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Pacheco Souza RS, Dos Reis MF, de Lima Ferreira LC, Morais MC, Lima AKS, Albuquerque Barbosa LR, de Melo GC, de Lacerda MVG. Standardization of DNA extraction from paraffinized spleen samples: molecular diagnosis of human malaria. Malar J 2023; 22:361. [PMID: 38012686 PMCID: PMC10683280 DOI: 10.1186/s12936-023-04764-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/22/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND Plasmodium vivax is the main species responsible for human malaria in Brazil, and one of its manifestations is splenic malaria, though there are still challenges in its diagnosis. The present study aimed to standardize Plasmodium sp. DNA extraction from histological slices of spleen and diagnosis using real-time qPCR. METHODS This study performed a microtomy of a paraffin-embedded spleen as a positive control for P. vivax from a patient who had been previously diagnosed with the parasite. The sample was deparaffinized with xylol and ethanol, then DNA extraction was performed with two commercial kits. qPCR was carried out with the Taqman system for detection of Plasmodium sp. and was made species-specific using PvmtCOX1 gene. From 2015 to 2019, 200 spleen samples were obtained from trauma patients subjected to splenectomy in Manaus, Amazonas. All the samples were tested for cell-free human DNA (cfDNA). RESULTS The deparaffinization and the Plasmodium vivax DNA extraction method was successfully standardized, and the control sample was positive for P. vivax. Of the 200 samples, all qPCRs were negative, but they were positive for human PCR. CONCLUSION Paraffinization is practical and efficient for the preservation of samples, but the formation of bonds between proteins and DNA makes extraction difficult. Despite this, in this study, it was possible to standardize a method of DNA extraction for detecting P. vivax.
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Affiliation(s)
| | | | - Luiz Carlos de Lima Ferreira
- Amazonas State University (UEA), Manaus, Amazonas, 69040-000, Brazil
- Doctor Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, Amazonas, 69040-000, Brazil
| | - Manuela C Morais
- Federal University of Amazonas, Manaus, Amazonas, 69080-900, Brazil
| | | | - Laila Rowena Albuquerque Barbosa
- Amazonas State University (UEA), Manaus, Amazonas, 69040-000, Brazil
- Doctor Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, Amazonas, 69040-000, Brazil
| | - Gisely Cardoso de Melo
- Amazonas State University (UEA), Manaus, Amazonas, 69040-000, Brazil.
- Doctor Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, Amazonas, 69040-000, Brazil.
| | - Marcus Vinicius Guimaraes de Lacerda
- Leonidas & Maria Deane Institute (ILMD), Fiocruz, Manaus, Amazonas, 69057-070, Brazil
- Doctor Heitor Vieira Dourado Tropical Medicine Foundation, Manaus, Amazonas, 69040-000, Brazil
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Biruksew A, Demeke A, Birhanu Z, Kebede E, Golassa L, Mathebula EM, Yewhalaw D. Diagnostic performance of NxTek™ Eliminate Malaria-Pf test for the detection of Plasmodium falciparum in school children with asymptomatic malaria. Malar J 2023; 22:112. [PMID: 36991438 DOI: 10.1186/s12936-023-04529-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
Abstract
Background
One of the major roadblocks to the falciparum malaria elimination programme is the presence of a portion of the population, such as school children, with asymptomatic malaria infection. Targeting such reservoirs of infections is critical to interrupting transmission and enhancing elimination efforts. The NxTek™ Eliminate Malaria Pf test is a highly sensitive rapid diagnostic test (hsRDT) for the detection of HRP-2. However, knowledge gaps exist in Ethiopia on the diagnostic performance of hsRDT for the detection of Plasmodium falciparum in school children with asymptomatic malaria.
Methods
A school-based cross-sectional study was conducted from September 2021 to January 2022 on 994 healthy school children (aged 6–15 years). Finger-pricked whole blood samples were collected for microscopy, hsRDT, conventional RDT (cRDT or SD Bioline Malaria Ag Pf/P.v), and QuantStudio™ 3 Real—Time PCR system (qPCR). The hsRDT was compared to cRDT and microscopy. qPCR and microscopy were used as reference methods.
