Prevalence of symptoms of asthma
Prevalence of symptoms of asthma, rhinitis and atopic eczema among children and adolescents Brazilians identified by the International Study of Asthma and Allergies (ISAAC) - Phase 3
SUMMARY
PURPOSE: To determine the prevalence of symptoms related to asthma, rhinitis and atopic eczema in school (JV) between 6 and 7 years and adolescents (AD) between 13 and 14 years, residents in 20 Brazilian cities, using a standardized questionnaire writing of ISAAC, and to evaluate their association with the latitude, altitude and average annual temperature of the centres of residence.
METHODS: EC participated in the study and AD of the five regions of Brazil, totaling 23,422 ISAAC questionnaires answered by parents with CD and 58,144 by the AD. The indices of latitude, altitude and average annual temperature were obtained from the IBGE.
RESULTS: The prevalence averages for the EC and AD respectively, were: active asthma, 24.3 and 19.0%; rhinoconjunctivitis, 12.6 and 14.6%, and eczema flexural, 8.2 and 5.0% . And significant negative association was observed between latitude and prevalence of asthma diagnosed by doctor for the EC, severe asthma, a doctor diagnosed asthma, eczema and eczema flexural for AD. There was no association with the altitude of the centres.
CONCLUSION: The prevalence of asthma, rhinitis and atopic eczema in Brazil was variable. Values higher, especially for asthma and eczema, were observed in the centres located closer to the equator.
Introduction
The International Study of Asthma and Allergies in Childhood (ISAAC) was a milestone between the epidemiological studies on prevalence of asthma and allergic diseases in children and adolescents. The ISAAC is designed to assess the prevalence of asthma and allergic diseases in children in different parts of the world, employing standardized method (self-administered questionnaire written and / or video questionnaire) 1.2. The written questionnaire (QE) of self-administered ISAAC was the most employee, to be easily understood, low-cost, independent of the application by interviewer treinado1, 2.
The target audience should be formed by school (EC) in a given geographical area (center of ISAAC) of two age groups: 13 to 14 years and 6 to 7 years. The participation of EC in age from 6 to 7 years, although recommended, was not compulsory.
The sample under study should include all children of the age group under study, a randomized sample of schools.
Once defined geographic area and schools to be included, each head of research should select, based on school records, adolescents (AD) aged between 13 and 14 years, which would be invited to meet the QE. The selection of additional group of 6 to 7 years follow the same criteria, and parents of these children would be invited to address the QE.
In the first phase of ISAAC, were interviewed 463,801 AD (13 and 14 years) from 155 centres in 56 countries (Europe, Asia, Africa, North and South Americas and Oceania) and 257,800 EC (6 and 7 years) of 91 centres in 38 countries of those regions, except the África2-5.
The analysis of the results obtained at the end of phase 1, relating to asthma, showed that there has been wide variation in both age groups, with respect to the prevalence of wheezing in the past 12 months (active asthma), ranging from 4.1 to 32.1 % For the EC and from 2.1 to 32.2% for AD2, 3. The lowest values were documented in the Republic of Georgia and Estonia, and the highest in Austrália2, 3. In both age groups, Brazil was among the countries with the largest prevalências3, 6.
With regard to rhinitis, the variation in prevalence of symptoms was also related ampla4. The prevalence of nasal symptoms in the absence of cold in the last year ranged from 1.5 to 41.8% between the EC and 3.2 to 66.6% among AD4. Already the prevalence of nasal symptoms associated with ocular symptoms (allergic rhinoconjunctivitis) ranged from 0.8 to 14.9% for the EC and from 1.4 to 39.7% for the AD4. In general, there was agreement between the prevalence of asthma and rhinitis: centres with low prevalence of asthma (less than 5%: Indonesia, Albania, Romania, Georgia and Greece) had low prevalence of rhinitis, and those with very prevalence of asthma high (above 30%: Australia, New Zealand and United Kingdom) also had high prevalence of rinite3, 4.
The results of atopic eczema (AE) were those who had greater range of variation (up to 60 times), ranging between 0.3 and 20.5% 2.5. The highest values (above 15%) were observed in urban centers of Africa, Australia, North and West of Europe, and the lowest (less than 5%) in China, Eastern Europe and Asia Central2, 5.
