Impacts of long-term ragweed pollen load and other potential risk factors on ragweed pollen allergy among schoolchildren in Hungary.

INTRODUCTION AND OBJECTIVE: Hungary is one of the areas in Europe most infected with ragweed (Ambrosia artemisiifolia L.) and its pollen, and is the most important cause of seasonal allergic rhinoconjunctivitis in the country. The aim of the study was to investigate the association between ragweed pollen allergy and long-term ragweed pollen load, as well as analysis of the the impacts of additional potential risk factors on health outcomes. MATERIAL AND METHODS: A modified version of standardized questionnaires, based on the International Study of Asthma and Allergy in Childhood, were completed by the parents of schoolchildren aged 8 - 9 attending 3rd grade classes throughout the country. Pollen load was calculated for each settlement from daily ragweed pollen concentrations monitored by 19 monitoring stations in the country. Descriptive and analytical statistical methods were applied. RESULTS: At national level there was a significant inverse association between prevalence of ragweed allergy and its pollen load, but significance was lost after excluding data from Budapest, the capital city, due to the impact of urbanization. In the adjusted model, parental atopic disease was the strongest risk factor (either parent had atopic disease aOR=2.60; 95% CI=2.31-2.93 or both parents had atopic disease aOR=4.56; 95% CI=3.71-5.60). Further significant risk factors were male gender (aOR=1.52; 95% CI=1.36-1.71), lower respiratory infection in the first two years of life (aOR=1.91; 95% CI=1.70-2.16), and unshared children's room (aOR=1.22; 95% CI=1.09-1.37). Allergy was significantly less common among children whose parents received social aid (aOR=0.83; 95% CI=0.72-0.97) and whose mother smoked during pregnancy (aOR=0.80; 95% CI=0.64-0.99). CONCLUSIONS: Higher ragweed pollen exposure was not found to be associated with higher risk of ragweed allergy.

[Increase in prevalence of childhood asthma in Budapest between 1995 and 2003: correlation with air pollution data and total pollen count]. / A gyermekkori asztma prevalenciájának növekedése Budapesten 1995 és 2003 között a (változatlan) légszennyezettségi és pollen adatok tükrében.

INTRODUCTION: According to the data of the Hungarian pulmonological network, the prevalence of asthma in the last 15 years has increased (almost linearly) in Hungary. In 2004 it was 1.8%. There are only a few data about the prevalence of childhood asthma. AIMS: The aim of the authors was to measure the prevalence of bronchial asthma in childhood in Budapest in 1995, 1999 and 2003, using questionnaires directed to district pediatricians. METHODS: There were only two questions in these questionnaires: how many children are in their districts, and how many are suffering from asthma? Besides of this survey the dust, CO, NO(2) and SO(2) concentrations in the air were measured on-line at 8 points in Budapest, while ozone level measurements were also made at 2 stations. The counts of pollen and of fungal elements in the air were calculated separately for Buda and for Pest. RESULTS: In 1995, replies were received from 118 pediatricians in 11 districts, who were responsible for the supervision of 104,060 children, out of these 1.88+/-0.87% had been diagnosed as having asthma. In 1999 replies were sent by 153 physicians in 22 of the 23 districts, who had a total of 142,679 children under their care. These included 3228 asthmatics, i.e. a prevalence of 2.26+/-0.95%. In 2003 the authors received answers from all of the 23 districts of Budapest. The 204 pediatricians were responsible for the supervision of 176 049 children. The number of patients with the diagnosis of asthma was 4712 (corresponding for a prevalence of 2.68+/-1.3%). The increase between 1995 and 1999, and between 1999 and 2003 was highly significant (p < 0.0001). This significant increase was valid even when the authors analysed only those 11 districts, which answered already in 1995. The level of air pollution in Budapest did not deteriorate in the period in question, and the concentration of pollen grains of plants causing allergy did not increase compared to previous years. CONCLUSIONS: On the basis of the results of more than 100 thousand children, the authors conclude that between 1995 and 2003 the proportion of asthmatic children increased by 50% in Budapest, while the air pollution did not deteriorate and the pollen concentration from sensitizing plants did not increase.