Epidemiology of mutant Plasmodium falciparum parasites lacking histidine-rich protein 2/3 genes in Eritrea 2 years after switching from HRP2-based RDTs

Mihreteab, Selam; Anderson, Karen; Pasay, Cielo; Smith, David J.; Gatton, Michelle L.; Cunningham, Jane; Berhane, Araia; Cheng, Qin

doi:10.1038/s41598-021-00714-8

Cited by 22 publications

(30 citation statements)

References 26 publications

(36 reference statements)

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“…In this study, a conventional PCR method was used to detect pfhrp2/3 deletions 5 . The status of pfhrp2/3 genes were then verified by protein expression levels measured using commercially available HRP2 and pLDH detection ELISA kit 27 , 28 and our results from PCR and ELISA were consistent. Genotyping was carried out for a subset of samples in order to understand the evolution of gene deleted parasites in relation to genetic diversity, genetic relatedness and population structure of the parasites.…”

Section: Discussionmentioning

confidence: 55%

“…The second DBS was used to elute proteins using a previously described method 27 , 28 with a modification of eluting at room temperature for 3 h, instead of at 12 °C for 12 h. Proteins were eluted into 200 µL and stored at −20 °C until use. Eluate (100 µL each) was used to measure the expression of HRP2 (Quantimal Celisa Pf HRP2 Assay kit, Cellabs, Cat number: KM 810) and pLDH (Quantimal Celisa Pf pLDH Assay kit, Cellabs, Cat number: KM7) following manufacturer’s instructions.…”

Section: Methodsmentioning

confidence: 99%

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Spatiotemporal dynamics of Plasmodium falciparum histidine-rich protein 2 and 3 deletions in Peru

Valdivia

Anderson

Smith

et al. 2022

Sci Rep

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Peru was the first country where pfhrp2 and pfhrp3 gene deletions were detected despite the fact that rapid diagnostics tests are not commonly used for confirmatory malaria diagnosis. This context provides a unique scenario to study the dynamics of pfhrp2 and pfhrp3 gene deletions without apparent RDTs selection pressure. In this study we characterized the presence of pfhrp2 and pfhrp3 genes on 325 P. falciparum samples collected in Iquitos and surrounding communities between 2011 and 2018 in order to understand the dynamics of gene deletion prevalence, potential associations with clinical symptomatology and parasite genetic background. P. falciparum presence was confirmed by microscopy and PCR of 18 s rRNA, pfmsp1 and pfmsp2. Gene deletions were assessed by amplification of exon1 and exon2 of pfhrp2 and pfhrp3 using gene specific PCRs. Confirmation of absence of HRP2 expression was assessed by ELISA of HRP2 and pLDH. Genotyping of 254 samples were performed using a panel of seven neutral microsatellite markers. Overall, pfhrp2 and pfhrp3 dual gene deletions were detected in 67% (217/324) parasite samples. Concordance between pfhrp2 deletion and negligible HRP2 protein levels was observed (Cohen's Kappa = 0.842). Prevalence of gene deletions was heterogeneous across study sites (adjusted p < 0.005) but there is an overall tendency towards increase through time in the prevalence of dual pfhrp2/3-deleted parasites between 2011 (14.3%) and 2016 (88.39%) stabilizing around 65% in 2018. Dual deletions increase was associated with dominance of a single new parasite haplotype (H8) which rapidly spread to all study sites during the 8 study years. Interestingly, participants infected with dual pfhrp2/3-deleted parasites had a significantly lower parasitemias than those without gene deletions in this cohort. Our study showed the increase of pfhrp2/3 deletions in the absence of RDTs pressure and a clonal replacement of circulating lines in the Peruvian Amazon basin. These results suggest that other factors linked to the pfhrp2/3 deletion provide a selective advantage over non-deleted strains and highlight the need for additional studies and continuing surveillance.

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Section: Discussionmentioning

confidence: 55%

Section: Methodsmentioning

confidence: 99%

Spatiotemporal dynamics of Plasmodium falciparum histidine-rich protein 2 and 3 deletions in Peru

Valdivia

Anderson

Smith

et al. 2022

Sci Rep

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“…Prior to whole-genome sequencing (WGS) being readily available, a strategy to examine the presence/absence of genes flanking pfhrp2 and pfhrp3 was used, providing supporting evidence for chromosomal deletions around the pfhrp2 and pfhrp3 location [ 14 , 47 ]. Sanger sequencing of amplified pfhrp2 and pfhrp3 fragments has also been used to characterize partial deletions that occur within these genes [ 26 ], and to understand sequence structure and genetic diversity of these genes in gene-intact parasite population [ 29 , 48 ].…”

