Knowledge, Attitude, and Practice among Egyptian Travelers: Pre-travel Vaccination and Malaria Prophylaxis

Introduction: More than one third of travelers to developing countries report health problems when traveling. The Egyptian Ministry of Health reports the occurrence of 400 cases of malarial infection yearly among Egyptian travelers. This article aimed to assess the knowledge, attitude, and practice (KAP) of Egyptian travelers towards infectious diseases, vaccination, and malaria chemoprophylaxis. Methods: A survey was conducted at Cairo International Airport and included 1500 travelers. The questionnaire inquired about the travelers’ knowledge about infectious diseases at their destinations and their KAP regarding vaccination, malaria, and its prophylaxis. Results: Most travelers (68%) had poor knowledge, specifically; 90.2%, 85.6%, 88.5% did not know the endemic diseases at their destinations, the modes of disease transmission, or the protective measures against disease, respectively. Knowledge about malaria prevalence, symptoms, modes of transmission, and prevention was good in only 18%, 29.8%, 6.7%, and 21.4% of travelers, respectively. Poor practice of malaria prophylactic measures was found in 66.3% of travelers. Although 91.3% did not receive any vaccination, the general attitude towards vaccination was good. The total travel health knowledge, practice, general attitude toward vaccination, and the perceived benefits of malarial prophylaxis scores were significantly correlated with older age and high socioeconomic level. Most of the studied travelers (90.4%) did not carry or use malaria chemoprophylaxis. Ignorance was the main barrier to receiving vaccines (65.3%) and to adherence to malaria chemoprophylaxis (88.3%). Conclusion: Egyptian travelers have poor travel health knowledge and practices. Their knowledge and practice scores improve with older age, urban residence, and higher educational levels. They have a good attitude towards vaccination, and ignorance was the main barrier to sound practices

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Geregelte Waschwassereinspritzung in den Hydrozyklonunterlauf

In hydrocyclones, the classification efficiency is limited by the fines, which are discharged together with the water in the underflow. There have been several attempts focused on improving the washing of the sediment in the conical section of the hydrocyclone. Tangential water injection into the cyclone cone has been applied to displace feed pulp water in the underflow stream and increase the sharpness of the separation. The application of water injection in cyclones has been restricted, until now, to special cases and to separation in coarse ranges. A further disadvantage is its sensitivity to changing feed conditions. The present work presents an improved technique, which was done via an injection at the upper end of the apex or the conical end. An experimental program has been carried out to study the design and operational parameters which influence the injection process. At the beginning, water only experiments have been done to investigate the effect of the injection on the water distribution through the overflow and underflow openings, after which a series of suspension experiments were performed. The results showed that there are optimum conditions of the injection process. Operating the cyclone at these optimum conditions results in a greater washing effect and reduces consumption of wash water. The process is stabilized by controlled water injection specific to the underflow shape. This controlled wash water injection is applied to kaolin processing for improving the kaolin recovery in the overflow by reducing the kaolin losses in the cyclone underflow. It was found that the water injection through the apex can reduce the percentage fines in the underflow with more than 65%. At the same time, the overflow quality was kept constant and a stable or relatively smaller cut size (d50) was achieved. The experimental data which demonstrate the marked improvement of the separation curves using controlled water injection were presented. These results were supported by a mathematical model describes the injection effect in the hydrocyclone on the basis of the separation model of Schubert and Neesse [1]. The simulation results showed reasonably good agreement with the experimental ones.Die Klassierung im Hydrozyklon wird durch den Fehlaustrag der Feinteilchen, die zusammen mit dem Wasser durch den Unterlauf ausgetragen werden, beschränkt. Es hat mehrere Versuche gegeben, die sich auf die Durchführung einer Sedimentwäsche im konischen Teil des Hydrozyklons konzentrierten. Es wurde eine tangentiale Wassereinspritzung in den Zyklonkonus angewandt mit dem Ziel, das aufgegebene Wasser zum Oberlaufstrom abzuleiten und die Trennschärfe zu erhöhen. Die Anwendung der Wasserinjektion im Zyklon ist bislang auf spezielle Fälle der Separation im Grobkornbereich beschränkt geblieben. Ein weiterer Nachteil besteht in der Sensibilität dieser Methode gegenüber Fluktuationen im Hydrozykloneingang. Die vorgelegte Arbeit präsentiert eine weiterentwickelte Technik der Wasserinjektion am oberen Ende der Unterlaufdüse bzw. am Konusende. Das experimentelle Programm wurde darauf abgestimmt, die Einflüsse des Zyklongeometrie und der Prozessparameter, die den Injektionsprozess beeinflussen, zu untersuchen. Zunächst wurden die Experimente nur mit wassergespeistem Hydrozyklon durchgeführt, um die Wirkung der Injektion auf die Verteilung im Überlauf und Unterlauf zu untersuchen. Dann wurde mit Suspensionen weiter gearbeitet. Die Ergebnisse zeigen, dass es optimale Bedingungen für die Injektion gibt. Die Arbeit unter optimalen Bedingungen führt zu einer besseren Waschwirkung und reduziert den Waschwasserverbrauch. Der Prozess kann durch eine Regelung der Wassereinspritzung stabilisiert werden. Diese kontrollierte Waschwassereinspritzung wird in der Kaolinaufbereitung für die Reduzierung der Kaolinverluste im Zyklon-Unterlauf angewendet. Es wurde festgestellt, dass die Wasserinjektion in der Unterlaufdüse den Kaolingehalt im Unterlauf um mehr als 65% verringern kann. Gleichzeitig wird die Überlaufsqualität konstant gehalten und eine stabile oder sogar kleinere Trennkorngröße (d50) erreicht. Die experimentellen Daten, die die deutliche Verbesserung der Trennkurven durch kontrollierte Wassereinspritzung zeigen, werden diskutiert. Diese Ergebnisse über die Wirkung der Injektion im Hydrozyklon wurden durch ein mathematisches Modell auf der Grundlage des Trennmodells von Schubert und Neesse beschrieben [1]. Die Simulationsergebnisse zeigten gute Übereinstimmung mit den experimentellen Daten

Effect of polyacrylic acid molar mass as a surface modifier on rheological properties of calcium carbonate suspensions

Suspensions of calcium carbonate are of a major concern in various fields, such as coating, painting and ceramics and their rheological properties are very important. The effect of polyacrylic acid (PAA) of different molecular mass as a surface modifier on the surface and rheological properties of the aqueous suspension of calcium carbonate was investigated. The effect of the volume fraction of particles and polymer concentration on the viscosity at lower shear rate was discussed. The flow behavior of the concentrated suspension in the presence of PAA can be explained by the difference of the repulsive force among particles, induced by the adsorbed polymer. The results showed that the dispersibility is more pronounced by the steric hindrance behavior rather than the electrostatic behavior

Determining the SARS-CoV-2 Anti-Spike Cutoff Level Denoting Neutralizing Activity Using Two Commercial Kits

Background: The viral neutralization assay is the gold standard to estimate the level of immunity against SARS-CoV-2. This study analyzes the correlation between the quantitative Anti-SARS-CoV-2 QuantiVac ELISA (IgG) and the NeutraLISA neutralization assay. Methods: 650 serum samples were tested for both SARS-CoV-2 anti-spike (anti-S) immunoglobulin G (IgG) and neutralizing antibodies (nAbs) using kits by EUROIMMUN, Germany. Results: There was a significant correlation between levels of anti-S and nAbs (Spearman’s rho = 0.913). Among the positive samples for anti-S, 77.0% (n = 345) were positive for nAbs. There was a substantial agreement between anti-S and nAbs (Cohen’s kappa coefficient = 0.658; agreement of 83.38%). Considering NeutraLISA as a gold standard, anti-S had a sensitivity of 98.57%, specificity of 65.66%, NPV of 97.5%, and PPV of 77.0%. When the anti-S titer was greater than 18.1 RU/mL (57.9 BAU/mL), nAbs were positive, with a sensitivity of 90.0% and specificity of 91%. Conclusions: A titer of SARS-CoV-2 anti-S IgG can be correlated with levels of nAbs

Physicochemical study and application for pyrolusite separation from high manganese-iron ore in the presence of microorganisms

