Implementation of a novel ultrasound training programme for midwives in Malawi:A mixed methods evaluation using the RE-AIM framework

IntroductionDespite recommendation that all women receive an ultrasound in pregnancy prior to 24 weeks', this remains unavailable to many women in low-income countries where trained practitioners are scarce. Although many programmes have demonstrated efficacy, few have achieved longterm sustainability, with a lack of information about how best to implement such programmes. This mixed-methods study aimed to evaluate the implementation of a novel education package to teach ultrasound-naive midwives in Malawi basic obstetric ultrasound, assessing its impact in the context of the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework.MethodsThe study ran across six sites in Malawi between October 2020 and June 2021, encompassing three phases; pre-implementation, implementation and post-implementation. Twenty nine midwives underwent a bespoke education package with matched pre and post course surveys assessed their knowledge, attitudes and confidence and "hands on" assessments evaluating practical skills. Training evaluation forms and in-depth interviews explored their satisfaction with the package, with repeat assessment and remote image review evaluating maintenance of skills.Results28/29 midwives completed the training, with significant increases in knowledge, confidence and practical skills. Adherence to the education package varied, however many changes to the proposed methodology were adaptive and appeared to facilitate the efficacy of the programme. Unfortunately, despite reporting approval regarding the training itself, satisfaction regarding supervision and follow up was mixed, reflecting the difficulties encountered with providing ongoing in-person and remote support.ConclusionThis programme was successful in improving trainees' knowledge, confidence and skill in performing basic obstetric ultrasound, largely on account of an adaptive approach to implementation. The maintenance of ongoing support was challenging, reflected by trainee dissatisfaction. By evaluating the success of this education package based on its implementation and not just its efficacy, we have generated new insights into the barriers to sustainable upscale, specifically those surrounding maintenance

The Plasmodium falciparum STEVOR Multigene Family Mediates Antigenic Variation of the Infected Erythrocyte

Modifications of the Plasmodium falciparum–infected red blood cell (iRBC) surface have been linked to parasite-associated pathology. Such modifications enable the parasite to establish long-lasting chronic infection by evading antibody mediate immune recognition and splenic clearance. With the exception of the well-demonstrated roles of var-encoded PfEMP1 in virulence and immune evasion, the biological significance of other variant surface antigens (rif and stevor) is largely unknown. While PfEMP1 and RIFIN have been located on the iRBC surface, recent studies have located STEVOR at the iRBC membrane where it may be exposed on the erythrocyte surface. To investigate the role of STEVOR in more detail, we have developed antibodies against two putative STEVOR proteins and used a combination of indirect immunofluorescence assays (IFA), live IFA, flow cytometry, as well as agglutination assays, which enable us to demonstrate that STEVOR is clonally variant at the surface of schizont stage parasites. Crucially, expression of different STEVOR on the surface of the iRBC changes the antigenic property of the parasite. Taken together, our data for the first time demonstrate that STEVOR plays a role in creating antigenic diversity of schizont stage parasites, thereby adding additional complexity to the immunogenic properties of the iRBC. Furthermore, it clearly demonstrates that to obtain a complete understanding of how parasite-induced pathology is linked to variation on the surface of the iRBC, focusing the interactions of multiple multigene families needs to be considered

Training in Ultrasound to Determine Gestational Age (TUDA): Evaluation of a Novel Education Package to Teach Ultrasound-Naive Midwives Basic Obstetric Ultrasound in Malawi

