Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Malar J ; 20(1): 32, 2021 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-33422080

RESUMEN

BACKGROUND: Malaria remains highly endemic in Cameroon. The rapid emergence and spread of drug resistance was responsible for the change from monotherapies to artemisinin-based combinations. This systematic review and meta-analysis aimed to determine the prevalence and distribution of Plasmodium falciparum drug resistance markers within an evolving efficacy of anti-malarial drugs in Cameroon from January 1998 to August 2020. METHODS: The PRISMA-P and PRISMA statements were adopted in the inclusion of studies on single nucleotide polymorphisms (SNPs) of P. falciparum anti-malarial drug resistance genes (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, Pfatp6, Pfcytb and Pfk13). The heterogeneity of the included studies was evaluated using the Cochran's Q and I2 statistics. The random effects model was used as standard in the determination of heterogeneity between studies. RESULTS: Out of the 902 records screened, 48 studies were included in this aggregated meta-analysis of molecular data. A total of 18,706 SNPs of the anti-malarial drug resistance genes were genotyped from 47,382 samples which yielded a pooled prevalence of 35.4% (95% CI 29.1-42.3%). Between 1998 and 2020, there was significant decline (P < 0.0001 for all) in key mutants including Pfcrt 76 T (79.9%-43.0%), Pfmdr1 86Y (82.7%-30.5%), Pfdhfr 51I (72.2%-66.9%), Pfdhfr 59R (76.5%-67.8%), Pfdhfr 108 N (80.8%-67.6%). The only exception was Pfdhps 437G which increased over time (30.4%-46.9%, P < 0.0001) and Pfdhps 540E that remained largely unchanged (0.0%-0.4%, P = 0.201). Exploring mutant haplotypes, the study observed a significant increase in the prevalence of Pfcrt CVIET mixed quintuple haplotype from 57.1% in 1998 to 57.9% in 2020 (P < 0.0001). In addition, within the same study period, there was no significant change in the triple Pfdhfr IRN mutant haplotype (66.2% to 67.3%, P = 0.427). The Pfk13 amino acid polymorphisms associated with artemisinin resistance were not detected. CONCLUSIONS: This review reported an overall decline in the prevalence of P. falciparum gene mutations conferring resistance to 4-aminoquinolines and amino alcohols for a period over two decades. Resistance to artemisinins measured by the presence of SNPs in the Pfk13 gene does not seem to be a problem in Cameroon. Systematic review registration PROSPERO CRD42020162620.

2.
Pan Afr Med J ; 35: 13, 2020.
Artículo en Francés | MEDLINE | ID: mdl-32341734

RESUMEN

Introduction: The alloimmunization of the ABO blood group system is involved in neonatal jaundice with a considerable overall prevalence. The role of ABO incompatibility is relatively little known. The purpose of this study was to investigate neonatal jaundice due to feto-maternal ABO incompatibilities and to determine the link between the hemolysins value in the mother and the degree of jaundice observed in the infant. Methods: We conducted a cross-sectional study from June to November 2015. The study population was exclusively composed of moms who were blood type O with children who were a different blood type hospitalized in the Department of Neonatology at the Reference Hospital in the city of Yaoundé. Statistical analyses were performed using the GraphPadPrism 6 software with a confidence interval of 95%. Results: Hemolysins frequency was of 20.58% (7/34) and anti-A hemolysin was the most common type (85.7%; 6/7). The new-born who had blood type B had a greater concentration of bilirubin levels compared to those of the AB group (p = 0.01). Multiparity was not associated with the presence of hemolysin (p = 0.8) as well as blood type of the infant was not associated with the occurrence of the hemolysins in the mother (p = 0.5). Conclusion: Early neonatal jaundice or protracted neonatal jaundice are also caused by hemolysins anti-A and anti-B derived from the allo-ABO immunization. A study on a larger sample is recommended for better assessment.

