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Wei H, Li J, Liu Y, Cheng W, Huang H, Liang X, Huang W, Lin L, Zheng Y, Chen W, Wang C, Chen W, Xu G, Wei W, Chen L, Zeng Y, Lu Z, Li S, Lin Z, Wang J, Lin M. Rapid and Ultrasensitive Detection of Plasmodium spp. Parasites via the RPA-CRISPR/Cas12a Platform. ACS Infect Dis 2023; 9:1534-1545. [PMID: 37493514 DOI: 10.1021/acsinfecdis.3c00087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Microscopic examination of thick and thin blood smears stained with Giemsa dye is considered the primary diagnostic tool for the confirmation and management of suspected clinical malaria. However, detecting gametocytes is relatively insensitive, particularly in asymptomatic individuals with low-density Plasmodium infections. To complement existing diagnostic methods, a rapid and ultrasensitive point-of-care testing (POCT) platform for malaria detection is urgently needed and necessary. A platform based on recombinase polymerase amplification (RPA) followed by CRISPR/Cas12a (referred to as RPA-CRISPR/Cas12a) was developed and optimized for the determination of Plasmodium spp. parasites, particularly Plasmodium falciparum, using a fluorescence-based assay (FBDA), lateral flow test strips (LFTS), or naked eye observation (NEO). Then, the established platform was assessed with clinical malaria isolates. Under optimal conditions, the detection threshold was 1 copy/μL for the plasmid, and the limit of detection was 3.11-7.27 parasites/μL for dried blood spots. There was no cross-reactivity against blood-borne pathogens. For the accuracies of RPA-CRISPR/Cas12a, Plasmodium spp. and P. falciparum testing were 98.68 and 94.74%, respectively. The method was consistent with nested PCR results and superior to the qPCR results. RPA-CRISPR/Cas12a is a rapid, ultrasensitive, and reliable platform for malaria diagnosis. The platform requires no or minimal instrumentation for nucleic acid amplification reactions and can be read with the naked eye. Compared with similar diagnostic methods, this platform improves the reaction speed while reducing detection requirements. Therefore, this platform has the potential to become a true POCT for malaria parasites.
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Affiliation(s)
- Huagui Wei
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Jian Li
- School of Basic Medical Sciences, Hubei University of Medicine, Shiyan 442000, People's Republic of China
| | - Yaqun Liu
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou 521041, People's Republic of China
| | - Weijia Cheng
- Department of Clinical Laboratory, Wuchang Hospital Affiliated to Wuhan University of Science and Technology, Wuhan 430081, People's Republic of China
| | - Huiying Huang
- Medical Laboratory of Shenzhen Luohu People's Hospital, Shenzhen 518005, People's Republic of China
| | - Xueyan Liang
- Laboratory Medical Center, Huizhou Municipal Central Hospital, Huizhou 516008, People's Republic of China
| | - Weiyi Huang
- Key Laboratory of Environmental Pollution and Health Risk Assessment, Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Liyun Lin
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou 521041, People's Republic of China
| | - Yuzhong Zheng
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou 521041, People's Republic of China
| | - Weizhong Chen
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou 521011, People's Republic of China
| | - Chunfang Wang
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Wencheng Chen
- Guangxi Medical and Health Key Discipline Construction Project of the Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Guidan Xu
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Wujun Wei
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Liying Chen
- Industrial College of Biomedicine and Health Industry, Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Yongmei Zeng
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou 521011, People's Republic of China
| | - Zefang Lu
- Department of Medical Laboratory, Chaozhou People's Hospital Affiliated to Shantou University Medical College, Chaozhou 521011, People's Republic of China
| | - Shujuan Li
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou 521041, People's Republic of China
| | - Zongyun Lin
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Junli Wang
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
- Key Laboratory of Environmental Pollution and Health Risk Assessment, Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
- Reproductive Medicine, Guangxi Medical and Health Key Discipline Construction Project, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
| | - Min Lin
- Department of Reproductive Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, People's Republic of China
