falciparum culture samples. Extracted DNA was quantified by qPCR and droplet digital PCR (ddPCR). RESULTS DNA recovery was 5- to 10-fold higher for whole blood compared to DBS, resulting in a 2- to 3-fold lower LOD for both extraction methods compared to DBS. For whole blood, a magnetic bead-based method resulted in a DNA recovery rate of 88-98% when extracting from whole blood compared to 17-33% for a spin-column based method. For extractions from DBS, the magnetic bead-based method resulted in 8-20% DNA recovery, while the spin-column based method resulted in only 2% DNA recovery. The Tween-Chelex method was superior to other methods with 15-21% DNA recovery, and even more sensitive than extractions from whole blood samples. The direct PCR method was found to have the lowest LOD overall for both, whole blood and DBS. CONCLUSIONS Pronounced differences in LOD and DNA yield need to be considered when comparing prevalence estimates based on molecular methods and when selecting sampling protocols for other molecular surveillance applications.
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12
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Dharmaratne ADVTT, Dini S, O’Flaherty K, Price DJ, Beeson J, McGready R, Nosten F, Fowkes FJI, Simpson JA, Zaloumis SG. Quantification of the dynamics of antibody response to malaria to inform sero-surveillance in pregnant women. Malar J 2022; 21:75. [PMID: 35248084 PMCID: PMC8897879 DOI: 10.1186/s12936-022-04111-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 02/28/2022] [Indexed: 12/02/2022] Open
Abstract
Background Malaria remains a major public health threat and tools sensitive to detect infections in low malaria transmission areas are needed to progress elimination efforts. Pregnant women are particularly vulnerable to malaria infections. Throughout pregnancy they access routine antenatal care, presenting a unique sentinel population to apply novel sero-surveillance tools to measure malaria transmission. The aim of this study was to quantify the dynamic antibody responses to multiple antigens during pregnancy so as to identify a single or multiple antibody response of exposure to malaria in pregnancy. Methods This study involved a secondary analysis of antibody responses to six parasite antigens [five commonly studied merozoite antigens and the variant surface antigen 2-chondroitin sulphate A (VAR2CSA), a pregnancy-specific erythrocytic antigen] measured by enzyme-linked immunosorbent assay (ELISA) over the gestation period until delivery (median of 7 measurements/woman) in 250 pregnant women who attended antenatal clinics located at the Thai-Myanmar border. A multivariate mixture linear mixed model was used to cluster the pregnant women into groups that have similar longitudinal antibody responses to all six antigens over the gestational period using a Bayesian approach. The variable-specific entropy was calculated to identify the antibody responses that have the highest influence on the classification of the women into clusters, and subsequent agreement with grouping of women based on exposure to malaria during pregnancy. Results Of the 250 pregnant women, 135 had a Plasmodium infection detected by light microscopy during pregnancy (39% Plasmodium falciparum only, 33% Plasmodium vivax only and 28% mixed/other species), defined as cases. The antibody responses to all six antigens accurately identified the women who did not have a malaria infection detected during pregnancy (93%, 107/115 controls). Antibody responses to P. falciparum merozoite surface protein 3 (PfMSP3) and P. vivax apical membrane antigen 1 (PvAMA1) were the least dynamic. Antibody responses to the antigens P. falciparum apical membrane antigen 1 (PfAMA1) and PfVAR2CSA were able to identify the majority of the cases more accurately (63%, 85/135). Conclusion These findings suggest that the combination of antibodies, PfAMA1 and PfVAR2CSA, may be useful for sero-surveillance of malaria infections in pregnant women, particularly in low malaria transmission settings. Further investigation of other antibody markers is warranted considering these antibodies combined only detected 63% of the malaria infections during pregnancy. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04111-y.
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13
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A dataset and benchmark for malaria life-cycle classification in thin blood smear images. Neural Comput Appl 2022. [DOI: 10.1007/s00521-021-06602-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Yin J, Li M, Yan H, Zhou S, Xia Z. Laboratory diagnosis for malaria in the elimination phase in China: efforts and challenges. Front Med 2022; 16:10-16. [PMID: 35226298 PMCID: PMC8883009 DOI: 10.1007/s11684-021-0889-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/10/2021] [Indexed: 01/19/2023]
Abstract
Malaria remains a global health challenge, although an increasing number of countries will enter pre-elimination and elimination stages. The prompt and precise diagnosis of symptomatic and asymptomatic carriers of Plasmodium parasites is the key aspect of malaria elimination. Since the launch of the China Malaria Elimination Action Plan in 2010, China has formulated clear goals for malaria diagnosis and has established a network of malaria diagnostic laboratories within medical and health institutions at all levels. Various external quality assessments were implemented, and a national malaria diagnosis reference laboratory network was established to strengthen the quality assurance in malaria diagnosis. Notably, no indigenous malaria cases have been reported since 2017, but the risk of re-establishment of malaria transmission cannot be ignored. This review summarizes the lessons about malaria diagnosis in the elimination phase, primarily including the establishments of laboratory networks and quality control in China, to better improve malaria diagnosis and maintain a malaria-free status. A reference is also provided for countries experiencing malaria elimination.
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Affiliation(s)
- Jianhai Yin
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China.
| | - Mei Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China
| | - He Yan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China
| | - Shuisen Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China
| | - Zhigui Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai, 200025, China.
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15
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Pasaribu AP, Nasution IS, Sembiring K, Fahmi F, Pasaribu S. Comparison of the performance of the CareStart Malaria Pf/Pan Combo test and field microscopy in the diagnosis of Plasmodium vivax malaria in North Sumatera, Indonesia. Malar J 2022; 21:27. [PMID: 35093067 PMCID: PMC8800299 DOI: 10.1186/s12936-022-04057-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 01/19/2022] [Indexed: 11/23/2022] Open
Abstract
Background In areas where malaria is endemic and where trained microscopists are not available, rapid diagnostic tests (RDTs) are needed not only to allow prompt treatment without delay but also to prevent overdiagnosis and overtreatment based on clinical judgements that may lead to drug resistance. This study aimed to compare the performances of the CareStart Pf/Pan Combo test to field microscopy, which is considered to be the gold standard for malaria diagnosis. Methods Any person with a fever or a history of fever within 48 h who came to the health centre was recruited for the study and tested both by the CareStart Pf/Pan test and by field microscopy. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were analysed with both methods. Results Two-hundred study participants were enrolled: 96 (48%) were found to be positive through microscopy, while 100 (50%) participants were found to be positive through RDT. The RDT produced four false-positive results. High sensitivity and specificity were observed for the CareStart Pf/Pan test (100 and 96.15%, respectively). The CareStart Pf/Pan test also showed excellent agreement with the field microscopy results. Conclusion The Carestart Pf/Pan could be used as an alternative diagnostic test in malaria-endemic areas where facility for performing microscopy is not available.
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Laboratory Detection of Malaria Antigens: a Strong Tool for Malaria Research, Diagnosis, and Epidemiology. Clin Microbiol Rev 2021; 34:e0025020. [PMID: 34043447 DOI: 10.1128/cmr.00250-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The identification and characterization of proteins produced during human infection with Plasmodium spp. have guided the malaria community in research, diagnosis, epidemiology, and other efforts. Recently developed methods for the detection of these proteins (antigens) in the laboratory have provided new types of data that can inform the evaluation of malaria diagnostics, epidemiological investigations, and overall malaria control strategies. Here, the focus is primarily on antigens that are currently known to be detectable in human specimens and on their impact on the understanding of malaria in human populations. We highlight historical and contemporary laboratory assays for malaria antigen detection, the concept of an antigen profile for a biospecimen, and ways in which binary results for a panel of antigens could be interpreted and utilized for different analyses. Particular emphasis is given to the direct comparison of field-level malaria diagnostics and laboratory antigen detection for the development of an external evaluation scheme. The current limitations of laboratory antigen detection are considered, and the future of this developing field is discussed.
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Mahittikorn A, Masangkay FR, Kotepui KU, De Jesus Milanez G, Kotepui M. Comparative performance of PCR using DNA extracted from dried blood spots and whole blood samples for malaria diagnosis: a meta-analysis. Sci Rep 2021; 11:4845. [PMID: 33649410 PMCID: PMC7921648 DOI: 10.1038/s41598-021-83977-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 02/10/2021] [Indexed: 11/24/2022] Open
Abstract
Polymerase chain reaction (PCR) using deoxyribonucleic acid (DNA) extracted from dried blood spots (DBS) provides a fast, inexpensive, and convenient method for large-scale epidemiological studies. This study compared the performance of PCR between DNA extracted from DBS and DNA obtained from whole blood for detecting malarial parasites. Primary studies assessing the diagnostic performance of PCR using DNA extracted from DBS and whole blood for detecting malarial parasites were obtained from the ISI Web of Science, Scopus, and PubMed databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were plotted in forest plots using Review Manager version 5.3. Statistical analysis was performed via random-effects meta-analysis. Data heterogeneity was assessed using the I2 statistic. Of the 904 studies retrieved from the databases, seven were included in this study. The pooled meta-analysis demonstrated no significant difference in the comparative performance of PCR for detecting malaria parasites between DNA extracted from DBS and that extracted from whole blood (OR 0.85; 95% CI 0.62–1.16; I2 = 78%). However, subgroup analysis demonstrated that PCR using DNA extracted from DBS was less accurate in detecting Plasmodium vivax than that using DNA extracted from whole blood (OR = 0.85; 95% CI 0.77–0.94). In conclusion, a significant difference in detecting P. vivax was observed between PCR using DNA extracted from DBS and that using DNA extracted from whole blood. Therefore, P. vivax in endemic areas should be identified and detected with care with PCR using DNA obtained from DBS which potentially leads to a negative result. Further studies are required to investigate the performance of PCR using DBS for detecting P. vivax and other malarial parasites to provide data in research and routine surveillance of malaria, especially with renewed efforts towards the eradication of the disease.
