scholarly journals Prevalence of Pfhrp2 and Pfhrp3 Gene Deletions in Plasmodium Falciparum Isolates and their Performance of Hrp2 Based Malaria Rapid Diagnostic Tests in Three Districts of Ghana

2021 ◽  
Vol 8 (3) ◽  
pp. 22-30
Author(s):  
Aquel Rene Lopez
Keyword(s):  
Plasmodium Falciparum ◽  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Diagnostic Tests ◽  
False Negative ◽  
False Negative Rate ◽  
Rapid Diagnostic Tests ◽  
Malaria Rapid Diagnostic Test ◽  
Exon 2 ◽  
Malaria Rapid Diagnostic Tests

Malaria rapid diagnostic tests (MRDTs) are important for malaria disease management. However, the performance of the RDTs is affected when the targeted antigens in the parasite have a variation or are altogether absent. The most common parasite target antigen in RDTs, Plasmodium falciparum histidine-rich protein 2 (HRP2), has been reported to be absent in some P. falciparum parasites. 371 patient samples, from Akuapem North (58.5%), Atiwa East (21.3%), and from New Juaben (20.2%), were used in the study. PCR provided the highest number, 14.8% (55/371), of positive detections for falciparum infections. Microscopy detected parasites in 20/261 (7.7%) samples, and the minimum parasite density by microscopy was 430 parasites/µL. Out of the 371 samples, 27 (7.3%) were positive by RDT. The highest RDT positivity rate, 13.3% (10/75), was observed at New Juaben. False-negative RDT results were obtained in 43/55 (78.2%) of the negative branded RDT kits. Only two microscopies positive sample were RDT positive. Using 18SrDNA PCR, 55 (14.8%) samples were positive for P. falciparum. In Akuapem North, 79.2 % (19/24) of the PCR positive samples had P. falciparum parasites that lacked exon 2 of PFHRP2. An overall RDT positivity rate of 7.3% (27/371) and false-negative rate of 78.2% (43/55) were observed for the study sites. Plasmodium falciparum parasite populations with deletions of the PFHRP2 and PFHRP3 genes are present in Ghana. There is an urgent need to investigate the prevalence and geographic distribution of these parasites. Keywords: Histidine Rich Protien (HRP), Malaria Rapid Diagnostic Test (MRDT), Malaria, Rapid Diagnostic Test (RDT).

scholarly journals Clinical overlap between malaria and pneumonia: can malaria rapid diagnostic test play a role?

2011 ◽  
Vol 5 (03) ◽  
pp. 199-203 ◽  
Author(s):  
Kingsley Nnanna Ukwaja ◽  
Olufemi B Aina ◽  
Ademola A Talabi
Keyword(s):  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Diagnostic Tests ◽  
Health Centre ◽  
Rapid Diagnostic Tests ◽  
Case Definition ◽  
Sub Saharan Africa ◽  
Malaria Rapid Diagnostic Test ◽  
Chi Square ◽  
Symptom Overlap

Introduction: Malaria and pneumonia account for 40% of mortality among children under five years of age in sub-Saharan Africa. Due to lack of diagnostic facilities, their management is based on the integrated management of childhood illnesses (IMCI) strategy. Symptoms of malaria and pneumonia overlap in African children, necessitating dual IMCI classifications at health centres and treatment with both antibiotics and antimalarials. This study determined the prevalence of malaria-pneumonia symptom overlap and confirmed the diagnosis of malaria in these cases using a rapid diagnostic test. Methodology: Consecutive consultations of 1,216 children (two months to five years old) were documented over a three-month period in a comprehensive health centre. Malaria rapid diagnostic tests were conducted only for children who had symptom overlap. Results: Of the 1,216 children enrolled, 1,090 (90%) reported cough or fever. Among the children fulfilling the malaria case definition, 284 (30%) also met the pneumonia case definition. Twenty-three percent (284) of all children enrolled met the criteria for both malaria and pneumonia. However, only 130 (46%) of them had a positive result for malaria using a malaria rapid diagnostic test. During a malaria-pneumonia overlap, female children (chi-square 5.9, P = 0.01) and children ≥ one year (chi-square 4.8, P = 0.003) were more likely to seek care within two days of fever. Conclusion: Dual treatment with antimalarials and antibiotics in children with malaria-pneumonia overlap may result in unnecessary over-prescription of antimalarial medications. Use of rapid diagnostic tests in their management can potentially avoid over-prescribing of malaria medications.

scholarly journals PO 8271 PFHRP2 GENE DELETIONS IN PLASMODIUM FALCIPARUM AND SCHISTOSOMA MANSONI CO-INFECTIONS: AN EMERGING CHALLENGE FOR MALARIA RAPID DIAGNOSTIC TESTS

2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A25.2-A25
Author(s):  
Hilda Echelibe ◽  
Masumbe Netongo Palmer ◽  
Nji Akindeh ◽  
Wilfred Mbacham
Keyword(s):  
Plasmodium Falciparum ◽  
Schistosoma Mansoni ◽  
Diagnostic Tests ◽  
False Negative ◽  
Rapid Diagnostic Tests ◽  
Sub Saharan Africa ◽  
P Value ◽  
Gene Deletions ◽  
Malaria Rdts ◽  
Malaria Rapid Diagnostic Tests