IntroductionAlthough ultrasound to determine gestational age is fundamental to the optimum management of pregnancy and is recommended for all women by the World Health Organisation, it remains unavailable to many women in low-income countries where trained practitioners are scarce. This study aimed to evaluate a novel, context-specific education package to teach midwives basic obstetric ultrasound, including the determination of gestational age by measurement of fetal femur length.MethodsThe study was conducted across six sites in Malawi in January 2021. Following a virtual “training of the trainers”, local teams delivered a 10-day programme encompassing both didactic and “hands on” components. Matched pre and post course tests assessed participants' knowledge of key concepts, with Objective Structured Clinical Examinations used to evaluate practical skills. To achieve a pass, trainees were required to establish the gestational age to within ±7 days of an experienced practitioner and achieve an overall score of &amp;gt;65% on five consecutive occasions. A matched pre and post course survey explored participants' attitudes and confidence in performing ultrasound examinations.ResultsOf the 29 midwives who participated, 28 finished the programme and met the criteria specified to pass. 22 midwives completed the matched knowledge tests, with the mean (SD) score increasing from 10.2 (3.3) to 18 (2.5) after training (P &amp;lt;0.0001). Mean difference 7.9, 95% CI 6.5–9.2. Midwives passed 87% of the Observed Structured Clinical Examinations, establishing the gestational age to within ±7 days of an experienced practitioner in 89% of assessments. Beliefs regarding the importance of antenatal ultrasound increased post course (p = 0.02), as did confidence in performing ultrasound examinations (p &amp;lt;0.0001).ConclusionThis study demonstrates not only that ultrasound-naive practitioners can be taught to perform basic obstetric ultrasound dating scans, confidently and competently, after 10 days of training, but also that local teams can be orientated to successfully deliver the programme virtually. Previous ultrasound training initiatives, while often more comprehensive in their syllabus, have been of considerably longer duration and this is likely to be a barrier to upscaling opportunities. We propose that this focused training increases the potential for widescale and sustainable implementation.</jats:sec

Comparative proteomic analysis of metabolically labelled proteins from Plasmodium falciparum isolates with different adhesion properties

The virulence of Plasmodium falciparum relates in part to the cytoadhesion characteristics of parasitized erythrocytes but the molecular basis of the different qualitative and quantitative binding phenotypes is incompletely understood. This paucity of information is due partly to the difficulty in working with membrane proteins, the variant nature of these surface antigens and their relatively low abundance. To address this two-dimensional (2D) protein profiles of closely related, but phenotypically different laboratory strains of P. falciparum have been characterized using proteomic approaches. Since the mature erythrocyte has no nucleus and no protein synthesis capability, metabolic labelling of proteins was used to selectively identify parasite proteins and increase detection sensitivity. A small number of changes (less than 10) were observed between four different P. falciparum laboratory strains with distinctive cytoadherence properties using metabolic labelling, with more parasite protein changes found in trophozoite iRBCs than ring stage. The combination of metabolic labelling and autoradiography can therefore be used to identify parasite protein differences, including quantitative ones, and in some cases to obtain protein identifications by mass spectrometry. The results support the suggestion that the membrane protein profile may be related to cytoadherent properties of the iRBCs. Most changes between parasite variants were differences in iso-electric point indicating differential protein modification rather than the presence or absence of a specific peptide

The Malaria Secretome: From Algorithms to Essential Function in Blood Stage Infection

The malaria agent Plasmodium falciparum is predicted to export a “secretome” of several hundred proteins to remodel the host erythrocyte. Prediction of protein export is based on the presence of an ER-type signal sequence and a downstream Host-Targeting (HT) motif (which is similar to, but distinct from, the closely related Plasmodium Export Element [PEXEL]). Previous attempts to determine the entire secretome, using either the HT-motif or the PEXEL, have yielded large sets of proteins, which have not been comprehensively tested. We present here an expanded secretome that is optimized for both P. falciparum signal sequences and the HT-motif. From the most conservative of these three secretome predictions, we identify 11 proteins that are preserved across human- and rodent-infecting Plasmodium species. The conservation of these proteins likely indicates that they perform important functions in the interaction with and remodeling of the host erythrocyte important for all Plasmodium parasites. Using the piggyBac transposition system, we validate their export and find a positive prediction rate of ∼70%. Even for proteins identified by all secretomes, the positive prediction rate is not likely to exceed ∼75%. Attempted deletions of the genes encoding the conserved exported proteins were not successful, but additional functional analyses revealed the first conserved secretome function. This gave new insight into mechanisms for the assembly of the parasite-induced tubovesicular network needed for import of nutrients into the infected erythrocyte. Thus, genomic screens combined with functional assays provide unexpected and fundamental insights into host remodeling by this major human pathogen

The M18 aspartyl aminopeptidase of Plasmodium falciparum binds to human erythrocyte spectrin in vitro