Results
The prevalence of Plasmodium falciparum was 1.51%, 2.2%. 2.2% and 4.52%, by microscopy, hsRDT, cRDT and qPCR, respectively. Using qPCR as reference, the sensitivity of hsRDT was higher (48.89%) than the microscopy (33.3%), and showed 100% specificity and a positive predictive value (PPV). Microscopy showed similar specificity and PPV as hsRDT. Using microscopy as a reference, the diagnostic perforrmances of both hsRDT and cRDT were similar. Both RDTs demonstrated identical diagnostic performances in both comparison methods.
Conclusions
hsRDT has the same diagnostic performance as cRDT but improved diagnostic characteristics than microscopy for detection of P. falciparum in school children with asymptomatic malaria. It can be a useful tool for the national malaria elimination plan of Ethiopia.
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Mohammed R, Asres MS, Gudina EK, Adissu W, Johnstone H, Marrast AC, Donini C, Duparc S, Yilma D. Efficacy, Safety, Tolerability, and Pharmacokinetics of MMV390048 in Acute Uncomplicated Malaria. Am J Trop Med Hyg 2023; 108:81-84. [PMID: 36509063 PMCID: PMC9833083 DOI: 10.4269/ajtmh.22-0567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/29/2022] [Indexed: 12/12/2022] Open
Abstract
An open label, phase IIa study conducted in Ethiopia evaluated the efficacy, safety, tolerability, and pharmacokinetics of a single 120-mg dose of the phosphatidylinositol 4-kinase inhibitor MMV390048 in Plasmodium vivax malaria. The study was not completed for operational reasons and emerging teratotoxicity data. For the eight adult male patients enrolled, adequate clinical and parasitological response at day 14 (primary endpoint) was 100% (8/8). Asexual parasites and gametocytes were cleared in all patients by 66 and 78 hours postdose, respectively. There were two recurrent P. vivax infections (days 20 and 28) and a new Plasmodium falciparum infection (day 22). MMV390048 exposure in P. vivax patients was lower than previously observed for healthy volunteers. Mild adverse events, mainly headache and gastrointestinal symptoms, were reported by eight patients. Single-dose MMV390048 (120 mg) rapidly cleared asexual parasites and gametocytes in patients with P. vivax malaria and was well tolerated.
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Affiliation(s)
- Rezika Mohammed
- Department of Internal Medicine, University of Gondar Hospital, Gondar, Ethiopia
| | | | - Esayas Kebede Gudina
- Jimma University Clinical Trial Unit, Jimma University Institute of Health, Jimma, Ethiopia;,Department of Internal Medicine, Jimma University Institute of Health, Jimma, Ethiopia
| | - Wondimagegn Adissu
- Jimma University Clinical Trial Unit, Jimma University Institute of Health, Jimma, Ethiopia;,School of Medical Laboratory Sciences, Jimma University Institute of Health, Jimma, Ethiopia
| | | | | | | | - Stephan Duparc
- Medicines for Malaria Venture, Geneva, Switzerland,Address correspondence to Stephan Duparc, Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215 Geneva 15, Switzerland. E-mail:
| | - Daniel Yilma
- Jimma University Clinical Trial Unit, Jimma University Institute of Health, Jimma, Ethiopia;,Department of Internal Medicine, Jimma University Institute of Health, Jimma, Ethiopia
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4
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Schneider KA, Salas CJ. Evolutionary genetics of malaria. Front Genet 2022; 13:1030463. [DOI: 10.3389/fgene.2022.1030463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022] Open
Abstract
Many standard-textbook population-genetic results apply to a wide range of species. Sometimes, however, population-genetic models and principles need to be tailored to a particular species. This is particularly true for malaria, which next to tuberculosis and HIV/AIDS ranks among the economically most relevant infectious diseases. Importantly, malaria is not one disease—five human-pathogenic species of Plasmodium exist. P. falciparum is not only the most severe form of human malaria, but it also causes the majority of infections. The second most relevant species, P. vivax, is already considered a neglected disease in several endemic areas. All human-pathogenic species have distinct characteristics that are not only crucial for control and eradication efforts, but also for the population-genetics of the disease. This is particularly true in the context of selection. Namely, fitness is determined by so-called fitness components, which are determined by the parasites live-history, which differs between malaria species. The presence of hypnozoites, i.e., dormant liver-stage parasites, which can cause disease relapses, is a distinct feature of P. vivax and P. ovale sp. In P. malariae inactivated blood-stage parasites can cause a recrudescence years after the infection was clinically cured. To properly describe population-genetic processes, such as the spread of anti-malarial drug resistance, these features must be accounted for appropriately. Here, we introduce and extend a population-genetic framework for the evolutionary dynamics of malaria, which applies to all human-pathogenic malaria species. The model focuses on, but is not limited to, the spread of drug resistance. The framework elucidates how the presence of dormant liver stage or inactivated blood stage parasites that act like seed banks delay evolutionary processes. It is shown that, contrary to standard population-genetic theory, the process of selection and recombination cannot be decoupled in malaria. Furthermore, we discuss the connection between haplotype frequencies, haplotype prevalence, transmission dynamics, and relapses or recrudescence in malaria.
