scholarly journals Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions among patients in the DRC enrolled from 2017 to 2018

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessica N. McCaffery ◽  
Douglas Nace ◽  
Camelia Herman ◽  
Balwan Singh ◽  
Eric Mukomena Sompwe ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Sub Saharan Africa ◽  
Gene Deletions ◽  
Blood Samples ◽  
Antigen Assay ◽  
Single Deletion ◽  
Republic Of The Congo ◽  
Sub Saharan ◽  
High Concentrations ◽  
Study Sites

AbstractRapid diagnostic tests (RDTs) detecting histidine-rich protein 2 (HRP2) and HRP3 are widely used throughout sub-Saharan Africa (SSA) to diagnose Plasmodium falciparum malaria. However, multiple SSA countries have reported pfhrp2 and pfhrp3 (pfhrp2/3) gene deletions. Blood samples (n = 1109) collected from patients with P. falciparum infection from six health facilities throughout the Democratic Republic of the Congo (DRC) from March 2017 to January 2018 were evaluated for pfhrp2/3 deletions. Samples were assayed for HRP2, pan-Plasmodium LDH (pLDH) and aldolase (pAldolase) antigens by bead-based multiplex antigen assay. Samples with low HRP2 concentration compared to pLDH and pAldolase antigens were selected for further pfhrp2/3 genotyping PCRs. The majority of blood samples (93.3%, 1035/1109) had high concentrations of the HRP2 antigen. Single deletions of pfhrp2 were identified in 0.27% (3/1109) of screened samples, with one sample from each of the Kapolowe, Mikalayi, and Rutshuru study sites. A pfhrp3 single deletion (0.09%, 1/1109) was found in the Kapolowe site. Dual pfhrp2 and pfhrp3 deletions were not observed. Due to, the low numbers of pfhrp2 deletions and the sporadic locations of these deletions, the use of HRP2-based RDTs appears to still be appropriate for these locations in DRC.

scholarly journals Deletions of the Plasmodium falciparum pfhrp2 and pfhrp3 genes among patients enrolled at six locations in the DRC: 2017–2018

2021 ◽  
Author(s):  
Jessica N. McCaffery ◽  
Douglas Nace ◽  
Camelia Herman ◽  
Balwan Singh ◽  
Eric Mukomena Sompwe ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Sub Saharan Africa ◽  
Gene Deletions ◽  
Blood Samples ◽  
Antigen Assay ◽  
Single Deletion ◽  
Republic Of The Congo ◽  
Sub Saharan ◽  
High Concentrations ◽  
Study Sites

Abstract Background: Rapid diagnostic tests (RDTs) detecting histidine-rich protein 2 (HRP2) and HRP3 are widely used throughout sub-Saharan Africa (SSA) to diagnose Plasmodium falciparum malaria. However, multiple SSA countries have reported pfhrp2 and pfhrp3 (pfhrp2/3) gene deletions. Methods: Blood samples (n=1109) collected from patients with P. falciparum infection from six health facilities throughout the Democratic Republic of the Congo (DRC) from March 2017 to January 2018 were evaluated for pfhrp2/3 deletions. Samples were assayed for HRP2, pan-Plasmodium LDH (pLDH) and aldolase (pAldolase) antigens by bead-based multiplex antigen assay. Samples with low HRP2 concentration compared to pLDH and pAldolase antigens were selected for further pfhrp2/3 genotyping PCRs.Results: The majority of blood samples (93.3%, 1035/1109) had high concentrations of the HRP2 antigen. Single deletions of pfhrp2 were identified in 0.27% (3/1109) of screened samples, with one sample from each of the Kapolowe, Mikalayi, and Rutshuru study sites. A pfhrp3 single deletion (0.09%, 1/1109) was found in the Kapolowe site. Dual pfhrp2 and pfhrp3 deletions were not observed. Conclusions: Due to, the low numbers of pfhrp2 deletions and the sporadic locations of these deletions, the use of HRP2-based RDTs appears to still be appropriate for these locations in DRC.