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Nyein PP, Tillakeratne S, Phyu S, Yee MM, Lwin MM, Htike KL, Aung MT, Grebely J, Applegate T, Hanson J, Matthews G, Lin KS. Evaluation of Simplified HCV Diagnostics in HIV/HCV Co-Infected Patients in Myanmar. Viruses 2023; 15:v15020521. [PMID: 36851736 PMCID: PMC9967037 DOI: 10.3390/v15020521] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
To evaluate a decentralised testing model and simplified treatment protocol of hepatitis C virus (HCV) infection to facilitate treatment scale-up in Myanmar, this prospective, observational study recruited HIV-HCV co-infected outpatients receiving sofosbuvir/daclatasvir in Yangon, Myanmar. The study examined the outcomes and factors associated with a sustained virological response (SVR). A decentralised "hub-and-spoke" testing model was evaluated where fingerstick capillary specimens were transported by taxi and processed centrally. The performance of the Xpert HCV VL Fingerstick Assay in detecting HCV RNA was compared to the local standard of care ( plasma HCV RNA collected by venepuncture). Between January 2019 and February 2020, 162 HCV RNA-positive individuals were identified; 154/162 (95%) initiated treatment, and 128/154 (84%) returned for their SVR12 visit. A SVR was achieved in 119/154 (77%) participants in the intent-to-treat population and 119/128 (93%) participants in the modified-intent-to-treat population. Individuals receiving an antiretroviral therapy were more likely to achieve a SVR (with an odds ratio (OR) of 7.16, 95% CI 1.03-49.50), while those with cirrhosis were less likely (OR: 0.26, 95% CI 0.07-0.88). The sensitivity of the Xpert HCV VL Fingerstick Assay was 99.4% (95% CI 96.7-100.0), and the specificity was 99.2% (95% CI 95.9-99.9). A simplified treatment protocol using a hub-and-spoke testing model of fingerstick capillary specimens can achieve an SVR rate in LMIC comparable to well-resourced high-income settings.
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Affiliation(s)
| | - Shane Tillakeratne
- The Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
- Correspondence:
| | - Sabai Phyu
- Department of Tropical and Infectious Diseases, Specialist Hospital Waibargi, Yangon W5C4+6J7, Myanmar
| | | | - Mya Mya Lwin
- Department of Microbiology, University of Medicine 2, Yangon 644-704, Myanmar
| | - Kyaw Linn Htike
- Myanmar-Australia Research Collaboration for Health Laboratory, Yangon W5C4+6J7, Myanmar
| | - May Thu Aung
- Myanmar-Australia Research Collaboration for Health Laboratory, Yangon W5C4+6J7, Myanmar
| | - Jason Grebely
- The Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Tanya Applegate
- The Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Josh Hanson
- The Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
- Cairns and Hinterland Hospital and Health Service, Cairns North, QLD 4870, Australia
| | - Gail Matthews
- The Kirby Institute, University of New South Wales, Sydney, NSW 2052, Australia
| | - Kyaw Swar Lin
- Specialist Hospital Mingaladon, Yangon X42H+J4, Myanmar
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Chen X, Zhou Q, Yuan W, Shi Y, Dong S, Luo X. Visual and rapid identification of Chlamydia trachomatis and Neisseria gonorrhoeae using multiplex loop-mediated isothermal amplification and a gold nanoparticle-based lateral flow biosensor. Front Cell Infect Microbiol 2023; 13:1067554. [PMID: 36926514 PMCID: PMC10011439 DOI: 10.3389/fcimb.2023.1067554] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/15/2023] [Indexed: 03/08/2023] Open
Abstract
Sexually transmitted chlamydia and gonorrhea infections caused by the bacteria Chlamydia trachomatis and Neisseria gonorrhoeae remain a major public health concern worldwide, particularly in less developed nations. It is crucial to use a point of care (POC) diagnostic method that is quick, specific, sensitive, and user-friendly to treat and control these infections effectively. Here, a novel molecular diagnostic assay, combining multiplex loop-mediated isothermal amplification (mLAMP) with a visual gold nanoparticles-based lateral flow biosensor (AuNPs-LFB) was devised and used for highly specific, sensitive, rapid, visual, and easy identification of C. trachomatis and N. gonorrhoeae. Two unique independent primer pairs were successful designed against the ompA and orf1 genes of C. trachomatis and N. gonorrhoeae, respectively. The optimal mLAMP-AuNPs-LFB reaction conditions were determined to be 67°C for 35 min. The detection procedure, involving crude genomic DNA extraction (~5 min), LAMP amplification (35 min), and visual results interpretation (<2 min), can be completed within 45 min. Our assay has a detection limit of 50 copies per test, and we did not observe any cross-reactivity with any other bacteria in our testing. Hence, our mLAMP-AuNPs-LFB assay can potentially be used for POC testing to detect C. trachomatis and N. gonorrhoeae in clinical settings, particularly in underdeveloped regions.
