Acute respiratory tract infection symptoms and the uptake of dual influenza and pneumococcal vaccines among Hajj pilgrims

Background: Hajj pilgrims are encouraged to take influenza and pneumococcal vaccines prior to their travelto safeguard against acute respiratory tract infections (ARTIs). It is unclear whether dual immunisationwith influenza and pneumococcal vaccines have had any impact on ARTI symptoms. To this end, we haveexamined the data of the last several years to assess whether combined influenza and pneumococcalvaccination has affected the rate of ARTI symptoms among Hajj pilgrims.Materials and methods: Hajj pilgrims from United Kingdom, Australia, Saudi Arabia and Qatar who attendedthe congregation between 2005 and 2015 were included in this study. Data from surveillance studiesor clinical trials involving Hajj pilgrims were used. In this analysis we have made use of the raw data toconstruct a trend line graph with the prevalence of combined cough and fever (as a proxy for ARTI) againstthe uptake of combined influenza and pneumococcal vaccines, and to estimate the relative risk (RR) ofARTI with 95% confidence interval (95% CI).Results: Data of a pooled sample of 9350 pilgrims, aged 0.5–90 years with a male to female ratio of 1.1, wereanalysed. Although vaccination uptake did not rise significantly over the years, there was also no observed meaningfulbenefit of combined vaccination (RR = 1.1; 95% CI 0.8–1.4), the rates of ARTI symptoms demonstrateda decline over the last several years. The findings of this analysis highlight that the prevalence of ‘cough and fever’among Hajj pilgrims is on decline but the uptake of combined influenza and pneumococcal vaccines remainsunchanged over years, and the decline can not be attributed to dual influenza and pneumococcal vaccination.Conclusions: Acute respiratory tract infections among Hajj pilgrims are decreasing, it is unclear if thereduction is due to vaccine uptake, but the data and analysis have some limitations

Influenza vaccination among Australian Hajj pilgrims: uptake, attitudes, and barriers

Background: Hajj is the largest annual mass gathering where the risk of respiratory infection is high. Although the Saudi Arabian authority recommends influenza vaccination for Hajj pilgrims, the uptake is variable. Influenza vaccine uptake data among Australian Hajj pilgrims is not readily available. Therefore, we aimed to estimate the influenza vaccination uptake rate and identify both attitudes and barriers to vaccine uptake from two consecutives surveys at Hajj in 2011 and 2012. Methods: Using an anonymous self‐administered questionnaire, surveys were conducted in Mecca, Saudi Arabia, among Hajj pilgrims from Australia in 2011 and 2012. Pilgrims staying in “Australian” tents were recruited serially. Results: In 2011, 431 Australian pilgrims completed the survey—median age was 42 (range 7–86) years, 55% were male; 65% reported receiving influenza vaccine. In 2012, 535 pilgrims of median age 43 (range 12–83) years completed the survey, 62% were male; 89% reported receiving the vaccine. Both in 2011 and 2012, common reasons for not receiving the vaccine were the pilgrims' reliance on their “natural immunity” (33 and 26%, respectively, p = 0.4) and believing that they would rarely catch influenza or come in contact with influenza patients (18 and 29%, respectively, p = 0.1). In 2012, when asked why they had received the vaccine, 65% pilgrims responded that it was because of the tour group leaders' recommendation. Conclusion: Influenza vaccine uptake among Australian Hajj pilgrims seems satisfactory and increasing but could be better because many pilgrims have misconceptions about vaccines. Tour operators may play a greater role in promoting vaccination

