EMERGENCE OF NEW STRAINS OF SARS-COV-2: AFRICA’S FATE AND ITS PREPAREDNESS AGAINST COVID-19 INFECTION WAVES

Background: Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2) has infected over 100million individuals worldwide with diverse impacts on nations. The rising cases of new strains and resultant infection waves create an urgent need to assess the readiness of countries especially in Africa to mitigate the impact on community transmission. This paper delivers a brief synopsis of the novel SARS-CoV-2, emerging cases of new variants reported worldwide, and implications for genetic surveillance of disease transmission in low-and middle-income countries (LMICs) especially Africa. Materials and Methods: Literature search used keywords like SARS-CoV-2; COVID-19 epidemiology; pandemic waves; corona outbreak, clinical syndromes, treatments, prevention and control. Cross-sectional and observational studies published on COVID-19 from 2019 till date of study provided main information sources. Databases such as Web of Science, Embase, PubMed and Google Scholar were utilised. Main findings: Over 220 countries have documented COVID-19 cases with varied severity till date. Before the spikes in resurgence, a highly virulent mutated (>90% fatality rate) novel strain of COVID-19 had been documented. There is very little data to ascertain the impact of the COVID-19 infection waves in LMICs. Discussion: LMICs especially African countries still grapple with significant challenges like inefficient surveillance mechanisms, inadequate vaccination coverage, inadequate enforcement of environmental health strategies, poor health systems etc. Hence, Africa’s fate remains dicey in the face of the dynamic evolution of the SARS-CoV-2 and other identified challenges. Conclusion:  The adoption of a multidisciplinary approach to mitigate the impact of emergence of mutant SARS-CoV-2 variants and resurgence of infection spike is recommende

Progress towards the 2020 targets for HIV diagnosis and antiretroviral treatment in South Africa

Background: The UNAIDS targets for 2020 are to achieve a 90% rate of diagnosis in HIV-positive individuals, to provide antiretroviral treatment (ART) to 90% of HIV-diagnosed individuals and to achieve virological suppression in 90% of ART patients.Objectives: To assess South Africa’s progress towards the 2020 targets and variations in performance by province.Methods: A mathematical model was fitted to HIV data for each of South Africa’s provinces, and for the country as a whole. Numbers of HIV tests performed in each province were estimated from routine data over the 2002–2015 period, and numbers of patients receiving ART in each province were estimated by fitting models to reported public and private ART enrolment statistics.Results: By the middle of 2015, 85.5% (95% CI: 84.5% – 86.5%) of HIV-positive South African adults had been diagnosed, with little variation between provinces. However, only 56.9% (95% CI: 55.3% – 58.7%) of HIV-diagnosed adults were on ART, with this proportion varying between 50.8% in North West and 72.7% in Northern Cape. In addition, 78.4% of adults on ART were virally suppressed, with rates ranging from 69.7% in Limpopo to 85.9% in Western Cape. Overall, 3.39 million (95% CI: 3.26–3.52 million) South Africans were on ART by mid-2015, equivalent to 48.6% (95% CI: 46.0% – 51.2%) of the HIV-positive population. ART coverage varied between 43.0% in Gauteng and 63.0% in Northern Cape.Conclusion: Although South Africa is well on its way to reaching the 90% HIV diagnosis target, most provinces face challenges in reaching the remaining two 90% targets

HIV epidemic drivers in South Africa: A model-based evaluation of factors accounting for inter-provincial differences in HIV prevalence and incidence trends

Background: HIV prevalence differs substantially between South Africa’s provinces, but the factors accounting for this difference are poorly understood.Objectives: To estimate HIV prevalence and incidence trends by province, and to identify the epidemiological factors that account for most of the variation between provinces.Methods: A mathematical model of the South African HIV epidemic was applied to each of the nine provinces, allowing for provincial differences in demography, sexual behaviour, male circumcision, interventions and epidemic timing. The model was calibrated to HIV prevalence data from antenatal and household surveys using a Bayesian approach. Parameters estimated for each province were substituted into the national model to assess sensitivity to provincial variations.Results: HIV incidence in 15–49-year-olds peaked between 1997 and 2003 and has since declined steadily. By mid-2013, HIV prevalence in 15–49-year-olds varied between 9.4% (95% CI: 8.5%–10.2%) in Western Cape and 26.8% (95% CI: 25.8%–27.6%) in KwaZulu-Natal. When standardising parameters across provinces, this prevalence was sensitive to provincial differences in the prevalence of male circumcision (range 12.3%–21.4%) and the level of nonmarital sexual activity (range 9.5%–24.1%), but not to provincial differences in condom use (range 17.7%–21.2%), sexual mixing (range 15.9%–19.2%), marriage (range 18.2%–19.4%) or assumed HIV prevalence in 1985 (range 17.0%–19.1%).Conclusion: The provinces of South Africa differ in the timing and magnitude of their HIV epidemics. Most of the heterogeneity in HIV prevalence between South Africa’s provinces is attributable to differences in the prevalence of male circumcision and the frequency of nonmarital sexual activity