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Affiliation(s)
- Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Frederick Ramirez Masangkay
- Department of Medical Technology, Institute of Arts and Sciences, Far Eastern University-Manila, Manila, Philippines
| | - Kwuntida Uthaisar Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Giovanni De Jesus Milanez
- Department of Medical Technology, Institute of Arts and Sciences, Far Eastern University-Manila, Manila, Philippines
| | - Manas Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand.
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Magneto-optical diagnosis of symptomatic malaria in Papua New Guinea. Nat Commun 2021; 12:969. [PMID: 33579923 PMCID: PMC7881035 DOI: 10.1038/s41467-021-21110-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 01/07/2021] [Indexed: 11/20/2022] Open
Abstract
Improved methods for malaria diagnosis are urgently needed. Here, we evaluate a novel method named rotating-crystal magneto-optical detection (RMOD) in 956 suspected malaria patients in Papua New Guinea. RMOD tests can be conducted within minutes and at low cost. We systematically evaluate the capability of RMOD to detect infections by directly comparing it with expert light microscopy, rapid diagnostic tests and polymerase chain reaction on capillary blood samples. We show that compared to light microscopy, RMOD exhibits 82% sensitivity and 84% specificity to detect any malaria infection and 87% sensitivity and 88% specificity to detect Plasmodium vivax. This indicates that RMOD could be useful in P. vivax dominated elimination settings. Parasite density correlates well with the quantitative magneto-optical signal. Importantly, residual hemozoin present in malaria-negative patients is also detectable by RMOD, indicating its ability to detect previous infections. This could be exploited to reveal transmission hotspots in low-transmission settings. Here Arndt et al. establish rotating-crystal magneto-optical detection (RMOD) as a near-point-of-care diagnostic tool for malaria detection and report a sensitivity and specificity of 82% and 84%, respectively, as validated by analyzing a clinical population in a high transmission setting in Papua New Guinea.
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Jiang K, Jokhun DS, Lim CT. Microfluidic detection of human diseases: From liquid biopsy to COVID-19 diagnosis. J Biomech 2021; 117:110235. [PMID: 33486262 PMCID: PMC7832952 DOI: 10.1016/j.jbiomech.2021.110235] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 01/04/2021] [Indexed: 12/12/2022]
Abstract
Microfluidic devices can be thought of as comprising interconnected miniaturized compartments performing multiple experimental tasks individually or in parallel in an integrated fashion. Due to its small size, portability, and low cost, attempts have been made to incorporate detection assays into microfluidic platforms for diseases such as cancer and infection. Some of these technologies have served as point-of-care and sample-to-answer devices. The methods for detecting biomarkers in different diseases usually share similar principles and can conveniently be adapted to cope with arising health challenges. The COVID-19 pandemic is one such challenge that is testing the performance of both our conventional and newly-developed disease diagnostic technologies. In this mini-review, we will first look at the progress made in the past few years in applying microfluidics for liquid biopsy and infectious disease detection. Following that, we will use the current pandemic as an example to discuss how such technological advancements can help in the current health challenge and better prepare us for future ones.
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Affiliation(s)
- Kuan Jiang
- Mechanobiology Institute, National University of Singapore, Singapore
| | | | - Chwee Teck Lim
- Mechanobiology Institute, National University of Singapore, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore; Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore.
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20
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Mudare N, Matsena-Zingoni Z, Makuwaza A, Mamini E, Munyati SS, Gwanzura L, Midzi N, Mutambu SL, Mason P, Kobayashi T, Mharakurwa S. Detecting Plasmodium falciparum in community surveys: a comparison of Paracheck Pf® Test and ICT Malaria Pf® Cassette Test to polymerase chain reaction in Mutasa District, Zimbabwe. Malar J 2021; 20:14. [PMID: 33407488 PMCID: PMC7789522 DOI: 10.1186/s12936-020-03536-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/07/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Microscopy and rapid diagnostic tests (RDTs) are the main techniques used to diagnose malaria. While microscopy is considered the gold standard, RDTs have established popularity as they allow for rapid diagnosis with minimal technical skills. This study aimed to compare the diagnostic performance of two Plasmodium falciparum histidine-rich protein 2 (PfHRP2)-based RDTs (Paracheck Pf® Test (Paracheck) and Malaria Pf™ ICT (ICT)) to polymerase chain reaction (PCR) in a community survey. METHODS A cross-sectional study was conducted between October 2012 and December 2014 in Mutasa District, Manicaland Province, eastern Zimbabwe. Households were randomly selected using satellite imagery, and 224 households were visited. Residents present in the household on the date of the visit were recruited for the study. Participants of all age groups from the selected households were screened with Paracheck and ICT RDTs in parallel. Dried blood spots (DBS) and thin and thick smears were collected. Parasite DNA extracted from the DBS was subjected to nested PCR targeting the Plasmodium cytochrome b mitochondrial gene. Data analysis was performed using the Cohen's Kappa test to determine the interrater agreement and the sensitivity and specificity of the diagnostic test were reported. RESULTS Results from a total of 702 participants were analysed. Most were females, 397 (57%), and the median age of participants was 21 years with an interquartile range of 9-39 years. Of those who were screened, 8 (1.1%), 35 (5.0%), and 21 (2.9%) were malaria parasite positive by microscopy, RDT and PCR, respectively. Paracheck and ICT RDTs had a 100% agreement. Comparing RDT and PCR results, 34 participants (4.8%) had discordant results. Most of the discordant cases were RDT positive but PCR negative (n = 24). Half of those RDT positive, but PCR negative individuals reported anti-malarials to use in the past month, which is significantly higher than reported anti-malarial drug use in the population (p < 0.001). The participant was febrile on the day of the visit, but relying on PfHRP2-based RDT would miss this case. Among the diagnostic methods evaluated, with reference to PCR, the sensitivity was higher with the RDT (52.4%) while specificity was higher with the microscopy (99.9%). The positive predictive value (PPV) was higher with the microscopy (87.5%), while the negative predictive values were similar for both microscopy and RDTs (98%). Overall, a strong correlated agreement with PCR was observed for the microscopy (97.9%) and the RDTs (95.2%). CONCLUSIONS Paracheck and ICT RDTs showed 100% agreement and can be used interchangeably. As malaria transmission declines and Zimbabwe aims to reach malaria elimination, management of infected individuals with low parasitaemia as well as non-P. falciparum infection can be critical.
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Affiliation(s)
| | | | | | - Edmore Mamini
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | | | - Lovemore Gwanzura
- Biomedical Research and Training Institute, Harare, Zimbabwe.,University of Zimbabwe, College of Health Sciences, Institute of Continuing Health Education, Harare, Zimbabwe
| | | | | | - Peter Mason
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Tamaki Kobayashi
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Sungano Mharakurwa
- Africa University, Mutare, Zimbabwe. .,Biomedical Research and Training Institute, Harare, Zimbabwe.
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Ultrasensitive CRISPR-based diagnostic for field-applicable detection of Plasmodium species in symptomatic and asymptomatic malaria. Proc Natl Acad Sci U S A 2020; 117:25722-25731. [PMID: 32958655 PMCID: PMC7568265 DOI: 10.1073/pnas.2010196117] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Detection of submicroscopic malaria in asymptomatic individuals is needed for eradication and remains a diagnostic gap in resource-limited settings. Nonfalciparum clinical diagnostics are a second gap, as these infections have a low parasite density and are commonly undetected. We describe an integrated, 60-min, ultrasensitive and specific CRISPR-based diagnostic for the four major pathogenic Plasmodium species that can fill these gaps. Using the SHERLOCK (specific high-sensitivity enzymatic reporter unlocking) platform, we designed assays with limits of detection below that recommended by the World Health Organization. These assays have a simplified sample preparation method: the SHERLOCK parasite rapid extraction protocol, which eliminates complicated nucleic acid extraction steps. Our work further translates the SHERLOCK platform into a field-deployable diagnostic. Asymptomatic carriers of Plasmodium parasites hamper malaria control and eradication. Achieving malaria eradication requires ultrasensitive diagnostics for low parasite density infections (<100 parasites per microliter blood) that work in resource-limited settings (RLS). Sensitive point-of-care diagnostics are also lacking for nonfalciparum malaria, which is characterized by lower density infections and may require additional therapy for radical cure. Molecular methods, such as PCR, have high sensitivity and specificity, but remain high-complexity technologies impractical for RLS. Here we describe a CRISPR-based diagnostic for ultrasensitive detection and differentiation of Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae, using the nucleic acid detection platform SHERLOCK (specific high-sensitivity enzymatic reporter unlocking). We present a streamlined, field-applicable, diagnostic comprised of a 10-min SHERLOCK parasite rapid extraction protocol, followed by SHERLOCK for 60 min for Plasmodium species-specific detection via fluorescent or lateral flow strip readout. We optimized one-pot, lyophilized, isothermal assays with a simplified sample preparation method independent of nucleic acid extraction, and showed that these assays are capable of detection below two parasites per microliter blood, a limit of detection suggested by the World Health Organization. Our P. falciparum and P. vivax assays exhibited 100% sensitivity and specificity on clinical samples (5 P. falciparum and 10 P. vivax samples). This work establishes a field-applicable diagnostic for ultrasensitive detection of asymptomatic carriers as well as a rapid point-of-care clinical diagnostic for nonfalciparum malaria species and low parasite density P. falciparum infections.