3.
Front Immunol ; 10: 2827, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31849991

RESUMEN

Background: This study aimed to investigate the association of plasma levels of IL-33, a mucosal alarmin known to elicit type-2 immunity, with infection and liver fibrosis profiles of school children from an endemic area for Schistosoma mansoni, malaria and hepatitis (B & C) in rural Cameroon. Methods: A cross-sectional study enrolling schoolchildren from 5 public schools was conducted. Single schistosomiasis, malaria and hepatitis infections or co-infections were assessed by kato katz, microscopy, and rapid diagnostic tests, respectively. Hepatic fibrosis was assessed by ultrasound according to WHO Niamey guidelines and plasma levels of Interleukin 33 were determined by ELISA. All statistics were performed using R studio software. Principal findings: We found a prevalence of 13.5% (37/275), 18.2% (50/275), and 8% (22/275), respectively for schistosomiasis, malaria and hepatitis (B or C) single infections. Only 7.6% (21/275) of co-infections were reported. Although Plasma IL-33 showed a minimal negative risk for schistosomiasis infection (AOR 0.99; 95% CI 0.97-1.01), S. mansoni infected participants had lower levels of plasma IL-33 (p = 0.003) which decreased significantly as eggs burdens increased (p = 0.01) with a negative Pearson coefficient of r = -0.22. Hepatic fibrosis occurred in 47.3% (130/275) of our study population independently from plasma levels of IL-33 (AOR 1.00; 95% CI 0.99-1.01). Conclusion/Significance: Our data failed to show an association between plasma IL-33 levels and liver disease but convincingly report on a negative association between plasma IL-33 levels and schistosomiasis infection and egg burden in school children from a polyparasitic schistosomiasis endemic area.


Asunto(s)
Interleucina-33/sangre , Esquistosomiasis mansoni/sangre , Adolescente , Animales , Camerún/epidemiología , Niño , Coinfección/sangre , Coinfección/epidemiología , Femenino , Hepatitis/sangre , Hepatitis/epidemiología , Humanos , Cirrosis Hepática/sangre , Cirrosis Hepática/epidemiología , Malaria/sangre , Malaria/epidemiología , Masculino , Prevalencia , Población Rural , Schistosoma mansoni , Esquistosomiasis mansoni/epidemiología
4.
Front Immunol ; 9: 2295, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30356757

RESUMEN

Background and Methods: Schistosomiasis is debilitating and reported to impair immune responsiveness of infected hosts. In Cameroon, mass drug administration (MDA) is used in schoolchildren to reduce transmission of S. haematobium and S. mansoni. The effects of MDA and the impact of schistosomiasis on the titers of antibodies in vaccinated children have been poorly studied. We therefore assessed the prevalence of schistosomiasis in schoolchildren, eight months after MDA, in two locations: Barombi Koto (BK), endemic for S. haematobium (N = 169) and Yoro (Y), endemic for S. mansoni (N = 356). Age, gender, residence time and frequency of contact with river water were assessed as risk factors for infection and morbidity in both localities. In 70 schoolchildren from BK and 83 from Y, ultrasound was used to assess morbidity according to the WHO guidelines. Evaluation of measles antibodies was performed in previously vaccinated schoolchildren (14 with S. haematobium and 12 egg-negative controls from BK and 47 with S. mansoni and12 egg-negative controls from Y). Principal Findings and conclusions: The prevalence of S. haematobium was 25. 4% in BK (43/169) and 34.8% for S. mansoni in Y (124/356), indicating the persistent transmission of schistosomiasis despite MDA. Older age (AOR 1.31; 95%CI 1.12-1.54) and higher frequencies of exposure to river water (AOR 1.99; 95%CI 1.03-3.86) were identified as risks for infection in BK whereas only older age (OR 1.15; 95%CI 1.04-1.27) was a risk for infection in Y. Bladder pathology (score 2 to 5) was observed in 29.2% (7/24) of egg-positive children in BK and liver pathology (pattern C) in 31.1% (19/61) of egg-positive children in Y. There was a positive correlation between S. haematobium egg burden and bladder pathology (AOR 1.01; 95% CI 0.99-1.02) and positive correlation between S. mansoni-driven liver pathology and female gender (AOR 3.01; 95% CI 0.88-10.26). Anti-measles antibodies in vaccinated children were significantly lower in S. mansoni-infected when compared to egg-negative controls (p = 0.001), which was not observed in the S. haematobium-infected group from BK. Our results demonstrate a questionable efficacy of MDA alone in halting schistosomiasis transmission and confirm a possible immunomodulatory effect of S. mansoni on response to vaccines.