Upon obtaining such data, several other studies have been conducted in order to verify the relationship between the prevalence of asthma and allergic diseases and possible risk factors. The immunization of rotina7, notifications of tuberculose8, 9 and the pattern alimentar10 were some of the factors studied. In a recent study, Weiland et al. assessed the possible relationship between latitude, relative humidity and temperature annual change in the centres of participants ISAAC Phase 1 and the prevalence of asthma and diseases alérgicas11. There negative relationship between these parameters and the prevalence of asthma symptoms. Moreover, the prevalence of symptoms of eczema is positively related with the latitude and negatively with the average temperature environment, that is, with minor local variations in temperature have been associated with increased levels of prevalência11. In conclusion, these authors suggest that the climate is an important factor and able to interfere in the prevalence of asthma and EA11.
In Latin America, the end of the first phase of ISAAC, Mallol et al. documented significant relationship between prevalence and severity of asthma and latitude of the centres participating avaliados12. Some of these centres were Brazilians.
The small number of centres Brazilian participants of phase 1, combined with the absence of centres in some regions of the country, prevented the realization of that avaliação6, 13.14. This study aimed to evaluate the relationship between prevalence of symptoms of asthma, rhinitis and eczema and latitude from different centres Brazilian participants or not the ISAAC phase 3.
Patients and methods
Twenty-one centers, 20 Brazilian cities participated in this study. The students evaluated were selected as recommended by the protocol ISAAC1, 15. In each centre, as stipulated in the geographical area that the study would be conducted, called to the Municipal Secretary of Education the relationship of the schools located there. Then there was raffle (table of random numbers) that part of the study. Cities, states and regions where the study was conducted were: Manaus, Amazonas, North (N), Belem, Para N; Natal, Rio Grande do Norte, Northeast (NE); Recife, Pernambuco, NE; Caruaru, Pernambuco , NE; Maceio Alagoas, NE; Aracaju, Sergipe, NE; Feira de Santana, Bahia, NE; Salvador, Bahia, NE; Vitoria da Conquista, Bahia, NE; Brasilia, Federal District, hundred-West (CO); Belo Horizonte , Minas Gerais, Southeast (SE); Nova Iguacu, Rio de Janeiro, SE; Sao Paulo (West and South), Sao Paulo, SE; Santo Andre Sao Paulo, SE; Curitiba, Parana South (S); Itajaí Santa Catarina, S; Passo Fundo, Rio Grande do Sul, S; Porto Alegre, Rio Grande do Sul, S; Santa Maria, Rio Grande do Sul, S. Part of these centres had the data adopted by ISAAC International Data Center and were regarded as official centres (Tables 1 and 2). The study was approved by the respective committees of ethics, and all signed the expiry of free and informed consent.
You decided not by evaluating the age group from 6 to 7 years (not compulsory) the following centres: Bethlehem, Recife, rabbits, Brasilia, Belo Horizonte, Curitiba, Passo Fundo, Porto Alegre and Santa Maria.
The study began in 2002 and was completed in 2003, as recommended by the ISAAC, obeying, when possible, the same period of data collection in all centres. In the Southern Region, where the seasons are better defined, was held before the spring, thus avoiding possible seasonal influences.
After the definition of the sample in each of the cities, the QE ISAAC, previously translated and validated (Brazilian culture) 14,16,17, was answered by parents or guardians of the EC, 6 and 7 years of age (n = 23,422) and by the AD in classrooms (n = 58,144, 13-14 years of age). The data were entered manually into the database provided by the coordinators of the general protocol ISAAC.
The module asthma, were considered the questions about symptoms, severity and medical diagnosis of asthma, namely: wheezing in the past 12 months (active asthma); wheezing intense able to confine the talks in the past 12 months (severe asthma); asthma ever in life (diagnosed asthma) 1.3.
The module rhinitis, were considered the issues relating to symptoms of rhinitis, allergic rhinoconjunctivitis and serious forms of rhinitis: sneezing, nasal obstruction and coryza ever in the past 12 months (rhinitis); problems associated with nasal itching and tearing eyes with the past 12 months (allergic rhinoconjunctivitis); nasal problem interfering with daily activity (severe rhinitis) 1.4.
Of the questions about eczema, were assessed for the symptoms and severity: skin rash that appears and disappears in the last 12 months (eczema), this same characteristic skin rash in places (eczema flexural); rash and pruriginoso that interferes with sleep in last 12 months (severe eczema) 1.5.
The values of latitude, altitude and average annual temperature of each of the participating centres were obtained from the Brazilian Institute of Geography and Estatística18.