Toward optically defned mechanical geometry

In the field of optomechanics, radiation forces have provided a particularly high level ofcontrol over the frequency and dissipation of mechanical elements. In this dissertation, wefirst propose a class of optomechanical systems in which light exerts a similarly profoundinfluence over two other fundamental parameters: geometry and mass. By applying an opticaltrap to one lattice site of an extended phononic crystal, we show it should be possible tocreate a tunable, localized mechanical mode. Owing to light's simultaneous and constructivecoupling with the structure's continuum of modes, we estimate that a trap power at the levelof a single intracavity photon should be capable of producing a significant effect within arealistic, chip-scale device. In the second half of the dissertation, we discuss progress towardrealizing the requisite two-dimensional phononic crystal membranes for such experiments.We report the results of several fabrication techniques (each with their own drawbacks),finding it is possible to consistently produce 100 nm to 300 nm thick stoichiometric Si 3N4freestanding crystals with an area as large as 20 millimeter square, up to 2750 crystal unit cells, andtethers as narrow as around 1.5 microns, using wafer-scale photolithography. Preliminary mechanicalcharacterization verifies that these devices indeed exhibit the phononic bandgap required forlaser-induced localization experiments (with a ratio of gap width to band edge frequency ashigh as 80%).Dans le domaine de l'optomécanique, les forces de radiation ont permis un particulièrementgrand degré de contrôle sur la fréquence et la dissipation d'éléments mécaniques. Dansle cadre de cette dissertation, nous proposons d'abord une catégorie de systèmes optomé-caniques où la lumière exerce une forte influence similaire sur deux autres paramètres fondamentaux: la géométrie et la masse. En appliquant un piège optique au site réticulaired'un cristal phononique élargi, nous démontrons qu'il devrait être possible de créer un modemécanique localisé accordable. En raison des couplages simultanés et constructifs de la lumière avec le continuum de modes de la structure, nous estimons qu'un pouvoir de trappeau niveau de la cavité unique d'un photon devrait pouvoir produire un effet significatif àl'intérieur d'un appareil à puce. Dans la deuxième moitié de la dissertation, nous discutonsdu progrès accompli en vue de produire les membranes de cristal phononique à deux dimensionsnécessaire à de telles expériences. Nous présentons les résultats de plusieurs techniquesde fabrication (chacune avec ses lacunes particulières) et attestons qu'il est possible de produireconstamment 100 nm à 300 nm de cristaux Si3N4 stoechiométriques indépendants épaisavec une superficie pouvant aller jusqu'à 20 mm2, jusqu'à 2750 de cristal avec des mailles etdes ancrages aussi minces que 1.5 micron, en utilisant la photolithographie à l'échelle d'uneplaquette. La caractérisation mécanique préliminaire indique que ces appareils exhibent lebord de bande phononique requis pour des expériences de localisation au laser (avec un ratiode fréquence aussi élevé que 80 % entre la largeur de bande et le bord de la bande)

Prevention of respiratory viral infection among Hajj pilgrims

Hajj is one of the five basic tenets of Islam. Every practicing, financially and physically capable, Muslim is required to perform Hajj at least once in his/her lifetime. Each year up to three million people from more than 180 countries assemble in Mecca, Saudi Arabia, to perform Hajj pilgrimage. Severe crowding, shared accommodation, poor personal hygiene, and environmental pollution at Hajj may collectively lead to increased transmission of respiratory viruses. Influenza-like illness (ILI) is one of the most common medical presentations to primary care, mostly due to viral infection, in which pneumonia is the leading cause of hospital admission during Hajj. Therefore, I endeavoured to study the epidemiology of respiratory viruses among pilgrims including newly emergent viruses such as Middle East coronavirus (MERS-CoV) and assessed preventive strategies primarily focussing on facemasks effectiveness and evaluating influenza vaccine uptake. Methods To understand the epidemiology of respiratory infection during Hajj, a cross-sectional study was conducted among pilgrims from Saudi Arabia, Australia and Qatar. A nasal swab was collected from any participant who developed ILI to identify the causative agent. After that, we explored the possible preventive measures to reduce the transmission of respiratory viral infection such as influenza vaccine and facemasks. For influenza vaccine, an anonymous survey was conducted to assess the uptake of influenza vaccine, and explore the attitudes and barriers to, and perception of vaccination. At the same time, a pilot trial was conducted to explore the feasibility of establishing a large-scale trial to test the effectiveness of facemasks in preventing respiratory viral infection among Hajj pilgrims. The outcome of the pilot trial was encouraging and suggested that it was feasible to do a large-scale trial. Therefore, we conducted a large-scale randomised controlled trial (RCT) to test the effectiveness of facemasks in preventing respiratory viral infection over three consecutive Hajj seasons (2013, 2014, 2015). Results In 2013, we recruited 1038 pilgrims from Saudi Arabia, Australia and Qatar during the first day of Hajj and followed them closely for four days to comprehend the epidemiology of respiratory viral infection during the Hajj. About 11% of the pilgrims reported ILI; 38% of which had laboratory-confirmed viral infections. Rhinovirus was the commonest cause of ILI among Hajj pilgrims (25%) followed by influenza A (4%). Also, other types of viruses were reported such as adenovirus (2%), human coronavirus OC43/229E (2%) and parainfluenza virus 3, 1 (2%). MERS-CoV was considered a health risk at that year (2013), luckily, it was not detected in any sample in this study. The studies showed that influenza vaccine uptake was increased among Hajj pilgrims specifically the Australian. On the other hand, symptoms of respiratory infection were decreased. However, it is uncertain if this decrease is due to vaccination. Contrarily, facemasks uptake among Hajj pilgrims remained unchanged in the last 10 years with an average uptake of 50% according to a systematic review synthesised by myself and colleagues. Moreover, the large-scale RCT showed that pilgrims did not use facemasks adequately; and those who used facemasks had no statistically significant benefit against laboratory-confirmed or clinical viral respiratory tract infections. Conclusion Epidemiology of virus infection during Hajj showed that rhinovirus was the most common causative agent. Also, there were other respiratory viruses reported including influenza, adenovirus but not MERS-CoV. Influenza vaccine uptake is improving among Hajj pilgrims, while facemasks had lower uptake. Facemasks use did not prevent clinical or laboratory-confirmed respiratory viral infection during Hajj. This is may be due to poor compliance of pilgrims in using facemasks