Asunto(s)
Vacuna Antisarampión/inmunología , Sarampión/inmunología , Sarampión/prevención & control , Población Rural , Schistosoma/inmunología , Esquistosomiasis/inmunología , Esquistosomiasis/parasitología , Adolescente , Adulto , Animales , Camerún/epidemiología , Niño , Femenino , Interacciones Huésped-Parásitos/inmunología , Interacciones Huésped-Patógeno/inmunología , Humanos , Masculino , Sarampión/virología , Morbilidad , Vigilancia de la Población , Prevalencia , Factores de Riesgo , Adulto Joven
5.
Pathog Glob Health ; 108(7): 323-33, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25388906

RESUMEN

BACKGROUND: In this post-hoc analysis, we determined the influence of single nucleotide polymorphisms in host candidate immune genes on the outcome of drug resistant malaria in Cameroon. METHODS: Human DNA from 760 patients from a previous clinical trial was subjected to mass spectrometry-based single nucleotide polymorphism (SNP) genotyping. Allele frequencies of candidate immune genes were calculated for 62 SNPs on 17 human chromosomes for their possible involvement in clearance of drug-resistant parasites with the triple mutations of pfcrt76T, pfmdr86Y, and pfmdr1246Y (TY) and pfdhfr51I, pfdhfr59R, pfdhfr108N, and pfdhps437G (IRNG) which were determined by dotblot or PCR-restriction analysis. Differences in SNP frequencies and association analysis were carried out by comparing Chi-square odds ratios (ORs) and stratified by Mantel-Haenzel statistics. An adjusted P value (OR) <0·0008 was considered significant. RESULTS: Post-treatment drug failure rates were amodiaquine (36·4%); sulpadoxine/pyrimethamine-amodiaquine combination (15·4%); and sulphadoxine/pyrimethamine (18·1%). SNPs in IL22, IL-4R1, and CD36 appeared to have been associated with clearance of resistant parasites [p  =  0·017, OR (C allele):1·44, 95% CI (OR): 1·06-1·95]; [P  =  0·014, OR  =  1·31, 95% CI (OR): 1·07-1·83]; [P  =  5·78×10(-5), OR  =  0·27, 95%CI (OR): 0·13-0·54], respectively, with high fever (>39°C for 48 hours) [IL-22, P  =  0·01, OR  =  1·5, 95% CI (OR): 1·8-2·1] and also in high frequency among the Fulani participants [P  =  0·006, OR  =  1·83, 95% CI (OR): 1·11-3·08)]. The CD36-1264 null allele was completely absent in the northern population. CONCLUSION: Independent association of SNPs in IL22 and IL-4 with clearance of amodiaquine- and sulphadoxine/pyrimethamine-resistant parasites did not reach statistical significance, but may suggest that not all drug-resistant mutants are adversely affected by the same immune-mediated mechanisms of clearance.


Asunto(s)
Predisposición Genética a la Enfermedad , Interleucina-4/genética , Interleucinas/genética , Malaria Falciparum/genética , Malaria Falciparum/inmunología , Plasmodium falciparum/inmunología , Amodiaquina/farmacología , Antimaláricos/farmacología , Camerún , Preescolar , Combinación de Medicamentos , Resistencia a Medicamentos , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Lactante , Recién Nacido , Malaria Falciparum/parasitología , Masculino , Plasmodium falciparum/efectos de los fármacos , Polimorfismo de Nucleótido Simple , Pirimetamina/farmacología , Sulfadoxina/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA