Respiratory Tract Disease In Children Research Articles

Epidemiological and antigenic analysis of respiratory syncytial virus in hospitalised Tunisian children, from 2000 to 2002.

Human respiratory syncytial virus (RSV) is the major viral cause of lower respiratory tract disease in children. Infections with the virus occur as annual winter epidemics in temperate climates, placing considerable pressure on the provision of hospital beds. Most molecular epidemiological studies have, until now, focused on isolates from infants in industrialised countries. No data have been available with regard to RSV strains from northern Africa. In this report, a recent RSV outbreak in Tunisia was studied and results showed that 176 of 815 (21.6%) nasopharyngeal aspirates collected from hospitalised children were RSV-positive by immunofluorescence assay. This RSV outbreak showed a temperature-dependent pattern (P=0.026) but no significant association with rainfall. A total of 73 RSV-positive samples were tested by two reverse-transcription-polymerase chain reaction assays (RT-PCR): RT-PCR-1, which amplifies the RNA of all RSV strains, and RT-PCR-2, which allows subgroup classification of RSV. Analysis by hybridisation assay of RT-PCR-2-amplified 1B protein gene products showed a higher prevalence of group B RSV than that of group A (82.5% vs. 17.5% among the typed strains). Knowledge of the variants is important in terms of both diagnosis and definition of a vaccine composition.

Geoprocessing and health promotion: social and environmental inequalities, Brazil

To characterize social inequalities that represent risk conditions for respiratory tract diseases in children and to describe geoprocessing techniques to identify homogeneous social groups and intervention actions for health promotion. The study area comprised the surroundings of a health school center in the city of S o Paulo. Based on 1991 census, housing data on 49 census units in the study area were statistically analyzed and it was obtained the mean of characteristic social and environment variables in these units. Together with local representatives, variables were selected that made up composite indicators related to social insertion and housing quality to allow identifying different conditions of potential exposure to respiratory tract diseases. Using geoprocessing techniques, four homogeneous groups were identified in terms of potential exposure to risk conditions for respiratory diseases. It was obtained a spatial configuration of the groups reflecting different needs in the study area. The methodological instruments used revealed to be important for the development of local actions to be implemented in services that operate in specific geographical areas. The study contributed to the identification of risk conditions in the health center area, making it possible the joint and inter-sector discussion of conditions related to respiratory tract diseases in children, aiming at promoting equity and improving child health.

Effects of socioeconomic status on presentation with acute lower respiratory tract disease in children in Salvador, Northeast Brazil.

Two different socioeconomic groups of children with pneumonia were studied, and their clinical and demographic aspects were evaluated. The diagnosis of pneumonia was based on findings of cough and tachypnea, or on crackles on auscultation or on radiologically confirmed infiltrate. This was a prospective cross-sectional study conducted at the Professor Hosannah de Oliveira Pediatric Center, which cares for children of lower socioeconomic status (PHOPC), and at one private hospital which cares for children from middle to high socioeconomic status (Aliança Hospital, AH). Demographics and clinical differences were assessed by the Pearson chi-square test or Fisher's exact test as appropriate; means of continuous variables were compared by Mann-Whitney U-test. In a 26-month period, 3,431 cases were recruited. The 2,476 cases identified at the PHOPC were younger than the 955 identified at AH (2.2 +/- 2.3 vs. 4.5 +/- 3.1 years, P < 0.0001) and had higher scores for severity (3.5 +/- 1.5 vs. 2.7 +/- 1.7, P < 0.0001), duration of hospitalization (days) (10.9 +/- 12.1 vs. 6.2 +/- 7, P < 0.0001), frequency of tobacco smoker in the household (48% vs. 31%, P < 0.0001), cardiopathy (15.3% vs. 5.9%, P = 0.003), fever (44.4% vs. 36.3%, P = 0.0001), tachypnea (67.6% vs. 32.3%, P < 0.0001), crackles (69.5% vs. 64.9%, P = 0.02), somnolence (19.9% vs. 10.4%, P < 0.0001), malnutrition (13.7% vs. 5%, P < 0.0001), hospitalization rate (27.4% vs. 22.5%, P = 0.003), and death (0.9% vs. 0.1%, P = 0.009). However, other features were more frequent among AH cases: parent's university level of education (38.2% vs. 1.0%, P < 0.0001), underlying chronic illness (40.6% vs. 28.5%, P < 0.0001), asthma (62.7% vs. 50.8%, P = 0.01), rhinitis (9.2% vs. 0.4%, P < 0.0001), previous use of antibiotics (34.3% vs. 27.1%, P = 0.001), and wheezing (53.1% vs. 42.2%, P < 0.0001). Children of lower socioeconomic status have more serious lower respiratory tract disease, whereas children with pneumonia of middle to high socioeconomic status have more allergic diseases (rhinitis, asthma) and wheezing.