Our experience with van nes rotationplasty for locally advanced lower extremity tumours

Abstract OBJECTIVE: To present an early experience with the time-tested technique of Van Ness Rotationplasty to save distal lmbs. METHODS: Van Nes Rotationplasty for locally advanced lower extremity tumours. A reterorespective audit was conducted at Aga Khan University Hospital, Karachi, and comprised cases of bone and soft tissue sarcoma who underwent Van Ness Rotationplasty over seven years from January 2005 to December 2011. Demographic data, family history, past history, co-morbids, date since diagnosis, duration of symptoms, type of tumour, metastasis, pre-op and post-op functional status, recurrence and survival were collected. RESULTS: Of the 351 cases of bone and soft tissue sarcoma, 9 (2.6%) underwent Van Ness Rotationplasty and were included in the study. The mean duration of symptoms was 7±3SD months (range: 8-41 months). All except 1(11.1%) were osteogenic sarcomas. All except 1(11.1%) involved distal femur. Overall, 7(77.8%) had localised Enneking stage IIB disease. Two (22.2%) patients expired due to metastatic disease, but none had local recurrence. Complete excision of tumour was achieved in all (100%) patients. Longest follow-up was of 34 months while the shortest was of 6 months. No local recurrences were noted. Functional recovery was good. Two (22.2%) patients had simultaneous sciatic nerve repair as part of the primary procedure. Both of them had good motor function at the time of final follow-up. Mean Musculoskeletal Tumour Societyscore was 23.88±2SD. CONCLUSIONS: Van Nes Rotationplasty was found to be a successful alternative to amputation in cases of locally advancedtumours of distal femur or proximal tibia

Quantifying the Impact of Dust Sources on Urban Physical Growth and Vegetation Status: A Case Study of Saudi Arabia

Recently, dust has created many problems, including negative effects on health, and environmental and economic costs, for people who live both near to and far from sources of dust. The aim of this study is to evaluate and quantify the impact of dust sources located inside Saudi Arabia on the physical growth and vegetation status of cities. In order to do so, satellite data sets, simulated surface data, and soil data for Saudi Arabia from 2000 to 2021 were used. In the first step, a dust sources map of the study area was generated using multi-criteria decision analysis. Land surface temperature (LST), vegetation cover, soil moisture, precipitation, air humidity, wind speed, and soil erodibility factors were considered as effective criteria in identifying dust sources. In the second step, built-up land and vegetation status maps of major cities located at different distances from dust sources were generated for different years based on spectral indicators. Then, the spatiaotemporal change of built-up land and vegetation status of the study area and major cities were extracted. Finally, impacts of major dust sources on urban physical growth and vegetation were quantified. The importance degrees of soil erodibility, wind speed, soil moisture, vegetation cover, LST, air humidity, and precipitation to identify dust sources were 0.22, 0.20, 0.16, 0.15, 0.14, 0.07, and 0.05, respectively. Thirteen major dust sources (with at least 8 years of repetition) were identified in the study area based on the overlap of the effective criteria. The identified major dust sources had about 300 days with Aerosol Optical Depth (AOD) values greater than 0.85, which indicates that these dust sources are active. The location of the nine major dust sources identified in this study corresponds to the location of the dust sources identified in previous studies. The physical growth rates of cities located 400 km from a major dust source (DMDS) are 46.2% and 95.4%, respectively. The reduction rates of average annual normalized difference vegetation index (NDVI) in these sub-regions are 0.006 and 0.002, respectively. The reduction rate of the intensity of vegetation cover in the sub-region close to dust sources is three times higher than that of the sub-region farther from dust sources. The coefficients of determination (R2) between the DMDS and urban growth rate and the NDVI change rate are 0.52 and 0.73, respectively, which indicates that dust sources have a significant impact on the physical growth of cities and their vegetation status.Institutional Fund ProjectsPeer Reviewe

