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Background Helminths are modulators of the host immune system, and infections with these parasites have been associated with protection against allergies and autoimmune diseases. The human host is often infected with multiple helminth parasites and most studies to date have investigated the effects of helminths in the context of infections with single parasite or types of parasites (e.g. geohelminths). In this study, we investigated how co-infections with three nematodes affect markers of allergic inflammation and asthma in children. We selected Ascaris lumbricoides and Trichuris trichiura, two parasites that inhabit the human intestine and Toxocara spp (Toxocara canis and/or T. cati), intestinal roundworms of dogs and cats that cause systemic larval infection in humans. These parasites were selected as the most prevalent helminth parasites in our study population. Results 36.4% of children were infected with one parasite; 12.7% with 2 and 5.2% with 3. Eosinophilia >4% and >10% was present in 74.3% and 25.5% of the children, respectively. Total IgE > 200 IU/mL, sIgE ⩾ 0.70 kU/L and SPT positivity were present in 59.7%, 37.1% and 30% of the children, respectively. 22.7% had recent asthma (12.0% non-atopic and 10.7% atopic). Helminth infections were associated in a dose-dependent way to decrease in the prevalence of SPT and increase in eosinophilia, total IgE, and the production of the regulatory cytokine IL-10 by unstimulated peripheral blood leukocytes. No association with asthma was observed. Conclusions Helminth co-infections in this population were associated with increased markers of the Th2 immune response, and with a host immune regulatory phenotype that may suppress allergic effector responses such as immediate hypersensitivity reactions in the skin. [ABSTRACT FROM AUTHOR]

Background: In addition to controversies as to the definition of nosocomial pneumonia (NP) because of the lack of a widely accepted diagnostic standard, there has been no agreement concerning the time span from hospital admission to disease onset. This study aims at both estimating the time span, in hours, from admission to the occurrence of suspected NP and investigating risk factors that might influence this time span., Methods: This is a cohort study, and subjects were patients with nosocomial infection acquired in the intensive care unit of Edgard Santos University Hospital (HUPES/ICU) in Salvador, Brazil, from January 1995 to December 1997. Patients were observed from admission to 48 hours after discharge from the intensive care unit. The time span from admission to occurrence of suspected NP, the reason for admission, patient's origin, history of surgery, general anesthesia, mechanical ventilation, and use of antibiotic were analyzed and given a multivariate analysis using Cox regression model., Results: Among 246 patients with nosocomial infection, 198 (80.5%) were suspected cases of NP, whereas 48 patients (19.5%) were not classified as such. The mean time, in hours, for the NP-free time span was 85.1 +/- 3.5 hours, and the median time was 72 hours when estimated by Kaplan-Meier method. Patients admitted from surgical heart procedures who had been given general anesthesia, mechanical ventilation, and antibiotics showed statistically significant shorter mean time spans from admission to NP occurrence when compared with the other patients. Age >or=50 years, use of mechanical ventilation, and use of antibiotics were associated with NP., Conclusions: Our finding for the estimated mean NP-free time span at the HUPES/ICU is somewhat in accordance with the literature (48 to 72 hours). Patients at HUPES/ICU might be considered as showing early NP, because they were diagnosed before the 5th day after admission. Preventive measures to NP should be reviewed and intensified at the HUPES/ICU, especially as related to mechanical ventilation.