For analysis of the data, employees were non-parametric tests: Spearman's correlation coefficient (RS) and the calculation of the confidence interval of 95% (95%). In all tests, falling to 5% the level of rejection in the event of invalidity.
Results
Among the EC, the prevalence averages were: active asthma, 24.3%, with higher values in Sao Paulo - and Vitoria da Conquista West; severe asthma, 6.1% and the highest in Sao Paulo - and West Christmas; asthma diagnosed by doctor, 10.3% (Manaus and Christmas); rhinitis, 25.7% (Bahia, Feira de Santana, Salvador and Vitoria da Conquista); rhinoconjunctivitis, 12.6% (Bahia); severe rhinitis, 17.1% (Bahia), eczema, 11.5% (Nova Iguacu, Christmas and Aracaju); flexural eczema, 8.2% (Christmas, Aracaju and Nova Iguacu), and severe eczema, 5.0% (Christmas and Aracaju) (Table 1).
Among the AD, the prevalence averages were: active asthma, 19.0%, with higher values in El Salvador and Vitoria da Conquista, severe asthma, 4.7%, with higher values in Vitoria da Conquista and Aracaju; asthma diagnosed by doctor, 13.6% (Bethlehem, Porto Alegre and rabbits); rhinitis, 29.6% (Bethlehem, Salvador and Vitoria da Conquista); allergic rhinoconjunctivitis, 14.6% (Bethlehem, Salvador and Vitoria da Conquista); severe rhinitis , 17.4% (Bahia), eczema, 8.9% (Bethlehem, Aracaju and Salvador); flexural eczema, 5.0% (Aracaju, Vitoria da Conquista and Christmas), and severe eczema, 4.4% (Bahia and Aracaju) (Table 2).
The study of the association between the latitude of the centres and the prevalence of symptoms and severity of asthma, rhinitis and EA showed statistically significant and negative for asthma diagnosed by doctor (RS = -0622; 95% -0885 to -0056, p = 0031) to the EC, severe asthma (RS = -0565; 95% -0806 to -0163, p = 0008), asthma diagnosed by doctor (RS = -0479; 95% -0761 to -0046, p = 0028), eczema ( RS = -0718; 95% -0881 to -0405, p = 0.0002) and eczema flexural (RS = -0530; 95% -0788 to -0115, p = 0013) for AD. In other words, the shorter the latitude (greater proximity to the Equator), the greater the prevalence of affirmative answers to these questions.
Regarding the annual average temperature, there were significant and positive association with the diagnosis of asthma by a doctor (RS = 0459, 95% CI 0.02 to 0749, p = 0037), and with eczema (RS = 0541; 0129 to 95% 0794, p = 0011) between the AD. Thus, the higher the average annual temperature, the greater the prevalence of medical diagnosis of asthma and eczema.
Discussion
The prevalence rates of asthma and allergic diseases were observed in higher centers of North and Northeast regions, the exception made for asthma, which was also observed in the South Region three times the increase in the number of centers participating in relation to ISAAC fase16 , 13.14, the presence of centres of the five regions of the country and the high level of return on QE distribuídos2, 3 allow us to accept the sample assessed here as representative of Brazil.
The ISAAC phase 1 in Latin America focused data from 17 centers in nine countries and brought together 36,264 and 52,549 EC AD. The prevalence of asthma and related symptoms showed up high and variable, as described for industrialized countries or developed regions mundo12 of. The prevalence of asthma active ranged between 8.6 and 32.1% for the EC and between 6.6 and 27.0% for AD, and the highest levels of prevalence were observed in the centres next to the line of Ecuador. Moreover, is not documented relationship between exposure to air pollution, early exposure to respiratory and gastrointestinal infections and prevalence of asma12. They put in check the validity of the hygiene hypothesis for Latin America as a todo12.
Et al Weiland. investigated the relationship between climate (latitude, range of annual changes in outside temperature (difference between the annual maximum and minimum annual) and moisture content intra) and the prevalence of atopic diseases using data from ISAAC phase 1 (146 centres). For symptoms of asthma, there inverse relation between altitude, annual changes in temperature and relative humidity intradomiciliar11. The analysis of these data showed part, to the western European countries, there has been an increase in the prevalence of symptoms of asthma in combination with increased humidity annual intra estimada11. In this study, we found significant and negative relationship to a doctor diagnosed asthma among the EC and asthma diagnosed by medical and severe asthma among AD. This fact could be explained by differences in the conduct and name of the disease throughout the country. However, when considering the prevalence of serious forms, see the same behavior to the AD. That fact certainly reinforces the highest prevalence of asthma in the north of the country. This finding is supported by significant and positive relationship observed between average temperature and prevalence of asthma diagnosed.
