| Popis: |
Through the use of the same questionnaire translated to several Languages, the ISAAC study demonstrated that asthma prevalence among children and adolescents greatly vary around the world, being less than 2% in some places and more than 25% in others. In Mexico the prevalence is also variable, being for example approximately 5% in Mexico City and approximately 12% in Merida, Yucatán. This variability in the asthma frequency correlates inversely with the altitude of the region and directly with its temperature. According to official statistics, the nationwide annual incidence of asthma in Mexico is 2.78 per 1000 inhabitants. In last decades an epidemic rise of asthma cases was recorded in many parts of the world, which seems to become stabilized from the middle of 90's onward. Asthma frequency augments in some months of the year, being in Mexico much higher between October and January. The peak incidence of asthma occurs among children, diminishes in adolescence and early adulthood, and slightly rises in subsequent age-periods. During childhood, asthma frequency is higher in males, but after adolescence becomes more common among women. In Mexico, asthma mortality has been gradually declining since more than 15 years ago. |
