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1.
Med Vet Entomol ; 37(4): 782-792, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37540228

RESUMO

Visceral leishmaniasis (VL, kala azar), caused by Leishmania donovani, transmitted by Phlebotomus orientalis, is a serious systemic disease that causes high morbidity and mortality rates in Sudan and other parts of East Africa and the world. Despite progress in understanding the epidemiology of the disease in East Africa, little is known about the host preference of P. orientalis in kala azar endemic villages of Sudan, which have some of the highest VL incidence rates in the world. The present study used host choice experiments and blood-meal identification approaches to determine the host preference of P. orientalis in kala azar endemic villages in Gedarif state, eastern Sudan. In the host choice experiment, tent traps were used to compare the attractiveness of cows, donkeys, sheep and goats for host-seeking P. orientalis. In the blood-meal identification study, blood-fed P. orientalis females, captured inside houses and peri-domestic habitats, were subjected to molecular typing using cytochrome b gene (cyt b) amplification and sequence analysis. Cows and donkeys were the most attractive to blood-seeking P. orientalis, followed by goats. Similarly, the blood-meal analysis of P. orientalis showed that the vector preferentially feeds on cows, followed by donkeys, humans and goats. The human blood index of P. orientalis was 19.4% (42/216), indicating a high zoophilic habit of the vector, both inside and outside the houses. Although the order of host preference varied by location, it was clear that cows are the most preferred host of P. orientalis in the area. Results are discussed in relation to the role of domestic/livestock animals in VL zoopotentiation and zooprophylaxis. Inference is made on the potential impact of insecticide treatment of cows in control of the vector and the transmission of VL in Sudan and other parts of East Africa.


Assuntos
Doenças dos Bovinos , Doenças das Cabras , Leishmaniose Visceral , Phlebotomus , Psychodidae , Doenças dos Ovinos , Feminino , Humanos , Animais , Bovinos , Ovinos , Leishmaniose Visceral/veterinária , Sudão/epidemiologia , Equidae , Cabras
3.
Mediators Inflamm ; 2016: 7987686, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27433028

RESUMO

Background. The most prominent variant surface antigens (VSAs) of Plasmodium falciparum are the var gene-encoded Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family, which serves as a parasite-sequestering ligand to endothelial cells. In this study we have examined the antibody reactivity of autologous plasma from symptomatic and asymptomatic malaria infected children against the infected erythrocytes' surface antigens using flow cytometry. Methods. Ethidium-bromide-labelled erythrocytic mature forms of P. falciparum parasites obtained from symptomatic and asymptomatic children were sequentially incubated with autologous plasma and fluorescein isothiocyanate-conjugated (FITC) antihuman IgG. Plasma antibody reactivity was detected by flow cytometry. Results. Asymptomatic children had more prevalence of trophozoites in peripheral blood (66%) compared to symptomatic children (16%), p = 0.002. The mean percentage of infected RBCs reacting with autologous sera was 89.78 among symptomatic children compared to 79.62 among asymptomatic children (p = 0.09). Moreover, the mean fluorescence intensity (MFI) in the asymptomatic was significantly higher compared to symptomatic children (p value = 0.040). Conclusion. Variant surface antigens on Plasmodium falciparum infected RBCs from symptomatic malaria children tend to be better recognized by IgG antibodies. This may suggest a role of some IgG antibodies in severity of malaria.


Assuntos
Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Plasmodium falciparum/patogenicidade , Trofozoítos/imunologia , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Criança , Eritrócitos/imunologia , Eritrócitos/parasitologia , Feminino , Citometria de Fluxo , Humanos , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Masculino , Proteínas de Protozoários
4.
Emerg Infect Dis ; 20(10): 1637-44, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25272023

RESUMO

Numerous studies have indicated a strong association between amplification of the multidrug resistance-1 gene and in vivo and in vitro mefloquine resistance of Plasmodium falciparum. Although falciparum infection usually is not treated with mefloquine, incorrect diagnosis, high frequency of undetected mixed infections, or relapses of P. vivax infection triggered by P. falciparum infections expose non-P. falciparum parasites to mefloquine. To assess the consequences of such unintentional treatments on P. vivax, we studied variations in number of Pvmdr-1 (PlasmoDB accession no. PVX_080100, NCBI reference sequence NC_009915.1) copies worldwide in 607 samples collected in areas with different histories of mefloquine use from residents and from travelers returning to France. Number of Pvmdr-1 copies correlated with drug use history. Treatment against P. falciparum exerts substantial collateral pressure against sympatric P. vivax, jeopardizing future use of mefloquine against P. vivax. A drug policy is needed that takes into consideration all co-endemic species of malaria parasites.