BackgroundMalaria and schistosomiasis are infections that have a great impact in sub-Saharan Africa based on their high morbidity and mortality rates. We suggest the possibility that the microenvironment created from interactions between the parasites involved generates a pressure on the malaria parasite which could in turn favour the parasite’s adaptation or escape through Pfhrp2 gene deletions. Thus, this study aimed at determining the association between the co-infection with both parasites and false-negative PfHRP2-based malaria rapid diagnostic tests which occur because of these deletions.MethodsThis pilot study was conducted in a total of 149 children aged 7–17 years living in Yorro, located in the Mbam-Inoubou division of the Center region of Cameroon. We collected fresh stool samples from each participant to identify Schistosoma mansoni (Sm) eggs by Kato Katz method and blood samples to identify the ring stages of Plasmodium falciparum (Pf) by thick smear. Malaria rapid diagnostic test and Pfhrp2 gene polymerase chain reaction were performed. The association between the co-infection with Sm/Pf and the false-negative malaria RDTs was determined by the Fisher’s exact test. A p value<0.05 was considered statistically significant.ResultsOur results showed that samples were singly infected with Sm, Pf, co-infected (Sm/Pf) and negative for both infections at frequencies of 12%, 43%, 30.2% and 14.8% respectively. False-negative PfHRP2-based RDTs were observed in 4.7% of the participants. A higher frequency (5/7) of the cases with false-negative malaria RDTs were co-infected with Sm/Pf. A p value of 0.027 showed statistical significance in the association of Sm/Pf co-infection and false-negative PfHRP2-based RDTs.ConclusionA significant association of Plasmodium falciparum and Schistosoma mansoni co-infection with false-negative PfHRP2-based RDTs supports the case for a plausible implication of Pfhrp2 gene deletions, with consequences for malaria rapid diagnostic testing.

scholarly journals Modelling the epidemiology of malaria and spread of HRP2-negative Plasmodium falciparum following the replacement of HRP2-detecting rapid diagnostic tests

2022 ◽  
Vol 2 (1) ◽  
pp. e0000106
Author(s):  
Alisha Chaudhry ◽  
Jane Cunningham ◽  
Qin Cheng ◽  
Michelle L. Gatton
Keyword(s):  
Plasmodium Falciparum ◽  
Diagnostic Tests ◽  
False Negative ◽  
Parasite Prevalence ◽  
Rapid Diagnostic Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Malaria Rapid Diagnostic Tests ◽  
The Impact

Malaria rapid diagnostic tests (RDTs) are dominated by products which use histidine-rich protein 2 (HRP2) to detect Plasmodium falciparum. The emergence of parasites lacking the pfhrp2 gene can lead to high rates of false-negative results amongst these RDTs. One solution to restore the ability to correctly diagnose falciparum malaria is to switch to an RDT which is not solely reliant on HRP2. This study used an agent-based stochastic simulation model to investigate the impact on prevalence and transmission caused by switching the type of RDT used once false-negative rates reached pre-defined thresholds within the treatment-seeking symptomatic population. The results show that low transmission settings were the first to reach the false-negative switch threshold, and that lower thresholds were typically associated with better long-term outcomes. Changing the diagnostic RDT away from a HRP2-only RDT is predicted to restore the ability to correctly diagnose symptomatic malaria infections, but often did not lead to the extinction of HRP2-negative parasites from the population which continued to circulate in low density infections, or return to the parasite prevalence and transmission levels seen prior to the introduction of the HRP2-negative parasite. In contrast, failure to move away from HRP2-only RDTs leads to near fixation of these parasites in the population, and the inability to correctly diagnose symptomatic cases. Overall, these results suggest pfhrp2-deleted parasites are likely to become a significant component of P. falciparum parasite populations, and that long-term strategies are needed for diagnosis and surveillance which do not rely solely on HRP2.

scholarly journals Field Evaluation of Cholkit Rapid Diagnostic Test for Vibrio Cholerae O1 During a Cholera Outbreak in Malawi, 2018

2020 ◽  
Vol 7 (11) ◽  
Author(s):  
Innocent Chibwe ◽  
Watipaso Kasambara ◽  
Mathews Kagoli ◽  
Harry Milala ◽  
Charity Gondwe ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Diagnostic Tests ◽  
Field Evaluation ◽  
Rapid Diagnostic Tests ◽  
Cholera Outbreak ◽  
Vibrio Cholerae O1

Abstract Rapid diagnostic tests (RDTs) for cholera are an important emerging tool for surveillance, yet the currently available tests have several limitations. We assess the performance of a new RDT, Cholkit, during a cholera outbreak in Malawi compared with culture and find a sensitivity of 93.0% (95% CI, 83.0%–98.1%) and a specificity of 95.7% (95% CI, 78.1%–100.0%).

scholarly journals Genetic variation of pfhrp2 in Plasmodium falciparum isolates from Yemen and the performance of HRP2-based malaria rapid diagnostic test

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Wahib M. Atroosh ◽  
Hesham M. Al-Mekhlafi ◽  
Adel Al-Jasari ◽  
Hany Sady ◽  
Ahmed K. Al-Delaimy ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Genetic Variation ◽  
Diagnostic Test ◽  
Rapid Diagnostic Test ◽  
Malaria Rapid Diagnostic Test
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