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Affiliation(s)
- Xu Chen
- The Second Clinical College, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou, China
- Clinical Medical Laboratory of the Second Affiliated Hospital, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou, China
- *Correspondence: Xinhua Luo, ; Shilei Dong, ; Xu Chen,
| | - Qingxue Zhou
- Clinical Laboratory, Hangzhou Women’s Hospital, Hangzhou, Zhejiang, China
| | - Wei Yuan
- Department of Quality Control, Guizhou Provincial Center for Clinical Laboratory, Guiyang, Guizhou, China
| | - Yuanfang Shi
- The Second Clinical College, Guizhou University of Traditional Chinese Medicine, Guiyang, Guizhou, China
| | - Shilei Dong
- Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, Zhejiang, China
- *Correspondence: Xinhua Luo, ; Shilei Dong, ; Xu Chen,
| | - Xinhua Luo
- Department of Infectious Disease, Guizhou Provincial People’s Hospital, Guiyang, Guizhou, China
- *Correspondence: Xinhua Luo, ; Shilei Dong, ; Xu Chen,
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Wu Y, Zhang Y, Zhu ZW, Xue QQ, Zou MH, Sun M, Li YY, Zhao JH. Rapid and Visual Detection of Toxoplasma gondii in Blood Samples from Pet Cats and Dogs by Loop-Mediated Isothermal Amplification. Vector Borne Zoonotic Dis 2022; 22:512-519. [PMID: 36201229 DOI: 10.1089/vbz.2022.0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: Toxoplasma gondii is an obligate intracellular parasite that invades nearly all nucleated cells of a broad spectrum of vertebrate hosts, and which may cause serious disease in immunocompromised patients, as well as in the immunologically incompetent fetus. This study aimed to establish a loop-mediated isothermal amplification (LAMP) technique to rapidly detect T. gondii in the blood infection by targeting the 529 bp repeat element of T. gondii. Methods: A turbidity monitoring system, together with visual reagent, was used to test the amplification result of the LAMP assay. In addition, the specificity and sensitivity of the LAMP assay were measured. Results: The results suggest that the successfully established LAMP assay profile can detect the DNA of T. gondii at 67°C within 40 min. The limit of detection of the LAMP assay was 101 copies/μL. No cross reaction occurred with Plasmodium vivax, Toxocara cati, Clonorchis sinensi, Spirometra mansoni or Cryptosporidium parvum. We validated the developed LAMP assay by detecting T. gondii in DNA extracted from 353 blood samples collected from domestic cats and dogs. The percentages of positive results in detecting these blood samples by LAMP and conventional PCR were 5.38% and 2.83%, respectively. Conclusions: Our findings show that the developed LAMP assay offers higher analytical sensitivity than conventional PCR and good analytical specificity, minimizes aerosol contamination, and can be applied to on-site rapid detection of T. gondii.
