Prostate cancer in Africa is a significant public health problem with a consistently increasing high mortality rate. The World Health Organization (WHO) estimates that 80
Plant genetic engineering goes back to over 40 years ago with the first genetically modified tobacco expressing the nopaline synthase gene. Since then, genetic engineering has emerged as an important technology as various sectors have included it in their strategic plans with potential impact on healthcare, agriculture and industry. One important aspect is the engineering of plants as bioreactors for production of vaccines, monoclonal antibodies, pesticides, orphan drugs, dyes and many other recombinant novel products. This process is referred to as plant molecular pharming. Plant molecular pharming has numerous benefits over conventional methods such as the use of animal cell lines and prokaryotic systems to produce recombinant products. These benefits include cost effectiveness, rapid and high mass production, easy scalability, accessibility and sustainability. Some African countries such as South Africa have adopted plant molecular pharming and have increased human and infrastructural capacity development, collaborations, and public sensitisation coupled with enabling policies and regulatory frameworks. However, in most of Africa, the sector faces numerous challenges including the lack of funding and expertise, low public acceptance, and poor to inadequate polices and regulatory frameworks. Despite the caveats surrounding the technology, it remains a significantly important tool for addressing global health challenges and fostering biotechnology innovations. Therefore, this review explores plant molecular pharming methods and associated products, advantages, strategies taken to improve the technology, regulatory and social- economic issues surrounding the technology in Africa.
BACKGROUND:Schistosomiasis disease that affects millions of people in sub-Saharan Africa, with a range of impacts on both host immune responses and the gut microbiome. The gut microbiota plays a fundamental role in the host's nutrition, metabolism, protection against pathogens, and modulation of host immunity. Understanding the role of the gut microbiome in pathophysiology of Schistosoma mansoni infection and how it influences host immune response, is essential for developing a more comprehensive view of disease progression and potential therapeutic strategies. METHODOLOGY:A cross-sectional study was carried out on 140 faecal samples collected from school children aged 10-15years residing in the schistosomiasis endemic hot spots of the Albert-Nile, Pakwach district, Northern Uganda. The samples were categorised by S. mansoni infection intensity based on the Kato Katz test. Faecal DNA was isolated, and microbiota composition was determined by 16 S rRNA V3-V4 sequencing. Plasma Th1/Th2 profiling of 13 cytokines was carried out on the Luminex platform and compared with respect to S. mansoni infection intensities. RESULTS:The genera Phascolarctobaterium and Prevotella_7 were significantly enriched (padj < 0.05, LDA > 3.0) in the high S. mansoni infection intensity group whereas, Ruminobacter and Alloprevotella were enriched in the low infection intensity group. We observed significantly lower systemic Th1/Th2 cytokine levels between the high intensity infection and the control samples (padj < 0.05). Linear regression analysis using all cytokines as covariates showed that the genus Alloprevotella, Streptococcus, Gastranaerophilales and Ruminobacter were associated with systemic IL6 response. CONCLUSION:There are alterations in the gut microbiota of S. mansoni infected children with distinct genera that discriminate the high and low infection intensity that could be potentially used as biomarkers. There is an association between the gut microbiota and systemic cytokine response whose mechanism in chronic disease pathophysiology needs to be further investigated.
