Quantitative evaluation of the strategy to eliminate human African trypanosomiasis in the Democratic Republic of Congo

Background: The virulent vector-borne disease, Gambian human African trypanosomiasis (HAT), is one of several diseases targeted for elimination by the World Health Organization. This article utilises human case data from a high-endemicity region of the Democratic Republic of Congo in conjunction with a suite of novel mechanistic mathematical models to address the effectiveness of on-going active screening and treatment programmes and compute the likely time to elimination as a public health problem (i.e. <1 case per 10,000 per year). Methods: The model variants address uncertainties surrounding transmission of HAT infection including heterogeneous risk of exposure to tsetse bites, non-participation of certain groups during active screening campaigns and potential animal reservoirs of infection. Results: Model fitting indicates that variation in human risk of tsetse bites and participation in active screening play a key role in transmission of this disease, whilst the existence of animal reservoirs remains unclear. Active screening campaigns in this region are calculated to have been effective, reducing the incidence of new human infections by 52–53 % over a 15-year period (1998–2012). However, projections of disease dynamics in this region indicate that the elimination goal may not be met until later this century (2059–2092) under the current intervention strategy. Conclusions: Improvements to active detection, such as screening those who have not previously participated and raising overall screening levels, as well as beginning widespread vector control in the area have the potential to ensure successful and timely elimination

Passive GPS-Free Navigation for Small UAVs

Abstract — A method for passive GPS-free navigation of a small Unmanned Aerial Vehicle with a minimal sensor suite (limited to an inertial measurement unit and a monocular camera) is presented. The navigation task is cast as a Simul-taneous Localization and Mapping (SLAM) problem. While SLAM has been the subject of a great deal of research, the highly non-linear system dynamics and limited sensor suite available in this application presents a unique set of chal-lenges which have not previously been addressed. In this particular application solutions based on Extended Kalman Filters have been shown to diverge and alternate techniques are required. In this paper an Unscented Kalman Filter is applied to the navigation problem, which leads to a consistent estimate of vehicle and feature states. This paper presents: (a) simulatio

Pedagogical advantages of 3D virtual field trips and the challenges for their adoption

In a six-month long Innovate UK-funded project (November 2015 – April 2016), we investigated the feasibility of creating a sustainable national 3D ‘virtual field-trips’ (VFT) software service, to support and deliver field trip-based education through a virtual channel in schools and higher education institutions (HEIs). The idea of a 3D VFT service emerged from Virtual Skiddaw App, the 3D virtual geology fieldtrip, of The Open University’s (OU) Open Science Laboratory . In the feasibility project, we (at the OU) (co-investigator) along with Daden (project-lead) and Design Thinkers, UK (co-investigator) we looked into the technical, pedagogical, commercial and service design aspects of the 3D VFT service. In this presentation, we focussed on the pedagogy strand of this feasibility project: pedagogical advantages of 3D VFTs, and the challenges for their adoption in schools and HEIs. We discussed the following: pedagogical underpinnings of 3D virtual environments and 3D VFTs in disciplines such as geology, biology, environmental science/studies and geography which are founded on field observations, exploration and enquiry; potential of integrating VFTs within the curricula in schools and in HEIs; perceptions of educators, students and assessment bodies towards 3D VFTs, and virtual fieldwork, in general; we used the Virtual Skiddaw App in workshops and presentations to illustrate the concept of a 3D VFT; views of stakeholders towards the 3D VFT service: advantages, challenges and their requirements from this service. Our empirical investigations have been user-centred – focussing on the stakeholders and particularly, the end-users such as educators, students and fieldwork specialists, and we have interacted with them via interviews, service design workshops, demonstrations and a survey to elicit their perceptions and requirements

Assessing the impact of aggregating disease stage data in model predictions of human African trypanosomiasis transmission and control activities in Bandundu province (DRC)

