scholarly journals Improved Detectability of Plasmodium falciparum Clones with Repeated Sampling in Incident and Chronic Infections in Burkina Faso

2021 ◽  
Author(s):  
Aissata Barry ◽  
Shehu S. Awandu ◽  
Alfred B. Tiono ◽  
Lynn Grignard ◽  
Teun Bousema ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Burkina Faso ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Median Number ◽  
Chronic Infections ◽  
Repeated Sampling ◽  
Single Time Point ◽  
Complexity Of Infection ◽  
Time Point

We evaluated the detectability of Plasmodium falciparum clones when assessed on 3 consecutive days in incident and chronic infections in naturally exposed children living in an area of intense malaria transmission in Burkina Faso. The median number of clones by merozoite surface protein 2 (MSP2) genotyping was 3 (interquartile range [IQR] 2–5) in incident infections compared with 6 (IQR 4–8) in chronic infections (P < 0.0001). When all clones detected on days 1-3 were considered as true complexity of infection, sampling on day 1 detected only 69.4% (109/157) or 68.3% (228/334) of all clones in incident and chronic infections, respectively. Our findings demonstrate that a large proportion of clones are missed by single time-point sampling. In addition, because of the high complexity of infection early in incident infections, our data suggest many infections may be caused by genetically complex inocula.

scholarly journals Estimating True Antimalarial Efficacy by Heteroduplex Tracking Assay in Patients with Complex Plasmodium falciparum Infections

2006 ◽  
Vol 51 (2) ◽  
pp. 521-527 ◽  
Author(s):  
Jesse J. Kwiek ◽  
Alisa P. Alker ◽  
Emily C. Wenink ◽  
Marjorie Chaponda ◽  
Linda V. Kalilani ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Treatment Efficacy ◽  
Parasite Burden ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Immunodeficiency Virus ◽  
High Prevalence ◽  
Before And After ◽  
Complexity Of Infection

ABSTRACT Heteroduplex tracking assays (HTAs) of Plasmodium falciparum merozoite surface protein 1 block-2 were used to assess complexity of infection and treatment efficacy in a trial of three antimalarial treatments in 141 Malawian pregnant women. An elevated complexity of infection (COI) was associated with anemia, parasite burden, and human immunodeficiency virus infection but was not associated with age or gravidity. Comparisons of HTA patterns before and after treatment allowed the classification of 20 of 30 (66%) recurrent episodes as either definite treatment failures or reinfections. An elevated COI was strongly associated with treatment failure (P = 0.003). An algorithm was developed to assign a probability of failure for the 10 indeterminate participants, some of whose infections shared a single variant of high prevalence (>10%). By summing these probabilities, treatment efficacy was estimated.

scholarly journals Familial Correlation of Immunoglobulin G Subclass Responses to Plasmodium falciparum Antigens in Burkina Faso

2001 ◽  
Vol 69 (2) ◽  
pp. 996-1001 ◽  
Author(s):  
Christophe Aucan ◽  
Yves Traoré ◽  
Francis Fumoux ◽  
Pascal Rihet
Keyword(s):  
Plasmodium Falciparum ◽  
Burkina Faso ◽  
Immunoglobulin G ◽  
Genetic Factors ◽  
Vaccine Development ◽  
Correlation Coefficients ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Blood Stage ◽  
Igg Subclass

ABSTRACT Host genes are thought to determine the immune response to malaria infection and the outcome. Cytophilic antibodies have been associated with protection, whereas noncytophilic antibodies against the same epitopes may block the protective activity of the protective ones. To assess the contribution of genetic factors to immunoglobulin G (IgG) subclass responses against conserved epitopes and Plasmodium falciparum blood-stage extracts, we analyzed the isotypic distribution of the IgG responses in 366 individuals living in two differently exposed areas in Burkina Faso. We used one-way analysis of variance and pairwise estimators to calculate sib-sib and parent-offspring correlation coefficients, respectively. Familial patterns of inheritance of IgG subclass responses to defined antigens and P. falciparum extracts appear to be similar in the two areas. We observed a sibling correlation for the IgG, IgG1, IgG2, IgG3, and IgG4 responses directed against ring-infected-erythrocyte surface antigen, merozoite surface protein 1 (MSP-1), MSP-2, andP. falciparum extract. Moreover, a parent-offspring correlation was found for several IgG subclass responses, including the IgG, IgG1, IgG2, IgG3, and IgG4 responses directed against conserved MSP-2 epitopes. Our results indicated that the IgG subclass responses against P. falciparum blood-stage antigens are partly influenced by host genetic factors. The localization and identification of these genes may have implications for immunoepidemiology and vaccine development.

scholarly journals Temporal Variation of the Merozoite Surface Protein-2 Gene of Plasmodium falciparum