Paenibacillus polymyxa bacteria strain as a surface modifier in a flotation process could remove 64.89% of $MnO_2$ from high manganese iron ore. A concentrate containing 3.7% $MnO_2$, 0.5% $SiO_2$ and 71.30% $Fe_2O_3$, with a hematite recovery of 72.46% is produced from a feed containing 8.79% $MnO_2$, 0.49% $SiO_2$ and 67.90% $Fe_2O_3$. The bio-flotation results indicated that such type of bacteria is selective for upgrading El-Gedida iron ore from the Western Desert of Egypt. The role of Paenibacillus polymyxa on the surface properties of pyrolusite and hematite single minerals was investigated through zeta potential, FTIR and adsorption measurements

Validation of EGCRISC for Chronic Hepatitis C Infection Screening and Risk Assessment in the Egyptian Population

<div><p>Chronic HCV infection, a highly endemic disease in Egypt, is usually asymptomatic for decades after infection. Prediction questionnaire tool was proofed to be a valuable, feasible and efficient instrument for the screening of several diseases. We previously developed an Egyptian HCV risk screening tool (EGCRISC). This study aims to validate/modify EGCRISC. A cross-sectional study testing 4579 individuals by EGCRISC as well as ELISA/PCR was performed. The sample was a stratified cluster sampling from urban and rural areas in Upper and Lower Egypt using a proportional allocation technique. The degree of agreement and positive and negative posttest probabilities were calculated. ROC curve was done and the cutoff points were customized for best performance. The total score was further classified into three levels according to the risk load. The mean age of the participants was 41.1±12.2 in whom HCV prevalence was 8.6%. EGCRISC, particularly after modifying the cutoff points, has a good discriminating ability. The degree of agreement was at least 68.1% and the positive posttest probability ranged from 5% to 37.2% whereas the negative posttest probability was in the range 1% to 17%. We conclude that EGCRISC is a valid tool that can potentially screen for HCV infection risk in Egypt and could diminish the demand for mass serologic screening in those apparently at minimal risk. Extensive use of electronic and self- or interviewer-administered risk-based screening strategy may simplify and promote overall screening and detection of HCV dissimilar communities.</p></div

Asymptomatic versus symptomatic SARS-CoV-2 infection: a cross-sectional seroprevalence study

Abstract Background Although symptomatic SARS-CoV-2 infection predisposes patients to develop complications, the asymptomatic SARS-CoV-2 infection state is of public health importance being a hidden source of infection. Moreover, the asymptomatic state may camouflage the actual burden of the disease. Methods Data of 1434 seropositive participants for SARS-CoV-2 spike (anti-S) and/or nucleocapsid antibodies (anti-N) were retrieved from a larger cross-sectional survey on COVID-19. Relevant data were retrieved from records including socio-demographic, medical, and behavioral characteristics of seropositive participants as well as history of COVID-19 symptoms during the last 6 months. Symptomatic/asymptomatic SARS-CoV-2 infection was categorized based on the history of the presence or absence of COVID-19 symptoms. Results The rate of asymptomatic SARS-CoV-2 infection was 34.9%. There was a statistically significant difference between symptomatic and asymptomatic participants regarding age, residence, medical conditions, habits, and infection control measures. The number of symptoms was positively correlated with anti-S titer and both were positively correlated with adult body mass index. Slum areas residence, client-facing occupation or being a healthcare worker, having lung disease, having blood group type A, never practicing exercise or social distancing, never using soap for hand washing, and minimal engagement in online working/studying were independent factors associated with the symptomatic state. Patients having less than three symptoms were less likely to be diagnosed by any means. Conclusions One-third of SARS-CoV-2 infections in our study were asymptomatic. This mandates applying proper measures to prevent transmission even from apparently healthy individuals. Modifiable factors associated with symptomatic infection should be controlled to reduce the risk of COVID-19 complications

The scoring system for the selected risk factors.

<p>ROC curve analysis for the best cutoff point discriminating HCV positive and HCV negative status. Old cut off value was included in the table. Cutoff values respected in our prediction model are displayed in a red color font. ~ old cut off value</p

Summary of EGCRISC strata, factors, scores and cut-off points.

<p>Summary of EGCRISC strata, factors, scores and cut-off points.</p