scholarly journals Malaria case clinical profiles and Plasmodium falciparum parasite genetic diversity: a cross sectional survey at two sites of different malaria transmission intensities in Rwanda

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Fredrick Kateera ◽  
Sam L. Nsobya ◽  
Stephen Tukwasibwe ◽  
Petra F. Mens ◽  
Emmanuel Hakizimana ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Malaria Case ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Plasmodium Falciparum Parasite ◽  
Clinical Profiles ◽  
Falciparum Parasite

scholarly journals Chronic Plasmodium falciparum infections in an area of low intensity malaria transmission in the Sudan

Parasitology ◽  
2000 ◽  
Vol 120 (5) ◽  
pp. 447-456 ◽  
Author(s):  
A. A. HAMAD ◽  
I. M. EL HASSAN ◽  
A. A. EL KHALIFA ◽  
G. I. AHMED ◽  
S. A. ABDELRAHIM ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Marker Gene ◽  
Allelic Polymorphism ◽  
Chain Reaction ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Polymerase Chain ◽  
The Village ◽  
Eastern Sudan

Chronic Plasmodium falciparum malaria infections in a Sudanese village, in an area of seasonal and unstable malaria transmission, were monitored and genetically characterized to study the influence of persistent infection on the immunology and epidemiology of low endemicity malaria. During the October–December malaria season of 1996, 51 individuals out of a population of 420 had confirmed and treated P. falciparum malaria in the village of Daraweesh in eastern Sudan. In a cross-sectional survey carried out in December 1996, an additional 6 individuals were found to harbour a microscopically negative but polymerase chain reaction (PCR)-positive P. falciparum infection. On 1 January 1997, a cohort of 43 individuals aged from 9 to 53, recruited from this group of recently malaria-infected individuals agreed to donate fortnightly blood samples for the next 9 months, the first 6 of which constitute the long Sudanese dry season when transmission falls to undetectable levels. Each blood sample was tested for the presence of persistent malaria infection by microscopy and PCR. Parasite-positive samples were genotyped using PCR assays that detect allelic polymorphism at the MSP-1, MSP-2 and GLURP marker gene loci. Of 43 individuals 16 were found to maintain chronic P. falciparum infections which were continuously genetically characterized.

scholarly journals Effect of 4 years of seasonal malaria chemoprevention on the acquisition of antibodies to Plasmodium falciparum antigens in Ouelessebougou, Mali

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Almahamoudou Mahamar ◽  
Djibrilla Issiaka ◽  
Ahamadou Youssouf ◽  
Sidi M. Niambele ◽  
Harouna M. Soumare ◽  
...  
Keyword(s):  
At Risk ◽  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
Confidence Intervals ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Transmission Season ◽  
Malaria Transmission Season ◽  
Seasonal Malaria Chemoprevention ◽  
Antibody Levels

Abstract Background More than 200 million people live in areas of highly seasonal malaria transmission where Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) was recommended in 2012 by WHO. This strategy is now implemented widely and protected more than 19 million children in 2018. It was previously reported that exposure to SMC reduced antibody levels to AMA1, MSP-142 and CSP, but the duration of exposure to SMC up to three 3 years, had no effect on antibody levels to MSP-142 and CSP. Methods In 2017, a cross-sectional survey was carried out 1 month after the last dose of SMC had been given to children aged 4–5 years randomly selected from areas where SMC had been given for 2 or 4 years during the malaria transmission season. A total of 461 children were enrolled, 242 children in areas where SMC had been implemented for 4 years and 219 children in areas where SMC had been implemented for 2 years. Antibody extracted from dry blood spots was used to measure IgG levels to the malaria antigens CSP, MSP-142 and AMA1 by ELISA. Results The prevalence of antibodies to MSP-142 was similar in children who had received SMC for 4 years compared to those who had received SMC for only 2 years (85.1 vs 86.0%, ajusted odd ratio (aOR) = 1.06, 95% confidence intervals (CI 0.62–1.80), p = 0.80). The prevalence of antibodies to AMA-1 and to CSP was not lower in children who received SMC for 4 years compared to those who had received SMC for only 2 years (95.3 vs 88.8%, aOR = 3.16, 95% CI 1.44–6.95, p = 0.004 for AMA-1; and 91.2 vs 81.9%, aOR = 3.14, 95% CI 1.70–5.76, p < 0.001 for CSP). Median antibody levels for anti-MSP-142 IgG were not significatively inferior in children who had received SMC for four rather than 2 years (0.88 (IQR: 0.64–1.15) and 0.95 ((0.68–1.15), respectively), anti-CSP (1.30 (1.00–1.56) and 1.17 (0.87–1.47)), and anti-AMA-1 (1.45 (1.24–1.68) and 1.41 (1.17–1.64)). Conclusion In an area of high seasonal malaria transmission, children who had received SMC for 4 years did not had lower seropositivity or antibody levels to AMA1, MSP-142 and CSP compared to children who had received SMC for only 2 years suggesting that children who have received SMC for 4 years may not be more at risk of malaria after the cessation of SMC than children who have received SMC for a shorter period.

scholarly journals Increase in the proportion of Plasmodium falciparum with kelch13 C580Y mutation and decline in pfcrt and pfmdr1 mutant alleles in Papua New Guinea

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Naoko Yoshida ◽  
Masato Yamauchi ◽  
Ryosuke Morikawa ◽  
Francis Hombhanje ◽  
Toshihiro Mita
Keyword(s):  
Plasmodium Falciparum ◽  
Papua New Guinea ◽  
New Guinea ◽  
Therapeutic Effects ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
In The Wild ◽  
Nationwide Surveillance ◽  
Greater Mekong Subregion ◽  
C580y Mutation

Abstract Background The C580Y mutation in the Plasmodium falciparum kelch13 gene is the most commonly observed variant in artemisinin-resistant isolates in the Greater Mekong Subregion (GMS). Until 2017, it had not been identified outside the GMS, except for Guyana/Amazonia. In 2017, three parasites carrying the C580Y mutation were identified in Papua New Guinea (PNG). As the C580Y allele rapidly spread in the GMS, there is concern that this mutant is now spreading in PNG. Methods In 2020, a cross-sectional survey was conducted at two clinics in Wewak, PNG. Symptomatic patients infected with P. falciparum were treated with artemether plus lumefantrine following a national treatment policy. Blood samples were obtained before treatment, and polymorphisms in kelch13, pfcrt, and pfmdr1 were determined. Parasite positivity was examined on day 3. The results were compared with those of previous studies conducted in 2002, 2003, and 2016–2018. Results A total of 94 patients were included in this analysis. The proportion of C580Y was significantly increased (2.2% in 2017, 5.7% in 2018, and 6.4% in 2020; p = 4.2 × 10–3). A significant upward trend was observed in the wild-type proportion for pfcrt (1.9% in 2016 to 46.7% in 2020; p = 8.9 × 10–16) and pfmdr1 (59.5% in 2016 to 91.4% in 2020; p = 2.3 × 10–6). Among 27 patients successfully followed on day 3, including three with C580Y infections, none showed positive parasitaemia. Conclusions Under the conditions of significant increases in pfcrt K76 and pfmdr1 N86 alleles in PNG, the increase in kelch13 C580Y mutants may be a warning indicator of the emergence of parasites resistant to the currently used first-line treatment regimen of artemether plus lumefantrine. Therefore, nationwide surveillance of molecular markers for drug resistance and assessment of its therapeutic effects are important.

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