Epidemiology of Childhood Asthma in Cairo ANI!WL

Asthma is a diftkuuh disease to study epiderniologicaUy because of its many definitions. Egypt is a tropical country, where the prevalence of asthma k considered low. In this &dy 20000 queatioanairea were distributed among children 3-15 ytars old, with Werent socioeconomic cklssea. 13028 QueStioanaircs were rctlmle4i. The prev&lW of asthma WBS 8.2%. The pmvalekce in relation to illeterate pancms, low socioeconomic class, houses with one bed room wu 10.2%, 10.2% and 11.2% respectively @ < O.OOQl). If only one person shared the patienti room the prevalence ratc:wes6.3%compatedto9. ~if4otmon~~Elleprinthesame~m (Crowding index). WHEEZING respiratory ill-’ aird asthma are respoasible.for a significant proportion of both acute and chronic illneSs in childhood. [lf]. One problem that has greatly hindered progress in the Intreductien l3& Iimvwer, in the context of an epidemiologichl imstiptition; ,+ cliical, physiologicandqu&onm&appmachescanbe used to e&tate the prevftlence of asthma, its am&ted risk factors and its natural history [&. epidemiology of asthma is the lack of a Because children may be unable to chrdafinitionaswellasastandar~ cooperate adequately with physiological instrument for dete&ng the condition testing and for reasons of feasibility in 506 Anissa M. El-Hefny, et al. epdiemiological studies of childhood asthma, questionnaires are the most widely used method for classifying subjects as affected [4]. Asthma in Egypt is a common health problem which caused considerable mar-. bidity and appreciable mortality and impose much demand on the time and costs of medical and hospital care. In Cairo 2.2% of diseased children attending the pediatric outpatient clinic (Cairo University Hospital) were found fo be complaining from bronchial asthma [5& In Giza, Egypt, the prevalence of asthma was 4.6% among school boys lo-19 years old [6]. The purpose of the present survey was to assess the prevalence of asthma among children 3-15 years old in Cairo, and to identify the importance of certain risk factors associated with childhood asthma. Subjects and Methods The present study was conducted in Cairo, the capital of Egypt, Cairo’s population is about 12 million. In winter the minimum temperature may be 6°C and rain occurs, though infrequently. In summer the average temperature is 32-36°C with a maximum of 40°C on few days. Humidity may be sometimes high. Questionnaires in Arabic language were developed specificially for the purpose of this survey. The qesstionnaires were distributed to children 3-15 years old attending ‘nursery, elementary and junior high schools in Cairo. A questionnaire was given to each student attending the chosen school and rdum was mandatory. In this survey, asthma was defined as a history of recurrent wheezing or symptoms of paroxysmal attacks of cough, dyspnea and a wheeze relieved spontaneously or with treatment. Results and Their Analysis Results of this study were summarized in figures 1-3 and in tables l-4. Data was entered on an IPMPC computer. The statistical analysis system (SAS) jackage was used for statistical analysis and Harvard graphics for drawing figures. Q&square tests were employed to determine statistical significance between categories. P-values less than 0.05 were considered significant. On the 20.000 school children in Cairo receiving questionnaires, 13028 responded back: a response rate of 65.14%. Analysis of school children in Cairo according to the questionnaires showed the overall prevalence of asthma to be 8.2% (Fig. 1). Males h$ a higher prevaleyy of asthma (1.2:l) than females. The age of onset of symptoms in the asthmatic children is shown in Fig. (2). Symptoms developed in 22.1% before the age of 1 year, in 44% before the age of 2 years, in 57.9% before the age of 5 years and in 42.1% after the age of 5 years. Epidemiology of Childhood Asthma in Cairo 507 Table (1) shows the prevalence of asthma among school children in relation to level of fathers’ and mothers’ education. Asthma was significantly more prevalent in children of illiterate fathers compared to those of college graduate fathers (10.2% vs 6.3%). This was statistically signficant (p < 0.0001). Asthma was also more prevalent in children of illiterate mothers comapred to those of graduate mothers (9.2% vs 5.8%). This was statistically significant @ < 0.0001). Table (2). shows asthma prevalence in relation to family income. Prevalence was substantially higher in these families with monthly incomes of s 50 L. E. compared to those with monthly incomes over 300 L. E. (10.2% vs 6.4%). This was statistically significant (P c 0.001). The frequency of asthma in relation to the number of persons in the family was not found to be statistically significant (Table 3). The relationship between the fequency of asthma and the number of rooms in the house is shown in Table (3). The prevalence of asthma was significantly higher in homes with 1 or 2 rooms compared to those with 4 or more rooms (11.2% vs 5.8%) this was statistically significant (P c 0.001). The frequency of asthma was also significantly related to the number of persons sharing the same bedroom with the asthmatic child (Table 3). Asthma prevalence was 10.5% if or more persons shared the same room with the asthmatic child, compared to 6.3% if only one person shared the room with the child. This was statistically significant (P c 0.0001). The Crowding index (number of person/number of room in significant house) bore a strong direct relation to the a frequency of asthma. The higher the crowding index the more prevalent was the asthma (fig. 3 & Table 3). This was found to be statistically significant (P < 0.0001). If the crowding index was < 1.5 asthma prevalence was 5. %, after which asthma prevalence increased gradually up to 10.5% with a crowding index of 5.5 or more In our study a positive family history of asthma or other allergic illnesses in the family increased the likelyhood that the child will have asthma. In families with negative family history of asthma the prevalence of asthma in children was 7.0%, whereas in families with a positive history of asthma the prevalence of asthma in children was 25.1%. If family history was negative for other allergic illnesses, the prevalence of asthma was 6.8%, whereas prevalence increased significantly to 20.1% if the family history was positive. Similarily, if the students had a negative history of other allergies the prevalence of asthma in the group was 7.1% increasing up to 16.7% if the student’s history was positive. All the above correlation between asthma prevalence and either family or personal history of atopy were considered statistically significant @ < 0.001) (Table 4). A 508 Anissa M. El-Hefny, et al child’s history of other allergic illnesses was found to increase the likelyhood of earlier onset of asthma. This relation was statistically significant (P c O.tKJl). Table (1): Frequency of Asthma Among School Children in Relation to Parents Education in Cairo.