Section: Molecular Confirmation Of Pfhrp2 and ...mentioning

confidence: 99%

“…For these increasingly common scenarios, more intense sampling is required to obtain accurate and precise prevalence estimates at the country-level for decision making purposes. Furthermore, nationwide RDT change is a highly challenging process involving recall and/or destruction of RDTs, selection and distribution of alternative quality RDTs may be more difficult to acquire due to limited number of suppliers and increased costs, re-training health care workers, continuous performance surveillance, and other logistical challenges [ 26 ]. Thus, the decision to change RDTs should not be made lightly and must be informed by accurate, timely surveillance data and precise prevalence estimates of pfhrp2 /3 deletions causing negative HRP2-RDTs.…”

Section: Introductionmentioning

confidence: 99%

Screening strategies and laboratory assays to support Plasmodium falciparum histidine-rich protein deletion surveillance: where we are and what is needed

Beshir

Parr

Cunningham

et al. 2022

Malar J

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Rapid diagnostic tests (RDTs) detecting Plasmodium falciparum histidine-rich protein 2 (HRP2) have been an important tool for malaria diagnosis, especially in resource-limited settings lacking quality microscopy. Plasmodium falciparum parasites with deletion of the pfhrp2 gene encoding this antigen have now been identified in dozens of countries across Asia, Africa, and South America, with new reports revealing a high prevalence of deletions in some selected regions. To determine whether HRP2-based RDTs are appropriate for continued use in a locality, focused surveys and/or surveillance activities of the endemic P. falciparum population are needed. Various survey and laboratory methods have been used to determine parasite HRP2 phenotype and pfhrp2 genotype, and the data collected by these different methods need to be interpreted in the appropriate context of survey and assay utilized. Expression of the HRP2 antigen can be evaluated using point-of-care RDTs or laboratory-based immunoassays, but confirmation of a deletion (or mutation) of pfhrp2 requires more intensive laboratory molecular assays, and new tools and strategies for rigorous but practical data collection are particularly needed for large surveys. Because malaria diagnostic strategies are typically developed at the national level, nationally representative surveys and/or surveillance that encompass broad geographical areas and large populations may be required. Here is discussed contemporary assays for the phenotypic and genotypic evaluation of P. falciparum HRP2 status, consider their strengths and weaknesses, and highlight key concepts relevant to timely and resource-conscious workflows required for efficient diagnostic policy decision making.

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“…Protein elution was conducted from 2 × 5 mm punch of DBS (equivalent to 11.2 μl of blood or 5.6 μl of plasma, [ 18 ]), with a final elution in 1120 μl of buffer (1/200) [ 19 ]. Quantitative ELISA-based detection was conducted using Quantimal™ CELISA Ultra-sensitive PfHRP2 Malaria (Cellabs, Australia) according to manufacturer’s instructions [ 20 ]. Samples were tested in duplicate.…”

Section: Methodsmentioning

confidence: 99%

Surveillance of pfhrp2 and pfhrp3 gene deletions among symptomatic Plasmodium falciparum malaria patients in Central Vietnam

Thang

Rovira-Vallbona²,

Binh

et al. 2022

Malar J

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Background Malaria rapid diagnostic tests (RDTs) remain the main point-of-care tests for diagnosis of symptomatic Plasmodium falciparum malaria in endemic areas. However, parasites with gene deletions in the most common RDT target, histidine rich protein 2 (pfhrp2/HRP2), can produce false-negative RDT results leading to inadequate case management. The objective of this study was to determine the prevalence of hrp2/3 deletions causing false-negative RDT results in Vietnam (Gia Lai and Dak Lak provinces). Methods Individuals presenting with malaria symptoms at health facilities were screened for P. falciparum infection using light microscopy and HRP2-RDT (SD Bioline Malaria Antigen Pf/Pv RDT, Abbott). Microscopically confirmed P. falciparum infections were analysed for parasite species by 18S rRNA qPCR, and pfhrp2 and pfhrp3 exon2 deletions were investigated by nested PCR. pfhrp2 amplicons were sequenced by the Sanger method and HRP2 plasma levels were determined by enzyme-linked immunosorbent assay (ELISA). Results The prevalence of false-negative RDT results among symptomatic cases was 5.6% (15/270). No pfhrp2 and pfhrp3 deletions were identified. False-negative RDT results were associated with lower parasite density (p = 0.005) and lower HRP2 plasma concentrations (p < 0.001), as compared to positive RDT. Conclusions The absence of hrp2/3 deletions detected in this survey suggests that HRP2-based malaria RDTs remain effective for the diagnosis of symptomatic P. falciparum malaria in Central Vietnam.

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Epidemiology of mutant Plasmodium falciparum parasites lacking histidine-rich protein 2/3 genes in Eritrea 2 years after switching from HRP2-based RDTs

Cited by 22 publications

References 26 publications

Spatiotemporal dynamics of Plasmodium falciparum histidine-rich protein 2 and 3 deletions in Peru

Spatiotemporal dynamics of Plasmodium falciparum histidine-rich protein 2 and 3 deletions in Peru

Screening strategies and laboratory assays to support Plasmodium falciparum histidine-rich protein deletion surveillance: where we are and what is needed

Surveillance of pfhrp2 and pfhrp3 gene deletions among symptomatic Plasmodium falciparum malaria patients in Central Vietnam

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