Background Sleeping sickness caused by Trypanosoma brucei rhodesiense is a fatal disease and endemic in Southern and Eastern Africa. There is an urgent need to develop novel diagnostic and control tools to achieve elimination of rhodesiense sleeping sickness which might be achieved through a better understanding of trypanosome gene expression and genetics using endemic isolates. Here, we describe transcriptome profiles and population structure of endemic T. b. rhodesiense isolates in human blood in Malawi. Methodology Blood samples of r-HAT cases from Nkhotakota and Rumphi foci were collected in PaxGene tubes for RNA extraction before initiation of r-HAT treatment. 100 million reads were obtained per sample, reads were initially mapped to the human genome reference GRCh38 using HiSat2 and then the unmapped reads were mapped against Trypanosoma brucei reference transcriptome (TriTrypDB54_TbruceiTREU927) using HiSat2. Differential gene expression analysis was done using the DeSeq2 package in R. SNP calling from reads that were mapped to the T. brucei genome was done using GATK in order to identify T.b. rhodesiense population structure. Results 24 samples were collected from r-HAT cases of which 8 were from Rumphi and 16 from Nkhotakota foci. The isolates from Nkhotakota were enriched with transcripts for cell cycle arrest and stumpy form markers, whereas isolates in Rumphi focus were enriched with transcripts for folate biosynthesis and antigenic variation pathways. These parasite focus-specific transcriptome profiles are consistent with the more virulent disease observed in Rumphi and a less symptomatic disease in Nkhotakota associated with the non-dividing stumpy form. Interestingly, the Malawi T.b. rhodesiense isolates expressed genes enriched for reduced cell proliferation compared to the Uganda T.b. rhodesiense isolates. PCA analysis using SNPs called from the RNAseq data showed that T. b. rhodesiense parasites from Nkhotakota are genetically distinct from those collected in Rumphi. Conclusion Our results suggest that the differences in disease presentation in the two foci is mainly driven by genetic differences in the parasites in the two major endemic foci of Rumphi and Nkhotakota rather than differences in the environment or host response.
Introduction: Cytokine dysregulation is a key feature of HIV-1 infection with plasma Interleukin 6 (IL-6) largely observed to enhance HIV-1 replication whereas Interferon gamma (IFN-γ) inhibits it. Notably, IL-6 inhibits IFN-γ secretion through the STAT3 pathway to support HIV-1 survival. High IL-6: IFN-γ ratios may thus be linked to HIV-1 persistence. Although these cytokines are often evaluated separately, we assessed IL-6: IFN-γ ratio as a predictor of HIV-1 immune state and viral suppression. Methodology: A cross-sectional study was conducted with 240 people living with HIV on Antiretroviral Therapy (ART). Assessments included viral load, CD4 T-cell counts, IL-6, and IFN-γ, followed by the calculation of IL-6: IFN-γ ratios. Participants were categorized into viral suppressing (< 1000 copies) and non-suppressing (> 1000 copies) groups, as well as severe immune suppression (< 200 CD4 T-cells) and non-severe (> 200 CD4 T-cells). Correlations among HIV-1 viral load, CD4 counts, and cytokine levels were analyzed, and Welch’s T-test was used for comparisons. Results No significant correlations were found between HIV-1 viral load, CD4 counts, and the cytokine levels or ratios. However, IL-6 and IL-6: IFN-γ ratios were higher in viral suppressing patients (p = 0.024 and p = 0.017, respectively), while IFN-γ levels did not vary significantly. Among patients on ART for six months, IL-6 was elevated in viral non-suppressing individuals (p = 0.005). The classification accuracy of IL-6, IFN-γ, and their ratio varied, identifying 59%, 41%, and 65% of patients as viral suppressing or non-suppressing. Conclusion The IL-6: IFN-γ ratio enhances the classification accuracy of individuals living with HIV-1 compared to independent tests, though it is not a direct replacement for viral load or CD4 counts. Understanding IL-6 secretion patterns and their impact on IFN-γ may require a comprehensive cytokine profile and comparison with ART-naïve HIV-1 infected individuals.
Background Human African Trypanosomiasis (HAT) is a health burden in most remote areas of Sub-Saharan Africa. Only 2 species of the Trypanosome parasites, namely, T. b. rhodesiense and T. b. gambiense can establish infection in humans whereas other trypanosome parasites are lysed by human serum APOL-1 protein. The mechanism of T. b. gambiense resistance to APOL-1 activity is complex and involves several parasite factors. On the other hand, T. b. rhodesiense evades the lytic activity of APOL-1 by intracellular expression of a Serum Resistance Associated (SRA) gene that binds to APOL-1 when uptaken by the parasite thereby disabling APOL-1 from causing cellular membrane rupture. APOL-1 has 2 variants, namely, APOL-1 G1 and APOL-1 G2 with the later having mutations on the SRA binding sites which restores APOL-1 lytic activity in parasite lysis assays. This phenomenon remains elusive in clinical setting as limited data is available. In the present study we investigated the genetic diversity of T. b. rhodesiense SRA gene and APOL-1 genotypes in Malawian r-HAT clinical phenotypes. Methods T. b. rhodesiense SRA gene from Malawi endemic HAT samples (n= 77) as well as from Zambia and Uganda (n= 13) was amplified by PCR and PCR products were commercially sequenced. APOL-1 variants were identified by restriction fragment length polymorphism (RFLP) after a PCR amplification (n= 61). Results and conclusion Sequencing data revealed a heterozygosity of the SRA gene within Malawi T. b. rhodesiense isolates. Malawian SRA gene was genetically different from some isolates in Uganda and Zambia. Contrary to the current understanding that APOL-1 G2 variants are immune to T. b. rhodesiense infection, severe cases of r-HAT in G2 individuals were identified. This study has brought new insight in understanding the determinants of r-HAT severity. ### Competing Interest Statement The authors have declared no competing interest.
Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense cause human African trypanosomiasis (HAT), a neglected tropical disease that constitutes an important public health issue in sub-Saharan Africa. In the absence of a vaccine, only chemotherapy and vector control has been used to combat the disease. Environmental factors, such as exposure to infected tsetse files, and genetic factors such as variants in the APOL1 gene have been shown to contribute to the risk of developing HAT. However, the known factors only explain a small part of the risk of developing trypanosomiasis. We have undertaken a genome wide association study (GWAS) using 3813 samples from T. b. gambiense and T.b. rhodesiense HAT foci in Guinea, Côte d’Ivoire, Cameroon, DRC, Malawi and Uganda. 2141 samples were genotyped on the H3Africa SNP chip followed by a genotyping a validation cohort of an additional 1,627 samples at candidate loci. After the primary and validation studies we identified a novel locus near SMOC2 with genome-wide significance. We also identified suggestive associations near NXN, NTNG1 and NCKAP5 that have stronger associations with disease susceptibility than the APOL1 loci that has been previously identified by hypothesis driven approaches. These genes offer new entry points for future studies of the underlying genetic mechanisms of HAT.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThis work was supported by Human Heredity and Health in Africa (H3Africa) programme under Wellcome Trust grant number 099310/Z/12/Z and H3Africa grant number H3A-18- 004. H3Africa is managed by the Science for Africa Foundation (SFA Foundation) in partnership with Wellcome, NIH and AfSHG. The views expressed herein are those of the author(s) and not necessarily those of the SFA Foundation and her partners.### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The Minister de la Sante Publique (Democratic Republic of Congo) gave ethical approval for this work No 1/2013; Ministere de la Sante et de la Lutte Contre le SIDA of Cote d'Ivoıre gave ethical approval for this work; Uganda Vector Control Division Research Ethics Committee (Ministry of Health), gave ethical approval for this work ; Uganda National Council for Science and Technology HS 1344 gave ethical approval for this work; Comite Consultatif de Deontologie et d'Ethique [CCDE] de l'Institut de Recherche pour le Developpement: gave ethical approval for this work; 1-22/04/2013; Cameroon (Le Comite National d'Ethique de la Recherche pour la Sante Humain: 2013/364/L/CNERSH/ SP), Comite National D'Ethique et de la Recherche 2014/No 38/ MSLS/CNER-dkn) gave ethical approval for this work Malawi National Health Sciences Research Committee, protocol numbers NHSRC15/4/1399 and Malawi 1213 gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors
Abstract Background Malaria and schistosomiasis are significant parasitic diseases in Uganda and coinfections with the two are not uncommon in areas endemic to both parasites. The aim of this study was to determine the effect of P. falciparum and S. mansoni coinfection on the gene expression in peripheral blood of school age children aged between 10–15 years.Methods A cross sectional study of children aged 10–15 years, was conducted in selected sites along the Albert Nile in Pakwach District in northwest Uganda. Quantitative PCR (qPCR) was used to test for S. mansoni and P. falciparum infection. Furthermore samples that were sequenced using Illumina NovaSeq S4 and the reads aligned to the GRCh38 human genome were matched with those with S. mansoni and P. falciparum qPCR results. Differential gene expression analysis was done using DESeq2.Results Of the 210 study particpants, 76.2% (160/210) were P. falciparum positive, 91% (191/210) were S. mansoni positive and 150 (71%) had coinfection with both P. falciparum and S. mansoni, which was slightly fewer coinfections than expected by chance (Fisher exact test p-value of 0.02). RNAseq data was obtained for 33 participants of which 17 had P. falciparum and S. mansoni coinfection, 4 S. mansoni infection only, 1 had P. falciparum infection only while 11 were uninfected. Principal component analysis revealed clustering of gene expression by gender and infection status when S. mansoni and P. falciparum coinfected children were compared with uninfected children. We observed 15 DEGs of which 2 (CEPT1 