1998 ◽  
Vol 66 (1) ◽  
pp. 239-246 ◽  
Author(s):  
Damon Eisen ◽  
Helen Billman-Jacobe ◽  
Vikki F. Marshall ◽  
Dave Fryauff ◽  
Ross L. Coppel
Keyword(s):  
Plasmodium Falciparum ◽  
Pcr Amplification ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Amino Acid Sequences ◽  
Gene Encoding ◽  
Blood Samples ◽  
Irian Jaya ◽  
Time Points ◽  
Time Point

ABSTRACT Extensive polymorphism of key parasite antigens is likely to hamper the effectiveness of subunit vaccines against Plasmodium falciparum infection. However, little is known about the extent of the antigenic repertoire of naturally circulating strains in different areas where malaria is endemic. To address this question, we conducted a study in which blood samples were collected from parasitemic individuals living within a small hamlet in Western Irian Jaya and subjected to PCR amplification using primers that would allow amplification of the gene encoding merozoite surface protein-2 (MSP2). We determined the nucleotide sequence of the amplified product and compared the deduced amino acid sequences to sequences obtained from samples collected in the same hamlet 29 months previously.MSP2 genes belonging to both major allelic families were observed at both time points. In the case of the FC27 MSP2family, we observed that the majority of individuals were infected by parasites expressing the same form of MSP2. Infections with parasites expressing 3D7 MSP2 family alleles were more heterogeneous. No MSP2 alleles observed at the earlier time point were detectable at the later time point, either for the population as a whole or for individuals who were assayed at both time points. We examined a subset of the infected patients by using blood samples taken between the two major surveys. In no patients could we detect reinfection by a parasite expressing a previously encountered form of MSP2. Our results are consistent with the possibility that infection induces a form of strain-specific immune response against the MSP2 antigen that biases against reinfection by parasites bearing identical forms of MSP2.

scholarly journals Allelic diversity of merozoite surface protein genes (msp1 and msp2) and clinical manifestations of Plasmodium falciparum malaria cases in Aceh, Indonesia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Kurnia Fitri Jamil ◽  
Nandha Rizki Pratama ◽  
Sylvia Sance Marantina ◽  
Harapan Harapan ◽  
Muhammad Riza Kurniawan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Liver Function ◽  
Severe Malaria ◽  
Clinical Manifestation ◽  
Allelic Diversity ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Malaria Control Programme ◽  
Co Morbidity ◽  
Aceh Province

Abstract Background The malaria control programme in Indonesia has successfully brought down malaria incidence in many parts in Indonesia, including Aceh Province. Clinical manifestation of reported malaria cases in Aceh varied widely from asymptomatic, mild uncomplicated to severe and fatal complications. The present study aims to explore the allelic diversity of merozoite surface protein 1 gene (msp1) and msp2 among the Plasmodium falciparum isolates in Aceh Province and to determine their potential correlation with the severity of malaria clinical manifestation. Methods Screening of over 500 malaria cases admitted to the hospitals in 11 districts hospital within Aceh Province during 2013–2015, identified 90 cases of P. falciparum mono-infection without any co-morbidity. The subjects were clinically phenotyped and parasite DNA was extracted and polymerase chain reaction (PCR) amplified for the msp1 and msp2 allelic subfamilies. Results Analysis of clinical manifestation revealed that fever-chill is the most frequent symptom. Based on WHO criteria showed 19 cases were classified as severe and 71 as mild malaria. Analysis of msp1 gene revealed the presence of K1 allele subfamily in 34 subjects, MAD20 in 42 subjects, RO33 in 1 subject, and mixed allelic of K1 + MAD20 in 5 subjects, K1 + RO33 in 4 subjects, and MAD20 + RO33 in 4 subjects. Analysis of msp2 gene revealed 34 subjects carried the FC27 allelic subfamily, 37 subjects carried the 3D7 and 19 subjects carried the mixed FC27 + 3D7. Analysis of multiplicity of infection revealed that msp1 alleles is slightly higher than msp2 with the mean of MOI were 2.69 and 2.27, respectively. Statistical analysis to determine the association between each clinical manifestation and msp1 and msp2 alleles revealed that liver function abnormal value was associated with the msp2 mixed alleles (odds ratio (OR):0.13; 95%CI: 0.03–0.53). Mixed msp1 of K1 + RO33 was associated with severe malaria (OR: 28.50; 95%CI: 1.59–1532.30). Conclusion This study found a strong association between severe malaria in Aceh with subjects carrying the msp1 mixed alleles of K1 and RO33. The liver function abnormal value associated with the msp2 mixed allelic subfamilies. Further study in different geographic areas is recommended.

scholarly journals Plasmodium falciparum merozoite surface protein 2 is unstructured and forms amyloid-like fibrils

2009 ◽  
Vol 166 (2) ◽  
pp. 159-171 ◽  
Author(s):  
Christopher G. Adda ◽  
Vince J. Murphy ◽  
Margaret Sunde ◽  
Lynne J. Waddington ◽  
Jesse Schloegel ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Falciparum Merozoite
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