As for rhinitis and related symptoms, not document significant relationship between their prevalence and the variables analyzed for the two age groups, like other estudos11. On the other hand, there was significant and negative relationship between the prevalence of eczema and eczema flexural and latitude of the centres. Values higher occurred north of the country, as well as eczema in places with higher average temperatures. Exposure to higher temperatures and constant, the high moisture content environment, the greater exposure of the skin by using lighter clothes, combined with higher frequency of skin diseases in this region could be some of the reasons to justify the increase in prevalence of eczema , Designation that can accommodate several tables skin. However, the same behavior observed with the prevalence of eczema flexural, characteristic of AD, calls into question the previously indicated. This waved to the heat and humidity as risk factors for EA. Unlike observed in this study, Weiland et al. documented increase in the prevalence of eczema and related symptoms, in both age groups, with increasing latitude and decrease with the increase of the magnitude of annual average temperature outside, and with increasing relative humidity of intra ar11.
Nnoruka et al., When assessing children with Nigerian EA, identified intolerance to heat, moisture and excessive sweating intradomiciliary as aggravating factors for the EA19, like outros20. Already Fernandez-Mayoralas et al. documented influence of air pollution on the prevalence of AD in adolescents who lived the city of Cartagena (Spain) 21. The authors found high levels of prevalence of AD and serious forms between those who were exposed to higher levels of poluição21. In this study, did not notice any influence of air pollution on the prevalence of AD, especially if we consider the centers of St. Paul and St. Andrew where they are traditionally the highest documented levels of air pollution in the country.
In conclusion, with the increased number of participants in this study centers in Brazil, we find, as observed in Latin America at the end of phase 1, higher frequency of medical diagnosis of asthma, for CD and AD, and most serious forms of asthma, eczema and eczema flexural between AD population centers nearest to the line of the equator. The identification of risk factors to which the inhabitants of these centres is to be exposed fundamental step towards the possible elucidation of the pathogenesis of asthma and allergies in those localities.
SUMMARY
PURPOSE: To determine the prevalence of symptoms related to asthma, rhinitis and atopic eczema in school (JV) between 6 and 7 years and adolescents (AD) between 13 and 14 years, residents in 20 Brazilian cities, using a standardized questionnaire writing of ISAAC, and to evaluate their association with the latitude, altitude and average annual temperature of the centres of residence.
METHODS: EC participated in the study and AD of the five regions of Brazil, totaling 23,422 ISAAC questionnaires answered by parents with CD and 58,144 by the AD. The indices of latitude, altitude and average annual temperature were obtained from the IBGE.
RESULTS: The prevalence averages for the EC and AD respectively, were: active asthma, 24.3 and 19.0%; rhinoconjunctivitis, 12.6 and 14.6%, and eczema flexural, 8.2 and 5.0% . And significant negative association was observed between latitude and prevalence of asthma diagnosed by doctor for the EC, severe asthma, a doctor diagnosed asthma, eczema and eczema flexural for AD. There was no association with the altitude of the centres.
CONCLUSION: The prevalence of asthma, rhinitis and atopic eczema in Brazil was variable. Values higher, especially for asthma and eczema, were observed in the centres located closer to the equator.
Introduction
The International Study of Asthma and Allergies in Childhood (ISAAC) was a milestone between the epidemiological studies on prevalence of asthma and allergic diseases in children and adolescents. The ISAAC is designed to assess the prevalence of asthma and allergic diseases in children in different parts of the world, employing standardized method (self-administered questionnaire written and / or video questionnaire) 1.2. The written questionnaire (QE) of self-administered ISAAC was the most employee, to be easily understood, low-cost, independent of the application by interviewer treinado1, 2.
The target audience should be formed by school (EC) in a given geographical area (center of ISAAC) of two age groups: 13 to 14 years and 6 to 7 years. The participation of EC in age from 6 to 7 years, although recommended, was not compulsory.
The sample under study should include all children of the age group under study, a randomized sample of schools.