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Costa GL, Alvarenga DAM, Aguiar ACC, Louzada J, Pereira DB, de Oliveira TF, Fonseca Júnior AA, Carvalho LH, Ferreira Alves de Brito C, Nóbrega de Sousa T. Improving the Molecular Diagnosis of Malaria: Droplet Digital PCR-Based Method Using Saliva as a DNA Source. Front Microbiol 2022; 13:882530. [PMID: 35633683 PMCID: PMC9136408 DOI: 10.3389/fmicb.2022.882530] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/20/2022] [Indexed: 12/20/2022] Open
Abstract
Malaria is an acute febrile disease caused by a protozoan of the genus Plasmodium. Light microscopy (LM) is the gold standard for the diagnosis of malaria. Despite this method being rapid and inexpensive, it has a low limit of detection, which hampers the identification of low parasitemia infections. By using multicopy targets and highly sensitive molecular techniques, it is possible to change this scenario. In this study, we evaluated the performance of droplet digital PCR (ddPCR) to detect Plasmodium DNA obtained from saliva samples (whole saliva and buccal swab) of 157 individuals exposed to malaria transmission from the Brazilian Amazon region. We used the highly sensitive ddPCR method with non-ribosomal multicopy targets for Plasmodium vivax (Pvr47) and Plasmodium falciparum (Pfr364). There was good concordance between the quantitative real-time PCR (qPCR) results from the saliva and blood, except for mixed-species infections. The sensitivity of qPCR was 93% for blood, 77% for saliva, and 47% for swabs. Parasite DNA was not detected in saliva samples in low-density infections compared with the detection in blood samples. ddPCR showed increased sensitivity for detecting Plasmodium in the blood and swabs (99% in blood, 73% in saliva, and 59% in swabs). Notably, ddPCR detected more mixed infections in the blood (15%), saliva (9%), and swabs (18%) than qPCR. Our data showed that the differences between ddPCR and qPCR were the result of a higher number of P. falciparum infections detected by ddPCR. Overall, there was a moderate correlation between parasite densities estimated by the different methods in the blood. Our findings highlight the possibility of using non-invasive sample collection methods for malaria diagnosis by targeting multicopy sequences combined with highly sensitive molecular methods.
