Epidemiological study of the prevalence of allergic reactions to Hymenoptera in a rural population in the Mediterranean area

Background Systemic allergic reactions to Hymenoptera venom occur in a perc entage that varies from 0.4 to 3.3%. Epidemiological studies indicate that from 15 to 25% of the general population can be sensitized to different Hym enoptera venom as well as the fact that the degree of exposure may be relat ed to the prevalence found in those studies. Objective The objective of this study was to evaluate the prevalence of ins ect sting allergy and the venom sensitization in a rural population to thre e Hymenoptera previously found in the area: Polistes dominulus (Pd), Vespul a germanica (Vg) and honey bee (Hb). Methods A rural community located in the south-east of Spain, close to the Mediterranean Sea, was selected since the stinging Hymenoptera having been previously identified. A random sample of 310 subjects from the village cen sus was studied. A questionnaire and a serum sample were obtained from ever y patient. The evaluation was conducted by a family doctor, who focused on the reactions to Hymenoptera sting, age, sex, occupation, atopia, previous Hymenoptera sting, stinging insect, interval to last sting and average stin gs per year. RAST to Hymenoptera venoms were also determined. Results The prevalence of systemic reactions was 2.3% (57.6% of them had a positive RAST). Large local reactions were found in 26.4% (only 28.5% of th em had a positive RAST). Asymptomatic sensitization (positive RAST) was obs erved in 16.4% of subjects without reaction. Only a weak correlation betwee n subjects with less than 3 years' interval to last sting exposure and posi tive RAST results was noted, whether they presented with a clinical reactio n or not (P < 0.05). Conclusions The prevalence of systemic sting reactions in our rural communi ty is higher than other general populations in the same Mediterranean area, and similar to other rural populations studied. The degree of exposure inf luences not only the prevalence found but also the detection of specific se rum IgE.