Since the turn of the century, the global community has made great progress towards the elimination of gambiense human African trypanosomiasis (HAT). Elimination programs, primarily relying on screening and treatment campaigns, have also created a rich database of HAT epidemiology. Mathematical models calibrated with these data can help to fill remaining gaps in our understanding of HAT transmission dynamics, including key operational research questions such as whether integrating vector control with current intervention strategies is needed to achieve HAT elimination. Here we explore, via an ensemble of models and simulation studies, how including or not disease stage data, or using more updated data sets affect model predictions of future control strategies

Adding tsetse control to medical activities contributes to decreasing transmission of sleeping sickness in the Mandoul focus (Chad)

Background Gambian sleeping sickness or HAT (human African trypanosomiasis) is a neglected tropical disease caused by Trypanosoma brucei gambiense transmitted by riverine species of tsetse. A global programme aims to eliminate the disease as a public health problem by 2020 and stop transmission by 2030. In the South of Chad, the Mandoul area is a persistent focus of Gambian sleeping sickness where around 100 HAT cases were still diagnosed and treated annually until 2013. Pre-2014, control of HAT relied solely on case detection and treatment, which lead to a gradual decrease in the number of cases of HAT due to annual screening of the population. Methods Because of the persistence of transmission and detection of new cases, we assessed whether the addition of vector control to case detection and treatment could further reduce transmission and consequently, reduce annual incidence of HAT in Mandoul. In particular, we investigated the impact of deploying ‘tiny targets’ which attract and kill tsetse. Before tsetse control commenced, a census of the human population was conducted and their settlements mapped. A pre-intervention survey of tsetse distribution and abundance was implemented in November 2013 and 2600 targets were deployed in the riverine habitats of tsetse in early 2014, 2015 and 2016. Impact on tsetse and on the incidence of sleeping sickness was assessed through nine tsetse monitoring surveys and four medical surveys of the human population in 2014 and 2015. Mathematical modelling was used to assess the relative impact of tsetse control on incidence compared to active and passive screening. Findings The census indicated that a population of 38674 inhabitants lived in the vicinity of the Mandoul focus. Within this focus in November 2013, the vector is Glossina fuscipes fuscipes and the mean catch of tsetse from traps was 0.7 flies/trap/day (range, 0-26). The catch of tsetse from 44 sentinel biconical traps declined after target deployment with only five tsetse being caught in nine surveys giving a mean catch of 0.005 tsetse/trap/day. Modelling indicates that 70.4% (95% CI: 51-95%) of the reduction in reported cases between 2013 and 2015 can be attributed to vector control with the rest due to medical intervention. Similarly tiny targets are estimated to have reduced new infections dramatically with 62.8% (95% CI: 59–66%) of the reduction due to tsetse control, and 8.5% (95% 8–9%) to enhanced passive detection. Model predictions anticipate that elimination as a public health problem could be achieved by 2018 in this focus if vector control and screening continue at the present level and, furthermore, there may have been virtually no transmission since 2015. Conclusion This work shows that tiny targets reduced the numbers of tsetse in this focus in Chad, which may have interrupted transmission and the combination of tsetse control to medical detection and treatment has played a major role in reducing in HAT incidence in 2014 and 2015

Mammalian Y chromosomes retain widely expressed dosage-sensitive regulators

The human X and Y chromosomes evolved from an ordinary pair of autosomes, but millions of years ago genetic decay ravaged the Y chromosome, and only three per cent of its ancestral genes survived. We reconstructed the evolution of the Y chromosome across eight mammals to identify biases in gene content and the selective pressures that preserved the surviving ancestral genes. Our findings indicate that survival was nonrandom, and in two cases, convergent across placental and marsupial mammals. We conclude that the gene content of the Y chromosome became specialized through selection to maintain the ancestral dosage of homologous X-Y gene pairs that function as broadly expressed regulators of transcription, translation and protein stability. We propose that beyond its roles in testis determination and spermatogenesis, the Y chromosome is essential for male viability, and has unappreciated roles in Turner (tm) s syndrome and in phenotypic differences between the sexes in health and disease