and RETREG1) were downregulated and 13 (GAS6, DEXI, PALMD, SAMD15 AC138028.4, GFOD1-AS1, AC034102.6, AC005153.1, AC020914.1, AC017028.2, AC244502.3, AC013486.1, AC106760.1) upregulated when S. mansoni and P. falciparum coinfected children were compared with uninfected children. The differentially expressed genes are associated with inflammation and fibrosis and also included regulatory long noncoding RNA.Conclusions By molecular detection, this study observed a high prevalence of P. falciparum among the school age children (10–15 years) living in the S. mansoni endemic hotspots along the Albert-Nile region of Pakwach district, northwestern Uganda. The study shows differential expression of genes associated with inflammation and fibrosis among coinfected when compared to the uninfected children.
Background Malaria and schistosomiasis are important parasitic diseases. Coinfections of these have been reported in areas endemic to both parasites. The aim of this study was to determine the association between Schistosoma mansoni (S. mansoni) and Plasmodium falciparum (P. falciparum) infection intensities among school age children living along the Albert Nile. Methods A cross sectional study of 210 children aged 10–15 years, was conducted in selected sites along the Albert Nile in Pakwach District in northwest Uganda. The Circulating Anodic Antigen (CAA) test and quantitative PCR (qPCR) were used to test for S. mansoni infection intensity and quantitative PCR used to test for P. falciparum infection intensity. Results Of the 210 study particpants, 76.2% (160/210) were malaria positive whereas 91% (191/210) were S. mansoni positive. There were only 1% (3/210) infections of each of Necator americanus and Strongyloides stercolaris. Of the P. falciparum positive children 57.5% (92/160) were male; on the other hand 53.4% (102/191) of the S. mansoni positive children were male. Overall, 150 of the 210 children tested (71%) had co-infection with both P. falciparum and S. mansoni. There was a significant association (p-value = 7.306e-10, r2 = 0.17) between P. falciparum qPCR Ct-value and S. mansoni qPCR Ct-value. There was a significant association (p-value = 7.306e-10, r2 = 0.17) between P. falciparum intensity (qPCR Ct-value) and S. mansoni intensity (qPCR Ct-value) among the children test. Conclusions By molecular detection, this study observed a high prevalence of P. falciparum among the school age children (10–15 years) living in the S. mansoni endemic hotspots along the Albert-Nile region of Pakwach district, northwestern Uganda.
Over 290 million people are infected by schistosomes worldwide. Schistosomiasis control efforts focus on mass drug treatment with praziquantel (PZQ), a drug that kills the adult worm of all Schistosoma species. Nonetheless, re-infections have continued to be detected in endemic areas with individuals living in the same area presenting with varying infection intensities. Our objective was to characterize the transcriptome profiles in peripheral blood of children between 10-15 years with varying intensities of Schistosoma mansoni infection living along the Albert Nile in Uganda. RNA extracted from peripheral blood collected from 44 S. mansoni infected (34 high and 10 low by circulating anodic antigen [CAA] level) and 20 uninfected children was sequenced using Illumina NovaSeq S4 and the reads aligned to the GRCh38 human genome. Differential gene expression analysis was done using DESeq2. Principal component analysis revealed clustering of gene expression by gender when S. mansoni infected children were compared with uninfected children. In addition, we identified 14 DEGs between S. mansoni infected and uninfected individuals, 56 DEGs between children with high infection intensity and uninfected individuals, 33 DEGs between those with high infection intensity and low infection intensity and no DEGs between those with low infection and uninfected individuals. We also observed upregulation and downregulation of some DEGs that are associated with fibrosis and its regulation. These data suggest expression of fibrosis associated genes as well as genes that regulate fibrosis in S. mansoni infection. The relatively few significant DEGS observed in children with schistosomiasis suggests that chronic S. mansoni infection is a stealth infection that does not stimulate a strong immune response.
