Reducing diarrhoea deaths in South Africa: costs and effects of scaling up essential interventions to prevent and treat diarrhoea in under-five children

Diarrhoea is one of the leading causes of morbidity and mortality in South African children, accounting for approximately 20% of under-five deaths. Though progress has been made in scaling up multiple interventions to reduce diarrhoea in the last decade, challenges still remain. In this paper, we model the cost and impact of scaling up 13 interventions to prevent and treat childhood diarrhoea in South Africa. Modelling was done using the Lives Saved Tool (LiST). Using 2014 as the baseline, intervention coverage was increased from 2015 until 2030. Three scale up scenarios were compared: by 2030, 1) coverage of all interventions increased by ten percentage points; 2) intervention coverage increased by 20 percentage points; 3) and intervention coverage increased to 99%. The model estimates 13 million diarrhoea cases at baseline. Scaling up intervention coverage averted between 3 million and 5.3 million diarrhoea cases. In 2030, diarrhoeal deaths are expected to reduce from an estimated 5,500 in 2014 to 2,800 in scenario one, 1,400 in scenario two and 100 in scenario three. The additional cost of implementing all 13 interventions will range from US$510 million (US$9 per capita) to US$960 million (US$18 per capita), of which the health system costs range between US$40 million (less than US$1 per capita) and US$170 million (US$3 per capita). Scaling up 13 essential interventions could have a substantial impact on reducing diarrhoeal deaths in South African children, which would contribute toward reducing child mortality in the post-MDG era. Preventive measures are key and the government should focus on improving water, sanitation and hygiene. The investments required to achieve these results seem feasible considering current health expenditure.

TiO2-based nanopowders and thin films for photocatalytical applications

TiO2-based nanopowders are elaborated by flame spray synthesis, FSS from organic precursors of titanium and chromium with the Cr content changing from 0 to 15 at.%. Well-crystallized nanopowders with high specific surface area SSA reaching 107 m2/g for undoped TiO2 and 177 m2/g for TiO2+15 at.% Cr are obtained. Thin films are deposited by rf reactive sputtering from metallic Ti and Ti-Cr targets in Ar+O2 flow controlled atmosphere. The adjustable area of Cr/Ti allows to obtain up to 16 at.% Cr in TiO2 thin films. X-ray diffraction, transmission electron spectroscopy, TEM, atomic force microscopy, AFM and optical spectrophotometry over the ultraviolet UV and visible VIS range of the light spectrum have been performed in order to characterize the nanomaterials. The particle size of nanopowders is within the range of 5-42 nm. Anatase is the predominating polymorphic form while the amount of rutile increases with Cr content to reach of about 25 wt.% at 15 at.% Cr. The post-deposition annealing of thin films in air at temperatures from 770 K to 1280 K modifies the phase composition, leads to irreversible transformation from anatase to rutile and affects the surface roughness. Structural and optical properties of TiO2-based nanopowders and thin films are compared. The effect of grain size and the level of chromium doping on the band gap Eg is discussed. Photocatalytic activity of the nanopowders is tested for degradation of methylene blue, MB

Influence of Cr on structural and optical properties of TiO2:Cr nanopowders prepared by flame spray synthesis

Influence of chromium incorporation on structural and optical properties of titanium dioxide nanopowders obtained by flame spray synthesis, FSS is studied by means of: X-ray diffraction, XRD; Raman spectroscopy; transmission electron spectroscopy, TEM; photoelectron spectroscopy, XPS and optical spectrophotometry over the ultraviolet, UV and visible range of the light spectrum from 250 nm to 2200 nm. The specific surface area, SSA, of the powders has been adjusted from 48 m2/g for TiO2 + 0.1at.% Cr to 177 m2/g for TiO2 + 15 at.% Cr which is accompanied by a decrease in the anatase grain size from 21 nm to 5 nm. The anatase-to-rutile ratio changes with Cr3+ concentration but there is no evidence of precipitation of chromium oxides or chromium titanates. Incorporation of Cr3+ into TiO2 lattice, as proved by XPS, is found to affect the electronic structure of TiO2, as indicated by the optical spectrophotometry. The impurity band is formed within the forbidden band gap of titanium dioxide which results in the additional absorption within the visible range of the light spectrum. The general aim of this work is to improve the visible light absorption and hence the efficiency of photocatalytic decomposition of organic contaminants

