Genetic diversity and population structure of <i>Plasmodium falciparum</i> in Kenyan–Ugandan border areas

Nderu, David; Kimani, Francis; Karanja, Evaline; Thiong’o, Kelvin; Akinyi, Maureen Veronica; Too, Edwin; Chege, William; Nambati, Eva Aluvaala; Wangai, Laura Nyawira; Meyer, Christian G.; Velavan, Thirumalaisamy P.

doi:10.1111/tmi.13223

Cited by 13 publications

(15 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the 2490 allele "81" found in the sample from Uganda has also been found in other African countries such as Kenya [41]. Furthermore, the TA1 (141/165) and Polyα (156) alleles found in the patient returning from Kenya, are commonly found in several localities of this country [41,42]. Also, the patient's sample with travel history to Guinea revealed a consistent MS pattern with a previous report from this country [43].…”

Section: Discussionsupporting

confidence: 82%

Molecular and epidemiological characterization of imported malaria cases in Chile

Escobar

Lucchi

Abdallah

et al. 2020

Malar J

View full text Add to dashboard Cite

Background: Chile is one of the South American countries certified as malaria-free since 1945. However, the recent increase of imported malaria cases and the presence of the vector Anopheles pseudopunctipennis in previously endemic areas in Chile require an active malaria surveillance programme. Methods: Specimens from 268 suspected malaria cases-all imported-collected between 2015 and 2018 at the Public Health Institute of Chile (ISP), were diagnosed by microscopy and positive cases were included for epidemiological analysis. A photo-induced electron transfer fluorogenic primer real-time PCR (PET-PCR) was used to confirm the presence of malaria parasites in available blood samples. Sanger sequencing of drug resistance molecular markers (pfk13, pfcrt and pfmdr1) and microsatellite (MS) analysis were performed in confirmed Plasmodium falciparum samples and results were related to origin of infection. Results: Out of the 268 suspected cases, 65 were Plasmodium spp. positive by microscopy. A total of 63% of the malaria patients were male and 37% were female; 43/65 of the patients acquired infections in South American endemic countries. Species confirmation of available blood samples by PET-PCR revealed that 15 samples were positive for P. falciparum, 27 for Plasmodium vivax and 4 were mixed infections. The P. falciparum samples sequenced contained four mutant pfcrt genotypes (CVMNT, CVMET, CVIET and SVMNT) and three mutant pfmdr1 genotypes (Y184F/ S1034C/N1042D/D1246Y, Y184F/N1042D/D1246Y and Y184F). MS analysis confirmed that all P. falciparum samples presented different haplotypes according to the suspected country of origin. Four patients with P. vivax infection returned to the health facilities due to relapses. Conclusion: The timely detection of polymorphisms associated with drug resistance will contribute to understanding if current drug policies in the country are appropriate for treatment of imported malaria cases and provide information about the most frequent resistant genotypes entering Chile.

show abstract

Section: Discussionsupporting

confidence: 82%

Molecular and epidemiological characterization of imported malaria cases in Chile

Escobar

Lucchi

Abdallah

et al. 2020

Malar J

View full text Add to dashboard Cite

show abstract

“…All the sequenced samples were used to amino acid repeats characterization with a number according to Baker et al [ 15 ] and recent repeats characterized in Kenya [ 42 ]. When two or more amino acid repeats overlapped, only the largest repeat was counted.…”

Section: Methodsmentioning

confidence: 99%

Deletion patterns, genetic variability and protein structure of pfhrp2 and pfhrp3: implications for malaria rapid diagnostic test in Amhara region, Ethiopia

Fuente

Yimar

García

et al. 2022

Malar J

View full text Add to dashboard Cite

Background Although rapid diagnostic tests (RDTs) play a key role in malaria-control strategies, their efficacy has been threatened by deletion and genetic variability of the genes pfhrp2/3. This study aims to characterize the deletion, genetic patterns and diversity of these genes and their implication for malaria RDT effectiveness, as well as their genetic evolution in the Amhara region of Ethiopia. Methods The study included 354 isolates from symptomatic patients from the Amhara region of Ethiopia who tested positive by microscopy. Exon 1–2 and exon 2 of genes pfhrp2 and -3 were amplified, and exon 2 was sequenced to analyse the genetic diversity, phylogenetic relationship and epitope availability. Results The deletion frequency in exon 1–2 and exon 2 was 22 and 4.6% for pfhrp2, and 68 and 18% for pfhrp3, respectively. Double deletion frequency for pfhrp2 and pfhrp3 was 1.4%. High genetic diversity, lack of clustering by phylogenetic analysis and evidence of positive selection suggested a diversifying selection for both genes. The amino-acid sequences, classified into different haplotypes, varied widely in terms of frequency of repeats, with novel amino-acid changes. Aminoacidic repetition type 2 and type 7 were the most frequent in all the sequences. The most frequent epitopes among protein sequences were those recognized by MAbs 3A4 and C1-13. Conclusion Deletions and high amino acidic variation in pfhrp2 and pfhrp3 suggest their possible impact on RDT use in the Amhara region, and the high genetic diversity of these genes could be associated with a diversifying selection in Ethiopia. Surveillance of these genes is, therefore, essential to ensure the effectiveness of public health interventions in this region. Graphical Abstract

show abstract

“…Of these, 214 (94%) PfHRP2 sequences and 81 (65%) of PfHRP3 occurred only once. Thirtynine new repeats were identified for PfHRP2 and 20 for PfHRP3 and PfHRP-3 was found structurally to have a lower degree of genetic variability than PfHRP2 (Nderu et al, 2019a;2019b;Barbadillo Ruiz, 2019). Figure 1 shows the structure, subcellular location and possible repeats found in the PfHRP genes.…”

Section: Genetic Variation Of Hrp Genesmentioning

confidence: 99%

Why Continue Studying HRP2 and HRP3 in Malaria?

Gunturiz

Chaparro

Carrasquilla

et al. 2020

American Journal of Infectious Diseases

View full text Add to dashboard Cite

The main malaria control strategy is rapid and accurate diagnosis followed by effective treatment. The quality of the diagnosis is relevant, since an erroneous diagnosis can generate an increase in morbidity and mortality significantly. The World Health Organization (WHO) has recommended that all patients with suspected malaria be diagnosed by microscopy or a Rapid Diagnostic Test (RDT) before treatment. Microscopy and RDT are the main options for diagnosing malaria in the field and in remote areas of endemic countries. This is in line with pillar 1 of the elimination strategy "Achieve universal access to malaria prevention, diagnosis and treatment". Most of the RDTs available on the market detect an antigen from the parasite produced throughout the life cycle of P. falciparum; this corresponds to the Histidine-Rich Protein 2 (HRP2). In general, HRP2-based RDTs are more sensitive and stable than those based on other Plasmodium antigens, making them the best choice in most endemic countries where P. falciparum malaria predominates. In this review we present evidence on the genetic variability of PfHRP2 and 3 and its potential effect on the efficacy of rapid tests routinely used to diagnose malaria and as main methodological tool elimination programs worldwide.

show abstract

Genetic diversity and population structure of Plasmodium falciparum in Kenyan–Ugandan border areas

Cited by 13 publications

References 34 publications

Molecular and epidemiological characterization of imported malaria cases in Chile

Molecular and epidemiological characterization of imported malaria cases in Chile

Deletion patterns, genetic variability and protein structure of pfhrp2 and pfhrp3: implications for malaria rapid diagnostic test in Amhara region, Ethiopia

Why Continue Studying HRP2 and HRP3 in Malaria?

Contact Info

Product

Resources

About