Limited polymorphism in k13 gene of Plasmodium falciparum and k12 of Plasmodium vivax isolates imported from African and Asian countries between 2014 and 2019 in Hangzhou city, China

Abstract Background Malaria causes major public health problems globally and drug resistance hinders its control and elimination. Molecular markers associated with drug resistance are considered as a beneficial tool to monitor the disease trends, evolution and distribution so as to help improve drug policy. Methods We collected 148 Plasmodium falciparum and 20 Plasmodium vivax isolates imported into Hangzhou city, China between 2014 and 2019. k13 gene of P. falciparum and k12 of P. vivax were sequenced. Polymorphisms and prevalence of k13 and k12 were analyzed. Results Most (98.65%, 146/148) P. falciparum infections were imported from Africa, and half P. vivax cases came from Africa and the other half from Asia. Nucleotide mutation prevalence was 2.03% (3/148) and the proportion of amino acid mutations was 0.68% (1/148). The amino acid mutation, A676S, was observed in an isolate from Nigeria. No mutation of k12 was observed from the parasites from African and Asian countries. Conclusions Limited polymorphism in k13 gene of P. falciparum isolates imported from African countries, but no evidence for the polymorphism of k12 in P. vivax samples from African and Asian countries was found. These results provide information for drug policy update in study region.

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Surveillance of molecular markers of antimalarial drug resistance in Plasmodium falciparum and Plasmodium vivax in Federally Administered Tribal Area (FATA), Pakistan

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s1678-994620216305 ◽

2021 ◽

Vol 63 ◽

Author(s):

Muhammad Faisal Nadeem ◽

Aamer Ali Khattak ◽

Nadia Zeeshan ◽

Hamza Zahid ◽

Usman Ayub Awan ◽

...

Keyword(s):

Drug Resistance ◽

Plasmodium Falciparum ◽

Molecular Markers ◽

Plasmodium Vivax ◽

Antimalarial Drug ◽

Antimalarial Drug Resistance ◽

Tribal Area

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Distribution of Duffy Phenotypes among Plasmodium vivax Infections in Sudan

Genes ◽

10.3390/genes10060437 ◽

2019 ◽

Vol 10 (6) ◽

pp. 437

Author(s):

Musab M.A. Albsheer ◽

Kareen Pestana ◽

Safaa Ahmed ◽

Mohammed Elfaki ◽

Eiman Gamil ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Plasmodium Vivax ◽

Real Time Pcr ◽

Blood Cells ◽

Vivax Infection ◽

Quantitative Real Time Pcr ◽

East African ◽

African Countries ◽

Human Red Blood Cells ◽

Duffy Negative

Negative Duffy expression on the surface of human red blood cells was believed to be a barrier for Plasmodium vivax infection in most Africans. However, P. vivax has been demonstrated to infect Duffy-negative individuals in several Central and East African countries. In this study, we investigated the distribution of Duffy blood group phenotypes with regard to P. vivax infection and parasitemia in Sudan. Out of 992 microscopic-positive malaria samples, 190 were identified as P. vivax positive infections. Among them, 186 were P. vivax mono-infections and 4 were mixed P. vivax and Plasmodium falciparum infections. A subset of 77 samples was estimated with parasitemia by quantitative real-time PCR. Duffy codons were sequenced from the 190 P. vivax positive samples. We found that the Duffy Fy(a-b+) phenotype was the most prevalent, accounting for 67.9% of all P. vivax infections, while homozygous Duffy-negative Fy(a-b-) accounted for 17.9% of the P. vivax infections. The prevalence of infection in Fy(a-b+) and Fy(a+b-)were significantly higher than Fy(a-b-) phenotypes (p = 0.01 and p < 0.01, respectively). A significantly low proportion of P. vivax infection was observed in Duffy negative individuals Fy(a-b-). This study highlights the prevalence of P. vivax in Duffy-negatives in Sudan and indicates low parasitemia among the Duffy-negative individuals.

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Plasmodium falciparum resistance to sulfadoxine-pyrimethamine in Africa: a systematic analysis of national trends

BMJ Global Health ◽

10.1136/bmjgh-2020-003217 ◽

2020 ◽

Vol 5 (11) ◽

pp. e003217

Author(s):

Floriano Amimo ◽

Ben Lambert ◽

Anthony Magit ◽

Jahit Sacarlal ◽

Masahiro Hashizume ◽

...

Keyword(s):

Drug Resistance ◽

Plasmodium Falciparum ◽

Intermittent Preventive Treatment ◽

Central Africa ◽

Gaussian Process Regression ◽

Eastern Africa ◽

African Countries ◽

Uncertainty Interval ◽

Systematic Analysis ◽

High Level

IntroductionThe rising burden of drug resistance is a major challenge to the global fight against malaria. We estimated national Plasmodium falciparum resistance to sulfadoxine-pyrimethamine (SP) across Africa, from 2000 to 2020.MethodsWe assembled molecular, clinical and endemicity data covering malaria-endemic African countries up to December 2018. Subsequently, we reconstructed georeferenced patient data, using pfdhps540E and pfdhps581G to measure mid-level and high-level SP resistance. Gaussian process regression was applied to model spatiotemporal standardised prevalence.ResultsIn eastern Africa, mid-level SP resistance increased by 64.0% (95% uncertainty interval, 30.7%–69.8%) in Tanzania, 55.4% (31.3%–65.2%) in Sudan, 45.7% (16.8%–54.3%) in Mozambique, 29.7% (10.0%–45.2%) in Kenya and 8.7% (1.4%–36.8%) in Malawi from 2000 to 2010. This was followed by a steady decline of 76.0% (39.6%–92.6%) in Sudan, 65.7% (25.5%–85.6%) in Kenya and 17.4% (2.6%–37.5%) in Tanzania from 2010 to 2020. In central Africa, the levels increased by 28.9% (7.2%–62.5%) in Equatorial Guinea and 85.3% (54.0%–95.9%) in the Congo from 2000 to 2020, while in the other countries remained largely unchanged. In western Africa, the levels have remained low from 2000 to 2020, except for Nigeria, with a reduction of 14.4% (0.7%–67.5%) and Mali, with an increase of 7.0% (0.8%–25.6%). High-level SP resistance increased by 5.5% (1.0%–20.0%) in Malawi, 4.7% (0.5%–25.4%) in Kenya and 2.0% (0.1%–39.2%) in Tanzania, from 2000 to 2020.ConclusionUnder the WHO protocols, SP is no longer effective for intermittent preventive treatment in pregnancy and infancy in most of eastern Africa and parts of central Africa. Strengthening health systems capacity to monitor drug resistance at subnational levels across the endemicity spectrum is critical to achieve the global target to end the epidemic.

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