Assuntos
Resistência a Medicamentos/efeitos dos fármacos , Malária Vivax/parasitologia , Mefloquina/uso terapêutico , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Plasmodium vivax/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Camboja/epidemiologia , Guiana Francesa/epidemiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Madagáscar/epidemiologia , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Malária Vivax/epidemiologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/genética , Sudão/epidemiologia
5.
BMC Immunol ; 15: 16, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24886212

RESUMO

BACKGROUND: The immune system plays a critical role in the development of co-infections, promoting or preventing establishment of multiple infections and shaping the outcome of pathogen-host interactions. Its ability to mediate the interplay between visceral leishmaniasis (VL) and malaria has been suggested, but poorly documented. The present study investigated whether concomitant infection with Leishmania donovani complex and Plasmodium falciparum in naturally co-infected patients altered the immunological response elicited by the two pathogens individually. RESULTS: Circulating levels of interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12p70, IL-13, IL-17A and tumor necrosis factor (TNF) were assessed in sera of patients infected with active VL and/or malaria and healthy individuals from Gedarif State, Sudan. Comparative analysis of cytokine profiles from co- and mono-infected patients highlighted significant differences in the immune response mounted upon co-infection, confirming the ability of L. donovani and P. falciparum to mutually interact at the immunological level. Progressive polarization towards type-1 and pro-inflammatory cytokine patterns characterized the co-infected patients, whose response partly reflected the effect elicited by VL (IFN-γ, TNF) and malaria (IL-2, IL-13), and partly resulted from a synergistic interaction of the two diseases upon each other (IL-17A). Significantly reduced levels of P. falciparum parasitaemia (P <0.01) were detected in the co-infected group as opposed to the malaria-only patients, suggesting either a protective or a non-detrimental effect of the co-infection against P. falciparum infection. CONCLUSIONS: These findings suggest that a new immunological scenario may occur when L. donovani and P. falciparum co-infect the same patient, with potential implications on the course and resolution of these diseases.


Assuntos
Coinfecção , Citocinas/sangue , Leishmaniose Visceral/sangue , Leishmaniose Visceral/imunologia , Malária/sangue , Malária/imunologia , Adolescente , Adulto , Criança , Feminino , Humanos , Leishmaniose Visceral/diagnóstico , Malária/diagnóstico , Malária Falciparum/sangue , Malária Falciparum/imunologia , Masculino , Plasmodium falciparum/imunologia , Sudão , Adulto Jovem
6.
Infect Drug Resist ; 17: 221-227, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38283109

RESUMO

Background: Due to the increasing resistance of Plasmodium falciparum to chloroquine (CQ) in Sudan, a shift from CQ to artesunate combined with sulfadoxine/pyrimethamine as a first-line treatment for uncomplicated falciparum malaria was adopted in 2004. This study aimed to determine the frequency distribution of K76T and N86Y mutations in P. falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes as key markers of resistance to CQ among P. falciparum isolates from patients in Nyala district of South Darfur state, west of Sudan. Methods: A descriptive, cross-sectional study was conducted among 75 P. falciparum isolates from Sudanese patients diagnosed with falciparum malaria mono-infection. Parasite DNA was extracted from dried blood spots and amplified using a nested polymerase chain reaction (PCR). Then, restriction fragment length polymorphism (RFLP) was used to detect the genetic polymorphisms in codons 76 of pfcrt and 86 of pfmdr1. PCR-RFLP products were analyzed using 1.5% gel electrophoresis to identify the genetic polymorphisms in the studied codons. The wild-type (pfcrt K76 and pfmdr1 N86), mutant (pfcrt 76T and pfmdr1 86Y) and mixed-type (pfcrt K76T and pfmdr1 N86Y) alleles were expressed as frequencies and proportions. Results: The wild-type pfcrt K76 allele was observed among 34.7% of isolates and the mutant 76T allele among 20% of isolates, while the mixed-type K76T allele was observed among 45.3% of isolates. On the other hand, 54.7% of isolates harbored the wild-type pfmdr1 N86 allele and 5.3% of isolates had the mutant 86Y allele, while the mixed-type N86Y allele was observed among 40% of isolates. Conclusion: The key molecular markers associated with CQ resistance (pfcrt 76T and pfmdr1 86Y) are still circulating in high frequency among P. falciparum isolates in South Darfur state, about twelve years after the official withdrawal of the drug as a treatment for uncomplicated falciparum malaria.