BackgroundIndividuals genetically susceptible to high schistosomiasis worm burden may contribute disproportionately to transmission and could be prioritized for control. Identifying genes involved may guide development of therapy.Methodology/Principal findingsA cohort of 606 children aged 10-15 years were recruited in the Albert Nile region of Uganda and assessed for Schistosoma mansoni worm burden using the Up-Converting Particle Lateral Flow (UCP-LF) test detecting circulating anodic antigen (CAA), point-of-care Circulating Cathodic Antigen (POC-CCA) and Kato-Katz tests. Whole genome genotyping was conducted on 326 children comprising the top and bottom 25% of worm burden. Linear models were fitted to identify variants associated with worm burden in preselected candidate genes. Expression quantitative trait locus (eQTL) analysis was conducted for candidate genes with UCP-LF worm burden included as a covariate. Single Nucleotide Polymorphism loci associated with UCP-LF CAA included IL6 rs2066992 (OR = 0.43, p = 0.0006) and rs7793163 (OR = 2.0, p = 0.0007); IL21 SNP kgp513476 (OR 1.79, p = 0.0025) and IL17B SNP kgp708159 (OR = 0.35, p = 0.0028). A haplotype in the IL10 locus was associated with lower worm burden (OR = 0.53, p = 0.015) and overlapped SNPs rs1800896, rs1800871 and rs1800872. Significant haplotypes (p<0.05, overlapping significant SNP) associated with worm burden were observed in IL6 and the Th17 pathway IL12B and IL17B genes. There were significant eQTL in the IL6, IL5, IL21, IL25 and IFNG regions.ConclusionsVariants associated with S. mansoni worm burden were in IL6, FCN2, RNASE3, IL10, IL12B and IL17B gene loci. However only eQTL associations remained significant after Bonferroni correction. In summary, immune balance, pathogen recognition and Th17 pathways may play a role in modulating Schistosoma worm burden. Individuals carrying risk variants may be targeted first in allocation of control efforts to reduce the burden of schistosomiasis in the community.
T. b. rhodesiense is the causative agent of Rhodesian human African trypanosomiasis (r-HAT) in Malawi. Clinical presentation of r-HAT in Malawi varies between foci and differs from East African HAT clinical phenotypes. The purpose of this study was to gain more insights into the transcriptomic profiles of patients with early stage 1 and late stage 2 HAT disease in Malawi. Whole blood from individuals infected with T. b. rhodesiense was used for RNA-Seq. Control samples were from healthy trypanosome negative individuals matched on sex, age range, and disease foci. Illumina sequence FASTQ reads were aligned to the GRCh38 release 84 human genome sequence using HiSat2 and differential analysis was done in R Studio using the DESeq2 package. XGR, ExpressAnalyst and InnateDB algorithms were used for functional annotation and gene enrichment analysis of significant differentially expressed genes. RNA-seq was done on 23 r-HAT case samples and 28 healthy controls with 7 controls excluded for downstream analysis as outliers. A total of 4519 genes were significant differentially expressed (p adjusted <0.05) in individuals with early stage 1 r-HAT disease (n = 12) and 1824 genes in individuals with late stage 2 r-HAT disease (n = 11) compared to controls. Enrichment of innate immune response genes through neutrophil activation was identified in individuals with both early and late stages of the disease. Additionally, lipid metabolism genes were enriched in late stage 2 disease. We further identified uniquely upregulated genes (log2 Fold Change 1.4-2.0) in stage 1 (ZNF354C) and stage 2 (TCN1 and MAGI3) blood. Our data add to the current understanding of the human transcriptome profiles during T. b. rhodesiense infection. We further identified biological pathways and transcripts enriched than were enriched during stage 1 and stage 2 r-HAT. Lastly, we have identified transcripts which should be explored in future research whether they have potential of being used in combination with other markers for staging or r-HAT.