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Nega D, Abebe A, Abera A, Gidey B, G/Tsadik A, Tasew G. Comprehensive competency assessment of malaria microscopists and laboratory diagnostic service capacity in districts stratified for malaria elimination in Ethiopia. PLoS One 2020; 15:e0235151. [PMID: 32584866 PMCID: PMC7316265 DOI: 10.1371/journal.pone.0235151] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 06/09/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Federal Ministry of Health (FMoH) Ethiopia achieved significant declines in malaria mortality and incidence and has recently launched malaria elimination in selected low transmission settings. Successful malaria elimination calls for rapid and accurate diagnosis of cases so that the patients can promptly be treated before the occurrence of transmission. Therefore, this study assessed the competency of malaria microscopists using panal slides, and laboratory service availability and readiness in terms of supplies and equipments in malaria elimination targeted districts in Ethiopia. METHOD A cross-sectional study was conducted from February to June 2018 in all hospitals, health centers and private clinics in 20 malaria elimination targeted districts, selected out of the 6 regional states in Ethiopia. All malaria microscopists available in the study health facilities during the study period were included in the study. Questionnaires were used for interviewing sociodemography of personnel and laboratory supplies. Per World Health Organization (WHO) criteria set for proficiency testing, 10 Giemsa stained malaria slide panels (8 positive low/high density pf/pv/Mixed and 2 negative slides) were administered to each study participant for performance assessment on malaria parasite detection, species identification and parasite count using light microscopy. The slide panels are PCR confirmed and WHO approved ones, which have been stored in the slide banks at the national reference laboratory in Ethiopian Public Health Institute. RESULT In this assessment, 17(16%) district hospitals, 71(67%) health centers (HCs) and 18(17%) private clinics (PCs) were included. Of the 18 PCs, only 10(55.6%) had license certificate. Of the study facilities, 91.5%(97) use light microscopy, 2.83%(3) use RDTs and 2.9%(3) use both microscopy and RDT to detect malaria. Accessible and appropriate storage of Giemsa was reported by 58.8%(10) hospitals, 81.7%(58) HCs & 72.2%(13) private clinics. Of the 1896 malaria positive & 474 negative slides administered to 237 study participants, 318(16.8%) slides reported falsely negative & 47(9.9%) reported falsely positive. The participants achieved "good" grade [Agreement(A): 84.6%, Kappa(K): 0.6] on parasite detection and "poor" agreement (A: 43.8%; K: 0.11) on every species identification. No or slight agreement seen on differentiation of P. falciparum from other species (A: 28.41%; K:0.29). Above 95%(201) of participants, did not count or used plus system of parasite estimation which is the least accurate and unreccomended method per WHO guideline. CONCLUSION In the current study, low performance of malaria microscopists particularly in species identification & poor to moderate capacity of laboratories observed. This is really a great obstacle to malaria elimination strategy of the country. Therefore, national malaria control and elimination program in collaboration with partners is supposed to provide comprehensive training for professionals giving laboratory service and to fulfill laboratory supplies to have the gold standard service.
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Affiliation(s)
- Desalegn Nega
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Abnet Abebe
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Adugna Abera
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Abeba G/Tsadik
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Geremew Tasew
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
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Survey of asymptomatic malaria and mosquito vectors in Muang Khua District of Phongsaly Province, China-Laos Border. Int J Infect Dis 2020; 96:141-147. [PMID: 32251803 DOI: 10.1016/j.ijid.2020.03.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/22/2020] [Accepted: 03/25/2020] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES The China-Laos border has been identified as an important origin of imported malaria outside China. The aim of this study was to describe the asymptomatic malaria infections and epidemic trend of malaria in the China-Laos border region. METHODS A prevalence survey and surveillance of mosquito vectors was conducted in Muang Khua District of Phongsaly Province, China-Laos border, to determine the parasite carriage rate using nested PCR and microscopy. The species composition of malaria vectors was determined by overnight trapping. Blood samples were collected from 354 local residents aged 1-72 years in Sankang village in 2016. A total of 2430 adult mosquitoes were collected from four other villages in Muang Khua District from June to August 2016. RESULTS The parasite carriage rate was 7.63% (27/354) by microscopy or 7.91% (28/354) by nested PCR. The results of surveillance of the mosquito vectors revealed that the predominant genera of adult mosquitoes were Culex (69.92%, 1699/2430) and Anopheles (21.48%, 522/2430). Anopheles sinensis (82.95%, 433/522) was identified as the predominant species among the seven members of Anopheles found in this border region. CONCLUSIONS A high prevalence of asymptomatic malaria was present and the most important malaria vector was Anopheles sinensis, suggesting that the malaria epidemic situation on the China-Laos border is serious.
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Krampa FD, Aniweh Y, Kanyong P, Awandare GA. Recent Advances in the Development of Biosensors for Malaria Diagnosis. SENSORS (BASEL, SWITZERLAND) 2020; 20:E799. [PMID: 32024098 PMCID: PMC7038750 DOI: 10.3390/s20030799] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/19/2019] [Accepted: 12/24/2019] [Indexed: 02/07/2023]
Abstract
The impact of malaria on global health has continually prompted the need to develop more effective diagnostic strategies that could overcome deficiencies in accurate and early detection. In this review, we examine the various biosensor-based methods for malaria diagnostic biomarkers, namely; Plasmodium falciparum histidine-rich protein 2 (PfHRP-2), parasite lactate dehydrogenase (pLDH), aldolase, glutamate dehydrogenase (GDH), and the biocrystal hemozoin. The models that demonstrate a potential for field application have been discussed, looking at the fabrication and analytical performance characteristics, including (but not exclusively limited to): response time, sensitivity, detection limit, linear range, and storage stability, which are first summarized in a tabular form and then described in detail. The conclusion summarizes the state-of-the-art technologies applied in the field, the current challenges and the emerging prospects for malaria biosensors.
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Affiliation(s)
- Francis D. Krampa
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 25, Legon, Accra, Ghana; (Y.A.); (P.K.); (G.A.A.)
- Department of Biochemistry, Cell & Molecular Biology, University of Ghana, P.O. Box LG 54, Legon, Accra, Ghana
| | - Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 25, Legon, Accra, Ghana; (Y.A.); (P.K.); (G.A.A.)
| | - Prosper Kanyong
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 25, Legon, Accra, Ghana; (Y.A.); (P.K.); (G.A.A.)
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, P.O. Box LG 25, Legon, Accra, Ghana; (Y.A.); (P.K.); (G.A.A.)
- Department of Biochemistry, Cell & Molecular Biology, University of Ghana, P.O. Box LG 54, Legon, Accra, Ghana
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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.
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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.
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Morgan AP, Brazeau NF, Ngasala B, Mhamilawa LE, Denton M, Msellem M, Morris U, Filer DL, Aydemir O, Bailey JA, Parr JB, Mårtensson A, Bjorkman A, Juliano JJ. Falciparum malaria from coastal Tanzania and Zanzibar remains highly connected despite effective control efforts on the archipelago. Malar J 2020; 19:47. [PMID: 31992305 PMCID: PMC6988337 DOI: 10.1186/s12936-020-3137-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/22/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tanzania's Zanzibar archipelago has made significant gains in malaria control over the last decade and is a target for malaria elimination. Despite consistent implementation of effective tools since 2002, elimination has not been achieved. Importation of parasites from outside of the archipelago is thought to be an important cause of malaria's persistence, but this paradigm has not been studied using modern genetic tools. METHODS Whole-genome sequencing (WGS) was used to investigate the impact of importation, employing population genetic analyses of Plasmodium falciparum isolates from both the archipelago and mainland Tanzania. Ancestry, levels of genetic diversity and differentiation, patterns of relatedness, and patterns of selection between these two populations were assessed by leveraging recent advances in deconvolution of genomes from polyclonal malaria infections. RESULTS Significant decreases in the effective population sizes were inferred in both populations that coincide with a period of decreasing malaria transmission in Tanzania. Identity by descent analysis showed that parasites in the two populations shared long segments of their genomes, on the order of 5 cM, suggesting shared ancestry within the last 10 generations. Even with limited sampling, two of isolates between the mainland and Zanzibar were identified that are related at the expected level of half-siblings, consistent with recent importation. CONCLUSIONS These findings suggest that importation plays an important role for malaria incidence on Zanzibar and demonstrate the value of genomic approaches for identifying corridors of parasite movement to the island.
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Affiliation(s)
- Andrew P Morgan
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Nicholas F Brazeau
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Billy Ngasala
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - 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
| | - Madeline Denton
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Mwinyi Msellem
- Training and Research, Mnazi Mmoja Hospital, Zanzibar, Tanzania
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Dayne L Filer
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Ozkan Aydemir
- Department of Laboratory Medicine and Pathology, Brown University, Providence, RI, 02912, USA
| | - Jeffrey A Bailey
- Department of Laboratory Medicine and Pathology, Brown University, Providence, RI, 02912, USA
| | - Jonathan B Parr
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
| | - Anders Bjorkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Jonathan J Juliano
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA.