7.
Trop Med Infect Dis ; 9(2)2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38393129

RESUMO

A study was carried out to compare the infection rates of Leishmania donovani in Phlebotomus orientalis sandflies at different microhabitats of a VL endemic village in Gedarif state, Sudan. DNA extracts of 1078 P. orientalis sand fly females sampled by CDC light traps from indoor, outdoor, peri-domestic, and sylvatic sites, in three transmission seasons, March-June 2016-18, in Helat-Belo village, were subjected to independent PCR amplifications targeting Leishmania kDNA and the cpb gene followed by ITS1 region sequencing. Leishmania kDNA was detected in 1.4% of the 1078 P. orientalis females captured in the area. Two of these specimens showed a characteristic 741 bp band of L. donovani after cpb gene amplification. The DNA sequence of the ITS1 region of the parasites matched the ITS1 L. donovani genotype F. There were no signficant differences between rates of infection of L. donovani in P. orientalis captured at different sites. Blood meals found in infected flies origninated from human (5 specimens), cattle (4 specimens) and donkey (2 specimens). The finding of fresh cow and donkey blood in the infected flies suggests the possible role of these animals in the zoopotentiation and/or zooprophylaxis against VL. The study provides important information for VL transmission models and control programs in East Africa.

8.
Curr Res Transl Med ; 72(1): 103414, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38246019

RESUMO

PURPOSE OF THE STUDY: The current study aimed to detect the frequency of normal and mutated APOL1 alleles in sickle cell disease (SCD) patients and test their relation with Microalbuminuria, Creatinine, Urea, Glomerular Filtration Rate (GFR), and Body Mass Index (BMI). PATIENTS AND METHODS: The study included 156 SCD subjects. Serum Creatinine (mg/dl) and Urea (mg/dl) as well as Microalbuminuria (mg/l) level were measured by using Biosystems kit (Biosystems, Barcelona, Spain) and Mindary BA88A semi-automated biochemistry analyzer. Glomerular filtration rate and body mass index were calculated by equations. Blood DNA extraction was achieved by using the modified G-DEX™IIb Genomic DNA Extraction Kit protocol. The PCR was done for the detection of the APOL1 G2 rs60910145 alleles by using allele-specific PCR and primers. RESULTS: The CC allele was more frequent in study cases (66.7%) than TT allele. The frequency of a mutated allele (CC) was insignificantly higher in males (67.8%) than in females (65.2%) and in rural (70.9%) than urban areas. It is also higher in Shankhab compared to other tribes and subjects 26-37 years compared to other, P˃0.05. Interstingly, the subjects who carry the CC allele showed a significantly higher level of Microalbuminuria, Creatinine, BMI, and Urea compared to those carry TT allele. Moreover, GFR is also higher in subjects who carry CC than TT allele but it is not significant. CONCULSION: Altogether, the study findings highlighted the link of normal and mutated APOL1 G2 rs60910145 alleles with SCD and displayed the significant value of mutated APOL1 allele in the prediction of early nephropathy in SCD patients.


Assuntos
Anemia Falciforme , Apolipoproteína L1 , Masculino , Feminino , Humanos , Alelos , Índice de Massa Corporal , Apolipoproteína L1/genética , Creatinina , Anemia Falciforme/complicações , Biomarcadores , Rim , Ureia , DNA
9.
PLOS Glob Public Health ; 4(5): e0002957, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753739

RESUMO

Malaria, a major global health concern, requires effective diagnostic tools for patient care, disease control, and elimination. The pathway from concept to the adoption of diagnostic products is complex, involving multiple steps and stakeholders. To map this process, our study introduces a malaria-specific diagnostic pathway, synthesising existing frameworks with expert insights. Comprising six major stages and 31 related activities, the pathway retains the core stages from existing frameworks and integrates essential malaria diagnostic activities, such as WHO prequalification processes, global stakeholder involvement, and broader health systems considerations. To understand the scope and availability of evidence guiding the activities along this pathway, we conducted an online survey with 113 participants from various stages of the malaria diagnostic pathway. The survey assessed perceptions on four critical attributes of evidence: clear requirements, alignment with user needs, accuracy and reliability, and public and free availability. It also explored the types of evidence used and the challenges and potential solutions related to evidence generation and use. Respondents reported using a broad range of formal and informal data sources. Findings indicated differing levels of agreement on the attributes across pathway stages, with notable challenges in the Approvals and Manufacturing stage and consistent concerns regarding the public availability of data/evidence. The study offers valuable insights for optimising evidence generation and utilisation across the malaria diagnostic pathway. It highlights the need for enhanced stakeholder collaboration, improved data availability, and increased funding to support effective evidence generation, sharing, and use. We propose actionable solutions, including the use of public data repositories, progressive data sharing policies, open-access publishing, capacity-building initiatives, stakeholder engagement forums, and innovative funding solutions. The developed framework and study insights have broader applications, offering a model adaptable for other diseases, particularly for neglected tropical diseases, which face similar diagnostic challenges.

