Aetiology and outcome of severe community-acquired pneumonia in children admitted to a paediatric intensive care unit

Objective. To determine the aetiological agents and outcome of severe community-acquired pneumonia (SCAP) in children admitted to the paediatric intensive care unit (PICU) at Kalafong Hospital, Pretoria. Patients and methods. An audit was done after a protocol was implemented to identify the aetiological agents in children with life-threatening SCAP admitted to the PICU from the emergency room. The following investigations were done as per protocol: blood culture, culture of the tracheal aspirate, immunofluorescence and culture of the nasopharyngeal aspirate, microscopy and culture of the gastric juice for Mycobacterium tuberculosis, and determination of HIV status. The following data, documented prospectively, were obtained from patient records: date of admission, age, gender, weight, duration of ventilation, duration of stay in the PICU, survival or death, and severity of illness as determined by means of the score for acute neonatal physiology (SNAP) or paediatric risk of mortality (PRISM) score depending on the child's age. Results. Twenty-three children were admitted over a 1-year period (1 November 1994-30 October 1995). Their median age was 10 weeks (range 2 weeks- 5 years) and the sex distribution was equal.Two children were HIV-infected. Twenty children received mechanical ventilation for a median period of 6.5 days (range 2- 16 days). Aetiological agents were identified in 15/23 children (65%).Respiratory syncytial virus (RSV) was the most common pathogen, identified in 7/23 children. Klebsiella pneumonia was the most common bacterial pathogen, identified in 5 children (2 blood cultures and 3 tracheal aspirates)

On-site screening for syphilis at an antenatal clinic

Objective. To determine the validity, predictive value and accuracy of the rapid plasma reagin card test performed on site to diagnose active syphilis in pregnant women so that immediate treatment can be offered to prevent congenital syphilis.Design. Open, descriptive study.Setting. Antenatal clinic, Mamelodi Hospital, Pretoria.Patients. Four hundred and seventy-four pregnant women attending the antenatal clinic for the first time were entered into the study.Methods. A rapid plasma reagin test was performed on site with no specialised equipment and the results were compared with those of the reference laboratory.Results. In the event of rapid plasma reagin titres of 1:8 and higher, indicative of active syphilis, the on-site rapid plasma reagin test had a sensitivity of 90.5%. The test had a sensitivity of 100% if the rapid plasma reagin titres were 1:16 and higher.Conclusion. The on-site rapid plasma reagin test identified all women with rapid plasma reagin titres higher than 1:8. This implies that all women whose fetuses were in danger of acquiring congenital syphilis were identified at the clinic and could be treated immediately

Congenital anomalies in black South African liveborn neonates at an urban academic hospital

Study objective. The aim was to study the spectrum of clinical problems and outcomes in infants born at an urban academic hospital. In consequence, as part of the overall study, the incidence of congenital anomalies and the outcomes of affected infants were recorded.Design. This was a prospective, hospital-based study, undertaken on liveborn infants born over a 3-year period, 1 May 1986 to 30 April 1989.Setting. Kalafong Hospital, Pretoria.Main results. A total of 17 351 liveborn infants was examined and the total congenital anomalies incidence was 11 ,87 per 1 000 Iivebirths. The central nervous system was the system most frequently involved (2,30 per 1 000 livebirths), followed by the musculoskeletal system (2,13 per 1 000 livebirths). The commonest individual congenital anomaly was Down syndrome (1,33 per 1 000 Iivebirths), followed by neural tube defects (0,99 per 1 000 livebirths) and ventricular septal defects (0,69 per 1 000 livebirths). In 11 % (2,25 per 1 000 livebirths) of neonatal deaths, infant loss was attributable to congenital anomalies.Conclusions. The incidence of congenital anomalies in black South African neonates, born in an urban setting, is as high as in other First- and Third-World countries, and the incidence of some individual congenital anomalies is higher. This study indicates the need for further research and the establishment of prenatal, genetics and paediatric facilities to manage these problems

Visualizing Buried Local Carrier Diffusion in Halide Perovskite Crystals via Two-Photon Microscopy.