scholarly journals HRP2 and HRP3 cross-reactivity and implications for HRP2-based RDT use in regions with Plasmodium falciparum hrp2 gene deletions

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Amy Kong ◽  
Scott A. Wilson ◽  
Yong Ah ◽  
Douglas Nace ◽  
Eric Rogier ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Clinical Sample ◽  
Cross Reactivity ◽  
Sub Saharan Africa ◽  
Gene Deletions ◽  
Clinical Sensitivity ◽  
Gene Coding ◽  
Malaria Rapid Diagnostic Tests ◽  
Sub Saharan ◽  
Multiplex Bead

Abstract Background The Plasmodium falciparum antigen histidine rich protein 2 (HRP2) is a preferred target for malaria rapid diagnostic tests (RDTs) because of its abundant production by the parasite and thermal stability. As a result, a majority of RDTs procured globally target this antigen. However, previous reports from South America and recent reports from sub-Saharan Africa and Asia indicate that certain P. falciparum parasites have deletions of the gene coding for HRP2. The HRP2 antigen is paralogous to another P. falciparum antigen HRP3 and some antibodies to HRP2 cross-react with HRP3. Multiple parasites have been described with deletions of one or both hrp2 and hrp3 genes. It is unclear how the various combinations of hrp2 and hrp3 deletion genotypes affect clinical sensitivity of HRP2-based RDTs. Methods Cross-reactivity between HRP2 and HRP3 was tested on malaria RDTs using culture-adapted P. falciparum parasites with both hrp2 and hrp3 intact or with one or both genes deleted. Ten-fold serial dilutions of four culture-adapted P. falciparum parasites [3D7 (hrp2+/hrp3+), Dd2 (hrp2−/hrp3+), HB3 (hrp2+/hrp3−) and 3BD5 (hrp2−/hrp3−)] ranging from 100,000 to 0.01 parasites/µL were prepared. HRP2, Plasmodium lactate dehydrogenase (pLDH) and aldolase concentrations were determined for the diluted samples using a multiplex bead assay. The samples were subsequently tested on three RDT products designed to detect P. falciparum by HRP2 alone or in combination with pLDH. Results At parasite densities of approximately 1000 parasites/µL, parasites that expressed either hrp2 or hrp3 were detected by all three RDTs. Multiplex based antigen measurement using HRP2- conjugated beads demonstrated higher antigen concentration when both hrp2 and hrp3 genes were intact (3D7 parasites, 47.9 ng/ml) compared to HB3 (3.02 ng/mL) and Dd2 (0.20 ng/mL) strains that had one gene deleted. 3D7 at 10 parasites/µL (0.45 ng/mL) was reactive on all three RDT products whereas none of the other parasites were reactive at that density. Conclusions Above a certain antigen threshold, HRP3 cross-reactivity on HRP2-based RDTs is sufficient to mask the effects of deletions of hrp2 only. Studies of hrp2 deletion and its effects on HRP2-based RDTs must be studied alongside hrp3 deletions and include clinical sample reactivity on HRP2-based tests.

scholarly journals Author response: Modelling the drivers of the spread of Plasmodium falciparum hrp2 gene deletions in sub-Saharan Africa

2017 ◽  
Author(s):  
Oliver J Watson ◽  
Hannah C Slater ◽  
Robert Verity ◽  
Jonathan B Parr ◽  
Melchior K Mwandagalirwa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Sub Saharan Africa ◽  
Author Response ◽  
Gene Deletions ◽  
Sub Saharan ◽  
Response Modelling

Conflicts in Biafra, Katanga and Cabinda as a result of the geopolitical legacy of colonialism

2020 ◽  
Vol 2020 (10-3) ◽  
pp. 238-246
Author(s):  
Olga Dzhenchakova
Keyword(s):  
Democratic Republic ◽  
Economic Factor ◽  
Colonial Period ◽  
Sub Saharan Africa ◽  
Negative Consequences ◽  
Post Colonial ◽  
Republic Of The Congo ◽  
Sub Saharan ◽  
The Republic ◽  
The Impact