<p>Abstract</p> <p>Background</p> <p>During erythrocytic schizogony, <it>Plasmodium falciparum </it>interacts with the human erythrocyte membrane when it enters into, grows within and escapes from the erythrocyte. An interaction between the <it>P. falciparum </it>M18 aspartyl aminopeptidase (<it>Pf</it>M18AAP) and the human erythrocyte membrane protein spectrin was recently identified using phage display technology. In this study, recombinant (r) <it>Pf</it>M18AAP was characterized and the interaction between the enzyme and spectrin, as well as other erythrocyte membrane proteins, analyzed.</p> <p>Methods</p> <p>r<it>Pf</it>M18AAP was produced as a hexahistidine-fusion protein in <it>Escherichia coli </it>and purified using magnetic bead technology. The pI of the enzyme was determined by two-dimensional gel electrophoresis and the number of subunits in the native enzyme was estimated from Ferguson plots. The enzymatic activity over a pH and temperature range was tested by a coupled enzyme assay. Blot overlays were performed to validate the spectrin-<it>Pf</it>M18AAP interaction, as well as identify additional interactions between the enzyme and other erythrocyte membrane proteins. Sequence analysis identified conserved amino acids that are expected to be involved in cofactor binding, substrate cleavage and quaternary structure stabilization.</p> <p>Results</p> <p>r<it>Pf</it>M18AAP has a molecular weight of ~67 kDa and the enzyme separated as three entities with pI 6.6, 6.7 and 6.9. Non-denaturing gel electrophoresis indicated that r<it>Pf</it>M18AAP aggregated into oligomers. An <it>in vitro </it>coupled enzyme assay showed that r<it>Pf</it>M18AAP cleaved an N-terminal aspartate from a tripeptide substrate with maximum enzymatic activity at pH 7.5 and 37°C. The spectrin-binding region of <it>Pf</it>M18AAP is not found in <it>Homo sapiens, Saccharomyces cerevisiae </it>and other<it>Plasmodium </it>species homologues. Amino acids expected to be involved in cofactor binding, substrate cleavage and quaternary structure stabilization, are conserved. Blot overlays with r<it>Pf</it>M18AAP against spectrin and erythrocyte membrane proteins indicated that r<it>Pf</it>M18AAP binds to spectrin, as well as to protein 4.1, protein 4.2, actin and glyceraldehyde 3-phosphate dehydrogenase.</p> <p>Conclusion</p> <p>Studies characterizing r<it>Pf</it>M18AAP showed that this enzyme interacts with erythrocyte spectrin and other membrane proteins. This suggests that, in addition to its proposed role in hemoglobin digestion, <it>Pf</it>M18AAP performs other functions in the erythrocyte host and can utilize several substrates, which highlights the multifunctional role of malaria enzymes.</p

Implementation of a novel ultrasound training programme for midwives in Malawi: A mixed methods evaluation using the RE-AIM framework

INTRODUCTION: Despite recommendation that all women receive an ultrasound in pregnancy prior to 24 weeks', this remains unavailable to many women in low-income countries where trained practitioners are scarce. Although many programmes have demonstrated efficacy, few have achieved longterm sustainability, with a lack of information about how best to implement such programmes. This mixed-methods study aimed to evaluate the implementation of a novel education package to teach ultrasound-naive midwives in Malawi basic obstetric ultrasound, assessing its impact in the context of the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework. METHODS: The study ran across six sites in Malawi between October 2020 and June 2021, encompassing three phases; pre-implementation, implementation and post-implementation. Twenty nine midwives underwent a bespoke education package with matched pre and post course surveys assessed their knowledge, attitudes and confidence and "hands on" assessments evaluating practical skills. Training evaluation forms and in-depth interviews explored their satisfaction with the package, with repeat assessment and remote image review evaluating maintenance of skills. RESULTS: 28/29 midwives completed the training, with significant increases in knowledge, confidence and practical skills. Adherence to the education package varied, however many changes to the proposed methodology were adaptive and appeared to facilitate the efficacy of the programme. Unfortunately, despite reporting approval regarding the training itself, satisfaction regarding supervision and follow up was mixed, reflecting the difficulties encountered with providing ongoing in-person and remote support. CONCLUSION: This programme was successful in improving trainees' knowledge, confidence and skill in performing basic obstetric ultrasound, largely on account of an adaptive approach to implementation. The maintenance of ongoing support was challenging, reflected by trainee dissatisfaction. By evaluating the success of this education package based on its implementation and not just its efficacy, we have generated new insights into the barriers to sustainable upscale, specifically those surrounding maintenance