BACKGROUND:Knowing the prevalence of schistosomiasis is key to informing programmes to control and eliminate the disease as a public health problem. It is also important to understand the impact of infection on child growth and development in order to allocate appropriate resources and effort to the control of the disease. METHODS:We conducted a survey to estimate the prevalence of schistosomiasis among school aged children in villages along the Albert-Nile shore line in the district of Pakwach, North Western Uganda. A total of 914 children aged between 10-15 years were screened for Schistosoma mansoni using the POC-CCA and Kato Katz (KK) techniques. The infection intensities were assessed by POC-CCA and KK as well as CAA tests. The KK intensities were also correlated with POC-CCA and with CAA intensity. Anthropometric measurements were also taken and multivariate analysis was carried out to investigate their association with infection status. RESULTS:The prevalence of schistosomiasis using the POC-CCA diagnostic test was estimated at 85% (95% CI: 83-87), being highest amongst children living closer to the Albert-Nile shoreline. Visual scoring of the POC-CCA results was more sensitive than the Kato Katz test and was positively correlated with the quantified infection intensities by the CAA test. The majority of the children were underweight (BMI<18.5), and most notably, boys had significantly lower height for age (stunting) than girls in the same age range (p < 0.0001), but this was not directly associated with S. mansoni infection. CONCLUSION:High prevalence of S. mansoni infection in the region calls for more frequent mass drug administration with praziquantel. We observed high levels of stunting which was not associated with schistosomiasis. There is a need for improved nutrition among the children in the area.
Abstract Background The prevalence of allergy-related diseases is increasing in low-income countries. Parasitic helminths, common in these settings, may be protective. We hypothesized that intensive, community-wide, anthelminthic mass drug administration (MDA) would increase allergy-related diseases, while reducing helminth-related morbidity. Methods In an open, cluster-randomized trial (ISRCTN47196031), we randomized 26 high-schistosomiasis-transmission fishing villages in Lake Victoria, Uganda, in a 1:1 ratio to receive community-wide intensive (quarterly single-dose praziquantel plus albendazole daily for 3 days) or standard (annual praziquantel plus 6 monthly single-dose albendazole) MDA. Primary outcomes were recent wheezing, skin prick test positivity (SPT), and allergen-specific immunoglobulin E (asIgE) after 3 years of intervention. Secondary outcomes included helminths, haemoglobin, and hepatosplenomegaly. Results The outcome survey comprised 3350 individuals. Intensive MDA had no effect on wheezing (risk ratio [RR] 1.11, 95% confidence interval [CI] 0.64–1.93), SPT (RR 1.10, 95% CI 0.85–1.42), or asIgE (RR 0.96, 95% CI 0.82–1.12). Intensive MDA reduced Schistosoma mansoni infection intensity: the prevalence from Kato Katz examinations of single stool samples from each patient was 23% versus 39% (RR 0.70, 95% CI 0.55–0.88), but the urine circulating cathodic antigen test remained positive in 85% participants in both trial arms. Hookworm prevalence was 8% versus 11% (RR 0.55, 95% CI 0.31–1.00). There were no differences in anemia or hepatospenomegaly between trial arms. Conclusions Despite reductions in S. mansoni intensity and hookworm prevalence, intensive MDA had no effect on atopy, allergy-related diseases, or helminth-related pathology. This could be due to sustained low-intensity infections; thus, a causal link between helminths and allergy outcomes cannot be discounted. Intensive community-based MDA has a limited impact in high-schistosomiasis-transmission fishing communities, in the absence of other interventions. Clinical Trials Registration ISRCTN47196031.
Treatment of sleeping sickness and nagana is threatened by drug resistance. To guide drug use in sleeping sickness control, we set out to determine if cattle-derived drug resistant sleeping sickness causing parasites spill-over to humans as drug resistant; causing sleeping sickness treatment failure. We screened cattle (n= 2,750) and sleeping sickness patients (n=147) from south-eastern Uganda for drug resistant sleeping sickness [T. b. rhodesiense]] and nagana causing parasites [ T. brucei s.l. ] and hence determined their prevalence in either populations using sound statistical means. One in three cattle [949/2,750] was positive for T. brucei s.l. and about 90 of every 100 of these parasites had changes in their genes induced by drug use. More than half of the sleeping sickness patients carried T. b. rhodesiense with changes in their genes induced by drug use and their occurrence was spatially related to those in cattle. Drugs are still effective in both nagana and sleeping sickness control in south-eastern Uganda since the genetic changes in nagana and sleeping sickness causing parasites detected in this study do not reduce drug effectiveness against these parasites. It is very likely that genetic changes in T. b. rhodesiense occur in cattle and are then transmitted to humans.