The article considers the impact of the colonial past of some countries in sub-Saharan Africa and its effect on their development during the post-colonial period. The negative consequences of the geopolitical legacy of colonialism are shown on the example of three countries: Nigeria, the Democratic Republic of the Congo and the Republic of Angola, expressed in the emergence of conflicts in these countries based on ethno-cultural, religious and socio-economic contradictions. At the same time, the focus is made on the economic factor and the consequences of the consumer policy of the former metropolises pursuing their mercantile interests were mixed.

scholarly journals Promoting Scale-Up Across a Global Project Platform: Lessons from the Evidence to Action Project

2021 ◽  
Author(s):  
Laura Ghiron ◽  
Eric Ramirez-Ferrero ◽  
Rita Badiani ◽  
Regina Benevides ◽  
Alexis Ntabona ◽  
...  
Keyword(s):  
Family Planning ◽  
Scale Up ◽  
Scaling Up ◽  
Sub Saharan Africa ◽  
Health System Strengthening ◽  
Country Level ◽  
Look Ahead ◽  
Republic Of The Congo ◽  
Sub Saharan ◽  
Multi Stakeholder

AbstractThe USAID-funded flagship family planning service delivery project named Evidence to Action (E2A) worked from 2011 to 2021 to improve family planning and reproductive health for women and girls across seventeen nations in sub-Saharan Africa using a “scaling-up mindset.” The paper discusses three key lessons emerging from the project’s experience with applying ExpandNet’s systematic approach to scale up. The methodology uses ExpandNet/WHO’s scaling-up framework and guidance tools to design and implement pilot or demonstration projects in ways that look ahead to their future scale-up; develop a scaling-up strategy with local stakeholders; and then strategically manage the scaling-up process. The paper describes how a scaling-up mindset was engendered, first within the project’s technical team in Washington and then how they subsequently sought to build capacity at the country level to support scale-up work throughout E2A’s portfolio of activities. The project worked with local multi-stakeholder resource teams, often led by government officials, to equip them to lead the scale-up of family planning and health system strengthening interventions. Examples from project experience in the Democratic Republic of the Congo, Kenya, Nigeria, and Uganda illustrating key concepts are discussed. E2A also established a community of practice on systematic approaches to scale up as a platform for sharing learning across a variety of technical agencies engaged in scale-up work and to create learning opportunities for interacting with thought leaders around critical scale-up issues.

scholarly journals Protest, Internet Activism, and Sociopolitical Change in Sub-Saharan Africa

2020 ◽  
pp. 000276422097506
Author(s):  
Oscar Mateos ◽  
Carlos Bajo Erro
Keyword(s):  
Field Work ◽  
Sub Saharan Africa ◽  
Third Wave ◽  
Sociopolitical Change ◽  
The Third ◽  
Political Protests ◽  
Street Protest ◽  
Internet Activism ◽  
Republic Of The Congo ◽  
Sub Saharan

Sub-Saharan Africa has been the scene of a sizeable wave of social and political protests in recent years. These protests have many aspects in common, while at the same time there is a certain historic continuity connecting them to previous protests, with which they also have much in common. What makes them new, however, is a hybrid nature that combines street protest and online action, making them similar to protests occurring in other parts of the world during the same period. Based on a literature review and field work on three countries, Senegal, Burkina Faso, and the Democratic Republic of the Congo, this article addresses some of the main features of what some authors have called the “third wave of African protests.” The study points out how the digital environment is galvanizing a new process of popular opposition and enabling both greater autonomy for actors promoting the protests and greater interaction at the regional level. With the sociopolitical impact in the short and medium term still uncertain, the third wave of African protests is giving birth to a new political and democratic culture in the region as a whole.

scholarly journals Kelch 13-propeller polymorphisms in Plasmodium falciparum from Jazan region, southwest Saudi Arabia

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Ommer Mohammed Dafalla ◽  
Mohammed Alzahrani ◽  
Ahmed Sahli ◽  
Mohammed Abdulla Al Helal ◽  
Mohammad Mohammad Alhazmi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Saudi Arabia ◽  
Parasite Clearance ◽  
Sub Saharan Africa ◽  
Local Alignment ◽  
Nucleotide Polymorphisms ◽  
Gene Encoding ◽  
Synonymous Mutations ◽  
Search Tool ◽  
Sub Saharan

