scholarly journals Deletions of the Plasmodium falciparum histidine-rich protein 2/3 genes are common in field isolates from north-eastern Tanzania

Author(s):  
Robert D. Kaaya ◽  
Reginald A. Kavishe ◽  
Filemon F. Tenu ◽  
Johnson J. Matowo ◽  
Franklin W. Mosha ◽  
...  

Abstract Plasmodium falciparum parasites lacking histidine-rich protein 2 and 3 (pfhrp2/3) genes have been reported in several parts of the world. These deletions are known to compromise the effectiveness of HRP2-based malaria rapid diagnostic tests (HRP2-RDT). The National Malaria Control Programme (NMCP) in Tanzania adopted HRP2-RDTs as a routine tool for malaria diagnosis in 2009 replacing microscopy in many Health facilities. We investigated pfhrp2/3 deletions in 122 samples from two areas with diverse malaria transmission intensities in Northeastern Tanzania. Pfhrp2 deletion was confirmed in 1.6% of samples while pfhrp3 deletion was confirmed in 50% of samples. We did not find parasites with both pfhrp2 and pfhrp3 deletions among our samples. Results from this study highlight the need for systematic surveillance of pfhrp2/3 deletions in Tanzania to understand their prevalence and determine their impact on the performance of mRDT.

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Youssouf Diarra ◽  
Oumar Koné ◽  
Lansana Sangaré ◽  
Lassina Doumbia ◽  
Dade Bouye Ben Haidara ◽  
...  

Abstract Background The current first-line treatments for uncomplicated malaria recommended by the National Malaria Control Programme in Mali are artemether–lumefantrine (AL) and artesunate–amodiaquine (ASAQ). From 2015 to 2016, an in vivo study was carried out to assess the clinical and parasitological responses to AL and ASAQ in Sélingué, Mali. Methods Children between 6 and 59 months of age with uncomplicated Plasmodium falciparum infection and 2000–200,000 asexual parasites/μL of blood were enrolled, randomly assigned to either AL or ASAQ, and followed up for 42 days. Uncorrected and PCR-corrected efficacy results at days 28 and 42. were calculated. Known markers of resistance in the Pfk13, Pfmdr1, and Pfcrt genes were assessed using Sanger sequencing. Results A total of 449 patients were enrolled: 225 in the AL group and 224 in the ASAQ group. Uncorrected efficacy at day 28 was 83.4% (95% CI 78.5–88.4%) in the AL arm and 93.1% (95% CI 89.7–96.5%) in the ASAQ arm. The per protocol PCR-corrected efficacy at day 28 was 91.0% (86.0–95.9%) in the AL arm and 97.1% (93.6–100%) in the ASAQ arm. ASAQ was significantly (p < 0.05) better than AL for each of the aforementioned efficacy outcomes. No mutations associated with artemisinin resistance were identified in the Pfk13 gene. Overall, for Pfmdr1, the N86 allele and the NFD haplotype were the most common. The NFD haplotype was significantly more prevalent in the post-treatment than in the pre-treatment isolates in the AL arm (p < 0.01) but not in the ASAQ arm. For Pfcrt, the CVIET haplotype was the most common. Conclusions The findings indicate that both AL and ASAQ remain effective for the treatment of uncomplicated malaria in Sélingué, Mali.


2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A25.2-A25
Author(s):  
Hilda Echelibe ◽  
Masumbe Netongo Palmer ◽  
Nji Akindeh ◽  
Wilfred Mbacham

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.


2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Adiel K. Mushi ◽  
Julius J. Massaga ◽  
Celine I. Mandara ◽  
Godfrey M. Mubyazi ◽  
Filbert Francis ◽  
...  

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