Background: There is exponential growth in the interest and implementation of genomics research in Africa. This growth has been facilitated by the Human Hereditary and Health in Africa (H3Africa) initiative, which aims to promote a contemporary research approach to the study of genomics and environmental determinants of common diseases in African populations.Objective: The purpose of this article is to describe important challenges affecting genomics research implementation in Africa.Methods: The observations, challenges and recommendations presented in this article were obtained through discussions by African scientists at teleconferences and face-to-face meetings, seminars at consortium conferences and in-depth individual discussions.Results: Challenges affecting genomics research implementation in Africa, which are related to limited resources include ill-equipped facilities, poor accessibility to research centers, lack of expertise and an enabling environment for research activities in local hospitals. Challenges related to the research study include delayed funding, extensive procedures and interventions requiring multiple visits, delays setting up research teams and insufficient staff training, language barriers and an underappreciation of cultural norms. While many African countries are struggling to initiate genomics projects, others have set up genomics research facilities that meet international standards.Conclusions: The lessons learned in implementing successful genomics projects in Africa are recommended as strategies to overcome these challenges. These recommendations may guide the development and application of new research programs in low-resource settings.
Trypanosoma brucei are extracellular hemoflagellate protozoan parasites and one of the causative agents of a devastating zoonotic disease called African Trypanosomiasis. In humans, the disease is caused by Trypanosoma brucei rhodensiense and Trypanosoma brucei gambiense, which cross the blood brain barrier (BBB) causing neurological disorders which culminate in death if untreated. In some domestic animals and laboratory rodents, Trypanosoma brucei brucei causes a disease similar to that in humans. The mechanism by which Trypanosoma brucei brucei invade biological barriers including the BBB has not been fully elucidated. To further address this issue, Mardin Dardy Canine Kidney II (MDCKII) and Human dermal microvascular endothelial cell (HDMEC) monolayers were grown to confluence on transwell inserts to constitute in vitro biological barriers. MDCKII cells were chosen for their ability to form tight junctions similar to those formed by the BBB endothelial cells. Labeled trypanosomes were placed in the upper chamber of transwell inserts layered with confluent MDCKII/HDMEC monolayers and their ability to cross the monolayer over time evaluated. Our results show that only 0.5-1.25% of Trypanosoma brucei brucei were able to migrate across the monolayers after 3 h. By employing immune staining and confocal microscopic analysis we observed that trypanosomes were located at the tight junctions and inside the cell in the MDCK II monolayers indicating that they crossed the monolayer using both the paracellular and transcellular routes. Our observations also showed that there seemed to be no obvious degradation of junction proteins Zonula Ocludens-1, Occludin and Ecadherin. In the HDMEC cell monolayer, our scanning electron microscopy data showed that Trypanosoma brucei brucei is able to modulate the plasma membrane to form invaginations similar to cuplike structures formed by Tlymphocytes. However these structures seemed to be independent of vascular adhesion molecules suggesting that they could be more like the membrane ruffles formed by certain intracellular bacteria during invasion. Taken together, our data reveal a mechanism by which Trypanosoma brucei brucei is able to cross different biological barriers including the BBB without causing any obvious damage. (C) 2016 Elsevier Inc. All rights reserved.