Sublingual allergen-specific immunotherapy in allergic rhinitis and related pathologies: Efficacy in a paediatric population.

The aim of this study was to demonstrate the efficacy and safety of the sublingual-swallow allergen-specific immunotherapy (SLIT) in a paediatric population suffering from allergic rhinitis and related pathologies. From March 1994 through March 2000, at our ENT Department 4000 children (1800 male and 2200 female), aged 3 to14 years, were examined for recurrent nasal obstruction and nasal polyps. 2400 (60&#x0025;) of them were allergic and underwent the following investigations: Impedance test, Pure tone audiometry, rhinomanometry, Prick test, RAST, nasal provocation test and paranasal sinus TC without contrast media. Of the allergic group we admitted 288 patients(12&#x0025;) to a 3 yr SLIT, meeting the following criteria: children aged 5 years or more, mono-sensitised to one allergen and with family cooperation support. After three years of SLIT, we observed complete symptom remission and a marked improvement in instrumental examinations in 80&#x0025; of these children. The improvement was poor in 8&#x0025; of patients, while in 12&#x0025; of the subjects no changes in symptoms and instrumental results were detected. These results are in agreement with previously published studies and confirm that SLIT can be a valid tool for treating allergic upper respiratory tract diseases in children.

Respiratory syncytial virus subgroup A in hospitalized children in Zarqa, Jordan.

The epidemiology of RSV infection was investigated in 271 children aged less than 2 years admitted to the Zarqa Government Hospital, Jordan with bronchiolitis or bronchopneumonia. Nasopharyngeal washings were cultured and RSV antigen was detected by the direct immunofluorescence technique. Of the 271 specimens, 69 (25.46%) were positive for RSV, representing 50.36% of the respiratory viruses. All RSV isolates were typed as subgroup A by monoclonal antibody and confirmed by RT-PCR. RSV was prevalent in the hospitalised children in the coldest months of the year. The epidemics began in January or February, peaked in spring and then disappeared in summer. This study supports the idea that RSV subgroup A is a major contributor to winter outbreaks of respiratory tract disease in children, and health care workers in Jordan should consider the diagnosis during January-May each year.

Of bugs and drugs

PREVIEWChoosing appropriate antimicrobial therapy is no longer a simple process. Even for the common problems of respiratory tract disease in children and adults, selection is complicated by both increasing microbial resistance and the daunting number of extended-spectrum antibiotics now on the market. In this article, Drs Singh and Arrieta look at the problem from all aspects and give their specific recommendations.

Human milk lactoferrin inactivates two putative colonization factors expressed by Haemophilus influenzae.