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
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Canavati SE, Kelly GC, Quintero CE, Vo TH, Tran LK, Ohrt C, Ngo TD, Tran DT, Martin NJ. Risk factor assessment for clinical malaria among forest-goers in a pre-elimination setting in Phu Yen Province, Vietnam. Malar J 2019; 18:435. [PMID: 31861988 PMCID: PMC6923829 DOI: 10.1186/s12936-019-3068-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Accepted: 12/09/2019] [Indexed: 11/13/2022] Open
Abstract
Background The transition from malaria control to elimination requires understanding and targeting interventions among high-risk populations. In Vietnam, forest-goers are often difficult to test, treat and follow-up for malaria because they are highly mobile. If undiagnosed, forest-goers can maintain parasite reservoirs and contribute to ongoing malaria transmission. Methods A case–control study was conducted to identify malaria risk factors associated with forest-goers in three communes in Phu Yen Province, Vietnam. Cases (n = 81) were residents from the study area diagnosed with malaria and known to frequent forest areas. Controls (n = 94) were randomly selected forest-going residents from within the study area with no identified malaria infection. Participants were interviewed face-to-face using a standard questionnaire to identify malaria risk factors. Logistic regression was used to calculate odds ratios (ORs) and 95% CI for risk factors after adjusting for socio-demographic characteristics. Results Among the cases, malaria infection varied by species: 66.7% were positive for Plasmodium falciparum, 29.6% for Plasmodium vivax, and 3.7% were diagnosed as mixed infection. Cases were less likely than controls to use treated nets (aOR = 0.31; 95% CI 0.12–0.80), work after dark (aOR = 2.93; 95% CI 1.35, 6.34), bath in a stream after dark (aOR = 2.44; 95% CI 1.02–5.88), and collect water after dark (aOR = 1.99; 95% CI 1.02–3.90). Conclusions As Vietnam moves toward malaria elimination, these findings can inform behaviour change communication and malaria prevention strategies, incorporating the risk of after-dark and water-related activities, in this priority and difficult-to-access population group.
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Affiliation(s)
- Sara E Canavati
- Vysnova Partners, Inc., 4915 St. Elmo Ave., Bethesda, 20814, USA
| | - Gerard C Kelly
- Vysnova Partners, Inc., 4915 St. Elmo Ave., Bethesda, 20814, USA
| | - Cesia E Quintero
- Vysnova Partners, Inc., 4915 St. Elmo Ave., Bethesda, 20814, USA
| | - Thuan Huu Vo
- Vysnova Partners, Inc., 4915 St. Elmo Ave., Bethesda, 20814, USA
| | - Long Khanh Tran
- Vysnova Partners, Inc., 4915 St. Elmo Ave., Bethesda, 20814, USA
| | - Colin Ohrt
- Vysnova Partners, Inc., 4915 St. Elmo Ave., Bethesda, 20814, USA
| | - Thang Duc Ngo
- National Institute of Malariology, Parasitology and Entomology, 35 Trung Van, Hanoi, Vietnam
| | - Duong Thanh Tran
- National Institute of Malariology, Parasitology and Entomology, 35 Trung Van, Hanoi, Vietnam
| | - Nicholas J Martin
- Naval Medical Research Unit TWO, PSA Sembawang Deptford Rd., Building 7-4, Singapore, 759657, Singapore.
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Mukherjee D, Chora ÂF, Mota MM. Microbiota, a Third Player in the Host-Plasmodium Affair. Trends Parasitol 2019; 36:11-18. [PMID: 31787522 DOI: 10.1016/j.pt.2019.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 11/01/2019] [Accepted: 11/01/2019] [Indexed: 12/14/2022]
Abstract
Plasmodium, the causative agent of malaria, is responsible for more than 200 million new infections and 400 000 deaths yearly. While in recent years the influence of the microbiota in homeostasis and a wide variety of disorders has taken center stage, its contribution during malaria infections has only now started to emerge. The few published studies suggest two distinct but complementary directions. Plasmodium infections can cause significant alterations in host (at least gut) microbiota, and host gut microbiota can influence the clinical outcome of malaria infections. In this opinion article, we highlight the most fundamental unanswered questions in the field that will, hopefully, point future research directions towards unveiling key mechanistic insights of the Plasmodium-host-microbiota axis.
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Affiliation(s)
- Debanjan Mukherjee
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal.
| | - Ângelo Ferreira Chora
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Maria M Mota
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal.
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Ultrasensitive and label-free biosensor for the detection of Plasmodium falciparum histidine-rich protein II in saliva. Sci Rep 2019; 9:17495. [PMID: 31767887 PMCID: PMC6877566 DOI: 10.1038/s41598-019-53852-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/06/2019] [Indexed: 11/08/2022] Open
Abstract
Malaria elimination is a global public health priority. To fulfil the demands of elimination diagnostics, we have developed an interdigitated electrode sensor platform targeting the Plasmodium falciparum Histidine Rich Protein 2 (PfHRP2) protein in saliva samples. A protocol for frequency-specific PfHRP2 detection in phosphate buffered saline was developed, yielding a sensitivity of 2.5 pg/mL based on change in impedance magnitude of the sensor. This protocol was adapted and optimized for use in saliva with a sensitivity of 25 pg/mL based on change in resistance. Further validation demonstrated detection in saliva spiked with PfHRP2 from clinical isolates in 8 of 11 samples. With a turnaround time of ~2 hours, the label-free platform based on impedance sensors has the potential for miniaturization into a point-of-care diagnostic device for malaria elimination.
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Bendezu J, Villasis E, Morales Ruiz S, Garro K, Infante B, Gutierrez-Loli R, Rodríguez P, Fernández-Díaz M, Gamboa D, Torres K. Evaluation of Plasmodium falciparum MSP10 and its development as a serological tool for the Peruvian Amazon region. Malar J 2019; 18:327. [PMID: 31547821 PMCID: PMC6757379 DOI: 10.1186/s12936-019-2959-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 09/11/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Different antigens are needed to characterize Plasmodium falciparum infection in terms of seroreactivity and targets for invasion inhibition, in order to guide and identify the proper use of such proteins as tools for the development of serological markers and/or as vaccine candidates. METHODS IgG responses in 84 serum samples from individuals with P. falciparum infection [classified as symptomatic (Sym) or asymptomatic (Asym)], or acute Plasmodium vivax infection, from the Peruvian Amazon region, were evaluated by enzyme-linked immunosorbent assays specific for a baculovirus-produced recombinant protein P. falciparum Merozoite Surface Protein 10 (rMSP10) and for non-EGF region selected peptides of PfMSP10 selected by a bioinformatics tool (PfMSP10-1, PfMSP10-2 and PfMSP10-3). Monoclonal antibodies against the selected peptides were evaluated by western blotting, confocal microscopy and inhibition invasion assays. RESULTS Seroreactivity analysis of the P. falciparum Sym- and Asym-infected individuals against rMSP10 showed a higher response as compared to the individuals with P. vivax acute infection. IgG responses against peptide PfMSP10-1 were weak. Interestingly high IgG response was found against peptide PfMSP10-2 and the combination of peptides PfMSP10-1 + PfMSP10-2. Monoclonal antibodies were capable of detecting native PfMSP10 on purified schizonts by western blot and confocal microscopy. A low percentage of inhibition of merozoite invasion of erythrocytes in vitro was observed when the monoclonal antibodies were compared with the control antibody against AMA-1 antigen. Further studies are needed to evaluate the role of PfMSP10 in the merozoite invasion. CONCLUSIONS The rMSP10 and the PfMSP10-2 peptide synthesized for this study may be useful antigens for evaluation of P. falciparum malaria exposure in Sym and Asym individuals from the Peruvian Amazon region. Moreover, these antigens can be used for further investigation of the role of this protein in other malaria-endemic areas.
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Affiliation(s)
- Jorge Bendezu
- Laboratorios de Investigación y Desarrollo, FARVET, Carretera Panamericana Sur No 766 km 198.5, Chincha Alta, Ica, Peru.
| | - Elizabeth Villasis
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicina Tropical Alexander von Humboldt-Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru
| | - Sandra Morales Ruiz
- Laboratorios de Investigación y Desarrollo, FARVET, Carretera Panamericana Sur No 766 km 198.5, Chincha Alta, Ica, Peru
| | - Katherine Garro
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Berónica Infante
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Renzo Gutierrez-Loli
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Pamela Rodríguez
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Manolo Fernández-Díaz
- Laboratorios de Investigación y Desarrollo, FARVET, Carretera Panamericana Sur No 766 km 198.5, Chincha Alta, Ica, Peru
| | - Dionicia Gamboa
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicina Tropical Alexander von Humboldt-Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru
| | - Katherine Torres
- Laboratorios de Investigación y Desarrollo "Abraham Vaisberg Wolach, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru.
- Instituto de Medicina Tropical Alexander von Humboldt-Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, Peru.
