Palestine, Eastern Mediterranean

Why was this centre selected for ISAAC?

In a personal communication, year 2000, with Professor Ameen Thalji, a researcher in Pediatric’s health in the West Bank and Jerusalem, he reported a gradient increase of childhood infections as seen at the emergency rooms and hospitals’ clinics in the past 10 years. Thalji and Abdeen agreed that a potential justification could be the increased effect of indoor allergen especially house dusts mites and smoking, and outdoor air pollution by traffic and allergens which were also believed to be the main risk factors for increasing asthma in the Palestinian children (Professor Ameen Thalji and Professor Hani Abdeen, personal communication, 2000). Similarly, a case control study in Gaza Strip at the refugees’ camps (1) indicated that house dust mites were probably important allergens in the region and has a major role in asthma trends and its severity among children especially at the coastal areas. Also, kerosene use for heating and cooking was a strong potential risk factor for developing asthma symptoms in those children, in addition to the effect of smoking and house dust mites. Therefore, poverty and humidity in Palestine and especially in Gaza Strip were considered important risk factors for asthma too.

Until year 2000, there was no real work that described the real situation or explored the possible risk factors and determinants of asthma in Palestine. The urban-rural and inland-coastal area differences were not studied in depth. Therefore, we decided at Al Quds University-Palestine in cooperation with KULeven Belgium to initiate several studies in two selected area (West Bank and Gaza Strip) that provide a framework for further etiological research into lifestyle, environmental, genetic and medical care factors affecting asthma prevalence and incidence. Ramallah governorate, the inland area, and Gaza governorate, the coastal area, were chosen for implementing the series of studies that was planned according to ISAAC protocols (phase three and phase 2).

ISAAC studies were used as a research that led to obtaining my own PhD, Nuha El Sharif PhD, from the K.U.Leuven.

Center findings

ISAAC Phase Three studies:

This phase was done in two governorates: Gaza and Ramallah governorates. After a two-stage stratified systematic sampling, approximately 14,500 schoolchildren, from the first and second grades of elementary school (ages 5 to 8 years) and eighth and ninth school grades (ages 12 to 15 years), were invited to participate in a survey using ISAAC phase III questionnaires and protocols.

The main study results showed that younger children had a higher 12-month wheezing prevalence rate of 9.6% compared to older children (7.2%) and more physician-diagnosed asthma (8.4% and 5.9%, respectively). However, nocturnal cough and exercise-related wheezing were higher in the older age group compared with younger children. Younger children living in North Gaza district showed slightly higher prevalence rates for asthma and asthma symptoms, but older children had higher rates in Ramallah district. After adjustment using logistic regression analysis, male sex, living in inland areas, and younger age were shown to predict 12-month wheezing and physician-diagnosed asthma (2).

ISAAC phase 2

In the fall of 2000, 3382 schoolchildren aged 6-12 year were surveyed in 12 schools in Ramallah governorate, using ISAAC-phase III, parents-administered translated questionnaire. The crude prevalence rates for "wheezing ever", "wheezing in the previous 12 months", and "physician-diagnosed asthma"' were 17.1%, 8.8% and 9.4% respectively, with urban areas having higher prevalence rates than rural areas. Within urban areas, refugee camps had higher prevalence rates than cities. Yet, within the rural areas, the 12 months prevalence was lower in the deprived villages than other residence. Place of residence remained significant for asthma and asthma symptoms, after adjusting for gender, age, and place of birth (3).

To investigate the role of familial, early days’ exposures, and indoor environmental determinants for asthma in children in Palestine, ISAAC phase 2 protocols were used. From the population of our previous study (3), a group of 273 children with wheeze in the past 12 months (of whom 99 children had physician-diagnosed asthma) were matched with an equal number of non-wheezing controls. This case-control study involved a parental questionnaire; skin prick testing (SPT) with mixed house dust mites, cat and dog dander, mixed grass, mixed trees pollen, Alternaria, olives tree, and cockroach extracts, and serum for total and specific IgE for the same 8 allergens (4). Moreover, to evaluate the relationship between wheezing or sensitization and concentrations of mites, cat and dog allergens, and bacterial endotoxin samples were taken from the mattress and floor dust of a 110 children’s houses with reported wheezing and without wheezing (5,6).

The results showed that paternal asthma and maternal hay fever significantly tripled the risk for their children to have wheezing. Previous diagnoses of bronchial allergy, bronchitis, pneumonia, or whooping cough, and positive SPT for house dust mites and cockroaches were significantly more likely among wheezing and asthmatic children than controls. Specific IgE levels for house dust mites and cat allergens showed significantly higher risk to report wheezing. Domestic damp spots and visible moulds were reported more for both wheezing and asthmatic children. After adjustment for several environmental and socio-demographic factors using multivariate logistic regression analysis, paternal asthma, maternal hay fever, damp houses, and cockroach allergen positivity proved to be strong predictors for wheezing symptoms (4).

No consistent associations between allergen levels and either wheeze or specific atopic sensitization were found. Furthermore, no clear associations between mattress endotoxin levels and wheeze or atopy were found. Endotoxin in floor dust was inversely associated with atopic sensitization and wheeze, statistically significant only for atopic wheeze. Finally, a non-significant inverse association was observed between living room endotoxin and atopy within the non-wheezing control group (5,6).

The conclusion of phase 2 confirmed that familial “atopic" diseases are significant predictors of childhood asthma. Moreover, indoor environment such as domestic moulds also appears to play a role. Also, results suggest that endotoxin on living room floors might protect against atopic wheeze in the Palestinian children.

References

• Mumcuoglu KY, Abed Y, Armenios B, et al. Asthma in Gaza refugee camp children and its relationship with house dust mites. Ann.Allergy 1994; 72: 163-166.
• El-Sharif NA, Nemery B, Barghuthy F, Mortaja S, Qasrawi R, Abdeen Z. Geographical variations of asthma and asthma symptoms among schoolchildren aged 5 to 8 years and 12 to 15 years in Palestine: the International Study of Asthma and Allergies in Childhood (ISAAC). Ann Allergy Asthma Immunol. 2003 Jan;90(1):63-71.
• El-Sharif N, Abdeen Z, Qasrawi R, Moens G, Nemery B. Asthma prevalence in children living in villages, cities and refugee camps in Palestine. Eur Respir J. 2002 Jun;19(6):1026-34.
• El-Sharif N, Abdeen Z, Barghuthy F, Nemery B. Familial and environmental determinants for wheezing and asthma in a case-control study of school children in Palestine. Clin Exp Allergy. 2003 Feb;33(2):176-86.
• El Sharif N, Douwes J, Hoet PH, Doekes G, Nemery B. Concentrations of domestic mite and pet allergens and endotoxin in Palestine. Allergy. 2004 Jun;59(6):623-31.
• El-Sharif N, Douwes J, Hoet P, Nemery B.Childhood asthma and indoor aeroallergens and endotoxin in Palestine: a case-control study. J Asthma. 2006 Apr;43(3):241-7.