Couscous is widely consumed in Algeria, but it has been associated with several outbreaks. Couscous semolina may contain heat-resistant spores of Bacillus cereus group IV. These bacteria are mesophilic and potential producers of diarrheal toxin. The present study aimed at predicting (i) the prevalence and concentration of B. cereus group IV during couscous preparation at the time of consumption, and (ii) the number of consumers exposed to 10⁵ cfu/g or more B. cereus in Algeria, due to couscous consumed at home or during collective events. In a probabilistic exposure assessment model, couscous semolina preparation was divided into three modules (i) contamination at retail, (ii) inactivation of B. cereus during couscous steaming and (iii) growth during storage before serving. Each module was built using a combination of newly gathered data, literature studies, predictive models and expert opinions. Algeria was split into four regions: North, South, High Plateau and Kabylia. The main differences between the regions were the seasonal temperature and the consumption pattern. Annually, a total of 3000 people (0.007% total population) and 170 people (0.0004%) were estimated to be exposed to a concentration equal to or above 10⁵ cfu/g, due to home and collective consumption, respectively. The highest exposure came from couscous semolina kept at ambient temperature, in the south of Algeria during summer. Cold storage and consumption within the first 12 h after steaming are factors which limit the exposure to B. cereus group IV in couscous.

蒸粗麦粉在阿尔及利亚被广泛食用，但与几次暴发有关。粗粉蒸粗麦粉可能含有蜡状芽孢杆菌第四类的耐热孢子。这些细菌是嗜温细菌，是腹泻毒素的潜在生产者。本研究旨在预测（i）食用时蒸粗麦粉制备过程中蜡状芽孢杆菌IV组的患病率和浓度，以及（ii）阿尔及利亚接触10 ⁵ cfu / g或更多蜡状芽孢杆菌的消费者数量。，是由于在家中或集体活动中消耗了蒸粗麦粉。在概率暴露评估模型中，粗粉蒸粗麦粉制备分为三个模块（i）零售中的污染，（ii）蜡状芽孢杆菌的灭活蒸粗麦粉期间（iii）食用前在储存期间生长。每个模块都是结合新收集的数据，文献研究，预测模型和专家意见而构建的。阿尔及利亚分为四个地区：北部，南部，高原和卡比利亚。地区之间的主要差异是季节性温度和消费模式。据估计，由于家庭和集体消费，每年分别有3000人（总人口的0.007％）和170人（总人口的0.0004％）暴露于等于或高于10 ⁵ cfu / g的浓度。最高的暴露来自夏季期间阿尔及利亚南部处于环境温度的粗麦粉。蒸煮后头12小时内的冷藏和食用是限制暴露于蒸粗麦粉中的蜡状芽孢杆菌第四类。