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Affiliation(s)
- Gabriel Luíz Costa
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
| | - Denise Anete Madureira Alvarenga
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
| | | | - Jaime Louzada
- Health Sciences Center, Federal University of Roraima, Boa Vista, Brazil
| | | | | | | | - Luzia Helena Carvalho
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
| | - Cristiana Ferreira Alves de Brito
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
| | - Taís Nóbrega de Sousa
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Brazil
- *Correspondence: Taís Nóbrega de Sousa
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6
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Rosado J, Carrasco-Escobar G, Nolasco O, Garro K, Rodriguez-Ferruci H, Guzman-Guzman M, Llanos-Cuentas A, Vinetz JM, Nekkab N, White MT, Mueller I, Gamboa D. Malaria transmission structure in the Peruvian Amazon through antibody signatures to Plasmodium vivax. PLoS Negl Trop Dis 2022; 16:e0010415. [PMID: 35533146 PMCID: PMC9119515 DOI: 10.1371/journal.pntd.0010415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 05/19/2022] [Accepted: 04/12/2022] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND The landscape of malaria transmission in the Peruvian Amazon is temporally and spatially heterogeneous, presenting different micro-geographies with particular epidemiologies. Most cases are asymptomatic and escape routine malaria surveillance based on light microscopy (LM). Following the implementation of control programs in this region, new approaches to stratify transmission and direct efforts at an individual and community level are needed. Antibody responses to serological exposure markers (SEM) to Plasmodium vivax have proven diagnostic performance to identify people exposed in the previous 9 months. METHODOLOGY We measured antibody responses against 8 SEM to identify recently exposed people and determine the transmission dynamics of P. vivax in peri-urban (Iquitos) and riverine (Mazán) communities of Loreto, communities that have seen significant recent reductions in malaria transmission. Socio-demographic, geo-reference, LM and qPCR diagnosis data were collected from two cross-sectional surveys. Spatial and multilevel analyses were implemented to describe the distribution of seropositive cases and the risk factors associated with exposure to P. vivax. PRINCIPAL FINDINGS Low local transmission was detected by qPCR in both Iquitos (5.3%) and Mazán (2.7%); however, seroprevalence indicated a higher level of (past) exposure to P. vivax in Mazán (56.5%) than Iquitos (38.2%). Age and being male were factors associated with high odds of being seropositive in both sites. Higher antibody levels were found in individuals >15 years old. The persistence of long-lived antibodies in these individuals could overestimate the detection of recent exposure. Antibody levels in younger populations (<15 years old) could be a better indicator of recent exposure to P. vivax. CONCLUSIONS The large number of current and past infections detected by SEMs allows for detailed local epidemiological analyses, in contrast to data from qPCR prevalence surveys which did not produce statistically significant associations. Serological surveillance will be increasingly important in the Peruvian Amazon as malaria transmission is reduced by continued control and elimination efforts.
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Affiliation(s)
- Jason Rosado
- Unit of Malaria: Parasites and hosts, Institut Pasteur, Paris, France
- Sorbonne Université, ED 393, Paris, France
- Infectious Disease Epidemiology and Analytics G5 Unit, Institut Pasteur, Paris, France
| | - Gabriel Carrasco-Escobar
- School of Public Health, University of California San Diego, La Jolla, California, United States of America
- Health Innovation Laboratory, Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Peru
| | - Oscar Nolasco
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio de Malaria, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Katherine Garro
- Laboratorio de Malaria, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Mitchel Guzman-Guzman
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alejandro Llanos-Cuentas
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Narimane Nekkab
- Unit of Malaria: Parasites and hosts, Institut Pasteur, Paris, France
| | - Michael T. White
- Unit of Malaria: Parasites and hosts, Institut Pasteur, Paris, France
- Infectious Disease Epidemiology and Analytics G5 Unit, Institut Pasteur, Paris, France
| | - Ivo Mueller
- Unit of Malaria: Parasites and hosts, Institut Pasteur, Paris, France
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Dionicia Gamboa
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
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Obaldía N, Barahona I, Lasso J, Avila M, Quijada M, Nuñez M, Marti M. Comparison of PvLAP5 and Pvs25 qRT-PCR assays for the detection of Plasmodium vivax gametocytes in field samples preserved at ambient temperature from remote malaria endemic regions of Panama. PLoS Negl Trop Dis 2022; 16:e0010327. [PMID: 35394999 PMCID: PMC9020738 DOI: 10.1371/journal.pntd.0010327] [Citation(s) in RCA: 2] [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: 12/09/2021] [Revised: 04/20/2022] [Accepted: 03/14/2022] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND As the elimination of malaria in Mesoamerica progresses, detection of Plasmodium vivax using light microscopy (LM) becomes more difficult. Highly sensitive molecular tools have been developed to help determine the hidden reservoir of malaria transmission in low transmission settings. In this study we compare the performance of PvLAP5 and Pvs25 qRT-PCR assays to LM for the detection of Plasmodium vivax gametocytes in field samples