The Pathogenic Potential of Campylobacter concisus Strains Associated with Chronic Intestinal Diseases

Campylobacter concisus has garnered increasing attention due to its association with intestinal disease, thus, the pathogenic potential of strains isolated from different intestinal diseases was investigated. A method to isolate C. concisus was developed and the ability of eight strains from chronic and acute intestinal diseases to adhere to and invade intestinal epithelial cells was determined. Features associated with bacterial invasion were investigated using comparative genomic analyses and the effect of C. concisus on host protein expression was examined using proteomics. Our isolation method from intestinal biopsies resulted in the isolation of three C. concisus strains from children with Crohn's disease or chronic gastroenteritis. Four C. concisus strains from patients with chronic intestinal diseases can attach to and invade host cells using mechanisms such as chemoattraction to mucin, aggregation, flagellum-mediated attachment, “membrane ruffling”, cell penetration and damage. C. concisus strains isolated from patients with chronic intestinal diseases have significantly higher invasive potential than those from acute intestinal diseases. Investigation of the cause of this increased pathogenic potential revealed a plasmid to be responsible. 78 and 47 proteins were upregulated and downregulated in cells infected with C. concisus, respectively. Functional analysis of these proteins showed that C. concisus infection regulated processes related to interleukin-12 production, proteasome activation and NF-κB activation. Infection with all eight C. concisus strains resulted in host cells producing high levels of interleukin-12, however, only strains capable of invading host cells resulted in interferon-γ production as confirmed by ELISA. These findings considerably support the emergence of C. concisus as an intestinal pathogen, but more significantly, provide novel insights into the host immune response and an explanation for the heterogeneity observed in the outcome of C. concisus infection. Moreover, response to infection with invasive strains has substantial similarities to that observed in the inflamed mucosa of Crohn's disease patients

The kinetics of antibody binding to Plasmodium falciparum VAR2CSA PfEMP1 antigen and modelling of PfEMP1 antigen packing on the membrane knobs

<p>Abstract</p> <p>Background</p> <p>Infected humans make protective antibody responses to the PfEMP1 adhesion antigens exported by <it>Plasmodium falciparum </it>parasites to the erythrocyte membrane, but little is known about the kinetics of this antibody-receptor binding reaction or how the topology of PfEMP1 on the parasitized erythrocyte membrane influences antibody association with, and dissociation from, its antigenic target.</p> <p>Methods</p> <p>A Quartz Crystal Microbalance biosensor was used to measure the association and dissociation kinetics of VAR2CSA PfEMP1 binding to human monoclonal antibodies. Immuno-fluorescence microscopy was used to visualize antibody-mediated adhesion between the surfaces of live infected erythrocytes and atomic force microscopy was used to obtain higher resolution images of the membrane knobs on the infected erythrocyte to estimate knob surface areas and model VAR2CSA packing density on the knob.</p> <p>Results</p> <p>Kinetic analysis indicates that antibody dissociation from the VAR2CSA PfEMP1 antigen is extremely slow when there is a high avidity interaction. High avidity binding to PfEMP1 antigens on the surface of <it>P. falciparum</it>-infected erythrocytes in turn requires bivalent cross-linking of epitopes positioned within the distance that can be bridged by antibody. Calculations of the surface area of the knobs and the possible densities of PfEMP1 packing on the knobs indicate that high-avidity cross-linking antibody reactions are constrained by the architecture of the knobs and the large size of PfEMP1 molecules.</p> <p>Conclusions</p> <p>High avidity is required to achieve the strongest binding to VAR2CSA PfEMP1, but the structures that display PfEMP1 also tend to inhibit cross-linking between PfEMP1 antigens, by holding many binding epitopes at distances beyond the 15-18 nm sweep radius of an antibody. The large size of PfEMP1 will also constrain intra-knob cross-linking interactions. This analysis indicates that effective vaccines targeting the parasite's vulnerable adhesion receptors should primarily induce strongly adhering, high avidity antibodies whose association rate constant is less important than their dissociation rate constant.</p