Once defined geographic area and schools to be included, each head of research should select, based on school records, adolescents (AD) aged between 13 and 14 years, which would be invited to meet the QE. The selection of additional group of 6 to 7 years follow the same criteria, and parents of these children would be invited to address the QE.
In the first phase of ISAAC, were interviewed 463,801 AD (13 and 14 years) from 155 centres in 56 countries (Europe, Asia, Africa, North and South Americas and Oceania) and 257,800 EC (6 and 7 years) of 91 centres in 38 countries of those regions, except the África2-5.
The analysis of the results obtained at the end of phase 1, relating to asthma, showed that there has been wide variation in both age groups, with respect to the prevalence of wheezing in the past 12 months (active asthma), ranging from 4.1 to 32.1 % For the EC and from 2.1 to 32.2% for AD2, 3. The lowest values were documented in the Republic of Georgia and Estonia, and the highest in Austrália2, 3. In both age groups, Brazil was among the countries with the largest prevalências3, 6.
With regard to rhinitis, the variation in prevalence of symptoms was also related ampla4. The prevalence of nasal symptoms in the absence of cold in the last year ranged from 1.5 to 41.8% between the EC and 3.2 to 66.6% among AD4. Already the prevalence of nasal symptoms associated with ocular symptoms (allergic rhinoconjunctivitis) ranged from 0.8 to 14.9% for the EC and from 1.4 to 39.7% for the AD4. In general, there was agreement between the prevalence of asthma and rhinitis: centres with low prevalence of asthma (less than 5%: Indonesia, Albania, Romania, Georgia and Greece) had low prevalence of rhinitis, and those with very prevalence of asthma high (above 30%: Australia, New Zealand and United Kingdom) also had high prevalence of rinite3, 4.
The results of atopic eczema (AE) were those who had greater range of variation (up to 60 times), ranging between 0.3 and 20.5% 2.5. The highest values (above 15%) were observed in urban centers of Africa, Australia, North and West of Europe, and the lowest (less than 5%) in China, Eastern Europe and Asia Central2, 5.
Upon obtaining such data, several other studies have been conducted in order to verify the relationship between the prevalence of asthma and allergic diseases and possible risk factors. The immunization of rotina7, notifications of tuberculose8, 9 and the pattern alimentar10 were some of the factors studied. In a recent study, Weiland et al. assessed the possible relationship between latitude, relative humidity and temperature annual change in the centres of participants ISAAC Phase 1 and the prevalence of asthma and diseases alérgicas11. There negative relationship between these parameters and the prevalence of asthma symptoms. Moreover, the prevalence of symptoms of eczema is positively related with the latitude and negatively with the average temperature environment, that is, with minor local variations in temperature have been associated with increased levels of prevalência11. In conclusion, these authors suggest that the climate is an important factor and able to interfere in the prevalence of asthma and EA11.
In Latin America, the end of the first phase of ISAAC, Mallol et al. documented significant relationship between prevalence and severity of asthma and latitude of the centres participating avaliados12. Some of these centres were Brazilians.
The small number of centres Brazilian participants of phase 1, combined with the absence of centres in some regions of the country, prevented the realization of that avaliação6, 13.14. This study aimed to evaluate the relationship between prevalence of symptoms of asthma, rhinitis and eczema and latitude from different centres Brazilian participants or not the ISAAC phase 3.
Patients and methods
Twenty-one centers, 20 Brazilian cities participated in this study. The students evaluated were selected as recommended by the protocol ISAAC1, 15. In each centre, as stipulated in the geographical area that the study would be conducted, called to the Municipal Secretary of Education the relationship of the schools located there. Then there was raffle (table of random numbers) that part of the study. Cities, states and regions where the study was conducted were: Manaus, Amazonas, North (N), Belem, Para N; Natal, Rio Grande do Norte, Northeast (NE); Recife, Pernambuco, NE; Caruaru, Pernambuco , NE; Maceio Alagoas, NE; Aracaju, Sergipe, NE; Feira de Santana, Bahia, NE; Salvador, Bahia, NE; Vitoria da Conquista, Bahia, NE; Brasilia, Federal District, hundred-West (CO); Belo Horizonte , Minas Gerais, Southeast (SE); Nova Iguacu, Rio de Janeiro, SE; Sao Paulo (West and South), Sao Paulo, SE; Santo Andre Sao Paulo, SE; Curitiba, Parana South (S); Itajaí Santa Catarina, S; Passo Fundo, Rio Grande do Sul, S; Porto Alegre, Rio Grande do Sul, S; Santa Maria, Rio Grande do Sul, S. Part of these centres had the data adopted by ISAAC International Data Center and were regarded as official centres (Tables 1 and 2). The study was approved by the respective committees of ethics, and all signed the expiry of free and informed consent.