10.
BMC Infect Dis ; 13: 469, 2013 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-24103447

RESUMO

BACKGROUND: The Erythrocyte Binding Antigen (EBA) 175 has been considered as one of the most important Plasmodium falciparum (P. falciparum) merozoite ligands that mediate invasion of the erythrocytes through their sialated receptor: Glycophorin A (GPA). The effect of the EBA 175 dimorphic alleles (F and C) on the severity of the disease is not yet fully understood. Therefore this study was designed to assess the distribution of the divergent dimorphic alleles of P. falciparum EBA-175 (F and C) in three different geographical areas in Sudan and the possible association of this dimorphism with the severity of the disease. METHODS: A sum of 339 field isolates of P. falciparum obtained from patients in three different geographical areas in Sudan were screened for the dimorphic alleles (F, C) of the EBA-175 using nested PCR. RESULTS: The percentage of F, C, and mixed F/C alleles were; 41%, 51%, and 8% respectively. F and C alleles showed significantly different distributions in the various geographic areas (p = 0.00). There was no significant association between malaria clinical manifestation and P. falciparum EBA-175 F and C alleles frequencies. CONCLUSIONS: This study showed a significant differential distribution of F and C alleles in different geographical malaria endemic areas. No significant association was observed between F and C alleles and different malaria phenotypes.


Assuntos
Antígenos de Protozoários/genética , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/classificação , Plasmodium falciparum/isolamento & purificação , Adulto Jovem
11.
BMC Public Health ; 13: 332, 2013 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-23577673

RESUMO

BACKGROUND: In areas where visceral leishmaniasis (VL) and malaria are co-endemic, co-infections are common. Clinical implications range from potential diagnostic delay to increased disease-related morbidity, as compared to VL patients. Nevertheless, public awareness of the disease remains limited. In VL-endemic areas with unstable and seasonal malaria, vulnerability to the disease persists through all age-groups, suggesting that in these populations, malaria may easily co-occur with VL, with potentially severe clinical effects. METHODS: A retrospective case-control study was performed using medical records of VL patients admitted to Tabarakallah and Gedarif Teaching Hospitals (Gedarif State) and Al`Azaza kala-azar Clinic (Sennar State), Sudan (2005-2010). Patients positively diagnosed with VL and malaria were identified as cases, and VL patients without microscopy-detectable malaria as controls. Associations between patient characteristics and the occurrence of the co-infection were investigated using logistic regression analysis. Confirmation of epidemiological outcomes was obtained with an independently collected dataset, composed by Médecins Sans Frontières (MSF) at Um-el-Kher and Kassab Hospitals, Gedarif State (1998). RESULTS: The prevalence of malaria co-infection among VL surveyed patients ranged from 3.8 to 60.8%, with a median of 26.2%. Co-infected patients presented at hospital with deteriorated clinical pictures. Emaciation (Odds Ratio (OR): 2.46; 95% Confidence Interval (95% CI): 1.72-3.50), jaundice (OR: 2.52; 95% CI: 1.04-6.09) and moderate anemia (OR: 1.58; 95% CI: 1.10-2.28) were found to be positively associated with the co-infection, while severity of splenomegaly (OR: 0.53; 95% CI: 0.35-0.81) and, to a less extent, hepatomegaly (OR: 0.52; 95% CI: 0.27-1.01) appeared to be reduced by concomitant VL and malaria. The in-hospital case-fatality rates did not significantly differ between co- and mono-infected patients (OR: 1.13; 95% CI: 0.59-2.17). Conversely, a significantly increased mortality rate (OR: 4.38; 95% CI: 1.83-10.48) was observed by MSF amongst co-infected patients enrolled at Um-el-Kher and Kassab Hospitals, who also suffered an enhanced risk of severe anemia (OR: 3.44; 95% CI: 1.68-7.02) compared to VL mono-infections. CONCLUSIONS: In endemic VL areas with unstable seasonal malaria, like eastern Sudan, VL patients are highly exposed to the risk of developing concomitant malaria. Prompt diagnosis and effective treatment of malaria are essential to ensure that its co-infection does not result into poor prognoses.