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Affiliation(s)
- Yan Wu
- School of Medical Laboratory Science, Wannan Medical College, Wuhu, China
| | - Yan Zhang
- School of Medical Laboratory Science, Wannan Medical College, Wuhu, China
| | - Zhi-Wei Zhu
- Department of Medical Parasitology, Wannan Medical College, Wuhu, China
| | - Qi-Qi Xue
- Department of Medical Parasitology, Wannan Medical College, Wuhu, China
| | - Ming-Hui Zou
- Department of Medical Parasitology, Wannan Medical College, Wuhu, China
| | - Ming Sun
- Tiantian Pet Hospital, Wuhu, China
| | - Yuan-Yuan Li
- Department of Medical Parasitology, Wannan Medical College, Wuhu, China
| | - Jin-Hong Zhao
- Department of Medical Parasitology, Wannan Medical College, Wuhu, China.,Anhui Provincial Key Laboratory of Biological Macromolecules, Wuhu, China
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Gui Z, Cai H, Wu L, Miao Q, Yu JF, Cai T, Mao R. Visual closed dumbbell-mediated isothermal amplification (CDA) for on-site detection of Rickettsia raoultii. PLoS Negl Trop Dis 2022; 16:e0010747. [PMID: 36084136 PMCID: PMC9491570 DOI: 10.1371/journal.pntd.0010747] [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: 03/29/2022] [Revised: 09/21/2022] [Accepted: 08/18/2022] [Indexed: 11/28/2022] Open
Abstract
Spotted fever group (SFG) rickettsioses are important zoonoses, threatening human health seriously and gradually attracting more attention in the world. SFG rickettsiae are classified as neglected pathogens. If these pathogens are detected at all, they are usually recognized very late in the infection through indirect detection of specific antibodies. Previous studies have shown that Rickettsia raoultii (R. raoultii), a member of the SFG rickettsiae, occurs with increasing incidence in remote countries. Therefore, a rapid detection method for R. raoultii is in urgently need. In this study, a R. raoultii diagnosis method by closed dumbbell-mediated isothermal amplification (R-CDA) assay targeting a conserved sequence of the outer membrane protein A (OmpA) gene with high sensitivity and specificity was developed. This assay offered a rapid and simple method for on-site detection of R. raoultii. Firstly, four pairs of R-CDA primers were designed and the optimum primer set was selected to amplify target gene specifically and effectively. Then, a pair of outer primer was designed to accelerate the reaction based on the inner primers to establish the RO-CDA reaction. In addition, the results of real-time amplification curves, melting curves and end-point colorimetric judgements showed that the established visual RO-CDA reaction could accurately detect R. raoultii without cross-reaction with other closely related pathogens. Furthermore, the detection limit of visual RO-CDA assay was 10 copies/μL, which was feasible for on-site detection with merits of easy-operation, rapidity, high sensitivity, and specificity. In conclusion, the developed RO-CDA detection method could be helpful for pathogen screening and epidemic prevention at the point of care. Spotted fever group (SFG) rickettsioses are important neglected zoonoses throughout the world, with expanding known distribution, among which R. raoultii is an emerging member. As the clinical symptoms of R. raoultii is similar to other diseases, the accurate diagnosis of the pathogen based on the detection of genome plays a vital role in effective treatment and control at low infection levels. Due to the lack of on-site detection technology of Rickettsia raoultii in remote areas, the pathogen can only be treated in the late infection stage with specific clinical symptoms. Closed dumbbell-mediated isothermal amplification (CDA) is a method that rapidly amplifies nucleic acids under isothermal condition, which can help to resolve the problem of point of care detection for R. raoultii. The established R. raoultii detection approach based on CDA was feasible for on-site detection with merits of easy-operation, rapidity, high sensitivity, and specificity. At last, compared with PCR and LAMP, CDA method is simpler and more efficient to detect R. raoultii, which helps to improve the efficiency of detection and strengthen the prevention and control of this neglected but widely distributed disease.