You decided not by evaluating the age group from 6 to 7 years (not compulsory) the following centres: Bethlehem, Recife, rabbits, Brasilia, Belo Horizonte, Curitiba, Passo Fundo, Porto Alegre and Santa Maria.
The study began in 2002 and was completed in 2003, as recommended by the ISAAC, obeying, when possible, the same period of data collection in all centres. In the Southern Region, where the seasons are better defined, was held before the spring, thus avoiding possible seasonal influences.
After the definition of the sample in each of the cities, the QE ISAAC, previously translated and validated (Brazilian culture) 14,16,17, was answered by parents or guardians of the EC, 6 and 7 years of age (n = 23,422) and by the AD in classrooms (n = 58,144, 13-14 years of age). The data were entered manually into the database provided by the coordinators of the general protocol ISAAC.
The module asthma, were considered the questions about symptoms, severity and medical diagnosis of asthma, namely: wheezing in the past 12 months (active asthma); wheezing intense able to confine the talks in the past 12 months (severe asthma); asthma ever in life (diagnosed asthma) 1.3.
The module rhinitis, were considered the issues relating to symptoms of rhinitis, allergic rhinoconjunctivitis and serious forms of rhinitis: sneezing, nasal obstruction and coryza ever in the past 12 months (rhinitis); problems associated with nasal itching and tearing eyes with the past 12 months (allergic rhinoconjunctivitis); nasal problem interfering with daily activity (severe rhinitis) 1.4.
Of the questions about eczema, were assessed for the symptoms and severity: skin rash that appears and disappears in the last 12 months (eczema), this same characteristic skin rash in places (eczema flexural); rash and pruriginoso that interferes with sleep in last 12 months (severe eczema) 1.5.
The values of latitude, altitude and average annual temperature of each of the participating centres were obtained from the Brazilian Institute of Geography and Estatística18.
For analysis of the data, employees were non-parametric tests: Spearman's correlation coefficient (RS) and the calculation of the confidence interval of 95% (95%). In all tests, falling to 5% the level of rejection in the event of invalidity.
Results
Among the EC, the prevalence averages were: active asthma, 24.3%, with higher values in Sao Paulo - and Vitoria da Conquista West; severe asthma, 6.1% and the highest in Sao Paulo - and West Christmas; asthma diagnosed by doctor, 10.3% (Manaus and Christmas); rhinitis, 25.7% (Bahia, Feira de Santana, Salvador and Vitoria da Conquista); rhinoconjunctivitis, 12.6% (Bahia); severe rhinitis, 17.1% (Bahia), eczema, 11.5% (Nova Iguacu, Christmas and Aracaju); flexural eczema, 8.2% (Christmas, Aracaju and Nova Iguacu), and severe eczema, 5.0% (Christmas and Aracaju) (Table 1).
Among the AD, the prevalence averages were: active asthma, 19.0%, with higher values in El Salvador and Vitoria da Conquista, severe asthma, 4.7%, with higher values in Vitoria da Conquista and Aracaju; asthma diagnosed by doctor, 13.6% (Bethlehem, Porto Alegre and rabbits); rhinitis, 29.6% (Bethlehem, Salvador and Vitoria da Conquista); allergic rhinoconjunctivitis, 14.6% (Bethlehem, Salvador and Vitoria da Conquista); severe rhinitis , 17.4% (Bahia), eczema, 8.9% (Bethlehem, Aracaju and Salvador); flexural eczema, 5.0% (Aracaju, Vitoria da Conquista and Christmas), and severe eczema, 4.4% (Bahia and Aracaju) (Table 2).
The study of the association between the latitude of the centres and the prevalence of symptoms and severity of asthma, rhinitis and EA showed statistically significant and negative for asthma diagnosed by doctor (RS = -0622; 95% -0885 to -0056, p = 0031) to the EC, severe asthma (RS = -0565; 95% -0806 to -0163, p = 0008), asthma diagnosed by doctor (RS = -0479; 95% -0761 to -0046, p = 0028), eczema ( RS = -0718; 95% -0881 to -0405, p = 0.0002) and eczema flexural (RS = -0530; 95% -0788 to -0115, p = 0013) for AD. In other words, the shorter the latitude (greater proximity to the Equator), the greater the prevalence of affirmative answers to these questions.
