Viral aetiology of bronchiolitis in hospitalised children in Qatar.

BACKGROUND: Bronchiolitis is considered one of the earliest and most common causes of hospitalisation in young children. Development of molecular technologies allowed a better understanding of bronchiolitis aetiology. Results from cohort studies evaluating the association between single, multiple viral infections and clinical outcomes are conflicting. Data on viral bronchiolitis in children were found to be limited in Qatar. This study aimed to determine frequency and seasonal trends of viral pathogens causing acute bronchiolitis, and to explore association between viral pathogens, disease severity and length of stay (LOS). METHODS: This is a retrospective descriptive study, including children admitted in 2010 and 2011 with acute bronchiolitis. Presenting history, physical examination and respiratory viral co-infections as detected by molecular assays were analysed. RESULTS: At least one virus was detected in 315/369 (85.4%) of included children with single and multiple viruses in 67 and 33% of cases respectively. Respiratory syncytial virus (RSV) was the most detected virus, accounting for 51.2% followed by rhinovirus (RV) in 25.5% of cases. Fall and summer admissions were associated with longer LOS. On multivariate logistic regression analysis, retraction (OR 3.96; 95% CI 1.64,9.59) and age group 1-3 months (OR 3.09; 95% CI 1.06,9.05) were associated with longer LOS. Crepitation (OR 9.15; 95% CI 1.58,53.13), retraction (OR 4.10; 95% CI 1.05,16.12) and respiratory rate (OR 1.46; 95% CI 1.28,1.66) were associated with moderate to severe bronchiolitis. Identifying the viral agent did not influence disease severity or LOS. CONCLUSION: Clinical presentation is of more relevance to LOS and disease severity than the detected viruses. Future studies should investigate the interplay between climate characteristics, population's factors and the most detectable circulating viruses.

Porous media grain size distribution and hydrodynamic forces effects on transport and deposition of suspended particles.

The effects of porous media grain size distribution on the transport and deposition of polydisperse suspended particles under different flow velocities were investigated. Selected Kaolinite particles (2-30µm) and Fluorescein (dissolved tracer) were injected in the porous media by step input injection technique. Three sands filled columns were used: Fine sand, Coarse sand, and a third sand (Mixture) obtained by mixing the two last sands in equal weight proportion. The porous media performance on the particle removal was evaluated by analysing particles breakthrough curves, hydro-dispersive parameters determined using the analytical solution of convection-dispersion equation with a first order deposition kinetics, particles deposition profiles, and particle-size distribution of the recovered and the deposited particles. The deposition kinetics and the longitudinal hydrodynamic dispersion coefficients are controlled by the porous media grain size distribution. Mixture sand is more dispersive than Fine and Coarse sands. More the uniformity coefficient of the porous medium is large, higher is the filtration efficiency. At low velocities, porous media capture all sizes of suspended particles injected with larger ones mainly captured at the entrance. A high flow velocity carries the particles deeper into the porous media, producing more gradual changes in the deposition profile. The median diameter of the deposited particles at different depth increases with flow velocity. The large grain size distribution leads to build narrow pores enhancing the deposition of the particles by straining.

Clinical characteristics of patients with mpox infection in the United Arab Emirates: a prospective cohort study.

OBJECTIVES: The study aims to explore the risk factors, clinical characteristics, and outcomes of mpox infection in Abu Dhabi, United Arab Emirates (UAE). METHODS: A prospective cohort study was conducted at two communicable disease centers in Abu Dhabi, UAE and patients admitted with confirmed mpox infections between May 01, 2022 and December 31, 2022 were included in our study. RESULTS: A total of 176 mpox patients were admitted, of which 93% (n = 164) were men and mean age was 30.4 ± 7 years. Individuals presented with mucocutaneous lesions, most commonly on the genital and anal regions (n = 157; 89%). Only 70 (39.8%) gave a history of sexual exposure. The most common systemic symptoms reported were fever (n = 91; 52%), exanthema (n = 92; 52%), and inguinal lymphadenopathy (n = 60; 34%). Median timeframe from systemic symptoms to appearance of lesions was 4 days (interquartile range 4-6 days). Complications were observed in seven (4%) participants; two (1.1%) individuals developed conjunctivitis, four (2.3%) patients developed penile edema, and one (0.6%) case of myocarditis was reported. In 60% (n = 106) of patients, a potential source of sexual exposure was not identified. CONCLUSION: The clinical characteristics of mpox cases in the UAE are similar to those in other countries. However, cultural and religious factors likely prevent patient disclosure of sexual exposure and symptoms, contributing to the limited information about the disease in the Middle East.

Effectiveness of BBIBP-CorV vaccine against severe outcomes of COVID-19 in Abu Dhabi, United Arab Emirates.