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Rampazzo RC, Graziani AC, Leite KK, Surdi JA, Biondo CA, Costa ML, Jacomasso T, Cereda M, De Fazio M, Bianchessi MA, Moreira OC, Britto C, Costa JD, Góes VM, da Silva AJ, Krieger MA, Costa AD. Proof of Concept for a Portable Platform for Molecular Diagnosis of Tropical Diseases. J Mol Diagn 2019; 21:839-851. [DOI: 10.1016/j.jmoldx.2019.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/05/2019] [Accepted: 04/30/2019] [Indexed: 02/08/2023] Open
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Mwesigwa J, Slater H, Bradley J, Saidy B, Ceesay F, Whittaker C, Kandeh B, Nkwakamna D, Drakeley C, Van Geertruyden JP, Bousema T, Achan J, D’Alessandro U. Field performance of the malaria highly sensitive rapid diagnostic test in a setting of varying malaria transmission. Malar J 2019; 18:288. [PMID: 31455349 PMCID: PMC6712604 DOI: 10.1186/s12936-019-2929-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/22/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The Gambia has successfully reduced malaria transmission. The human reservoir of infection could further decrease if malaria-infected individuals could be identified by highly sensitive, field-based, diagnostic tools and then treated. METHODS A cross-sectional survey was done at the peak of the 2017 malaria season in 47 Gambian villages. From each village, 100 residents were randomly selected for finger-prick blood samples to detect Plasmodium falciparum infections using highly sensitive rapid diagnostic tests (HS-RDT) and PCR. The sensitivity and specificity of the HS-RDT were estimated (assuming PCR as the gold standard) across varying transmission intensities and in different age groups. A deterministic, age-structured, dynamic model of malaria transmission was used to estimate the impact of mass testing and treatment (MTAT) with HS-RDT in four different scenarios of malaria prevalence by PCR: 5, 15, 30, and 60%, and with seasonal transmission. The impact was compared both to MTAT with conventional RDT and mass drug administration (MDA). RESULTS Malaria prevalence by HS-RDT was 15% (570/3798; 95% CI 13.9-16.1). The HS-RDT sensitivity and specificity were 38.4% (191/497, 95% CI 34.2-42.71) and 88.5% (2922/3301; 95% CI 87.4-89.6), respectively. Sensitivity was the highest (50.9%, 95% CI 43.3-58.5%) in high prevalence villages (20-50% by PCR). The model predicted that in very low transmission areas (≤ 5%), three monthly rounds of MTAT with HS-RDT, starting towards the end of the dry season and testing 65 or 85% of the population for 2 consecutive years, would avert 62 or 78% of malaria cases (over 2 years), respectively. The effect of the intervention would be lower in a moderate transmission setting. In all settings, MDA would be superior to MTAT with HS-RDT which would be superior to MTAT with conventional RDT. CONCLUSION The HS-RDT's field sensitivity was modest and varied by transmission intensity. In low to very low transmission areas, three monthly rounds per year of MTAT with HS-RDT at 85% coverage for 2 consecutive years would reduce malaria prevalence to such low levels that additional strategies may achieve elimination. The model prediction would need to be confirmed by cluster-randomized trials.
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Affiliation(s)
- Julia Mwesigwa
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Hannah Slater
- 0000 0001 2113 8111grid.7445.2MRC Centre for Global Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, Norfolk Place, London, W2 1P UK ,0000 0000 8940 7771grid.415269.dPATH, 2201 Westlake Avenue, Seattle, USA
| | - John Bradley
- 0000 0004 0425 469Xgrid.8991.9MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | - Binta Saidy
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Fatima Ceesay
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Charles Whittaker
- 0000 0001 2113 8111grid.7445.2MRC Centre for Global Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, Norfolk Place, London, W2 1P UK
| | | | - Davis Nkwakamna
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Chris Drakeley
- 0000 0004 0425 469Xgrid.8991.9Department of Immunology and Infection, Faculty of Infectious Diseases and Tropical Medicine, London School of Hygiene and Tropical Medicine, London, UK
| | - Jean-Pierre Van Geertruyden
- 0000 0001 0790 3681grid.5284.bFaculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Teun Bousema
- 0000 0004 0444 9382grid.10417.33Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jane Achan
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
| | - Umberto D’Alessandro
- 0000 0004 0606 294Xgrid.415063.5Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, P.O. Box 273, Banjul, The Gambia
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Budge PJ, Odom John AR. The Longest Mile: Moving Malaria from Clinical Care to Elimination of Transmission. Clin Chem 2019; 65:946-948. [PMID: 31171527 DOI: 10.1373/clinchem.2019.303719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 05/07/2019] [Indexed: 11/06/2022]
Affiliation(s)
- Philip J Budge
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, MO
| | - Audrey R Odom John
- Departments of Pediatrics and Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO.
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Low YK, Chan J, Soraya GV, Buffet C, Abeyrathne CD, Huynh DH, Skafidas E, Kwan P, Rogerson SJ. Development of an Ultrasensitive Impedimetric Immunosensor Platform for Detection of Plasmodium Lactate Dehydrogenase. SENSORS 2019; 19:s19112446. [PMID: 31146340 PMCID: PMC6603725 DOI: 10.3390/s19112446] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/17/2019] [Accepted: 05/22/2019] [Indexed: 11/20/2022]
Abstract
Elimination of malaria is a global health priority. Detecting an asymptomatic carrier of Plasmodium parasites to receive treatment is an important step in achieving this goal. Current available tools for detection of malaria parasites are either expensive, lacking in sensitivity for asymptomatic carriers, or low in throughput. We investigated the sensitivity of an impedimetric biosensor targeting the malaria biomarker Plasmodium lactate dehydrogenase (pLDH). Following optimization of the detection protocol, sensor performance was tested using phosphate-buffered saline (PBS), and then saliva samples spiked with pLDH at various concentrations. The presence of pLDH was determined by analyzing the sensor electrical properties before and after sample application. Through comparing percentage changes in impedance magnitude, the sensors distinguished pLDH-spiked PBS from non-spiked PBS at concentrations as low as 250 pg/mL (p = 0.0008). Percentage changes in impedance magnitude from saliva spiked with 2.5 ng/mL pLDH trended higher than those from non-spiked saliva. These results suggest that these biosensors have the potential to detect concentrations of pLDH up to two logs lower than currently available best-practice diagnostic tools. Successful optimization of this sensor platform would enable more efficient diagnosis of asymptomatic carriers, who can be targeted for treatment, contributing to the elimination of malaria.
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Affiliation(s)
- Yu Kong Low
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, 792 Elizabeth Street, Melbourne, VIC 3000, Australia.
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3050, Australia.
| | - Jianxiong Chan
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3050, Australia.
| | - Gita V Soraya
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3050, Australia.
- Department of Biochemistry, Faculty of Medicine, Hasanuddin University, Makassar 90245, Indonesia.
| | - Christelle Buffet
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, 792 Elizabeth Street, Melbourne, VIC 3000, Australia.
| | - Chathurika D Abeyrathne
- Department of Electrical and Electronic Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
| | - Duc H Huynh
- Department of Electrical and Electronic Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
| | - Efstratios Skafidas
- Department of Electrical and Electronic Engineering, Melbourne School of Engineering, The University of Melbourne, Victoria 3010, Australia.
| | - Patrick Kwan
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Victoria 3050, Australia.
| | - Stephen J Rogerson
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, 792 Elizabeth Street, Melbourne, VIC 3000, Australia.
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Tedla M. A focus on improving molecular diagnostic approaches to malaria control and elimination in low transmission settings: Review. Parasite Epidemiol Control 2019; 6:e00107. [PMID: 31193331 PMCID: PMC6525315 DOI: 10.1016/j.parepi.2019.e00107] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/19/2019] [Accepted: 04/19/2019] [Indexed: 11/18/2022] Open
Abstract
The malaria elimination goal is back to the global agenda. Understanding its epidemiology in low transmission settings is crucial to design reliable strategies to detect a large reservoir of individuals infected with sub-microscopic (and often asymptomatic) infections characterized by low-parasite densities and gametocyte carriage. Traditional diagnostic methods such a light microscopy is widely used mainly in developing countries and as a result, the true picture of malaria epidemiology is misrepresented. In the last few decades, the advancement of molecular diagnostic tools significantly improved our understanding of the epidemiology of the diseases. However, the detection capacity of different molecular assays is determined by different factors such as the sensitivity of the assay and the transmission and infection dynamics of the disease particularly when there is low parasitic density in reservoir hosts. Hence, in this review, the epidemiology of malaria in low transmission settings and the priority in addressing the malaria control and elimination goals are highlighted.
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Worges M, Whitehurst N, Saye R, Ndiaye D, Yamo E, Yukich J. Performance Outcomes from Africa-Based Malaria Diagnostic Competency Assessment Courses. Am J Trop Med Hyg 2019; 100:851-860. [PMID: 30793691 PMCID: PMC6447135 DOI: 10.4269/ajtmh.18-0361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/03/2018] [Indexed: 11/07/2022] Open
Abstract
The U.S. President's Malaria Initiative-funded MalariaCare project implemented an external quality assurance scheme to support malaria diagnostics and case management across a spectrum of health facilities in participating African countries. A component of this program was a 5-day, malaria diagnostic competency assessment (MDCA) course for health facility laboratory staff conducting malaria microscopy. The MDCA course provided a method to quantify participant skill levels in microscopic examination of malaria across three major diagnosis areas: parasite detection, species identification, and parasite quantification. A total of 817 central-, regional-, and peripheral-level microscopists from 45 MDCA courses across nine African countries were included in the analysis. Differences in mean scores with respect to daily marginal performance were positive and statistically significant (P < 0.001) for each challenge type across all participants combined. From pretest to assessment day 4, mean scores for parasite detection, species identification, and parasite quantification increased by 19.1, 34.9, and 38.2 percentage points, respectively. In addition, sensitivity and specificity increased by 20.8 and 13.8 percentage points, respectively, by assessment day 4. Furthermore, the ability of MDCA participants to accurately report Plasmodium falciparum species when present increased from 44.5% at pretest to 67.1% by assessment day 4. The MDCA course rapidly improved the microscopy performance of participants over a short period of time. Because of its rigor, the MDCA course could serve as a mechanism for measuring laboratory staff performance against country-specific minimum competency standards and could easily be adapted to serve as a national certification course.
