Schistosomiasis messaging in endemic communities: Lessons and implications for interventions from rural Uganda,a rapid ethnographic assessment study

BackgroundOver 240 million people are infected with schistosomiasis, the majority in sub-Saharan Africa. In Uganda, high infection rates exist in communities on the shores of Lake Victoria. Praziquantel mass drug administration (MDA) delivered by village health teams is the mainstay of schistosomiasis control. However, treatment uptake remains suboptimal, with many people unaware of treatment or thinking it is only for children. Furthermore, people are often rapidly reinfected post-treatment due to continued exposure. In three Schistosoma mansoni high endemicity lake-shore communities in Mayuge district, Eastern Uganda, we investigated the sources of schistosomiasis information, remembered content of information, and the perception of information and related practices towards the control of schistosomiasis.Methods and principal findingsData were collected from September 2017 to March 2018 using a rapid ethnographic assessment that included transect walks, observations, individual in-depth interviews and focus group discussions. Data were analysed thematically using iterative categorisation. We found that the main sources of schistosomiasis information included health workers at government facilities, village health teams, teachers, and radio programmes produced by the Ministry of Health. These messages described the symptoms of schistosomiasis, but did not mention the side effects of praziquantel treatment. Despite this messaging, the main cause of the disease and transmission was unclear to most participants. The translation of schistosomiasis on the radio into the local language ‘ekidada’—meaning swollen stomach—increased, rather than reduced, confusion about the cause(s) of schistosomiasis, due to believed links between ekidada and witchcraft, and prompted a reluctance to engage with treatment or preventative efforts.Conclusion and significanceThis study highlights gaps in schistosomiasis messaging. We recommend MDA is complemented by effective, evidence-based messaging on schistosomiasis transmission, prevention, and treatment, that is sensitive to local language and context issues, resulting in clear, concise, and consistent messages, to increase effectiveness.     

Switching on plant genes by external chemical signals

During the past decade there has been rapidly increasing interest in the role of plant volatiles in insect-plant interactions and the induction of plant defence systems by both pathogens and herbivores. Scientists are striving to link the proximate studies elucidating pathways and genes with the ultimate adaptive studies that attempt to explain their ecological role. However, we still do not know whether plants 'talk' to one another by employing 'phytopheromones'.     

Infectious diseases of animals and plants: an interdisciplinary approach

Animal and plant diseases pose a serious and continuing threat to food security, food safety, national economies, biodiversity and the rural environment. New challenges, including climate change, regulatory developments, changes in the geographical concentration and size of livestock holdings, and increasing trade make this an appropriate time to assess the state of knowledge about the impact that diseases have and the ways in which they are managed and controlled. In this paper, the case is explored for an interdisciplinary approach to studying the management of infectious animal and plant diseases. Reframing the key issues through incorporating both social and natural science research can provide a holistic understanding of disease and increase the policy relevance and impact of research. Finally, in setting out the papers in this Theme Issue, a picture of current and future animal and plant disease threats is presented.     

T-helper cells as new players in ANCA-associated vasculitides

In anti-neutrophil cytoplasmic autoantibody-associated vasculitides (AAV), several observations support a key role of T-helper cells (CD4⁺ T cells) in disease pathophysiology. An expanded population of effector memory CD4⁺ T cells in AAV patients may contribute to tissue injury and disease progression. In addition, functional impairment of regulatory T cells (T_Regs) is reported in AAV patients. A fraction of T_Regs have the capacity to differentiate into Th17 cells in the context of a proinflammatory environment. Therefore, nonfunctionality of T_Regs described in AAV patients may be caused by their conversion into IL-17-producing cells that may contribute to granulomatous vasculitis. Further investigations directed at the plasticity of T_Regs in AAV patients are warranted.     

What have we learned from clinical trials in primary Sj?gren's syndrome about pathogenesis?

