Molecular epidemiological surveillance of Africa and Asia imported malaria in Wuhan, Central China: comparison of diagnostic tools during 2011–2018

Abstract

Background: Malaria remains a serious public health problem globally. As the elimination of indigenous malaria continues in China, imported malaria has gradually become a major health hazard. Well-timed and accurate diagnoses could support the timely implementation of therapeutic schedules, reveal the prevalence of imported malaria and avoid transmission of the disease. Methods: Blood samples were collected in Wuhan, China, from August 2011 to December 2018. All patients accepted microscopy and rapid diagnosis test (RDT) examinations. Subsequently, each of the positive or suspected positive cases was tested for four human-infectious Plasmodium species by using 18S rRNA-based nested PCR and Taqman probe-based real-time PCR. The results of the microscopy and the two molecular diagnostic methods were analysed. Importation origins were traced by country, and the prevalence of Plasmodium species was analysed by year. Results: A total of 296 blood samples, including 288 that were microscopy and RDT positive, 7 RDT and Plasmodium falciparum positive, and 1 suspected case, were collected and reanalysed. After application of the two molecular methods and sequencing, 291 cases including 245 P. falciparum, 15 Plasmodium vivax, 20 Plasmodium ovale, 6 Plasmodium malariae and 5 mixed infections (3 P. falciparum + P. ovale, 2 P. vivax + P. ovale) were confirmed. These patients had returned from Africa (95.53%) and Asia (4.47%). Although the prevalence displayed a small-scale fluctuation, the overall trend of the imported cases increased yearly. Conclusions: These results emphasize the necessity of combined utilization of the four tools for malaria diagnosis in clinic and in field surveys of potential risk regions worldwide including Wuhan.

A PCR-RFLP Technique to Assess the Geographic Origin of Plasmodium falciparum Strains in Central America

“…In particular, cross-border transmission from highly endemic countries to malaria-free regions is a continuing threat to national surveillance programs [ 26 ]. Asian countries like Kuwait [ 27 ], Malaysia [ 28 ], Turkey [ 29 ], and China [ 30 , 31 ], among others, report a high number of malaria cases from neighboring countries or Africa. North African countries, with no indigenous cases, also report a significant number of imported malaria cases from the sub-Saharan region [ 32 ].…”

Detection of Antimalarial Resistance-Associated Mutations in Plasmodium falciparum via a Platform of Allele-Specific PCR Combined with a Gold Nanoparticle-Based Lateral Flow Assay

“…However, it takes a long time and requires a professional to report the results. The qPCR is also often used for SNP detection of drug resistance genes, and it has the advantages of being fast and having high specificity ( 12 ). Because the equipment is expensive, it cannot be tested in the field, nor can it be widely promoted in resource-poor areas.…”

“…Therefore, the identification of SNPs is particularly important in disease diagnosis, biomedical research, food safety, and environmental analysis ( 9 ). Currently, PCR-restriction fragment length polymorphism (PCR-RFLP) ( 10 ), nested PCR ( 11 ), allele-specific PCR (AS-PCR) ( 6 ), real-time fluorescence quantitative PCR (qPCR) ( 12 ), loop-mediated isothermal amplification (LAMP) ( 13 ), Sanger sequencing ( 11 , 14 ), and gene chips ( 15 ) are commonly used to detect known SNPs. For unknown SNPs, single-strand conformation polymorphism (SSCP) ( 16 ), random amplified polymorphic DNA (RAPD) ( 17 ), high-throughput sequencing (next-generation sequencing [NGS]) ( 18 ), single-molecule real-time (SMRT) sequencing technology ( 19 ), and nanopore sequencing technology ( 20 ) are commonly used.…”

“…Another common method is sequencing, which is currently the gold standard for testing gene sequences ( 11 , 12 , 14 ). However, the test cycle is long, and the steps are too complicated, so the results cannot be obtained in time and cannot quickly be used in medical treatment for critical patients.…”

Rapid and Ultrasensitive Detection of Plasmodium spp. Parasites via the RPA-CRISPR/Cas12a Platform

“…were detected by the established rapid method, and the results were displayed in three forms (fluorescence signal, visible fluorescence, and LFTS). All samples were synchronously analyzed by nPCR as described in our previous report . Detailed information about the primers and TaqMan probes used for nPCR and qPCR is shown in Table S1.…”