To describe the principal evidence in the literature regarding the interrelationship among helminth infections, atopy, and asthma, a nonsystematic review of the literature was conducted. Among the publications on the subject, we found a number in which there was controversy regarding the capacity of geohelminth infections to inhibit responsiveness to skin allergy tests and to minimize the symptoms of allergic diseases. However, although small in number, studies of patients infected with Schistosoma spp. suggest that these helminths can inhibit the responsiveness to skin allergy testing and minimize asthma symptoms. Evidence provided by in vitro studies suggests that helminthiases inhibit T helper 1- and T helper 2-type immune responses. This opens new therapeutic possibilities for the treatment of immune system diseases.

Keywords: Asthma; Helminths; Hypersensitivity; Epidemiology.

Objective: To compare BCG vaccination involving a single intradermal dose and that involving multiple doses, one given with the multiple puncture technique, in terms of the protective effect against the subsequent onset of asthma. Methods: A retrospective cohort study involving 2,311 individuals having received the BCG vaccine. The patients were classified according to the number of doses of BCG vaccine administered (one; two; or three or more). The minimum follow-up period in order to determine whether there was any protective effect of BCG vaccination regarding the diagnosis of asthma was 10 years. Results: The sample included 1,317 individuals (56.99%) who had received only one BCG dose, 644 (27.87%) who had received two doses, and 350 (15.14%) who had received three or more doses. The number of patients diagnosed with asthma among those who had received one dose, two doses and three or more doses was, respectively, 216 (16.40%), 107 (16.61%) and 50 (14.28%). There were no significant differences among the groups. Conclusions: In the study sample, the prevalence of asthma among individuals having received multiple doses of the BCG vaccine was no different than that observed among those having received a single dose.

Keywords: Asthma; BCG vaccine; Immunization, secondary.

Objective: To evaluate the acceptability and reproducibility of spirometry in preschool children; to estimate the effect size of early termination of exhalation (ETE) on FVC, FEV1 and FEV0.5; and to evaluate the validity of FEV0.5 in curves with ETE. Methods: Spirometric data were obtained from 240 healthy preschool children, who were selected by simple sampling. On the basis of the best curve from each child according to the end of exhalation, three groups were formed: no ETE (nETE); ETE and flow ≤ 10% of the highest PEF (ETE≤10); and ETE and flow > 10% of the highest PEF value (ETE>10). The reproducibility of FVC, FEV1 and FEV0.5 was compared among the three groups. The effect of ETE on FVC, FEV1, and FEV0.5 was assessed. Results: Of the 240 children tested, 112 (46.5%)-82 (34.0%) of those in the nETE group and 30 (12.5%) of those in the ETE≤10 group-had acceptable curves for all the parameters. In 64 (27.0%) of those in the ETE>10 group, the curves were acceptable only for FEV0.5, increasing the proportion of children with valid FEV0.5 to 73.0%. There were no significant differences between the nETE and ETE≤10 groups in terms of the mean values of the parameters assessed. Conclusions: Maneuvers with ETE and flow ≤ 10% of the highest PEF are valid. In individuals with a flow > 10% of the highest PEF value, these maneuvers are only valid for FEV0.5.

Keywords: Spirometry; Child, preschool; Vital capacity; Forced expiratory volume; Reproducibility of results.