preserved at ambient temperature from malaria endemic regions of Panama. METHODS For this purpose, we collected a total of 83 malaria field samples during 2017-2020 preserved in RNAprotect (RNAp) of which 63 (76%) were confirmed P. vivax by LM and selected for further analysis. Additionally, 16 blood samples from local healthy malaria smear negative volunteers, as well as, from 15 malaria naïve lab-bred Aotus monkeys were used as controls. To optimize the assays, we first determined the minimum blood volume sufficient for detection of PvLAP5 and Pv18SrRNA using P. vivax infected Aotus blood that was preserved in RNAp and kept either at ambient temperature for up to 8 days before freezing or was snap-frozen at -80° Celsius at the time of bleeding. We then compared the mean differences in gametocyte detection rates of both qRT-PCR assays to LM and performed a multivariate correlation analysis of study variables. Finally, we determined the sensitivity (Se) and specificity (Sp) of the assays at detecting gametocytes compared to LM. RESULTS Blood volume optimization indicated that a blood volume of at least 60 μL was sufficient for detection of PvLAP5 and Pv18SrRNA and no significant differences were found between RNA storage conditions. Both PvLAP5 and Pvs25 qRT-PCR assays showed a 37-39% increase in gametocyte detection rate compared to LM respectively. Strong positive correlations were found between gametocytemia and parasitemia and both PvLAP5 and Pvs25 gametocyte markers. However, no significant differences were detected in the Se and Sp of the Pvs25 and PvLAP5 qRT-PCR assays, even though data from control samples suggested Pvs25 to be more abundant than PvLAP5. CONCLUSIONS This study shows that the PvLAP5 qRT-PCR assay is as Se and Sp as the gold standard Pvs25 assay and is at least 37% more sensitive than LM at detecting P. vivax gametocytes in field samples preserved in RNAp at ambient temperature from malaria endemic regions of Panama. AUTHOR SUMMARY Plasmodium vivax is one of the five species of malaria (P. falciparum, P. malariae, P. ovale and P. knowlesi) that are transmitted to man by the bite of female anopheles mosquitoes. It causes ~14.3 million cases mainly in Southeast Asia, India, the Western Pacific and the Americas annually. In the Americas, malaria remains a major problem in underdeveloped areas and indigenous communities in the Amazon region and eastern Panama, where it is endemic and difficult to eliminate. As malaria elimination progresses, detection of P. vivax by light microscopy (LM) becomes more difficult. Therefore, highly sensitive molecular tools have been developed that use genetic markers for the parasite to help determine the hidden reservoir of malaria transmission. This study compares the performance of two molecular assays based on the genetic markers of mature gametocytes PvLAP5 and Pvs25 with LM. The study shows that the PvLAP5 qRT-PCR assay is as sensitive and specific as the gold standard Pvs25 assay and is at least 37% more sensitive than LM at detecting P. vivax gametocytes. These data suggest that the PvLAP5 qRT-PCR assay can be a useful tool to help determine the hidden reservoir of transmission in endemic foci approaching elimination.
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Affiliation(s)
- Nicanor Obaldía
- Departamento de Investigaciones en Parasitología, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Panamá, Republic of Panamá
- Department of Immunology and Infectious Diseases, Harvard T.H. CHAN School of Public Health, Boston, Massachusetts, United States of America
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Itza Barahona
- Departamento de Control de Vectores, Dirección General de Salud Pública, Ministerio de Salud de Panamá, Panamá, Republic of Panamá
| | - José Lasso
- Departamento de Control de Vectores, Dirección General de Salud Pública, Ministerio de Salud de Panamá, Panamá, Republic of Panamá
| | - Mario Avila
- Departamento de Control de Vectores, Dirección General de Salud Pública, Ministerio de Salud de Panamá, Panamá, Republic of Panamá
| | - Mario Quijada
- Departamento de Investigaciones en Parasitología, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Panamá, Republic of Panamá
| | - Marlon Nuñez
- Departamento de Investigaciones en Parasitología, Instituto Conmemorativo Gorgas de Estudios de la Salud, Panamá City, Panamá, Republic of Panamá
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard T.H. CHAN School of Public Health, Boston, Massachusetts, United States of America
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
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Angrisano F, Robinson LJ. Plasmodium vivax - How hidden reservoirs hinder global malaria elimination. Parasitol Int 2021; 87:102526. [PMID: 34896312 DOI: 10.1016/j.parint.2021.102526] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 01/23/2023]
Abstract
Plasmodium vivax is the most geographically widespread human malaria parasite. Global malaria efforts have been less successful at reducing the burden of P. vivax compared to P. falciparum, owing to the unique biology and related treatment complexity of P. vivax. As a result, P. vivax is now the dominant malaria parasite throughout the Asia-Pacific and South America causing up to 14 million clinical cases every year and is considered a major obstacle to malaria elimination. Key features circumventing existing malaria control tools are the transmissibility of asymptomatic, low-density circulating infections and reservoirs of persistent dormant liver stages (hypnozoites) that are undetectable but reactivate to cause relapsing infections and sustain transmission. In this review we summarise the new knowledge shaping our understanding of the global epidemiology of P. vivax infections, highlighting the challenges for elimination and the tools that will be required achieve this.