In vitro and in vivo experimental data have pointed to new immunopathogenic mechanisms in primary Sj?gren's syndrome (pSS). The availability of targeted treatment modalities has opened new ways to selectively target these mechanistic pathways in vivo. This has taught us that the role of proinflammatory cytokines, in particular TNFα, is not crucial in the immunopathogenesis of pSS. B cells appear to play a major role, as depletion of B cells leads to restoration of salivary flow and is efficacious for treatment of extraglandular manifestations and mucosa-associated lymphoid tissue lymphoma. B cells also orchestrate T-cell infiltration and ductal epithelial dearrangement in the salivary glands. Gene profiling of salivary gland tissue in relation to B-cell depletion confirms that the axis of IFNα, B-cell activating factor, B-cell activation, proliferation and survival constitutes a major pathogenic route in pSS.     

Polarised Clathrin‐Mediated Endocytosis of EGFR During Chemotactic Invasion

Directed cell migration is critical for numerous physiological processes including development and wound healing. However chemotaxis is also exploited during cancer progression. Recent reports have suggested links between vesicle trafficking pathways and directed cell migration. Very little is known about the potential roles of endocytosis pathways during metastasis. Therefore we performed a series of studies employing a previously characterised model for chemotactic invasion of cancer cells to assess specific hypotheses potentially linking endocytosis to directed cell migration. Our results demonstrate that clathrin‐mediated endocytosis is indispensable for epidermal growth factor (EGF) directed chemotactic invasion of MDA‐MB‐231 cells. Conversely, caveolar endocytosis is not required in this mode of migration. We further found that chemoattractant receptor (EGFR) trafficking occurs by clathrin‐mediated endocytosis and is polarised towards the front of migrating cells. However, we found no role for clathrin‐mediated endocytosis in focal adhesion disassembly in this migration model. Thus, this study has characterised the role of endocytosis during chemotactic invasion and has identified functions mechanistically linking clathrin‐mediated endocytosis to directed cell motility.      

The role of 4-hydroxyphenylpyruvate dioxygenase in enhancement of solid-phase electron transfer by Shewanella oneidensis MR-1

We hypothesized that Shewanella oneidensis MR-1, a model dissimilatory metal-reducing bacterium, could utilize environmentally relevant concentrations of tyrosine to produce pyomelanin for enhanced Fe(III) oxide reduction. Because homogentisate is an intermediate of the tyrosine degradation pathway, and a precursor of a redox-cycling metabolite, pyomelanin, we evaluated the process of homogentisate production by S. oneidensis MR-1, in order to identify the key steps involved in pyomelanin production. We determined that two enzymes involved in this pathway, 4-hydroxyphenylpyruvate dioxygenase and homogentisate 1,2-dioxygenase are responsible for homogentisate production and oxidation, respectively. We used genetic analysis and physiological characterization of MR-1 strains either deficient in or displaying substantially increased pyomelanin production. The relative significance imparted by pyomelanin on solid-phase electron transfer was also addressed using electrochemical techniques, which allowed us to extend the genetic and physiological findings to biogeochemical cycling of metals. Based on our findings, environmental production of pyomelanin from available organic precursors could contribute to the survival of S. oneidensis MR-1 when dissolved oxygen concentrations become low, by providing an increased capacity for solid-phase metal reduction. This study demonstrates the role of organic precursors and their concentrations in pyomelanin production, solid phase metal reduction and biogeochemical cycling of iron.     

A simple method for studying whole sections of rice grain

We developed a new and simple method to collect sections of a whole brown rice kernel for investigation of histological properties. A single kernel of rice was dehydrated through a graded ethanol series, transferred to xylene, and embedded in paraffin. During sectioning of the blocks using a rotary microtome, we used a special adhesive tape to collect and place the sections on slides so they remained flat. The use of the adhesive tape technique combined with autofluorescence characteristics allowed us to visualize cell walls throughout an entire longitudinal or transverse section of a whole rice kernel. We obtained scanning electron microscopy images of the sections to determine section quality.