Halide perovskites have shown great potential for light emission and photovoltaic applications due to their remarkable electronic properties. Although the device performances are promising, they are still limited by microscale heterogeneities in their photophysical properties. Here, we study the impact of these heterogeneities on the diffusion of charge carriers, which are processes crucial for efficient collection of charges in light-harvesting devices. A photoluminescence tomography technique is developed in a confocal microscope using one- and two-photon excitation to distinguish between local surface and bulk diffusion of charge carriers in methylammonium lead bromide single crystals. We observe a large dispersion of local diffusion coefficients with values between 0.3 and 2 cm2·s-1 depending on the trap density and the morphological environment-a distribution that would be missed from analogous macroscopic or surface measurements. This work reveals a new framework to understand diffusion pathways, which are extremely sensitive to local properties and buried defects

Ending malnutrition in all its forms requires scaling up proven nutrition interventions and much more: a 129-country analysis.

BackgroundSustainable Development Goal (SDG) 2.2 calls for an end to all forms of malnutrition, with 2025 targets of a 40% reduction in stunting (relative to 2012), for wasting to occur in less than 5% of children, and for a 50% reduction in anaemia in women (15-49 years). We assessed the likelihood of countries reaching these targets by scaling up proven interventions and identified priority interventions, based on cost-effectiveness.MethodsFor 129 countries, the Optima Nutrition model was used to compare 2019-2030 nutrition outcomes between a status quo (maintained intervention coverage) scenario and a scenario where outcome-specific interventions were scaled up to 95% coverage over 5 years. The average cost-effectiveness of each intervention was calculated as it was added to an expanding package of interventions.ResultsOf the 129 countries modelled, 46 (36%), 66 (51%) and 0 (0%) were on track to achieve the stunting, wasting and anaemia targets respectively. Scaling up 18 nutrition interventions increased the number of countries reaching the SDG 2.2 targets to 50 (39%), 83 (64%) and 7 (5%) respectively. Intermittent preventative treatment of malaria during pregnancy (IPTp), infant and young child feeding education, vitamin A supplementation and lipid-based nutrition supplements for children produced 88% of the total impact on stunting, with average costs per case averted of US$103, US$267, US$556 and US$1795 when interventions were consecutively scaled up, respectively. Vitamin A supplementation and cash transfers produced 100% of the total global impact on prevention of wasting, with average costs per case averted of US$1989 and US$19,427, respectively. IPTp, iron and folic acid supplementation for non-pregnant women, and multiple micronutrient supplementation for pregnant women produced 85% of the total impact on anaemia prevalence, with average costs per case averted of US$9, US$35 and US$47, respectively.ConclusionsPrioritising nutrition investment to the most cost-effective interventions within the country context can maximise the impact of funding. A greater focus on complementing nutrition-specific interventions with nutrition-sensitive ones that address the social determinants of health is critical to reach the SDG targets

Health and economic benefits of achieving contraceptive and maternal health targets in small island developing states in the Pacific and Caribbean

INTRODUCTION: Reducing unmet need for modern contraception and expanding access to quality maternal health (MH) services are priorities for improving women's health and economic empowerment. To support investment decisions, we estimated the additional cost and expected health and economic benefits of achieving the United Nations targets of zero unmet need for modern contraceptive choices and 95% coverage of MH services by 2030 in select Small Island Developing States. METHODS: Five Pacific (Kiribati, Samoa, Solomon Islands, Tonga and Vanuatu) and four Caribbean (Barbados, Guyana, Jamaica and Saint Lucia) countries were considered based on population survey data availability. For each country, the Lives Saved Tool was used to model costs, health outcomes and economic benefits for two scenarios: business-as-usual (BAU) (coverage maintained) and coverage-targets-achieved, which scaled linearly from 2022 (following COVID-19 disruptions) coverage of evidence-based family planning and MH interventions to reach United Nations targets, including modern contraceptive methods and access to complete antenatal, delivery and emergency care. Unintended pregnancies, maternal deaths, stillbirths and newborn deaths averted by the coverage-targets-achieved scenario were converted to workforce, education and social economic benefits; and benefit-cost ratios were calculated. RESULTS: The coverage-targets-achieved scenario required an additional US$12.6M (US$10.8M-US$15.9M) over 2020-2030 for the five Pacific countries (15$82.4M to maintain BAU). This additional investment was estimated to avert 126 000 (40%) unintended pregnancies, 2200 (28%) stillbirths and 121 (29%) maternal deaths and lead to a 15-fold economic benefit of US$190.6M (US$67.0M-US$304.5M) by 2050. For the four Caribbean countries, an additional US$17.8M (US$15.3M-US$22.4M) was needed to reach the targets (4% more than US$405.4M to maintain BAU). This was estimated to avert 127 000 (23$426.2M (US$138.6M-US$745.7M) by 2050. CONCLUSION: Achieving full coverage of contraceptive and MH services in the Pacific and Caribbean is likely to have a high return on investment