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Tayipto Y, Liu Z, Mueller I, Longley RJ. Serology for Plasmodium vivax surveillance: A novel approach to accelerate towards elimination. Parasitol Int 2021; 87:102492. [PMID: 34728377 DOI: 10.1016/j.parint.2021.102492] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/30/2021] [Accepted: 10/28/2021] [Indexed: 01/13/2023]
Abstract
Plasmodium vivax is the most widespread causative agent of human malaria in the world. Despite the ongoing implementation of malaria control programs, the rate of case reduction has declined over the last 5 years. Hence, surveillance of malaria transmission should be in place to identify and monitor areas that require intensified malaria control interventions. Serological tools may offer additional insights into transmission intensity over parasite and entomological measures, especially as transmission levels decline. Antibodies can be detected in the host system for months to even years after parasite infections have been cleared from the blood, enabling malaria exposure history to be captured. Because the Plasmodium parasite expresses more than 5000 proteins, it is important to a) understand antibody longevity following infection and b) measure antibodies to more than one antigen in order to accurately inform on the exposure and/or immune status of populations. This review summarises current practices for surveillance of P. vivax malaria, the current state of research into serological exposure markers and their potential role for accelerating malaria elimination, and discusses further studies that need to be undertaken to see such technology implemented in malaria-endemic areas.
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Affiliation(s)
- Yanie Tayipto
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Zoe Liu
- The Institute for Mental and Physical Health and Clinical Translation, Barwon Health, Deakin University, Geelong, Victoria, Australia; School of Medicine, Centre for Molecular and Medical Research, Deakin University, Geelong, Australia
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Rhea J Longley
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia.
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Markwalter CF, Ngasala B, Mowatt T, Basham C, Park Z, Loya M, Muller M, Plowe C, Nyunt M, Lin JT. Direct Comparison of Standard and Ultrasensitive PCR for the Detection of Plasmodium falciparum from Dried Blood Spots in Bagamoyo, Tanzania. Am J Trop Med Hyg 2021; 104:1371-1374. [PMID: 33556035 DOI: 10.4269/ajtmh.20-1233] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 12/29/2020] [Indexed: 11/07/2022] Open
Abstract
Ultrasensitive PCR used in low-transmission malaria-endemic settings has revealed a much higher burden of asymptomatic infections than that detected by rapid diagnostic tests (RDTs) or standard PCR, but there is limited evidence as to whether this is the case in higher transmission settings. Using dried blood spots (DBS) collected among 319 schoolchildren in Bagamoyo, Tanzania, we found good correlation (Pearson's R = 0.995) between Plasmodium falciparum parasite densities detected by a DNA-based 18s rRNA real-time PCR (qPCR) and an RNA-based ultrasensitive RT-PCR (usPCR) for the same target. Whereas prevalence by usPCR was higher than that found by qPCR (37% versus 32%), the proportion of additionally detected low-density infections (median parasite density < 0.050 parasites/µL) represented an incremental increase. It remains unclear to what extent these low-density infections may contribute to the infectious reservoir in different malaria transmission settings.