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Affiliation(s)
- Matt Worges
- President’s Malaria Initiative (PMI) MalariaCare Project, Medical Care Development International, Silver Spring, Maryland
- Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Nicole Whitehurst
- President’s Malaria Initiative (PMI) MalariaCare Project, Medical Care Development International, Silver Spring, Maryland
| | - Renion Saye
- President’s Malaria Initiative (PMI) MalariaCare Project, Medical Care Development International, Bamako, Mali
| | | | - Emanuel Yamo
- President’s Malaria Initiative (PMI) MalariaCare Project, Medical Care Development International, Kisumu, Kenya
| | - Joshua Yukich
- Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
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Ghindilis AL, Chesnokov O, Ngasala B, Smith MW, Smith K, Mårtensson A, Oleinikov AV. Detection of sub-microscopic blood levels of Plasmodium falciparum using Tandem Oligonucleotide Repeat Cascade Amplification (TORCA) assay with an attomolar detection limit. Sci Rep 2019; 9:2901. [PMID: 30814636 PMCID: PMC6393570 DOI: 10.1038/s41598-019-39921-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/05/2019] [Indexed: 11/09/2022] Open
Abstract
Tandem Oligonucleotide Repeat Cascade Amplification (TORCA) based on signal rather than target amplification under isothermal conditions was developed for nucleic acid assays. The initial signal was generated by hybridization of single stranded DNA targets to immobilized recognition probes followed by hybrid cleavage with specific restriction endonuclease (REase), and release of trigger oligonucleotides (Tr1). The signal amplification chamber contained two bead types carrying single-stranded amplification probes and two amplification REases. The probes consisted of multiple tandem repeats of either Tr1 or another trigger Tr2, with the tandem-Tr1 anchored to the beads through the antisense Tr2 linker and vice versa. Addition of the recognition reaction solution and Tr1 hybridization to the anti-Tr1 linkers started cleavage and release of additional Tr1 and Tr2, resulting in exponential signal amplification. The cleavage cascade also released horseradish peroxidase (HRP) pre-attached to the amplification probes, and the resultant signal was measured colorimetrically. A TORCA assay was developed for detection of Plasmodium falciparum parasites in blood. It had the detection limit in the attomolar concentration range, successfully detecting sub-microscopic P. falciparum infections at less than 0.75 infected erythrocytes per microliter. Further TORCA optimization will likely produce the quantitative isothermal alternative to PCR at a fraction of its cost.
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Affiliation(s)
| | - Olga Chesnokov
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33428, USA
| | - 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, Akademiska sjukhuset, 751 85, Uppsala, Sweden
| | - Maria W Smith
- TORCATECH, LLC, 5210 104th Street SW, Mukilteo, WA, 98275, USA
| | - Kenneth Smith
- TORCATECH, LLC, 5210 104th Street SW, Mukilteo, WA, 98275, USA
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Akademiska sjukhuset, 751 85, Uppsala, Sweden
| | - Andrew V Oleinikov
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33428, USA
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Immuno-gold silver staining assays on capillary-driven microfluidics for the detection of malaria antigens. Biomed Microdevices 2019; 21:24. [PMID: 30810808 DOI: 10.1007/s10544-019-0376-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Accurate and affordable rapid diagnostic tests (RDTs) are indispensable but often lacking for many infectious diseases. Specifically, there is a lack of highly sensitive malaria RDTs that can detect low antigen concentration at the onset of infection. Here, we present a strategy to improve the sensitivity of malaria RDTs by using capillary-driven microfluidic chips and combining sandwich immunoassays with electroless silver staining. We used 5 μm fluorescent beads functionalized with capture antibodies (cAbs). These beads are self-assembled by capillary action in recessed "bead lanes", which cross the main flow path of chips microfabricated in Si and SU-8. The binding of analytes to detection antibodies (dAbs) and secondary antibodies (2ndAbs) conjugated to gold nanoparticles (NPs) allows the formation of a silver film on the beads. Such silver film masks the fluorescent core of the bead inversely proportional to the concentration of antigen in a sample. We illustrate this method using the recombinant malaria antigen Plasmodium falciparum histidine-rich-protein 2 (rPfHRP2) spiked in human serum. This antigen was a recombinant HRP2 protein expressed in Escherichia coli, which is also the standard reference material. The limit of detection (LOD) of our immunoassay was found to be less than 6 ng mL-1 of rPfHRP2 within 20 min, which is approaching the desired sensitivity needed in the Target Product Profile (TPP) for malaria elimination settings. The concept presented here is flexible and may also be utilized for implementing fluorescence immunoassays for the parallel detection of biomarkers on capillary-driven microfluidic chips.
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Honrado C, Ciuffreda L, Spencer D, Ranford-Cartwright L, Morgan H. Dielectric characterization of Plasmodium falciparum-infected red blood cells using microfluidic impedance cytometry. J R Soc Interface 2018; 15:rsif.2018.0416. [PMID: 30333248 PMCID: PMC6228484 DOI: 10.1098/rsif.2018.0416] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/05/2018] [Indexed: 02/07/2023] Open
Abstract
Although malaria is the world's most life-threatening parasitic disease, there is no clear understanding of how certain biophysical properties of infected cells change during the malaria infection cycle. In this article, we use microfluidic impedance cytometry to measure the dielectric properties of Plasmodium falciparum-infected red blood cells (i-RBCs) at specific time points during the infection cycle. Individual parasites were identified within i-RBCs using green fluorescent protein (GFP) emission. The dielectric properties of cell sub-populations were determined using the multi-shell model. Analysis showed that the membrane capacitance and cytoplasmic conductivity of i-RBCs increased along the infection time course, due to membrane alterations caused by parasite infection. The volume ratio occupied by the parasite was estimated to vary from less than 10% at earlier stages, to approximately 90% at later stages. This knowledge could be used to develop new label-free cell sorting techniques for sample pre-enrichment, improving diagnosis.
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Affiliation(s)
- C Honrado
- Faculty of Physical Sciences and Engineering, Institute for Life Sciences, University of Southampton, Southampton, UK
| | - L Ciuffreda
- Institute of Infection, Immunity and Inflammation, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - D Spencer
- Faculty of Physical Sciences and Engineering, Institute for Life Sciences, University of Southampton, Southampton, UK
| | - L Ranford-Cartwright
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - H Morgan
- Faculty of Physical Sciences and Engineering, Institute for Life Sciences, University of Southampton, Southampton, UK
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Hemben A, Ashley J, Tothill IE. An immunosensor for parasite lactate dehydrogenase detection as a malaria biomarker – Comparison with commercial test kit. Talanta 2018; 187:321-329. [DOI: 10.1016/j.talanta.2018.04.086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 11/25/2022]
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Pham NM, Karlen W, Beck HP, Delamarche E. Malaria and the 'last' parasite: how can technology help? Malar J 2018; 17:260. [PMID: 29996831 PMCID: PMC6042346 DOI: 10.1186/s12936-018-2408-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/03/2018] [Indexed: 01/09/2023] Open
Abstract
Malaria, together with HIV/AIDS, tuberculosis and hepatitis are the four most deadly infectious diseases globally. Progress in eliminating malaria has saved millions of lives, but also creates new challenges in detecting the 'last parasite'. Effective and accurate detection of malaria infections, both in symptomatic and asymptomatic individuals are needed. In this review, the current progress in developing new diagnostic tools to fight malaria is presented. An ideal rapid test for malaria elimination is envisioned with examples to demonstrate how innovative technologies can assist the global defeat against this disease. Diagnostic gaps where technology can bring an impact to the elimination campaign for malaria are identified. Finally, how a combination of microfluidic-based technologies and smartphone-based read-outs could potentially represent the next generation of rapid diagnostic tests is discussed.
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Affiliation(s)
- Ngoc Minh Pham
- Department of Health Sciences and Technology, ETH Zürich, Lengghalde 5, 8092, Zurich, Switzerland
| | - Walter Karlen
- Department of Health Sciences and Technology, ETH Zürich, Lengghalde 5, 8092, Zurich, Switzerland
| | - Hans-Peter Beck
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland.
- University of Basel, Petersgraben 1, 4001, Basel, Switzerland.
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Boyce RM, Hathaway N, Fulton T, Reyes R, Matte M, Ntaro M, Mulogo E, Waltmann A, Bailey JA, Siedner MJ, Juliano JJ. Reuse of malaria rapid diagnostic tests for amplicon deep sequencing to estimate Plasmodium falciparum transmission intensity in western Uganda. Sci Rep 2018; 8:10159. [PMID: 29977002 PMCID: PMC6033881 DOI: 10.1038/s41598-018-28534-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/25/2018] [Indexed: 01/29/2023] Open
Abstract
Molecular techniques are not routinely employed for malaria surveillance, while cross-sectional, community-based parasite surveys require significant resources. Here, we describe a novel use of malaria rapid diagnostic tests (RDTs) collected at a single facility as source material for sequencing to esimtate malaria transmission intensity across a relatively large catchment area. We extracted Plasmodium falciparum DNA from RDTs, then amplified and sequenced a region of the apical membrane antigen 1 (pfama1) using targeted amplicon deep sequencing. We determined the multiplicity of infection (MOI) for each sample and examined associations with demographic, clinical, and spatial factors. We successfully genotyped 223 of 287 (77.7%) of the samples. We demonstrated an inverse relationship between the MOI and elevation with individuals presenting from the highest elevation villages harboring infections approximately half as complex as those from the lowest (MOI 1.85 vs. 3.51, AOR 0.25, 95% CI 0.09-0.65, p = 0.004). This study demonstrates the feasibility and validity of using routinely-collected RDTs for molecular surveillance of malaria and has real-world utility, especially as the cost of high-throughpout sequencing continues to decline.