Assuntos
Coinfecção/epidemiologia , Leishmaniose Visceral/epidemiologia , Malária/epidemiologia , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Coinfecção/prevenção & controle , Feminino , Mortalidade Hospitalar/tendências , Humanos , Lactente , Recém-Nascido , Leishmaniose Visceral/complicações , Leishmaniose Visceral/prevenção & controle , Malária/complicações , Malária/prevenção & controle , Masculino , Estudos Retrospectivos , Fatores de Risco , Estações do Ano , Sudão/epidemiologia
12.
Asian Pac J Cancer Prev ; 24(12): 4071-4076, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38156839

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori) have been accepted as having an etiologic role in gastro-duodenal diseases as chronic gastritis, peptic ulcer, and gastric carcinoma. Methylation of CGI has been correlated with the tumorigenic process since it can inactivate tumor suppressor genes. CDH1 is a tumor suppressor gene that encodes the E-cadherin protein, which is preserving cell-cell connections. Early stages of gastric carcinogenesis may be affected by the promoter methylation-mediated inactivation of this gene. OBJECTIVE: This study aimed to investigate the methylation status of CDH1 using Methylation-Specific PCR (MSP) technique in clinical suspected patients with H. pylori infection who undergoing upper gastrointestinal endoscopy and correlated it with H. pylori detection by glmM PCR test. METHODS: Fifty gastric mucosal biopsies were selected from one hundred and five samples included in this study. The detection of H. pylori was performed with the PCR primers specific to glmM gene. Bisulfite modification was done and the methylation status of the CDH1 gene was detected using MSP reaction. RESULTS: H. pylori was detected in 36% (18/50) of study population using glmM gene PCR test, 89% (16/18) of H. pylori positive cases were CDH1 methylated  positive (chi-square, p-value=0.002). CDH1 methylation can be present in cancerous and noncancerous gastric mucosa, where 60% (18/30) of CDH1 methylation positive gastric mucosa showed gastritis as an endoscopy finding and gastric cancer in 6% (2/30). There was a significant correlation between and CDH1 methylation positive results and age group (P-value = 0.02). There was no significant correlation between CDH1 methylation positive results and participants gender (p-value=0.431) and clinical symptoms (all P-value > 0.05). CONCLUSION: This work suggested strong significance association between H. pylori infection and CDH1 methylation.


Assuntos
Gastrite Atrófica , Gastrite , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Helicobacter pylori/genética , Metilação de DNA , Gastrite/genética , Gastrite/patologia , Gastrite Atrófica/patologia , Mucosa Gástrica/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Biópsia , Fatores de Transcrição/genética , Infecções por Helicobacter/complicações , Infecções por Helicobacter/genética , Infecções por Helicobacter/patologia , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/genética , Caderinas/metabolismo
13.
Pak J Biol Sci ; 25(2): 175-181, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35234007

RESUMO

<b>Background and Objective:</b> Chronic Myelogenous Leukaemia (CML) is a clonal myeloproliferative tumor distinguished by the existence of the Philadelphia chromosome (Ph) resulting from the t (9, 22) (q34, q11) translocation. The BCR-ABL gene and the fusion protein, which has constitutive tyrosine kinase activity, are the outcome of this translocation. The purpose of this study is to determine the prevalence of the BCR-ABL T315I mutation in CML patients. <b>Materials and Methods:</b> Descriptive cross-sectional studies were conducted on 100 CML patients who visited RICK hospital between May, 2018-2019. T315I mutation analysis was done on all patients utilizing (RT/PCR) followed by RLFP to quantify the prevalence of Kinase Domain Mutation analysis (KDM) in CML. <b>Results:</b> The link between haematological parameters and ABL mutations in CML patients was shown to be a substantial positive correlation between T315I and haematological parameters (HB and WBC) but no correlation with PLT. The data revealed that 43 out of 99 CML had T315I, with highly prevalent gene express (43.4%) detected in all CML 56.6%. The correlation of T315I mutations with clinical status was positive significant (p-000). <b>Conclusion:</b> It can be concluded that T315I mutation became significantly higher in CML patients than in other groups of mutations. The detection of ABL kinase domain mutations may be a proper and valuable strategy for optimizing therapeutic methods and preventing treatment delays.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Inibidores de Proteínas Quinases , Estudos Transversais , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/epidemiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Mutação , Prevalência , Inibidores de Proteínas Quinases/farmacologia
14.
PLoS One ; 17(9): e0272847, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36048775

