Nasopharyngeal isolates and their clinical impact on young children with asthma: a pilot study.

INTRODUCTION: Respiratory infections have significant effects on childhood asthma. Viral respiratory infections, such as rhinovirus and respiratory syncytial virus are likely to be important in the development and exacerbation of asthma. In this study, we investigated the nasopharyngeal colonization in children with asthma to determine the prevalence of pathogens and their contribution to respiratory symptoms and airway resistance during winter. METHODS: From December 2016 to March 2017, 50 nasopharyngeal specimens were collected from 18 patients (age, 5.0±1.1 years) with asthma and 9 specimens from 9 control children (age, 4.9±1.0 years). Samples were tested for 19 viruses and 7 bacteria, using multiplex real-time PCR. Respiratory disease markers included the Global Asthma Network Questionnaire, the Common-Cold Questionnaire, the Global Initiative for Asthma assessment of asthma control, and the airway resistance at 5 Hz by forced-oscillation technique. RESULTS: The most commonly isolated organisms in both groups (patients and controls) were Streptococcus pneumoniae, Haemophilus influenzae, and rhinovirus. Most patients had multiple isolates (median, 3.5; range, 1-5), which changed during the study period. Types of isolates were 4 bacteria (S. pneumoniae, H. influenzae, Bordetella pertussis, and Bordetella parapertussis) and 6 viruses (rhinovirus, enterovirus, metapneumovirus, adenovirus, coronaviruses, and parainfluenza viruses). Similar isolates, including influenza A-H3 virus and bocavirus, were detected in the controls. Of the 9 patients with "wheezing disturbing sleep ≥1 per week", 6 had rhinovirus, 2 coronaviruses, and 1 no detectable viruses. Patients with mild common cold symptoms had significantly higher airway resistance at 5 Hz z-score (P=0.025). CONCLUSION: Multiple respiratory pathogens were isolated from many patients with asthma, which appeared to contribute to disease symptoms and airway resistance. Minimizing children's exposure to respiratory pathogens might be beneficial, especially during winter.

Seroprevalence of influenza A and B viruses among unvaccinated children in the United Arab Emirates: a cross-sectional study.

BACKGROUND: Young children are at increased risk of severe influenza disease and, thus, are good candidates for receiving annual vaccination. Nevertheless, the influenza vaccine is infrequently given to children in our region. The primary objectives of this study are to monitor the serologic immunities against influenza A and B viruses, and provide pediatric data that support the need for influenza vaccination in the community. METHODS: Influenza A and B virus-specific IgG antibodies were measured in 294 children (median age 4.1 years; range 1.9-12.5 years) between July 2014 and September 2015. RESULTS: The percentage of children who were seropositive for influenza A IgG was 15.8%, equivocal 7.4%, and negative 76.8%. The corresponding values for influenza B IgG were 31.3, 9.6, and 59.1%, respectively. There was a higher seropositivity rate for influenza B than for influenza A in all age groups. The percentage of children who were seropositive for either influenza A or B IgG was 27.9% and for both was only 2.7%. CONCLUSIONS: Most of the studied children are serologically naïve and, thus, are likely to acquire primary influenza disease. A national policy that endorses childhood influenza vaccination is highly advisable.

Seroprevalence of vaccine-preventable diseases among young children in the United Arab Emirates.

OBJECTIVES: In the United Arab Emirates (UAE), many vaccine-preventable diseases are notifiable and are often reported despite high estimated immunization coverage. The serological assessment of immunity against these infections (serosurveillance) complements disease surveillance (notification). This study aimed to assess the yet unmeasured serological immunities to nine vaccine-preventable infections among vaccinated Emirati children. METHODS: This cross-sectional study involved children who attended the Well-Child Care Programme of the Ambulatory Healthcare Services (Al-Ain, UAE) between July 2014 and September 2015. Serological testing was performed in 227 Emirati children (49% females); subjects were aged (mean±standard deviation) 45±14 months (median 43, range 23-71 months). RESULTS: The seroprevalence rates varied markedly among the studied vaccine-preventable diseases, ranging from 39.2% (pertussis) to 98.3% (rubella). Other high seroprevalence rates were noted for measles (98.2%) and poliovirus (92%). The seroprevalence rate for mumps was 82.8%, for varicella was 68.3%, for diphtheria was 86.4%, for tetanus was 89.9%, and for Haemophilus influenzae type B was 84.1%. CONCLUSIONS: A large number of the studied children had low seroprevalence rates against pertussis, varicella, and mumps. Studies are needed to explore whether modifying the national immunization programme could improve these low seroprevalence estimates.