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Affiliation(s)
- Zheng Gui
- Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Hwa Mei Hospital, University of Chinese Academy of Sciences, Ningbo, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, China
| | - Hao Cai
- Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Hwa Mei Hospital, University of Chinese Academy of Sciences, Ningbo, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, China
| | - Lin Wu
- Graduate School, Inner Mongolia Medical University, Hohhot, Inner Mongolia, China
| | - Qing Miao
- Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Hwa Mei Hospital, University of Chinese Academy of Sciences, Ningbo, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, China
| | - Jing feng Yu
- Department of Parasitology, Inner Mongolia Medical University, Hohhot, Inner Mongolia, China
- * E-mail: (JY); (TC); (RM)
| | - Ting Cai
- Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Hwa Mei Hospital, University of Chinese Academy of Sciences, Ningbo, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, China
- * E-mail: (JY); (TC); (RM)
| | - Rui Mao
- Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province, Hwa Mei Hospital, University of Chinese Academy of Sciences, Ningbo, China
- Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences, Ningbo, China
- * E-mail: (JY); (TC); (RM)
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Aisyah DN, Mayadewi CA, Budiharsana M, Solikha DA, Ali PB, Igusti G, Kozlakidis Z, Manikam L. Building on health security capacities in Indonesia: Lessons learned from the COVID-19 pandemic responses and challenges. Zoonoses Public Health 2022; 69:757-767. [PMID: 35618675 PMCID: PMC9348171 DOI: 10.1111/zph.12976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 04/13/2022] [Indexed: 12/01/2022]
Abstract
As an active member country of the WHO's International Health Regulation and Global Health Security Agenda, Indonesia, the world's fourth-most populous and largest archipelagic country has recorded the second-highest COVID-19 cases in Asia with over 1.8 million cases in early June 2021. This geographically and socially diverse country has a dynamic national and sub-national government coordination with decentralized authorities that can complicate a pandemic response which often requires nationally harmonized policies, adaptability to sub-national contexts and global interconnectedness. This paper analyses and reviews COVID-19 public data, regulations, guidance documents, statements and other related official documents to present a narrative that summarizes the government's COVID-19 response strategies. It further analyses the challenges and achievements of the country's zoonotic diseases preparedness and responses and lastly provides relevant recommendations. Findings are presented in four sections according to the Global Health Security Agenda capacities, namely epidemiological surveillance (detect capacity); laboratory diagnostic testing (respond capacity); data management and analysis (enable capacity); and the role of sub-national governments. The COVID-19 pandemic has been a catalyst for the rapid transformation of existing surveillance systems, inter-related stakeholder coordination and agile development from the pre-pandemic health security capacities. This paper offers several recommendations on surveillance, laboratory capacity and data management, which might be useful for Indonesia and other countries with similar characteristics beyond the COVID-19 response, such as achieving long-term health security, zoonoses and pandemic prevention, as well as a digital transformation of their governmental capacities.
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Affiliation(s)
- Dewi Nur Aisyah
- Department of Epidemiology and Public Health, Institute of Epidemiology and Health CareUniversity College LondonLondonUK
- Indonesia One Health University NetworkDepokIndonesia
| | | | | | - Dewi Amila Solikha
- Ministry of National Development Planning (BAPPENAS) of the Republic of IndonesiaJakartaIndonesia
| | - Pungkas Bahjuri Ali
- Ministry of National Development Planning (BAPPENAS) of the Republic of IndonesiaJakartaIndonesia
| | | | - Zisis Kozlakidis
- International Agency for Research on Cancer World Health OrganizationLyonFrance
| | - Logan Manikam
- Department of Epidemiology and Public Health, Institute of Epidemiology and Health CareUniversity College LondonLondonUK
- Aceso Global Health Consultants LimitedLondonUK
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Field Evaluation of a Hemozoin-Based Malaria Diagnostic Device in Puerto Lempira, Honduras. Diagnostics (Basel) 2022; 12:diagnostics12051206. [PMID: 35626361 PMCID: PMC9140950 DOI: 10.3390/diagnostics12051206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/05/2022] [Accepted: 05/09/2022] [Indexed: 02/01/2023] Open
Abstract
The diagnosis of malaria in Honduras is based mainly on microscopic observation of the parasite in thick smears or the detection of parasite antigens through rapid diagnostic tests when microscopy is not available. The specific treatment of the disease depends exclusively on the positive result of one of these tests. Given the low sensitivity of conventional methods, new diagnostic approaches are needed. This study evaluates the in-field performance of a device (Gazelle™) based on the detection of hemozoin. This was a double-blind study evaluating symptomatic individuals with suspected malaria in the department of Gracias a Dios, Honduras, using blood samples collected from 2021 to 2022. The diagnostic performance of Gazelle™ was compared with microscopy and nested 18ssr PCR as references. The sensitivity and specificity of Gazelle™ were 59.7% and 98.6%, respectively, while microscopy had a sensitivity of 64.9% and a specificity of 100%. The kappa index between microscopy and Gazelle™ was 0.9216 using microscopy as a reference. Both methods show similar effectiveness and predictive values. No statistical differences were observed between the results of the Gazelle™ compared to light microscopy (p = 0.6831). The turnaround time was shorter for Gazelle™ than for microscopy, but the cost per sample was slightly higher for Gazelle™. Gazelle™ showed more false-negative cases when infections were caused by Plasmodium falciparum compared to P. vivax. Conclusions: The sensitivity and specificity of Gazelle™ are comparable to microscopy. The simplicity and ease of use of the Gazelle™, the ability to run on batteries, and the immediacy of its results make it a valuable tool for malaria detection in the field. However, further development is required to differentiate Plasmodium species, especially in those regions requiring differentiated treatment.