RESUMO

BACKGROUND: Rapid Diagnostic Tests (RDTs) have become the cornerstone for the management of malaria in many endemic settings, but their use is constrained for several reasons: (i) persistent malaria antigen (histidine-rich protein 2; HRP2) leading to false positive test results; (ii) hrp2 deletions leading to false negative PfHRP2 results; and (iii) limited sensitivity with a detection threshold of around 100 parasites/µl blood (pLDH- and HRP2-based) leading to false negative tests. Microscopy is still the gold standard for malaria diagnosis, and allows for species determination and quantitation, but requires trained microscopists, maintained microscopes and has detection limit issues. Consequently, there is a pressing need to develop and evaluate more sensitive and accurate diagnostic tests. To address this need we have developed a direct on blood mini PCR-NALFIA test that combines the benefits of molecular biology with low infrastructural requirements and extensive training. METHODS: This is a Phase 3 diagnostic evaluation in 5 African countries. Study sites (Sudan, Ethiopia, Burkina, Kenya and Namibia) were selected to ensure wide geographical coverage of Africa and to address various malaria epidemiological contexts ranging from high transmission to near elimination settings with different clinical scenarios and diagnostic challenges. Study participants will be enrolled at the study health facilities after obtaining written informed consent. Diagnostic accuracy will be assessed following the WHO/TDR guidelines for the evaluation of diagnostics and reported according to STARD principles. Due to the lack of a 100% specific and sensitive standard diagnostic test for malaria, the sensitivity and specificity of the new test will be compared to the available diagnostic practices in place at the selected sites and to quantitative PCR as the reference test. DISCUSSION: This phase 3 study is designed to validate the clinical performance and feasibility of implementing a new diagnostic tool for the detection of malaria in real clinical settings. If successful, the proposed technology will improve the diagnosis of malaria. Enrolment started in November 2022 (Kenya) with assessment of long term outcome to be completed by 2023 at all recruitment sites. TRIAL REGISTRATION: Pan African Clinical Trial Registry (www.pactr.org) PACTR202202766889963 on 01/02/2022 and ISCRTN (www.isrctn.com/) ISRCTN13334317 on 22/02/2022.


Assuntos
Malária Falciparum , Malária , Antígenos de Protozoários/genética , Testes Diagnósticos de Rotina/métodos , Humanos , Quênia , Malária/diagnóstico , Malária/epidemiologia , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
15.
Trop Med Int Health ; 15(12): 1442-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20973878

RESUMO

OBJECTIVES: Rapid diagnostic tests (RDTs) are promoted for the diagnosis of malaria in many countries. The question arises whether laboratories where the current method of diagnosis is microscopy should also switch to RDT. This problem was studied in Kassala, Sudan where the issue of switching to RDT is under discussion. METHODS: Two hundred and three blood samples were collected from febrile patients suspected of having malaria. These were subsequently analysed with microscopy, RDT (SD Bioline P.f/P.v) and PCR for the detection and identification of Plasmodium parasites. RESULTS: Malaria parasites were detected in 36 blood samples when examined microscopically, 54 (26.6%) samples were found positive for malaria parasites by RDT, and 44 samples were positive by PCR. Further analysis showed that the RDT used in our study resulted in a relatively high number of false positive samples. When microscopy was compared with PCR, an agreement of 96.1% and k = 0.88 (sensitivity 85.7% and specificity 100%) was found. However, when RDT was compared with PCR, an agreement of only 81.2 and k = 0.48 (sensitivity 69% and specificity 84%) was found. CONCLUSION: PCR has proven to be one of the most specific and sensitive diagnostic methods, particularly for malaria cases with low parasitaemia. However, this technique has limitations in its routine use under resource-limited conditions, such as our study location. At present, based on these results, microscopy remains the best option for routine diagnosis of malaria in Kassala, eastern Sudan.


Assuntos
Malária/diagnóstico , Kit de Reagentes para Diagnóstico , Adolescente , Idoso , Criança , Tomada de Decisões , Países em Desenvolvimento , Feminino , Humanos , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Masculino , Microscopia , Parasitemia/diagnóstico , Reação em Cadeia da Polimerase/métodos , Sudão
16.
Malar J ; 9: 172, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20565854