The use of dexamethasone in women with preterm premature rupture of membranes - A multicentre, double-blind, placebocontrolled, randomised trial

No Abstract

CodonTest: Modeling Amino Acid Substitution Preferences in Coding Sequences

Codon models of evolution have facilitated the interpretation of selective forces operating on genomes. These models, however, assume a single rate of non-synonymous substitution irrespective of the nature of amino acids being exchanged. Recent developments have shown that models which allow for amino acid pairs to have independent rates of substitution offer improved fit over single rate models. However, these approaches have been limited by the necessity for large alignments in their estimation. An alternative approach is to assume that substitution rates between amino acid pairs can be subdivided into rate classes, dependent on the information content of the alignment. However, given the combinatorially large number of such models, an efficient model search strategy is needed. Here we develop a Genetic Algorithm (GA) method for the estimation of such models. A GA is used to assign amino acid substitution pairs to a series of rate classes, where is estimated from the alignment. Other parameters of the phylogenetic Markov model, including substitution rates, character frequencies and branch lengths are estimated using standard maximum likelihood optimization procedures. We apply the GA to empirical alignments and show improved model fit over existing models of codon evolution. Our results suggest that current models are poor approximations of protein evolution and thus gene and organism specific multi-rate models that incorporate amino acid substitution biases are preferred. We further anticipate that the clustering of amino acid substitution rates into classes will be biologically informative, such that genes with similar functions exhibit similar clustering, and hence this clustering will be useful for the evolutionary fingerprinting of genes

Recent acquisition of Helicobacter pylori by Baka Pygmies

Both anatomically modern humans and the gastric pathogen Helicobacter pylori originated in Africa, and both species have been associated for at least 100,000 years. Seven geographically distinct H. pylori populations exist, three of which are indigenous to Africa: hpAfrica1, hpAfrica2, and hpNEAfrica. The oldest and most divergent population, hpAfrica2, evolved within San hunter-gatherers, who represent one of the deepest branches of the human population tree. Anticipating the presence of ancient H. pylori lineages within all hunter-gatherer populations, we investigated the prevalence and population structure of H. pylori within Baka Pygmies in Cameroon. Gastric biopsies were obtained by esophagogastroduodenoscopy from 77 Baka from two geographically separated populations, and from 101 non-Baka individuals from neighboring agriculturalist populations, and subsequently cultured for H. pylori. Unexpectedly, Baka Pygmies showed a significantly lower H. pylori infection rate (20.8%) than non-Baka (80.2%). We generated multilocus haplotypes for each H. pylori isolate by DNA sequencing, but were not able to identify Baka-specific lineages, and most isolates in our sample were assigned to hpNEAfrica or hpAfrica1. The population hpNEAfrica, a marker for the expansion of the Nilo-Saharan language family, was divided into East African and Central West African subpopulations. Similarly, a new hpAfrica1 subpopulation, identified mainly among Cameroonians, supports eastern and western expansions of Bantu languages. An age-structured transmission model shows that the low H. pylori prevalence among Baka Pygmies is achievable within the timeframe of a few hundred years and suggests that demographic factors such as small population size and unusually low life expectancy can lead to the eradication of H. pylori from individual human populations. The Baka were thus either H. pylori-free or lost their ancient lineages during past demographic fluctuations. Using coalescent simulations and phylogenetic inference, we show that Baka almost certainly acquired their extant H. pylori through secondary contact with their agriculturalist neighbors