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Affiliation(s)
| | - Billy Ngasala
- 2Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Tonelia Mowatt
- 1Duke Global Health Institute, Duke University, Durham, North Carolina
| | - Christopher Basham
- 3Institute of Global Health and Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Zackary Park
- 3Institute of Global Health and Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Mwajabu Loya
- 2Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Meredith Muller
- 3Institute of Global Health and Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | | | - Myaing Nyunt
- 4University of Maryland School of Medicine, Baltimore, Maryland
| | - Jessica T Lin
- 3Institute of Global Health and Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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Barbosa LRA, da Silva EL, de Almeida ACG, Salazar YEAR, Siqueira AM, Alecrim MDGC, Vieira JLF, Bassat Q, de Lacerda MVG, Monteiro WM, Melo GC. An Ultra-Sensitive Technique: Using Pv-mtCOX1 qPCR to Detect Early Recurrences of Plasmodium vivax in Patients in the Brazilian Amazon. Pathogens 2020; 10:pathogens10010019. [PMID: 33396824 PMCID: PMC7823330 DOI: 10.3390/pathogens10010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Early recurrence of Plasmodium vivax is a challenge for malaria control in the field, particularly because this species is associated with lower parasitemia, which hinders diagnosis and monitoring through blood smear testing. Early recurrences, defined as the persistence of parasites in the peripheral blood despite adequate drug dosages, may arise from resistance to chloroquine. The objective of the study was to estimate early recurrence of P. vivax in the Brazilian Amazon by using a highly-sensitive detection method, in this case, PCR. METHODS An ultra-sensitive qPCR that targeted mitochondrial DNA was used to compare a standard qPCR that targeted 18S rDNA to detect early recurrence of P. vivax in very low densities in samples from patients treated with chloroquine. RESULTS Out of a total of 312 cases, 29 samples (9.3%) were characterized as recurrences, from which 3.2% (10/312) were only detected through ultra-sensitive qPCR testing. CONCLUSIONS Studies that report the detection of P. vivax early recurrences using light microscopy may severely underestimate their true incidence.
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Affiliation(s)
- Laila R. A. Barbosa
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus 69040-200, AM, Brazil
| | - Emanuelle L. da Silva
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- UNINILTONLINS—Universidade Nilton Lins, Unicenter, Manaus 69058-030, AM, Brazil
| | - Anne C. G. de Almeida
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus 69040-200, AM, Brazil
- FAMETRO—Faculdade Metropolitana de Manaus, Campus Central, Av. Constantino Nery, Chapada, Manaus 69050-000, AM, Brazil
| | - Yanka E. A. R. Salazar
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
| | - André M. Siqueira
- Fiocruz-Manguinhos—Fundação Oswaldo Cruz, Instituto de Pesquisa Clínica Evandro Chagas, Rio de Janeiro 21040-900, RJ, Brazil;
| | - Maria das Graças Costa Alecrim
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus 69040-200, AM, Brazil
| | | | - Quique Bassat
- ISGlobal, Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Spain;
- Centro de Investigação em Saúde de Manhiça (CISM), Fundação Clínic per la Recerca Biomédica, Maputo 1929, Mozambique
- Catalan Institution for Research and Advanced Studies (ICREA), Campus Clínic, Pg. Lluís Companys 23, 08010 Barcelona, Spain
- Pediatric Infectious Diseases Unit, Pediatrics Department, Hospital Sant Joan de Déu, University of Barcelona, 1867 Barcelona, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain
| | - Marcus V. G. de Lacerda
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus 69040-200, AM, Brazil
- Instituto Leônidas & Maria Deane, ILMD-Fiocruz-Fundação Oswaldo Cruz, Manaus 69057-070, AM, Brazil
| | - Wuelton M. Monteiro
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus 69040-200, AM, Brazil
| | - Gisely C. Melo
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus 69040-200, AM, Brazil; (L.R.A.B.); (E.L.d.S.); (A.C.G.d.A.); (Y.E.A.R.S.); (M.d.G.C.A.); (M.V.G.d.L.); (W.M.M.)
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus 69040-200, AM, Brazil
- Correspondence: ; Tel.: +55-92-99159-8604
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