RESUMO

BACKGROUND: Malaria infection and disease exhibit microgeographic heterogeneity which if predictable could have implications for designing small-area intervention. Here, the space-time clustering of Plasmodium falciparum infections using data from repeat cross-sectional surveys in Gezira State, a low transmission area in northern Sudan, is investigated. METHODS: Data from cross-sectional surveys undertaken in January each year from 1999-2009 in 88 villages in the Gezira state were assembled. During each survey, about a 100 children between the ages two to ten years were sampled to examine the presence of P. falciparum parasites. In 2009, all the villages were mapped using global positioning systems. Cluster level data were analysed for spatial-only and space-time clustering using the Bernoulli model and the significance of clusters were tested using the Kulldorff scan statistic. RESULTS: Over the study period, 96,022 malaria slide examinations were undertaken and the P. falciparum prevalence was 8.6% in 1999 and by 2009 this had reduced to 1.6%. The cluster analysis showed the presence of one significant spatial-only cluster in each survey year and one significant space-time cluster over the whole study period. The primary spatial-only clusters in 10/11 years were either contained within or overlapped with the primary space-time cluster. CONCLUSION: The results of the study confirm the generally low malaria transmission in the state of Gezira and the presence of spatial and space-time clusters concentrated around a specific area in the south of the state. Improved surveillance data that allows for the analysis of seasonality, age and other risk factors need to be collected to design effective small area interventions as Gezira state targets malaria elimination.


Assuntos
Malária Falciparum/epidemiologia , Malária Falciparum/transmissão , Plasmodium falciparum/isolamento & purificação , Vigilância da População/métodos , Criança , Pré-Escolar , Estudos Transversais , Feminino , Sistemas de Informação Geográfica , Geografia , Humanos , Malária Falciparum/parasitologia , Masculino , Microscopia , Modelos Estatísticos , Prevalência , Características de Residência , Medição de Risco , Fatores de Risco , Estações do Ano , Conglomerados Espaço-Temporais , Sudão/epidemiologia
17.
Malar J ; 9: 207, 2010 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-20642834

RESUMO

BACKGROUND: This study describes the laboratory evaluation of a novel diagnostic platform for malaria. The Magneto Optical Test (MOT) is based on the bio-physical detection of haemozoin in clinical samples. Having an assay time of around one minute, it offers the potential of high throughput screening. METHODS: Blood samples of confirmed malaria patients from different regions of Africa, patients with other diseases and healthy non-endemic controls were used in the present study. The samples were analysed with two reference tests, i.e. an histidine rich protein-2 based rapid diagnostic test (RDT) and a conventional Pan-Plasmodium PCR, and the MOT as index test. Data were entered in 2 x 2 tables and analysed for sensitivity and specificity. The agreement between microscopy, RDT and PCR and the MOT assay was determined by calculating Kappa values with a 95% confidence interval. RESULTS: The observed sensitivity/specificity of the MOT test in comparison with clinical description, RDT or PCR ranged from 77.2 - 78.8% (sensitivity) and from 72.5 - 74.6% (specificity). In general, the agreement between MOT and the other assays is around 0.5 indicating a moderate agreement between the reference and the index test. However, when RDT and PCR are compared to each other, an almost perfect agreement can be observed (k = 0.97) with a sensitivity and specificity of >95%. CONCLUSIONS: Although MOT sensitivity and specificity are currently not yet at a competing level compared to other diagnostic test, such as PCR and RDTs, it has a potential to rapidly screen patients for malaria in endemic as well as non-endemic countries.


Assuntos
Hemeproteínas/análise , Malária/diagnóstico , Óptica e Fotônica , Plasmodium/química , Kit de Reagentes para Diagnóstico/tendências , Antígenos de Protozoários/análise , Análise Química do Sangue , Estudos de Casos e Controles , Reações Falso-Positivas , Humanos , Magnetismo , Malária/epidemiologia , Microscopia , Plasmodium/genética , Reação em Cadeia da Polimerase , Proteínas de Protozoários/análise , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
18.
AIMS Microbiol ; 6(1): 65-74, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226915