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Affiliation(s)
- Ross M Boyce
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, 27599, USA.
| | - Nick Hathaway
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, 368 Plantation St., Worcester, Massachusetts, 01605, USA
| | - Travis Fulton
- Division of Epidemiology, University of North Carolina at Chapel Hill Gillings School of Global Public Health, 135 Dauer Drive, Chapel Hill, 27599, USA
| | - Raquel Reyes
- Division of General Medicine & Clinical Epidemiology, University of North Carolina at Chapel Hill, 5039 Old Clinic Building, CB 7110, Chapel Hill, 27599, USA
| | - Michael Matte
- Department of Community Health, Mbarara University of Science & Technology, P.O. Box 1410, Mbarara, Uganda
| | - Moses Ntaro
- Department of Community Health, Mbarara University of Science & Technology, P.O. Box 1410, Mbarara, Uganda
| | - Edgar Mulogo
- Department of Community Health, Mbarara University of Science & Technology, P.O. Box 1410, Mbarara, Uganda
| | - Andreea Waltmann
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, 27599, USA
| | - Jeffrey A Bailey
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, 368 Plantation St., Worcester, Massachusetts, 01605, USA
| | - Mark J Siedner
- Department of Medicine, Harvard Medical School and Massachusetts General Hospital, 125 Nashua Street, Suite 722, Boston, 02114, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, 27599, USA.,Division of Epidemiology, University of North Carolina at Chapel Hill Gillings School of Global Public Health, 135 Dauer Drive, Chapel Hill, 27599, USA.,Curriculum in Genetics and Microbiology, University of North Carolina at Chapel Hill, 321 South Columbia Street, Chapel Hill, NC, 27516, USA
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Kattenberg JH, Erhart A, Truong MH, Rovira-Vallbona E, Vu KAD, Nguyen THN, Nguyen VH, Nguyen VV, Bannister-Tyrrell M, Theisen M, Bennet A, Lover AA, Tran TD, Nguyen XX, Rosanas-Urgell A. Characterization of Plasmodium falciparum and Plasmodium vivax recent exposure in an area of significantly decreased transmission intensity in Central Vietnam. Malar J 2018; 17:180. [PMID: 29703200 PMCID: PMC5923009 DOI: 10.1186/s12936-018-2326-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/18/2018] [Indexed: 11/30/2022] Open
Abstract
Background In Vietnam, malaria transmission has been reduced to very low levels over the past 20 years, and as a consequence, the country aims to eliminate malaria by 2030. This study aimed to characterize the dynamics and extent of the parasite reservoir in Central Vietnam, in order to further target elimination strategies and surveillance. Methods A 1-year prospective cohort study (n = 429) was performed in three rural communities in Quang Nam province. Six malaria screenings were conducted between November 2014 and November 2015, including systematic clinical examination and blood sampling for malaria parasite identification, as well as molecular and serological analysis of the study population. Malaria infections were detected by light microscopy (LM) and quantitative real time PCR (qPCR), while exposure to Plasmodium falciparum and Plasmodium vivax was measured in the first and last survey by ELISA for PfAMA1, PfGLURP R2, PvAMA1, and PvMSP1-19. Classification and regression trees were used to define seropositivity and recent exposure. Results Four malaria infections (2 P. falciparum, 2 P. vivax) were detected in the same village by qPCR and/or LM. No fever cases were attributable to malaria. At the same time, the commune health centre (serving a larger area) reported few cases of confirmed malaria cases. Nevertheless, serological data proved that 13.5% of the surveyed population was exposed to P. falciparum and/or P. vivax parasites during the study period, of which 32.6% were seronegative at the start of the study, indicating ongoing transmission in the area. Risk factor analysis for seroprevalence and exposure to P. falciparum and/or P. vivax identified structural or economic risk factors and activity/behaviour-related factors, as well as spatial heterogeneity at the village level. Conclusions Previous studies in Central Vietnam demonstrated high occurrence of asymptomatic and sub-microscopic infections. However, in this study very few asymptomatic infections were detected despite serological evidence of continued transmission. Nonetheless, the factors associated with spatial heterogeneity in transmission could be evaluated using serological classification of recent exposure, which supports the usefulness of serological methods to monitor malaria transmission. Electronic supplementary material The online version of this article (10.1186/s12936-018-2326-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Annette Erhart
- Institute of Tropical Medicine, Nationalestraat 155, 2000, Antwerp, Belgium.,MRC Unit, Fajara, The Gambia.,Global Health Institute, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Minh Hieu Truong
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | | | - Khac Anh Dung Vu
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Thi Hong Ngoc Nguyen
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Van Hong Nguyen
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Van Van Nguyen
- Provincial Malaria Station Quang Nam/Center for Malaria and Goitre Control, Quang Nam Province, Tam Ky, Vietnam
| | | | | | - Adam Bennet
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Andrew A Lover
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Thanh Duong Tran
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Xuan Xa Nguyen
- National Institute of Malariology, Parasitology and Entomology, Vietnam, Luong The Vinh Street 245-Trung Van, BC 10.200 Tu Liem, Hanoi, Vietnam
| | - Anna Rosanas-Urgell
- Institute of Tropical Medicine, Nationalestraat 155, 2000, Antwerp, Belgium.
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Malaria burden and treatment targets in Kachin Special Region II, Myanmar from 2008 to 2016: A retrospective analysis. PLoS One 2018; 13:e0195032. [PMID: 29614088 PMCID: PMC5882093 DOI: 10.1371/journal.pone.0195032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 03/15/2018] [Indexed: 01/02/2023] Open
Abstract
Although drug-based treatment is the primary intervention for malaria control and elimination, optimal use of targeted treatments remains unclear. From 2008 to 2016, three targeted programs on treatment were undertaken in Kachin Special Region II (KR2), Myanmar. Program I (2008–2011) treated all confirmed, clinical and suspected cases; program II (2012–2013) treated confirmed and clinical cases; and program III (2014–2016) targeted confirmed cases only. This study aims to evaluate the impacts of the three programs on malaria burden individually based on the annual parasite incidence (API), slide positivity rate (SPR) and their relative values. The API is calculated from original collected data and the incidence rate ratio (IRR) for each year is calculated by using the first-year API as a reference in each program phase across the KR2. Same method is applied to calculate SPR and risk ratio (RR) at the sentinel hospital too. During program I (2008–2011), malaria burden was reduced by 61% (95%CI: 58%-74%) and the actual API decreased from 9.8 (95%CI: 9.6–10.1) per 100 person-years in 2008 to 3.8 (3.6–4.1) per 100 person-years in 2011. Amid program II (2012–2013), the malaria burden increased by 33% (95%CI: 22%-46%) and the actual API increased from 2.1(95%CI: 2.0–2.3) per 100 person-years in 2012 to 2.8 (95%CI: 2.7–2.9) per 100 person-years in 2013. During program III (2014–2016) the malaria burden increased furtherly by 60% (95%CI: 51% - 69%) and the actual API increased from 3.2(95%CI: 3.0–3.3) per 100 person-years in 2014 to 5.1 (95%CI: 4.9–5.2) per 100 person-years in 2016. Results of the slide positivity of the sentinel hospital also confirm these results. Resurgence of malaria was mainly due to Plasmodium vivax during program II and III. This study indicates that strategy adopted in program I (2008–2011) should be more appropriate for the KR2. Quality-assured treatment of all confirmed, clinical and suspected malaria cases may be helpful for the reduction of malaria burden.
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Animut A, Lindtjørn B. Use of epidemiological and entomological tools in the control and elimination of malaria in Ethiopia. Malar J 2018; 17:26. [PMID: 29329545 PMCID: PMC5767068 DOI: 10.1186/s12936-018-2172-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 01/08/2018] [Indexed: 11/13/2022] Open
Abstract
Malaria is the leading public health problem in Ethiopia where over 75% of the land surface is at risk with varying intensities depending on altitude and season. Although the mortality because of malaria infection has declined much during the last 15–20 years, some researchers worry that this success story may not be sustainable. Past notable achievements in the reduction of malaria disease burden could be reversed in the future. To interrupt, or even to eliminate malaria transmission in Ethiopia, there is a need to implement a wide range of interventions that include insecticide-treated bed nets, indoor residual spraying, improved control of residual malaria transmission, and improved diagnostics, enhanced surveillance, and methods to deal with the emergence of resistance both to drugs and to insecticides. Developments during the past years with increasing awareness about the role of very low levels of malaria prevalence can sustain infections, may also demand that tools not used in the routine control efforts to reduce or eliminate malaria, should now be made available in places where malaria transmission occurs.