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Giacomelli A, Monti ME, Grande R, Oreni L, Galimberti L, Ridolfo AL, Bonazzetti C, Sabaini F, Cordier L, Zambelli A, Rizzardini G, Galli M, Antinori S. The value of lamp to rule out imported malaria diagnosis: a retrospective observational study in Milan, Italy. Infect Dis (Lond) 2022; 54:410-417. [PMID: 34983306 DOI: 10.1080/23744235.2021.2023754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND The diagnosis of malaria in returning travellers could be a challenge in non-endemic settings. We aimed to assess the performance of LAMP in comparison with standard conventional diagnostic methods using real-time-polymerase chain reaction (PCR) in case of discordant results. METHODS All travellers returning from malaria-endemic areas who presented to our Emergency Department (ED) from January 2017 to December 2020 with signs and symptoms suggestive for malaria were included. Blood microscopy was the reference diagnostic method applied at our laboratory with LAMP implemented as an additional method to aid in malaria diagnosis. PCR was employed only in case of between test's discordant results. Sensitivity and specificity of microscopy compared to LAMP were calculated with the confidence interval of 95%. RESULTS Four-hundred and eight patients (55.6% male, median age 42 years) were screened for malaria. The diagnosis was confirmed in 49 cases (12%): 44 cases (90%) caused by Plasmodium falciparum. Peripheral blood smear missed to identify three malaria cases, which tested positive with LAMP and PCR. One case of malaria caused by P. malariae in a naive tourist, one case by P. falciparum in a semi-immune pregnant women and one case by P. falciparum in a previously treated semi-immune patient. All the discordant cases were characterized by a very low parasitaemia. Microscopy when compared to LAMP showed a sensitivity of 93.9% (95% confidence interval (CI) 83.1-98.7%) and a specificity of 100% (95% CI 98.9-100%). CONCLUSIONS In our non-endemic setting LAMP was able to identify malaria cases with low-level parasitaemia otherwise missed by blood microscopy.
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Affiliation(s)
- Andrea Giacomelli
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Maria Elena Monti
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Romualdo Grande
- Diagnostic Services, Clinical Microbiology, Virology and Bioemergence Diagnostics, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Letizia Oreni
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Laura Galimberti
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Anna Lisa Ridolfo
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Cecilia Bonazzetti
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy.,Luigi Sacco Department of Biomedical and Clinical Sciences DIBIC, Università degli Studi di Milano, Milan, Italy
| | - Federico Sabaini
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Laura Cordier
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Agostino Zambelli
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy
| | - Giuliano Rizzardini
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy.,School of Clinical Medicine, Faculty of Health Science, University of the Witwatersrand, Johannesburg, South Africa
| | - Massimo Galli
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy.,Luigi Sacco Department of Biomedical and Clinical Sciences DIBIC, Università degli Studi di Milano, Milan, Italy
| | - Spinello Antinori
- Department of Infectious Diseases, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy.,Luigi Sacco Department of Biomedical and Clinical Sciences DIBIC, Università degli Studi di Milano, Milan, Italy
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