Fabrication of Lead Free Borate Glasses Modified by Bismuth Oxide for Gamma Ray Protection Applications

In the present work, bismuth borate glass samples with the composition of (99-x) B2O3 + 1Cr2O3 + (x) Bi2O3 (x = 0, 5, 10, 15, 20, and 25 wt %) were prepared using the melt quenching technique. The mass attenuation coefficient (MAC) of the prepared glass samples was measured through a narrow beam technique using a NaI(Tl) scintillation detector. Four point sources were used (241Am, 133Ba, 152Eu, and 137Cs) to measure the MAC for the prepared glasses. The experimental data were compared with the theoretical results obtained from the XCOM, and it was shown that for all samples at all tested energies, the relative deviation between the samples is less than 3%. This finding signifies that the experimental data can adequately be used to evaluate the shielding ability of the glasses. The MAC of the sample with x = 25 wt % was compared with different lead borate glasses and the results indicated that the present sample has high attenuation which is very close to commercial lead borate glasses. We determined the transmission factor (TF), and found that it is small at low energies and increases as the energy increases. The addition of Bi2O3 leads to reduction in the TF values, which improves the shielding performance of the glass system. The half value layer (HVL) of the BCrBi-10 sample was 0.400 cm at 0.595 MeV, 1.619 cm at 0.2447 MeV, and 4.946 cm at 1.4080 MeV. Meanwhile, the HVL of the BCrBi-20 sample is equal to 0.171 and 4.334 cm at 0.0595 and 1.4080 MeV, respectively. The HVL data emphasize that higher energy photons tend to penetrate through the glasses with greater ease than lower energy photons. Furthermore, the fast neutron removable cross section (FNRC) was determined for the present samples and compared with lead borate glass and concrete, and the results showed a remarkable superiority of the bismuth borate glass samples

A Novel Computational Instrument Based on a Universal Mixture Density Network with a Gaussian Mixture Model as a Backbone for Predicting COVID-19 Variants’ Distributions

Various published COVID-19 models have been used in epidemiological studies and healthcare planning to model and predict the spread of the disease and appropriately realign health measures and priorities given the resource limitations in the field of healthcare. However, a significant issue arises when these models need help identifying the distribution of the constituent variants of COVID-19 infections. The emergence of such a challenge means that, given limited healthcare resources, health planning would be ineffective and cost lives. This work presents a universal neural network (NN) computational instrument for predicting the mainstream symptomatic infection rate of COVID-19 and models of the distribution of its associated variants. The NN is based on a mixture density network (MDN) with a Gaussian mixture model (GMM) object as a backbone. Twelve use cases were used to demonstrate the validity and reliability of the proposed MDN. The use cases included COVID-19 data for Canada and Saudi Arabia, two date ranges (300 and 500 days), two input data modes, and three activation functions, each with different implementations of the batch size and epoch value. This array of scenarios provided an opportunity to investigate the impacts of epistemic uncertainty (EU) and aleatoric uncertainty (AU) on the prediction model’s fitting. The model accuracy readings were in the high nineties based on a tolerance margin of 0.0125. The primary outcome of this work indicates that this easy-to-use universal MDN helps provide reliable predictions of COVID-19 variant distributions and the corresponding synthesized profile of the mainstream infection rate

Simple Moment Generating Function Optimisation Technique to Design Optimum Electronic Filter for Underwater Wireless Optical Communication Receiver

This paper introduces a new simple moment-generating function (MGF) design modelling method to conclude an optimum filter to maximize the Q-factor and increase the link communication span. This approach mitigates the pulse temporal dispersion, particularly the underwater wireless optical communication (UWOC) systems. Hence, some form of equalizing filter design is highly desirable. The model solution environment includes a Double Gamma Function (DGF) water channel impulse response, intersymbol interference (ISI), stochastic Poisson process, and additive Gaussian thermal noise (AGTN). The optimal filters exhibit temporal profiles comparable to those derived by published works based on complex Chernoff Bound (CB) and Modified Chernoff Bound (MCB) methods. The results show the impact of the optimum filter at a signal level and optical receiver level utilizing Eye-Diagrams and BER vs. Q-Factor, respectively. The computation involves four different UWOC propagation channel models for Coastal and Harbor waters. One of the main conclusions indicates that the optimum filter manages the temporal dispersion due to the ISI impairment correctly. Also, the proposed optimum filter reduces eye-opening and the corresponding Q-Factor by less than 15% for a five-times increase in pulse width for the same transmitted optical power level