The effectiveness of the inactivated BBIBP-CorV vaccine against severe COVID-19 outcomes (hospitalization, critical care admission and death due to COVID-19) and its long-term effectiveness have not been well characterized among the general population. We conducted a retrospective cohort study using electronic health records of 3,147,869 adults, of which 1,099,886 vaccinated individuals were matched, in a 1:1 ratio to 1,099,886 unvaccinated persons. A Cox-proportional hazard model with time varying coefficients was used to assess the vaccine effectiveness adjusting for age, sex, comorbidity, ethnicity, and the calendar month of entry into the study. Our analysis showed that the effectiveness was 79.6% (95% CI, 77.7 to 81.3) against hospitalization, 86% (95% CI, 82.2 to 89.0) against critical care admission, and 84.1% (95% CI, 70.8 to 91.3) against death due to COVID-19. The effectiveness against these severe outcomes declined over time indicating the need for booster doses to increase protection against severe COVID-19 outcomes.

Latent Tuberculosis Infection: Treatment Initiation and Completion Rates in Persons Seeking Immigration and Health Care Workers.

BACKGROUND: We assessed the factors associated with initiation and completion rates of latent tuberculosis (TB) infection treatment in persons evaluated at an infectious diseases outpatient clinic in central Massachusetts. The Centers for Disease Control and Prevention (CDC) estimates that there may be up to 14 million persons in the United States with a latent TB infection. The risk of developing active TB in these persons can range from 5% to 15%. Hence, treatment of latent TB infection is an important aspect of any plan attempting to eradicate TB from the United States. METHODS: We performed a retrospective chart review of patients referred to our outpatient infectious diseases clinic from December 2006 to October 2010. RESULTS: Overall treatment initiation and completion rates were 76% and 68%, respectively, in our cohort. Two factors that were statistically significant for higher rates of treatment completion were 4 or more follow-up visits during the course of treatment (P < 0.001) and persons seeking immigration (PSI) to the United States (P < 0.02). Rate of treatment refusal was higher in health care workers as compared to workers not in health care (35% vs 13%, P = 0.004, 95% confidence interval [CI]: 1.38-4.91). CONCLUSION: Our study reveals findings not previously reported in the US literature. We noted a high rate of treatment completion in persons seeking immigration to the United States. The second unique observation is the higher treatment completion rates in persons with 4 or more follow-up visits. We suggest that an emphasis on at least 4 follow-up visits can be an intervention that could improve the overall rates of treatment completion.

Modeling of the transport and deposition of polydispersed particles: Effects of hydrodynamics and spatiotemporal evolution of the deposition rate.

A time-distance-dependent deposition model is built to investigate the effects of hydrodynamic forces on the transport and deposition of polydispersed particles and the evolution of deposition rates with time and distance. Straining and the heterogeneity of the particle population are considered to play important roles in the decreasing distribution of deposition rates. Numerical simulations were applied in a series of sand column experiments at different fluid velocities for three different porous media. The effects of hydrodynamics forces are elaborated with the systematic variations of deposition dynamic parameters of the proposed model. With retention distributions with particle size as well as temporal and spatial evolutions of deposition rates, the transport and deposition mechanisms of polydispersed particles will be elucidated through the interplay of the variation of the particle size distribution of mobile particle populations and the geometrical change of the porous medium due to retention (straining and blocking).

Recrudescence of Plasmodium falciparum in a Primigravida After Nearly 3 Years of Latency.

We present a case of a primigravid woman who presented with Plasmodium falciparum nearly 3 years after she last visited a malaria-endemic region. We review the literature to identify case reports of recrudescent P. falciparum malaria during pregnancy, including those with prolonged latency. Reports of recrudescence of P. falciparum during pregnancy are limited. Plasmodium falciparum infection can persist for years. Recrudescence can occur with waning of immunity following departure from endemic areas. Pregnancy, particularly the primigravid state, is a risk factor for severe infection.

Modeling of retention and re-entrainment of mono- and poly-disperse particles: Effects of hydrodynamics, particle size and interplay of different-sized particles retention.

In this paper, numerical simulations of experimental data were performed with kinetic rate coefficients to characterize the retention and re-entrainment dynamics under different hydrodynamic conditions for monodisperse and polydisperse latex particles (3, 10, 16µm and the mixture). The results show that drastic increase in fluid velocity provokes hardly any remarkable decrease in retention in the presence of large energy barriers (>2000kT). Systematical increases in deposition and re-entrainment dynamic rates were observed with fluid velocity and/or particle size. Increased irreversible deposition rate indicates straining and wedging dominate deposition in this study. Excess retention of 3µm particle in the polydisperse particle suspension was observed. The origins are reckoned that deposited larger particles may hinder the re-entrainment of smaller particles near the grain-to-grain contact and can provide additional sites of attachment.