IMECE2005-80582 ACTIVE AND EVENT-DRIVEN PASSIVE MECHANICAL FAULT IDENTIFICATION IN GROUND VEHICLE SUSPENSION SYSTEMS

ABSTRACT Data interrogation methodologies are needed for identifying loads and faults in suspensions, tires, and other vehicle components to help design more durable systems and reduce the total cost of ownership. The application of passive and active data interrogation methodologies to passenger vehicle suspension systems is discussed here. For passive diagnostics, operating acceleration response data in conjunction with fundamental mechanics models are utilized. Mechanical faults in suspension components, e.g. degradation to shock, are identified using force state maps and transmissibility functions. First, it is shown that damage causes changes in the frequency characteristics of restoring forces, provided by the force state maps, which help to detect damage. Second, autoregressive nonlinear transmissibility models are used to locate faults and also characterize the degree to which faults alter nonlinear correlations in the response data. Force state maps are suited to narrow band inputs (e.g., sinusoidal) and transmissibility models are suited to broad-band inputs (e.g., random). This difference in preferential bandwidth for the two different data analysis methods motivates the selection of the diagnostic algorithm in an event-driven manner. For active diagnostics, experimental sensitivity functions, which are algebraic combinations of measured frequency response data, estimate the change in the forced response of the system with perturbation in stiffness or damping. By comparing the sensitivity functions to finite difference functions, faults can be detected, located, and quantified. The passive and active techniques are applied to experimental vehicle data and various issues (e.g., quantifying faults) are discussed

Identification of a PhenylthiazoleSmall Molecule with DualAntifungal and Antibiofilm ActivityAgainst Candida albicans andCandida auris

Candida species are a leading source of healthcare infections globally. The limited number of antifungal drugs combined with the isolation of Candida species, namely C. albicans and C. auris, exhibiting resistance to current antifungals necessitates the development of new therapeutics. The present study tested 85 synthetic phenylthiazole small molecules for antifungal activity against drug-resistant C. albicans. Compound 1 emerged as the most potent molecule, inhibiting growth of C. albicans and C. auris strains at concentrations ranging from 0.25–2μg/mL. Additionally, compound 1 inhibited growth of other clinically-relevant yeast (Cryptococcus) and molds (Aspergillus) at a concentration as low as 0.50μg/mL. Compound 1 exhibited rapid fungicidal activity, reducing the burden of C. albicans and C. auris below the limit of detection within 30 minutes. Compound 1 exhibited potent antibiofilm activity, similar to amphotericin B, reducing the metabolic activity of adherent C. albicans and C. auris biofilms by more than 66% and 50%, respectively. Furthermore, compound 1 prolonged survival of Caenorhabditis elegans infected with strains of C. albicans and C. auris, relative to the untreated control. The present study highlights phenylthiazole small molecules, such as compound 1, warrant further investigation as novel antifungal agents for drug-resistant Candida infections

Predicting risk of COPD in primary care:development and validation of a clinical risk score

OBJECTIVES: To develop and validate a clinical risk score to identify patients at risk of chronic obstructive pulmonary disease (COPD) using clinical factors routinely recorded in primary care. DESIGN: Case–control study of patients containing one incident COPD case to two controls matched on age, sex and general practice. Candidate risk factors were included in a conditional logistic regression model to produce a clinical score. Accuracy of the score was estimated on a separate external validation sample derived from 20 purposively selected practices. SETTING: UK general practices enrolled in the Clinical Practice Research Datalink (1 January 2000 to 31 March 2006). PARTICIPANTS: Development sample included 340 practices containing 15 159 newly diagnosed COPD cases and 28 296 controls (mean age 70 years, 52% male). Validation sample included 2259 cases and 4196 controls (mean age 70 years, 50% male). MAIN OUTCOME MEASURES: Area under the receiver operator characteristic curve (c statistic), sensitivity and specificity in the validation practices. RESULTS: The model included four variables including smoking status, history of asthma, and lower respiratory tract infections and prescription of salbutamol in the previous 3 years. It had a high average c statistic of 0.85 (95% CI 0.83 to 0.86) and yielded a sensitivity of 63.2% (95% CI 63.1 to 63.3) and specificity 87.4% (95% CI 87.3 to 87.5). CONCLUSIONS: Risk factors associated with COPD and routinely recorded in primary care have been used to develop and externally validate a new COPD risk score. This could be used to target patients for case finding