Regarding the annual average temperature, there were significant and positive association with the diagnosis of asthma by a doctor (RS = 0459, 95% CI 0.02 to 0749, p = 0037), and with eczema (RS = 0541; 0129 to 95% 0794, p = 0011) between the AD. Thus, the higher the average annual temperature, the greater the prevalence of medical diagnosis of asthma and eczema.
Discussion
The prevalence rates of asthma and allergic diseases were observed in higher centers of North and Northeast regions, the exception made for asthma, which was also observed in the South Region three times the increase in the number of centers participating in relation to ISAAC fase16 , 13.14, the presence of centres of the five regions of the country and the high level of return on QE distribuídos2, 3 allow us to accept the sample assessed here as representative of Brazil.
The ISAAC phase 1 in Latin America focused data from 17 centers in nine countries and brought together 36,264 and 52,549 EC AD. The prevalence of asthma and related symptoms showed up high and variable, as described for industrialized countries or developed regions mundo12 of. The prevalence of asthma active ranged between 8.6 and 32.1% for the EC and between 6.6 and 27.0% for AD, and the highest levels of prevalence were observed in the centres next to the line of Ecuador. Moreover, is not documented relationship between exposure to air pollution, early exposure to respiratory and gastrointestinal infections and prevalence of asma12. They put in check the validity of the hygiene hypothesis for Latin America as a todo12.
Et al Weiland. investigated the relationship between climate (latitude, range of annual changes in outside temperature (difference between the annual maximum and minimum annual) and moisture content intra) and the prevalence of atopic diseases using data from ISAAC phase 1 (146 centres). For symptoms of asthma, there inverse relation between altitude, annual changes in temperature and relative humidity intradomiciliar11. The analysis of these data showed part, to the western European countries, there has been an increase in the prevalence of symptoms of asthma in combination with increased humidity annual intra estimada11. In this study, we found significant and negative relationship to a doctor diagnosed asthma among the EC and asthma diagnosed by medical and severe asthma among AD. This fact could be explained by differences in the conduct and name of the disease throughout the country. However, when considering the prevalence of serious forms, see the same behavior to the AD. That fact certainly reinforces the highest prevalence of asthma in the north of the country. This finding is supported by significant and positive relationship observed between average temperature and prevalence of asthma diagnosed.
As for rhinitis and related symptoms, not document significant relationship between their prevalence and the variables analyzed for the two age groups, like other estudos11. On the other hand, there was significant and negative relationship between the prevalence of eczema and eczema flexural and latitude of the centres. Values higher occurred north of the country, as well as eczema in places with higher average temperatures. Exposure to higher temperatures and constant, the high moisture content environment, the greater exposure of the skin by using lighter clothes, combined with higher frequency of skin diseases in this region could be some of the reasons to justify the increase in prevalence of eczema , Designation that can accommodate several tables skin. However, the same behavior observed with the prevalence of eczema flexural, characteristic of AD, calls into question the previously indicated. This waved to the heat and humidity as risk factors for EA. Unlike observed in this study, Weiland et al. documented increase in the prevalence of eczema and related symptoms, in both age groups, with increasing latitude and decrease with the increase of the magnitude of annual average temperature outside, and with increasing relative humidity of intra ar11.
Nnoruka et al., When assessing children with Nigerian EA, identified intolerance to heat, moisture and excessive sweating intradomiciliary as aggravating factors for the EA19, like outros20. Already Fernandez-Mayoralas et al. documented influence of air pollution on the prevalence of AD in adolescents who lived the city of Cartagena (Spain) 21. The authors found high levels of prevalence of AD and serious forms between those who were exposed to higher levels of poluição21. In this study, did not notice any influence of air pollution on the prevalence of AD, especially if we consider the centers of St. Paul and St. Andrew where they are traditionally the highest documented levels of air pollution in the country.
In conclusion, with the increased number of participants in this study centers in Brazil, we find, as observed in Latin America at the end of phase 1, higher frequency of medical diagnosis of asthma, for CD and AD, and most serious forms of asthma, eczema and eczema flexural between AD population centers nearest to the line of the equator. The identification of risk factors to which the inhabitants of these centres is to be exposed fundamental step towards the possible elucidation of the pathogenesis of asthma and allergies in those localities.
0 komentar:
Post a Comment