Abstract Background Artemisinin-based combination therapy (ACT) is recommended at the initial phase for treatment of Plasmodium falciparum, to reduce morbidity and mortality in all countries where malaria is endemic. Polymorphism in portions of P. falciparum gene encoding kelch (K13)-propeller domains is associated with delayed parasite clearance after ACT. Of about 124 different non-synonymous mutations, 46 have been identified in Southeast Asia (SEA), 62 in sub-Saharan Africa (SSA) and 16 in both the regions. This is the first study designed to analyse the prevalence of polymorphism in the P. falciparum k13-propeller domain in the Jazan region of southwest Saudi Arabia, where malaria is endemic. Methods One-hundred and forty P. falciparum samples were collected from Jazan region of southwest Saudi Arabia at three different times: 20 samples in 2011, 40 samples in 2016 and 80 samples in 2020 after the implementation of ACT. Plasmodium falciparum kelch13 (k13) gene DNA was extracted, amplified, sequenced, and analysed using a basic local alignment search tool (BLAST). Results This study obtained 51 non-synonymous (NS) mutations in three time groups, divided as follows: 6 single nucleotide polymorphisms (SNPs) ‘11.8%’ in samples collected in 2011 only, 3 (5.9%) in 2011and 2016, 5 (9.8%) in 2011 and 2020, 5 (9.8%) in 2016 only, 8 (15.7%) in 2016 and 2020, 14 (27.5%) in 2020 and 10 (19.6%) in all the groups. The BLAST revealed that the 2011 isolates were genetically closer to African isolates (53.3%) than Asian ones (46.7%). Interestingly, this proportion changed completely in 2020, to become closer to Asian isolates (81.6%) than to African ones (18.4%). Conclusions Despite the diversity of the identified mutations in the k13-propeller gene, these data did not report widespread artemisinin-resistant polymorphisms in the Jazan region where these samples were collected. Such a process would be expected to increase frequencies of mutations associated with the resistance of ACT.

Detection of Genetic markers associated with Plasmodium falciparum drug resistance among malaria patients in Kaduna State, Nigeria

2021 ◽  
Vol 42 (2) ◽  
pp. 206-213
Author(s):  
G.Y. Benjamin ◽  
H.I. Inabo ◽  
M.H.I. Doko ◽  
B.O. Olayinka
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Phylogenetic Tree ◽  
Genetic Markers ◽  
Cross Sectional Study ◽  
Sub Saharan Africa ◽  
Health Concern ◽  
Cross Sectional ◽  
Blood Samples ◽  
Test Kit

Malaria is a disease of public health concern in Nigeria and sub-Saharan Africa. It is caused by intracellular parasites of the genus Plasmodium. The aim of this study was to detect genetic markers associated with Plasmodium falciparum drug resistance among malaria patients in Kaduna State, Nigeria. The study was a cross-sectional study that lasted from May 2018 to October 2018. Three hundred blood samples were collected from consenting individuals attending selected hospitals, in the three senatorial districts of Kaduna State, Nigeria. Structured questionnaire were used to obtain relevant data from study participants. The blood samples were screened for malaria parasites using microscopy and rapid diagnostic test kit. Polymerase Chain Reaction was used for detection of the drug resistance genes. Pfcrt, pfmdr1, pfdhfr, pfdhps and pfatpase6 genes were detected at expected amplicon sizes from the malaria positive samples. The pfatpase6 PCR amplicons were sequenced and a phylogenetic tree was created to determine their relatedness. Result showed that Pfcrt (80%) had the highest prevalence, followed by pfdhfr (60%), pfmdr1 (36%) and pfdhps (8%). Pfatpase6 was also detected in 73.3% of the samples, and a phylogenetic tree showed relatedness between the pfatpase6  sequences in this study and those deposited in the GenBank. In conclusion, the study detected that Plasmodium falciparum genes were associated with drug resistance to commonly used antimalarials.

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