Department of Parasitology, Leiden University Medical Centre, The Netherlands.
Int Arch Allergy Immunol. 2011;155(1):63-73. doi: 10.1159/000318704. Epub 2010 Nov 26.
Epidemiological data on food allergy are scarce in African countries. We studied the prevalence of food sensitization in Ghanaian schoolchildren.
Children (5-16 years; n = 1,714) from 9 Ghanaian schools were given parental consent to participate in the study. Adverse reactions and food consumption were determined by a questionnaire and atopy by skin prick testing (SPT) to peanut and 6 fruits. Subjects with positive SPTs were considered cases (n = 43) and matched with at least 1 control (n = 84), using age, sex, and school as matching criteria. Serum samples from case-control sets were analyzed for specific IgE (sIgE) to foods that elicited a positive SPT response in cases.
Overall, 11% of 1,407 children reported adverse reactions to foods, and 5% of 1,431 children showed a positive SPT reaction mostly directed against peanut and pineapple (both 2%). Although there was a positive association between adverse reactions and SPT responses to any food allergen in the urban children (adjusted OR = 3.6, 95% CI 1.2-10.8), most of the reported adverse reactions were not in children showing an SPT reaction to the specific food item. sIgE sensitization was very variable for the different foods, ranging from 0 to 100% in cases, and from 0 to 25% among controls. High IgE levels for a food item significantly increased the risk of SPT positivity to any food item in the urban, but not in the rural, schoolchildren.
Specific foods were identified to be allergenic in Ghana. We show a good association between SPT and sIgE in urban, but not in rural, schoolchildren. However, there was no clear association between reported adverse reactions to food and SPT or sIgE.
非洲国家的食物过敏流行病学数据较为匮乏。我们研究了加纳学童食物致敏的流行情况。
加纳 9 所学校的儿童(5-16 岁;n=1714)获得了父母的同意参与研究。通过问卷调查和对花生和 6 种水果的皮肤点刺试验(SPT)来确定不良反应和食物摄入情况。对 SPT 阳性的受试者,考虑为病例(n=43),并按照年龄、性别和学校作为匹配标准,与至少 1 名对照(n=84)进行匹配。从病例对照组中抽取血清样本,分析食物特异性 IgE(sIgE),以确定对病例中 SPT 阳性反应的食物。
总体而言,1407 名儿童中有 11%报告了食物不良反应,1431 名儿童中有 5%出现了 SPT 阳性反应,主要针对花生和菠萝(均为 2%)。尽管在城市儿童中,不良反应与任何食物过敏原的 SPT 反应之间存在正相关关系(调整后的 OR=3.6,95%CI 1.2-10.8),但大多数报告的不良反应并非在对特定食物有 SPT 反应的儿童中出现。不同食物的 sIgE 致敏情况差异很大,病例中范围为 0 至 100%,而对照中范围为 0 至 25%。食物的 IgE 水平较高会显著增加城市学童对任何食物 SPT 阳性的风险,但对农村学童没有影响。
确定了加纳的一些致敏食物。我们在城市学童中显示出 SPT 和 sIgE 之间的良好关联,但在农村学童中没有。然而,食物不良反应与 SPT 或 sIgE 之间没有明确的关联。