Haemophilus influenzae is a major cause of otitis media and other respiratory tract disease in children. The pathogenesis of disease begins with colonization of the upper respiratory mucosa, a process that involves evasion of local immune mechanisms and adherence to epithelial cells. Several studies have demonstrated that human milk is protective against H. influenzae colonization and disease. In the present study, we examined the effect of human milk on the H. influenzae IgA1 protease and Hap adhesin, two autotransported proteins that are presumed to facilitate colonization. Our results demonstrated that human milk lactoferrin efficiently extracted the IgA1 protease preprotein from the bacterial outer membrane. In addition, lactoferrin specifically degraded the Hap adhesin and abolished Hap-mediated adherence. Extraction of IgA1 protease and degradation of Hap were localized to the N-lobe of the bilobed lactoferrin molecule and were inhibited by serine protease inhibitors, suggesting that the lactoferrin N-lobe may contain serine protease activity. Additional experiments revealed no effect of lactoferrin on the H. influenzae P2, P5, and P6 outer-membrane proteins, which are distinguished from IgA1 protease and Hap by the lack of an N-terminal passenger domain or an extracellular linker region. These results suggest that human milk lactoferrin may attenuate the pathogenic potential of H. influenzae by selectively inactivating IgA1 protease and Hap, thereby interfering with colonization. Future studies should examine the therapeutic potential of lactoferrin, perhaps as a supplement in infant formulas.

Respiratory Syncytial Virus -- Successful Immunoprophylaxis at Last

Respiratory infections in infants and children, and their complications, are responsible for enormous morbidity throughout the world and, particularly in the developing world, for substantial mortality. Of the numerous known microbial causes, respiratory syncytial virus is by far the most important agent causing lower respiratory tract disease in children in the developed world. It is also highly contagious and is responsible for yearly epidemics in which approximately half of all children under 18 months of age are infected. In this country, approximately 1 to 3 percent of infected infants are hospitalized with pneumonia or bronchiolitis1. And, like many other . . .

Productive infection of isolated human alveolar macrophages by respiratory syncytial virus.

Respiratory syncytial virus (RSV) is a significant cause of lower respiratory tract disease in children and individuals with cell-mediated immunodeficiencies. Airway epithelial cells may be infected with RSV, but it is unknown whether other cells within the lung permit viral replication. We studied whether human alveolar macrophages supported RSV replication in vitro. Alveolar macrophages exposed to RSV demonstrated expression of RSV fusion gene, which increased in a time-dependent manner and correlated with RSV protein expression. RSV-exposed alveolar macrophages produced and released infectious virus into supernatants for at least 25 d after infection. Viral production per alveolar macrophage declined from 0.053 plaque-forming units (pfu)/cell at 24 h after infection to 0.003 pfu/cell by 10 d after infection and then gradually increased. The capability of alveolar macrophages to support prolonged RSV replication may have a role in the pulmonary response to RSV infection.

Maternal smoking during pregnancy and lower respiratory tract illness in early life.

In a national study of 12,743 children maternal, but not paternal, smoking was confirmed as having a significant influence on the reported incidence of bronchitis and admission to hospital for lower respiratory tract illness during the first five years of life. Reported rates of admissions to hospital for lower respiratory tract diseases were found to be as high in children born to mothers who stopped smoking during pregnancy as in those whose mothers smoked continuously both during and after pregnancy. Rates of admissions to hospital for lower respiratory tract diseases in children whose mothers started smoking only postnatally were no higher than in those whose mothers remained non-smokers. Postnatal smoking seemed to exert a significant influence on the reported incidence of bronchitis, but less than smoking during pregnancy. These findings suggest that maternal smoking influences the incidence of respiratory illnesses in children mainly through a congenital effect, and only to a lesser extent through passive exposure after birth.

Bacterial Flora of the Nasopharynx in Children

The high incidence of respiratory tract disease in children, coupled with the rather indiscriminate use of antimicrobial agents, stands in marked contrast to the paucity of exact data concerning the bacterial flora of the nasopharynx. The frequency of the development of resistant organisms which may lead to serious complications indicates that such data should be obtained. The purpose of the present communication is to report the results of the nasopharyngeal cultures from 1,116 infants and children. Material and Methods Thirteen hundred eighty-five cultures on 1,116 children between the ages of 3 weeks and 14 years were obtained in the outpatient clinic of the Children's Hospital of the University of Texas Medical Branch during the period from October, 1952, through July, 1954. The vast majority of cultures were from subjects having mild or severe respiratory tract symptoms, while 104 were from infants and children having no evidence of respiratory disease. Cultures