Seasonal variations in nasopharyngeal carriage of respiratory pathogens in healthy Italian children attending day-care centres or schools.
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The aim of this study was to investigate seasonal variations in the prevalence of the nasopharyngeal carriage of respiratory pathogens and identify factors affecting colonisation patterns in healthy children. The nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis during two seasons (autumn and spring) was evaluated in 1580 healthy children aged 1-7 years by means of a cohort study conducted in day-care centres and schools in eight Italian cities. A questionnaire was used to obtain the epidemiological data. In all, 309 children (19.5%) carried one or more respiratory pathogens in the autumn, and 375 children (23.7%) in the spring. This variation was due to H. influenzae alone or in combination (autumn: S. pneumoniae 60, 3.8%; H. influenzae 206, 13.0%, M. catarrhalis 71, 4.5%; spring: S. pneumoniae 75, 4.7%; H. influenzae 288, 18.2%, M. catarrhalis 82, 5.2%). Colonisation with two or more pathogens increased from 9.1% in the spring to 17.3% in the autumn. Seasonal variations occur in the prevalence of the nasopharyngeal carriage of respiratory pathogens in healthy children attending day-care centres or schools in Italy. However, although statistically significant, the difference was slight and had limited clinical relevance. Therefore, seasonal influence on the nasopharyngeal carriage of respiratory pathogens in healthy children was negligible. (+info)
An epidemiological study of Haemophilus influenzae at a Brazilian day care center.
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Day care centers are a relatively new phenomenon in Brazil that bring together large numbers of young children susceptible to contagious diseases. Haemophilus influenzae (Hi) is an important infection in the age range of those attending day care centers. In the present study, the carriage rate of Haemophilus influenzae was identified in 38 day care attendees age 6 to 37 months, and 23 staff members, at a day care center in Ribeirao Preto-Sao Paulo, in 1997. To identify the carriers, two nasopharyngeal swabs were collected; one in July and one in December. The rate of H. influenzae carriers among the children was 77%. Only 2 of 23 staff members (9%) had Hi. Among the children, there were 58 isolates in the two sampling periods; 6 of the Hi were serotype b, 1 was serotype e, and 48 isolates were non-typeable. Two were identified as H. parainfluenzae. One adult had a non-typeable Hi and 1 had H. paraphrohaemolyticus. Three of the 6 children with type B had received a conjugate vaccine against H. influenzae type b, but they still carried this bacterium in the nasopharynx (50%). Forty ribotype patterns were found among the isolates, showing a high exchange rate of nontypeable H. influenzae carriers. The results indicate that, because of the high and changing biotype of Hi carriage, day care centers should be carefully monitored as potential point source of HI disease in the community. (+info)
An outbreak of gastroenteritis associated with astrovirus serotype 1 in a day care center, in Rio de Janeiro, Brazil.
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Between June 4th and June 20th 1996 rotavirus, adenovirus, and astrovirus (HAstrV) were investigated in fecal samples from 27 children under three years old with acute diarrhea, attending the Bertha Lutz day care center, in Rio de Janeiro. All fecal samples were analyzed by polyacrylamide gel electrophoresis (PAGE), reverse transcriptase polymerase chain reaction (RT-PCR), enzyme immunoassays (EIA), and electron microscopy (EM). Nine of them (33%) showed positive results for HAstrV by at least one of the employed methodologies. Eight were positive by RT-PCR and EIA, and six by EM. All positive samples were inoculated onto HT-29 (human colon adenocarcinoma) cultured cells for HAstrV isolation and seven were positive after three passages. The sequencing analysis of eight RT-PCR products (449 bp) from gene that codifies VP2 protein, showed a total nucleotide identity among them and 98% with HAstrV-1 (strain Oxford type 1). This is the first report of a gastroenteritis outbreak associated with HAstrv-1 in a day care center in Rio de Janeiro and it reinforces the importance of this virus in association with infantile acute gastroenteritis. (+info)
Levels of persistent organic pollutants in several child day care centers.
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The concentrations of a suite of persistent organic chemicals were measured in multiple media in 10 child day care centers located in central North Carolina. Five centers served mainly children from low-income families, as defined by the federal Women, Infants, and Children (WIC) assistance program, and five served mainly children from middle-income families. The targeted chemicals were chosen because of their probable carcinogenicity, acute or chronic toxicity, or hypothesized potential for endocrine system disruption. Targeted compounds included polycyclic aromatic hydrocarbons (PAHs), pentachloro- and nonyl-phenol, bisphenol-A, dibutyl and butylbenzyl phthalate, polychlorinated biphenyls (PCBs), organochlorine pesticides, the organophosphate pesticides diazinon and chlorpyrifos, and the herbicide 2,4-dichlorophenoxyacetic acid (2,4D). Sampled media were indoor and outdoor air, food and beverages, indoor dust, and outdoor play area soil. Concentrations of the targeted compounds were determined using a combination of extraction and analysis methods, depending on the media. Analysis was predominantly by gas chromatography/mass spectrometry (GC/MS) or gas chromatography with electron capture detection (GC/ECD). Concentrations of the targeted pollutants were low and well below the levels generally considered to be of concern as possible health hazards. Potential exposures to the target compounds were estimated from the concentrations in the various media, the children's daily time-activity schedules at day care, and the best currently available estimates of the inhalation rates (8.3 m(3)/day) and soil ingestion rates (100 mg/day) of children ages 3-5. The potential exposures for the target compounds differed depending on the compound class and the sampled media. Potential exposures through dietary ingestion were greater than those through inhalation, which were greater than those through nondietary ingestion, for the total of all PAHs, the phenols, the organophosphate pesticides, and the organochlorine pesticides. Potential exposures through dietary ingestion were greater than those through nondietary ingestion, which were greater than those through inhalation, for those PAHs that are probable human carcinogens (B2 PAH), the phthalate esters, and 2,4D. For the PCBs, exposures through inhalation were greater than those through nondietary ingestion, and exposures through dietary ingestion were smallest. Differences in targeted compound levels between the centers that serve mainly low-income clients and those that serve mainly middle-income clients were small and depended on the compound class and the medium. (+info)
Day-care and meningococcal disease in young children.