TiO2: Cr nanopowders for hydrogen sensing

The aim of this research was to use nanocrystalline TiO2 and TiO2: Cr (0.1–10 at. % Cr) obtained by Flame Spray Synthesis, FSS, for hydrogen sensing. Morphological properties of nanopowders were investigated by Brunauer–Emmett–Teller, BET, adsorption isotherms, X-ray Diffraction, XRD, Scanning Electron Microscopy, SEM, and Transmission Electron Microscopy, TEM. Nanosensors were prepared in a form of circular tablets by pressing the nanopowder at the pressure of 25 MPa and heating up to 400oC. Dynamic changes in the electrical resistance ΔR/Ro upon hydrogen exposure were detected over low-to- medium concentration range of 50-3000 ppm at 200-400oC. The influence of particle size and Cr content on the sensor response was studied

Aetiology of vaginal discharge, urethral discharge, and genital ulcer in sub-Saharan Africa: A systematic review and meta-regression

Background: Syndromic management is widely used to treat symptomatic sexually transmitted infections in settings without aetiologic diagnostics. However, underlying aetiologies and consequent treatment suitability are uncertain without regular assessment. This systematic review estimated the distribution, trends, and determinants of aetiologies for vaginal discharge, urethral discharge, and genital ulcer in sub-Saharan Africa (SSA). Methods and findings: We searched Embase, MEDLINE, Global Health, Web of Science, and grey literature from inception until December 20, 2023, for observational studies reporting aetiologic diagnoses among symptomatic populations in SSA. We adjusted observations for diagnostic test performance, used generalised linear mixed-effects meta-regressions to generate estimates, and critically appraised studies using an adapted Joanna Briggs Institute checklist. Of 4,418 identified records, 206 reports were included from 190 studies in 32 countries conducted between 1969 and 2022. In 2015, estimated primary aetiologies for vaginal discharge were candidiasis (69.4% [95% confidence interval (CI): 44.3% to 86.6%], n = 50), bacterial vaginosis (50.0% [95% CI: 32.3% to 67.8%], n = 39), chlamydia (16.2% [95% CI: 8.6% to 28.5%], n = 50), and trichomoniasis (12.9% [95% CI: 7.7% to 20.7%], n = 80); for urethral discharge were gonorrhoea (77.1% [95% CI: 68.1% to 84.1%], n = 68) and chlamydia (21.9% [95% CI: 15.4% to 30.3%], n = 48); and for genital ulcer were herpes simplex virus type 2 (HSV-2) (48.3% [95% CI: 32.9% to 64.1%], n = 47) and syphilis (9.3% [95% CI: 6.4% to 13.4%], n = 117). Temporal variation was substantial, particularly for genital ulcer where HSV-2 replaced chancroid as the primary cause. Aetiologic distributions for each symptom were largely the same across regions and population strata, despite HIV status and age being significantly associated with several infection diagnoses. Limitations of the review include the absence of studies in 16 of 48 SSA countries, substantial heterogeneity in study observations, and impeded assessment of this variability due to incomplete or inconsistent reporting across studies. Conclusions: In our study, syndrome aetiologies in SSA aligned with World Health Organization guidelines without strong evidence of geographic or demographic variation, supporting broad guideline applicability. Temporal changes underscore the importance of regular aetiologic re-assessment for effective syndromic management

Factors that foster and deter STEM professional development among teachers

The present study seeks to identify teachers' perceptions regarding STEM teaching professional development and to identify the factors that facilitate or hinder the success of teachers' professional development. The participants of the study were 35 teachers. A qualitative approach was used for data collection by conducting semistructured interviews with 11 teachers out of 35. All the participants were involved in the three focus group sessions. The findings of the study revealed that teachers have various perceptions toward the STEM professional development based on their experience, knowledge, and skills. Moreover, the study revealed different factors influencing STEM professional development among teachers including personal characteristics and internal factors including attitudes and beliefs toward STEM professional development activities, and teachers' capacity. Also, external factors such as design of the training program, availability of training material, and timing of training. The findings of the study could benefit the decision-makers to be aware about these factors that influence professional development and the teachers' needs