BackgroundControl and elimination of human African trypanosomiasis (HAT) can be accelerated through the use of diagnostic tests that are more accurate and easier to deploy. The goal of this work was to evaluate the immuno-reactivity of antigens and identify candidates to be considered for development of a simple serological test for the detection of Trypanosoma brucei gambiense or T. b. rhodesiense infections, ideally both.Methodology/Principal FindingsThe reactivity of 35 antigens was independently evaluated by slot blot and ELISA against sera from both T. b. gambiense and T. b. rhodesiense infected patients and controls. The antigens that were most reactive by both tests to T. b. gambiense sera were the membrane proteins VSG LiTat 1.3, VSG LiTat 1.5 and ISG64. Reactivity to T. b. rhodesiense sera was highest with VSG LiTat 1.3, VSG LiTat 1.5 and SRA, although much lower than with T. b. gambiense samples. The reactivity of all possible combinations of antigens was also calculated. When the slot blot results of 2 antigens were paired, a VSG LiTat 1.3-ISG75 combination performed best on T. b. gambiense sera, while a VSG LiTat 1.3-VSG LiTat 1.5 combination was the most reactive using ELISA. A combination of SRA and either VSG LiTat 1.3 or VSG LiTat 1.5 had the highest reactivity on T. b. rhodesiense sera according to slot blot, while in ELISA, pairing SRA with either GM6 or VSG LiTat 1.3 yielded the best results.ConclusionsThis study identified antigens that were highly reactive to T. b. gambiense sera, which could be considered for developing a serological test for gambiense HAT, either individually or in combination. Antigens with potential for inclusion in a test for T. b. rhodesiense HAT were also identified, but because their reactivity was comparatively lower, a search for additional antigens would be required before developing a test for this form of the disease.
Citation for published version (APA): Biéler, S., Waltenberger, H., Barrett, M. P., McCulloch, R., Mottram, J. C., Carrington, M., Schwaeble, W., McKerrow, J., Phillips, M. A., Michels, P. A., Büscher, P., Sanchez, J-C., Bishop, R., Robinson, D. R., Bangs, J., Ferguson, M., Nerima, B., Albertini, A., Michel, G., ... Ndung'u, J. M. (2016). Evaluation of antigens for development of a serological test for Human African Trypanosomiasis. PLoS ONE, 11(12), 1-23. [e0168074]. https://doi.org/10.1371/journal.pone.0168074
Background The Hygiene Hypothesis proposes that infection exposure protects against inflammatory conditions. Helminths possess allergen-like molecules and may specifically modulate allergy-related immunological pathways to inhibit responses which protect against them. Mass drug administration is recommended for helminth-endemic communities to control helminth-induced pathology, but may also result in increased rates of inflammation-mediated diseases in resource-poor settings. Immunological studies integrated with implementation of helminth control measures may elucidate how helminth elimination contributes to ongoing epidemics of inflammatory diseases. We present the design of the Lake Victoria Island Intervention Study on Worms and Allergy-related diseases (LaVIISWA), a cluster-randomised trial evaluating the risks and benefits of intensive versus standard anthelminthic treatment for allergy-related diseases and other health outcomes. Methods/Design The setting is comprised of island fishing communities in Mukono district, Uganda. Twenty-six communities have been randomised in a 1:1 ratio to receive standard or intensive anthelminthic intervention for a three-year period. Baseline characteristics were collected immediately prior to intervention rollout, commenced in February 2013. Primary outcomes are reported wheeze in the past 12 months and atopy (skin prick test response and allergen-specific immunoglobulin (asIg) E concentration). Secondary outcomes are visible flexural dermatitis, helminth infections, haemoglobin, growth parameters, hepatosplenomegaly, and responses to vaccine antigens. The trial provides a platform for in-depth analysis of clinical and immunological consequences of the contrasting interventions. Discussion The baseline survey has been completed successfully in a challenging environment. Baseline characteristics were balanced between trial arms. Prevalence of Schistosoma mansoni , hookworm, Strongyloides stercoralis and Trichuris trichiura was 52%, 23%, 13%, and 12%, respectively; 31% of Schistosoma mansoni infections were heavy (>400 eggs/gram). The prevalence of reported wheeze and positive skin prick test to any allergen was 5% and 20%, respectively. Respectively, 77% and 87% of participants had Dermatophagoides - and German cockroach-specific IgE above 0.35 kUA/L. These characteristics suggest that the LaVIISWA study will provide an excellent framework for investigating beneficial and detrimental effects of worms and their treatment, and the mechanisms of such effects. Trial registration This trial was registered with Current Controlled Trials (identifier: ISRCTN47196031 ) on 7 September 2012.