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The Republic of Ireland has the highest incidence of meningococcal disease in Europe with 40% of all cases occurring in children under the age of 5 years. Attending day-care increases the risk of certain infections, including Haemophilus influenzae type b (Hib) meningitis. The risk of meningococcal disease associated with day-care is not known. We conducted a case-control study among pre-school children with 130 laboratory-confirmed cases and 390 controls, matched on age, gender and place of residence, to determine if day-care attendance was a risk factor for meningococcal disease. Multivariate analysis showed that day-care attenders had a lower risk of disease than non-attenders (OR 0.3, 95% CI 0.1-0.7) whereas the number of adults in a household, and household crowding were independent risk factors for disease. Asymptomatic carriers of Neisseria meningitidis are the main source of transmission and these carriers are usually adults. Regular day-care attendance may reduce this risk by removing children from close and prolonged contact with adults. (+info)
Age-dependent preference in human antibody responses to Streptococcus pneumoniae polypeptide antigens.
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Vulnerability to Streptococcus pneumoniae is most pronounced in children. The microbial virulence factors and the features of the host immune response contributing to this phenomenon are not completely understood. In the current study, the humoral immune response to separated Strep. pneumoniae surface proteins and the ability to interfere with Strep. pneumoniae adhesion to cultured epithelial cells were analysed in adults and in children. Sera collected from healthy adults recognized Strep. pneumoniae separated lectin and nonlectin surface proteins in Western blot analysis and inhibited on average 80% of Strep. pneumoniae adhesion to epithelial cells in a concentration-dependent manner. However, sera longitudinally collected from healthy children attending day care centres from 18 months of age and over the course of the following 2 years revealed: (a) development of antibodies to previously unrecognized Strep. pneumoniae surface proteins with age; (b) a quantitative increase in antibody responses, measured by densitometry, towards separated Strep. pneumoniae surface proteins with age; and (c) inhibition of Strep. pneumoniae adhesion to epithelial cells, which was 50% on average at 18 months of age, increased significantly to an average level of 80% inhibition at 42 months of age equalling adult sera inhibitory values. The results obtained in the current study, from the longitudinally collected sera from healthy children with documented repeated Strep. pneumoniae colonization, show that repeated exposures are insufficient to elicit an immune response to Strep. pneumoniae proteins at 18 months of age. This inability to recognize Strep. pneumoniae surface proteins may stem from the inefficiency of T-cell-dependent B-cell responses at this age and/or from the low immunogenicity of the proteins. (+info)
Detection of anti-Giardia lamblia serum antibody among children of day care centers.
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OBJECTIVES: To detect anti-Giardia lamblia serum antibodies in healthy children attending public day care centers and to assess serological tests as tools for estimating the prevalence of G. lamblia in endemic areas. METHODS: Three separate stool specimens and filter paper blood samples were collected from 147 children ranging from 0 to 6 years old. Each stool sample was processed using spontaneous sedimentation and zinc sulfate flotation methods. Blood samples were tested by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for Giardia IgG. RESULTS AND CONCLUSIONS: Of 147 individuals tested, 93 (63.3%) showed Giardia cysts in their feces. Using IIF and ELISA, serum antibodies were detected in 93 (63.3%) and 100 (68%) samples, respectively. Sensitivity of IIF and ELISA was 82% and 72%, respectively. However, ELISA revealed to be less specific (39%) than IIF (70%). IIF also showed a higher concordance with microscopic examination than ELISA. (+info)
Reduction of nasopharyngeal carriage of Streptococcus pneumoniae after administration of a 9-valent pneumococcal conjugate vaccine to toddlers attending day care centers.
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A double-blind, randomized study involving 264 toddlers attending day care centers was conducted to document the effect of a 9-valent pneumococcal conjugate vaccine on the carriage rate of pneumococci. Of 3750 cultures done on nasopharyngeal samples obtained from subjects during a 2-year follow-up period after vaccination, 65% were positive for Streptococcus pneumoniae. In all age windows, the rate of carriage of vaccine-type pneumococci was lower among subjects who received the pneumococcal vaccine than among control subjects, because the acquisition rate was lower in the former group. The effect was most pronounced among subjects aged < or =36 months. The sample size enabled us to study protection against carriage of S. pneumoniae serotypes 6B, 9V, 14, 19F, and 23F; significant protection against all serotypes except 19F was seen in the pneumococcal-vaccine group. The rate of carriage of serotype 6A (not included in the vaccine) was also reduced significantly, but the rate of carriage of serotype 19A (not included in the vaccine) was not. The rate of carriage of non-vaccine-type pneumococci (excluding serotype 6A) was higher in the pneumococcal-vaccine group than in the control group. (+info)