The use of an interferon-gamma release assay to screen for pediatric latent tuberculosis infection in the eastern region of the Emirate of Abu Dhabi.

OBJECTIVES: Intense migration to the United Arab Emirates from tuberculosis (TB) high-endemic areas presents a particular risk to the population. Screening for latent tuberculosis infection (LTBI) usually involves risk assessment, the tuberculin skin test (TST), and interferon-gamma release assay (IGRA). This study investigated the use of an IGRA to screen for LTBI and compared its performance with a risk assessment questionnaire. METHODS: This prospective cross-sectional study was conducted at seven Ambulatory Healthcare Services facilities in Abu Dhabi. Participants (88% Emiratis) were pediatric patients presenting for routine care. The QuantiFERON-TB Gold In-Tube test was performed and the parents completed a questionnaire assessing TB risk factors. RESULTS: Six-hundred and ninety-nine subjects (median age 8.7 years, interquartile range 9.2 years) were enrolled; 669 (96%) agreed to testing. Four patients had a positive IGRA; one had previously been treated for TB, resulting in three patients with LTBI. The estimated LTBI prevalence was 0.45% (95% confidence interval 0.09-1.3). A household contact from a TB high-endemic area was reported in 44%, travel to a TB high-endemic area in 10%, and contact with someone with a chronic cough in 7%, a TB case in 3%, a TST-positive case in 2%, and an IGRA-positive case in 2%. Fifty percent of participants had at least one risk factor. The risk assessment did not predict a positive IGRA. CONCLUSIONS: The questionnaire yielded a risk of TB exposure of 50%, however the LTBI prevalence, as defined by the IGRA, was low (0.45%).

Effects of Nigella sativa and thymoquinone on biochemical and subcellular changes in pancreatic ß-cells of streptozotocin-induced diabetic rats.

BACKGROUND: The present study investigated the effects of Nigella sativa aqueous extract and oil, as well as thymoquinone, on serum insulin and glucose concentrations in streptozotocin (STZ) diabetic rats. METHODS: Rats were divided into five experimental groups (control, untreated STZ-diabetic, and aqueous extract-, oil-, or thymoquinone-treated diabetic rats). Treated rats received 2 mL/kg, i.p., 5%N. sativa extract, 0.2 mL/kg, i.p., N. sativa oil, or 3 mg/mL, i.p., thymoquinone 6 days/week for 30 days. Serum insulin and glucose concentrations, superoxide dismutase (SOD) levels, and pancreatic tissue malondialdehyde (MDA) were determined. Electron microscopy was used to identify any subcellular changes. RESULTS: Diabetes increased tissue MDA and serum glucose levels and decreased insulin and SOD levels. Treatment of rats with N. sativa extract and oil, as well as thymoquinone, significantly decreased the diabetes-induced increases in tissue MDA and serum glucose and significantly increased serum insulin and tissue SOD. Ultrastructurally, thymoquinone ameliorated most of the toxic effects of STZ, including segregated nucleoli, heterochromatin aggregates (indicating DNA damage), and mitochondrial vacuolization and fragmentation. The aqueous extract of N. sativa also reversed these effects of STZ, but to a lesser extent. The N. sativa oil restored normal insulin levels, but failed to decrease serum glucose concentrations to normal. CONCLUSIONS: The biochemical and ultrastructural findings suggest that N. sativa extract and thymoquinone have therapeutic and protect against STZ-diabetes by decreasing oxidative stress, thus preserving pancreatic ß-cell integrity. The hypoglycemic effect observed could be due to amelioration of ß-cell ultrastructure, thus leading to increased insulin levels. Consequently, N. sativa and thymoquinone may prove clinically useful in the treatment of diabetics and in the protection of ß-cells against oxidative stress.