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Affiliation(s)
- Abebe Animut
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
| | - Bernt Lindtjørn
- Center for International Health, University of Bergen, Bergen, Norway
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Bastiaens GJH, Tiono AB, Okebe J, Pett HE, Coulibaly SA, Gonçalves BP, Affara M, Ouédraogo A, Bougouma EC, Sanou GS, Nébié I, Bradley J, Lanke KHW, Niemi M, Sirima SB, d’Alessandro U, Bousema T, Drakeley C. Safety of single low-dose primaquine in glucose-6-phosphate dehydrogenase deficient falciparum-infected African males: Two open-label, randomized, safety trials. PLoS One 2018; 13:e0190272. [PMID: 29324864 PMCID: PMC5764271 DOI: 10.1371/journal.pone.0190272] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022] Open
Abstract
Background Primaquine (PQ) actively clears mature Plasmodium falciparum gametocytes but in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals can cause hemolysis. We assessed the safety of low-dose PQ in combination with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) in G6PDd African males with asymptomatic P. falciparum malaria. Methods and findings In Burkina Faso, G6PDd adult males were randomized to treatment with AL alone (n = 10) or with PQ at 0.25 (n = 20) or 0.40 mg/kg (n = 20) dosage; G6PD-normal males received AL plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. In The Gambia, G6PDd adult males and boys received DP alone (n = 10) or with 0.25 mg/kg PQ (n = 20); G6PD-normal males received DP plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. The primary study endpoint was change in hemoglobin concentration during the 28-day follow-up. Cytochrome P-450 isoenzyme 2D6 (CYP2D6) metabolizer status, gametocyte carriage, haptoglobin, lactate dehydrogenase levels and reticulocyte counts were also determined. In Burkina Faso, the mean maximum absolute change in hemoglobin was -2.13 g/dL (95% confidence interval [CI], -2.78, -1.49) in G6PDd individuals randomized to 0.25 PQ mg/kg and -2.29 g/dL (95% CI, -2.79, -1.79) in those receiving 0.40 PQ mg/kg. In The Gambia, the mean maximum absolute change in hemoglobin concentration was -1.83 g/dL (95% CI, -2.19, -1.47) in G6PDd individuals receiving 0.25 PQ mg/kg. After adjustment for baseline concentrations, hemoglobin reductions in G6PDd individuals in Burkina Faso were more pronounced compared to those in G6PD-normal individuals receiving the same PQ doses (P = 0.062 and P = 0.022, respectively). Hemoglobin levels normalized during follow-up. Abnormal haptoglobin and lactate dehydrogenase levels provided additional evidence of mild transient hemolysis post-PQ. Conclusions Single low-dose PQ in combination with AL and DP was associated with mild and transient reductions in hemoglobin. None of the study participants developed moderate or severe anemia; there were no severe adverse events. This indicates that single low-dose PQ is safe in G6PDd African males when used with artemisinin-based combination therapy. Trial registration Clinicaltrials.gov NCT02174900 Clinicaltrials.gov NCT02654730
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Affiliation(s)
- Guido J. H. Bastiaens
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- * E-mail:
| | - Alfred B. Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Joseph Okebe
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Helmi E. Pett
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sam A. Coulibaly
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Bronner P. Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Muna Affara
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
| | - Alphonse Ouédraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Edith C. Bougouma
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Guillaume S. Sanou
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Kjerstin H. W. Lanke
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mikko Niemi
- Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sodiomon B. Sirima
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Umberto d’Alessandro
- Disease Control & Elimination Theme, Medical Research Council Unit, Fajara, The Gambia
- Department of Disease Control, Faculty of infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Abstract
In the mosquito-human life cycle, the six species of malaria parasites infecting humans (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale wallickeri, Plasmodium ovale curtisi, Plasmodium malariae, and Plasmodium knowlesi) undergo 10 or more morphological states, replicate from single to 10,000+ cells, and vary in total population from one to many more than 106 organisms. In the human host, only a small number of these morphological stages lead to clinical disease and the vast majority of all malaria-infected patients in the world produce few (if any) symptoms in the human. Human clinical disease (e.g., fever, anemia, coma) is the result of the parasite preprogrammed biology in concert with the human pathophysiological response. Caveats and corollaries that add variation to this host-parasite interaction include parasite genetic diversity of key proteins, coinfections, comorbidities, delays in treatment, human polymorphisms, and environmental determinants.
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Affiliation(s)
- Danny A Milner
- Harvard T.H. Chan School of Public Health, American Society for Clinical Pathology, Center for Global Health, Chicago, Illinois 60603
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Ranadive N, Kunene S, Darteh S, Ntshalintshali N, Nhlabathi N, Dlamini N, Chitundu S, Saini M, Murphy M, Soble A, Schwartz A, Greenhouse B, Hsiang MS. Limitations of Rapid Diagnostic Testing in Patients with Suspected Malaria: A Diagnostic Accuracy Evaluation from Swaziland, a Low-Endemicity Country Aiming for Malaria Elimination. Clin Infect Dis 2018; 64:1221-1227. [PMID: 28369268 PMCID: PMC5399938 DOI: 10.1093/cid/cix131] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/18/2017] [Indexed: 11/14/2022] Open
Abstract
Background. The performance of Plasmodium falciparum–specific histidine-rich protein 2–based rapid diagnostic tests (RDTs) to evaluate suspected malaria in low-endemicity settings has not been well characterized. Methods. Using dried blood spot samples from patients with suspected malaria at 37 health facilities from 2012 to 2014 in the low-endemicity country of Swaziland, we investigated the diagnostic accuracy of histidine-rich protein 2–based RDTs using qualitative polymerase chain reaction (PCR) (nested PCR targeting the cytochrome b gene) and quantitative PCR as reference standards. To explore reasons for false-negative and/or false-positive results, we used pfhrp2/3-specific PCR and logistic regression analyses of potentially associated epidemiological factors. Results. From 1353 patients, 93.0% of RDT-positive (n = 185) and 31.2% of RDT-negative samples (n = 340) were available and selected for testing. Compared with nested PCR, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RDTs were 51.7%, 94.1%, 67.3%, and 89.1%, respectively. After exclusion of samples with parasite densities <100/μL, which accounted for 75.7% of false-negative results and 33.3% of PCR-detectable infections, the sensitivity, specificity, PPV, and NPV were 78.8%, 93.7%, 62.3%, and 97.1%. Deletions of pfhrp2 were not detected. False-positivity was more likely during the second year and was not associated with demographics, recent malaria, health facility testing characteristics, or potential DNA degradation. Conclusions. In the low-transmission setting of Swaziland, we demonstrated low sensitivity of RDT for malaria diagnosis, owing to an unexpectedly high proportion of low-density infection among symptomatic subjects. The PPV was also low, requiring further investigation. A more accurate point-of-care diagnostic may be needed to support malaria elimination efforts.
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Affiliation(s)
| | - Simon Kunene
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Sarah Darteh
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | | | - Nomcebo Nhlabathi
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Nomcebo Dlamini
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Stanley Chitundu
- National Malaria Control Programme, Ministry of Health, Manzini, Swaziland
| | - Manik Saini
- Clinton Health Access Initiative, Mbabane, Swaziland
| | - Maxwell Murphy
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Adam Soble
- Clinton Health Access Initiative, Mbabane, Swaziland
| | - Alanna Schwartz
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, USA
| | - Michelle S Hsiang
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco (UCSF), San Francisco, CA, USA.,Department of Pediatrics, Benioff Children's Hospital and University of California, San Francisco, CA, USA.,Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA
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49
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Björkman A, Cook J, Sturrock H, Msellem M, Ali A, Xu W, Molteni F, Gosling R, Drakeley C, Mårtensson A. Spatial Distribution of Falciparum Malaria Infections in Zanzibar: Implications for Focal Drug Administration Strategies Targeting Asymptomatic Parasite Carriers. Clin Infect Dis 2018; 64:1236-1243. [PMID: 28431115 PMCID: PMC5399945 DOI: 10.1093/cid/cix136] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 12/30/2022] Open
Abstract
Background. Optimal use of mass/targeted screen-and-treat or mass or focal drug administration as malaria elimination strategies remains unclear. We therefore studied spatial distribution of Plasmodium falciparum infections to compare simulated effects of these strategies on reducing the parasite reservoir in a pre-elimination setting. Methods. P. falciparum rapid diagnostic tests (RDTs) and molecular (polymerase chain reaction [PCR]) and serological (enzyme-linked immunosorbent assay) analyses were performed on finger-prick blood samples from a population-based survey in 3 adjacent communities. Results. Among 5278 persons screened, 13 (0.2%) were positive by RDT and 123 (2.3%) by PCR. PCR-positive individuals were scattered over the study area, but logistic regression analysis suggested a propensity of these infections to cluster around RDT-positive individuals. The odds ratios for being PCR positive was 7.4 (95% confidence interval, 2.8–19.9) for those living in the household of an RDT-positive individual and 1.64 (1.0–2.8; P = .06) for those living within <300 m, compared with >1000 m. Treating everyone within households of RDT-positive individuals (1% population) would target 13% of those who are PCR positive. Treating all living within a radius of <300 or <1000 m (14% or 58% population) would target 30% or 66% of infections, respectively. Among 4431 serologically screened individuals, 26% were seropositive. Treating everyone within seropositive households (63% population) would target 77% of PCR-positive individuals. Conclusions. Presumptive malaria treatment seemed justified within RDT-positive households and potentially worth considering within, for example, a radius of <300 m. Serology was not discriminative enough in identifying ongoing infections for improving focal interventions in this setting but may rather be useful to detect larger transmission foci.
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Affiliation(s)
- Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jackie Cook
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,MRC Tropical Epidemiology Group, Faculty of Epidemiology and Population Health
| | - Hugh Sturrock
- Global Health Group, University of California, San Francisco, CA, USA
| | - Mwinyi Msellem
- Zanzibar Malaria Elimination Programme, Zanzibar Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Zanzibar Ministry of Health, Stone Town, Zanzibar, United Republic of Tanzania
| | - Weiping Xu
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Fabrizio Molteni
- Swiss Tropical and Public Health Institute, Dar es Salaam, Tanzania
| | - Roly Gosling
- Global Health Group, University of California, San Francisco, CA, USA
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health, Uppsala University, Sweden
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50
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Plasmodium Detection and Differentiation by Direct-on-Blood PCR Nucleic Acid Lateral Flow Immunoassay. J Mol Diagn 2018; 20:78-86. [DOI: 10.1016/j.jmoldx.2017.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 09/07/2017] [Accepted: 09/25/2017] [Indexed: 12/13/2022] Open
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