Diagnosing dementia: No easy job

<p>Abstract</p> <p>Background</p> <p>From both clinical experience and research we learned that in complex progressive disorders such as dementia, diagnosis includes multiple steps, each with their own clinical and research characteristics.</p> <p>Discussion</p> <p>Diagnosing starts with a trigger phase in which the GP gradually realizes that dementia may be emerging. This is followed by a disease-oriented diagnosis and subsequently a care -oriented diagnosis. In parallel the GP should consider the consequences of this process for the caregiver and the interaction between both. As soon as a comprehensive diagnosis and care plan are available, monitoring follows.</p> <p>Summary</p> <p>We propose to split the diagnostic process into four diagnostic steps, followed by a monitoring phase. We recommend to include these steps when designing studies on screening, diagnosis and monitoring of patients with dementia and their families.</p

Update of transmission modelling and projections of gambiense human African trypanosomiasis in the Mandoul focus, Chad

In recent years, a programme of vector control, screening and treatment of gambiense human African trypanosomiasis (gHAT) infections led to a rapid decline in cases in the Mandoul focus of Chad. To represent the biology of transmission between humans and tsetse, we previously developed a mechanistic transmission model, fitted to data between 2000 and 2013 which suggested that transmission was interrupted by 2015. The present study outlines refinements to the model to: (1) Assess whether elimination of transmission has already been achieved despite low-level case reporting; (2) quantify the role of intensified interventions in transmission reduction; and (3) predict the trajectory of gHAT in Mandoul for the next decade under different strategies. Method Our previous gHAT transmission model for Mandoul was updated using human case data (2000–2019) and a series of model refinements. These include how diagnostic specificity is incorporated into the model and improvements to the fitting method (increased variance in observed case reporting and how underreporting and improvements to passive screening are captured). A side-by-side comparison of fitting to case data was performed between the models. Results We estimated that passive detection rates have increased due to improvements in diagnostic availability in fixed health facilities since 2015, by 2.1-fold for stage 1 detection, and 1.5-fold for stage 2. We find that whilst the diagnostic algorithm for active screening is estimated to be highly specific (95% credible interval (CI) 99.9–100%, Specificity = 99.9%), the high screening and low infection levels mean that some recently reported cases with no parasitological confirmation might be false positives. We also find that the focus-wide tsetse reduction estimated through model fitting (95% CI 96.1–99.6%, Reduction = 99.1%) is comparable to the reduction previously measured by the decline in tsetse catches from monitoring traps. In line with previous results, the model suggests that transmission was interrupted in 2015 due to intensified interventions. Conclusions We recommend that additional confirmatory testing is performed in Mandoul to ensure the endgame can be carefully monitored. More specific measurement of cases, would better inform when it is safe to stop active screening and vector control, provided there is a strong passive surveillance system in place

20th Annual Elementary Choral Festivals

Program listing performers and works performe

Quantitative analyses and modelling to support achievement of the 2020 goals for nine neglected tropical diseases

Quantitative analysis and mathematical models are useful tools in informing strategies to control or eliminate disease. Currently, there is an urgent need to develop these tools to inform policy to achieve the 2020 goals for neglected tropical diseases (NTDs). In this paper we give an overview of a collection of novel model-based analyses which aim to address key questions on the dynamics of transmission and control of nine NTDs: Chagas disease, visceral leishmaniasis, human African trypanosomiasis, leprosy, soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. Several common themes resonate throughout these analyses, including: the importance of epidemiological setting on the success of interventions; targeting groups who are at highest risk of infection or re-infection; and reaching populations who are not accessing interventions and may act as a reservoir for infection,. The results also highlight the challenge of maintaining elimination ‘as a public health problem’ when true elimination is not reached. The models elucidate the factors that may be contributing most to persistence of disease and discuss the requirements for eventually achieving true elimination, if that is possible. Overall this collection presents new analyses to inform current control initiatives. These papers form a base from which further development of the models and more rigorous validation against a variety of datasets can help to give more detailed advice. At the moment, the models’ predictions are being considered as the world prepares for a final push towards control or elimination of neglected tropical diseases by 2020