RESUMO

Globally, tuberculosis is one of the major causes of morbidity and mortality in many countries. Previous studies suggest that the incidence and severity of tuberculosis are associated with low levels of vitamin D (Vit D). Therefore, this study aimed to determine the occurrence and associated factors of vitamin D3 deficiency in pulmonary tuberculosis patients at White Nile State, Sudan. 101 individuals of diagnosed pulmonary tuberculosis patients (71 males and 30 females) and 100 non-TB controls (58 males and 42 females) were included in this study. Sputum samples were obtained from TB patients and subjected to examination for acid-fast bacilli (AFB) using Ziehl-Neelsen (ZN) stain and Gene Xpert analysis. Blood samples were collected from both groups and Serum 25(OH)-vitamin D3 was determined by an Enzyme-Linked Immunosorbent Assay. HIV infection in Tuberculosis (TB) group was also investigated using the immunochromatographic test. In our study, the majority of TB patients were suffered from TB relapse (36.6%); non-HIV infected individuals (99.1%) or showed a positive result for AFB (61.4%) in Gene Xpert analysis. Moreover, there is a significant difference in microscopy findings and bacillary levels of AFB, and Rifampicin (RIF) susceptibility pattern of M. tuberculosis strain among sputum samples of TB patients, P-values less 0.0001. Furthermore, we found that TB patients were suffered from vitamin D deficiency. In particular, the mean of vitamin D level was significantly much lower in TB patients (26.7 ± 1.6) compared to non-TB controls (117.3 ± 3.2), P-value equal 0.0001. Likewise, it's much lower in females, individuals of 21-40 years old, and patients with high bacillary levels or those infected by Rifampicin resistance strain. Accordingly, our study was highlighted the TB and Vit D deficiency relationship and showed the need for further studies to a better understanding of the impact of TB on Vit D level and investigate whether vitamin D supplementation can have a role in the prevention and treatment of tuberculosis.

19.
PLoS Negl Trop Dis ; 14(7): e0008420, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32730340

RESUMO

Eumycetoma (mycotic mycetoma) is the fungal form of mycetoma, a subcutaneous infection occurring in individuals living in endemic areas of the disease. The Sudan is hyperendemic for mycetoma, with the highest incidence being reported from Gezira State, Central Sudan. The present study was conducted at the Gezira Mycetoma Center and aimed to determine the cause of black-grain eumycetoma in the state and describe its epidemiology. Black-grain specimens were collected during the surgical operation and direct detection of the causative agent was performed using M. mycetomatis species-specific PCR and ITS PCR followed by sequencing. Black-grain was reported from 93.3% of all confirmed mycetoma cases (n = 111/119), with a prevalence in young males. Of the 91 samples subjected to direct PCR, 90.1% (n = 82) gave positive results. The predominant species (88.2%) was Madurella mycetomatis. One sample was identified as M. fahalii, one as M. tropicana, and one matched the phytopathogenic species Sphaerulina rhododendricola. The highest endemic zones were Southern Gezira (76.6%) and Northern Sinnar (23.4%). The study confirmed that direct molecular detection on grains provides rapid and specific diagnosis of agents of eumycetoma.


Assuntos
Madurella/isolamento & purificação , Micetoma/microbiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Madurella/classificação , Madurella/genética , Masculino , Pessoa de Meia-Idade , Micetoma/epidemiologia , Filogenia , Sudão/epidemiologia , Adulto Jovem
20.
Parasit Vectors ; 13(1): 137, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171330

RESUMO

BACKGROUND: Routine molecular surveillance for imported drug-resistant malaria parasites to the USA and European Union is an important public health activity. The obtained molecular data are used to help keep chemoprophylaxis and treatment guidelines up to date for persons traveling to malaria endemic countries. Recent advances in next-generation sequencing (NGS) technologies provide a new and effective way of tracking malaria drug-resistant parasites. METHODS: As part of a technology transfer arrangement between the CDC Malaria Branch and the Istituto Superiore di Sanità (ISS), Rome, Italy, the recently described Malaria Resistance Surveillance (MaRS) protocol was used to genotype 148 Plasmodium falciparum isolates from Eritrea for kelch 13 (k13) and cytochrome b (cytb) genes, molecular markers associated with resistance to artemisinin (ART) and atovaquone/proguanil (AP), respectively. RESULTS: Spanning the full-length k13 gene, seven non-synonymous single nucleotide polymorphisms (SNPs) were found (K189N, K189T, E208K, D281V, E401Q, R622I and T535M), of which none have been associated with artemisinin resistance. No mutations were found in cytochrome b. CONCLUSION: All patients successfully genotyped carried parasites susceptible to ART and AP treatment. Future studies between CDC Malaria Branch and ISS are planned to expand the MaRS system, including data sharing, in an effort to maintain up to date treatment guidelines for travelers to malaria endemic countries.


Assuntos
Citocromos b/genética , Resistência a Medicamentos/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Proteínas de Protozoários/genética , África , Anti-Infecciosos/farmacologia , Antimaláricos/farmacologia , Artemisininas , Atovaquona/farmacologia , DNA de Protozoário/genética , Proteínas de Drosophila , Combinação de Medicamentos , Genótipo , Humanos , Itália , Malária Falciparum/parasitologia , Malária Falciparum/prevenção & controle , Proteínas dos Microfilamentos/genética , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Prevalência , Proguanil/farmacologia , Viagem
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