Department of Infectious Diseases, University of Gothenburg , Gothenburg , Sweden.
Department of Pediatrics, University of Gothenburg, Gothenburg, Sweden.
Clin Infect Dis. 2017 Oct 15;65(8):1371-1377. doi: 10.1093/cid/cix500.
Acute infectious gastroenteritis is an important cause of illness and death among children in low-income countries. In addition to rotavirus vaccination, actions to improve nutrition status, sanitation, and water quality are important to reduce enteric infections, which are frequent also among asymptomatic children. The aim of this study was to investigate if the high prevalence of these infections reflects that they often are not cleared properly by the immune response or rather is due to frequent pathogen exposure.
Rectal swabs were collected at time of acute diarrhea and 14 days later from 127 children, aged 2-59 months and living in rural Zanzibar, and were analyzed by real-time polymerase chain reaction targeting multiple pathogens.
At baseline, detection rates >20% were found for each of enterotoxigenic Escherichia coli, Shigella, Campylobacter, Cryptosporidium, norovirus GII, and adenovirus. At follow-up, a large proportion of the infections had become cleared (34-100%), or the pathogen load reduced, and this was observed also for agents that were presumably unrelated to diarrhea. Still, the detection frequencies at follow-up were for most agents as high as at baseline, because new infections had been acquired. Neither clearance nor reinfection was associated with moderate malnutrition, which was present in 21% of the children.
Children residing in poor socioeconomic conditions, as in Zanzibar, are heavily exposed to enteric pathogens, but capable of rapidly clearing causative and coinfecting pathogens.
急性感染性胃肠炎是低收入国家儿童患病和死亡的重要原因。除了轮状病毒疫苗接种外，改善营养状况、卫生和水质的措施对于减少肠道感染也很重要，这些感染在无症状儿童中也很常见。本研究旨在探讨这些感染的高流行率是否反映了它们通常不能被免疫反应清除，或者是由于频繁接触病原体。
从 2015 年 8 月至 2016 年 1 月，从坦桑尼亚桑给巴尔岛农村地区的 127 名 2-59 月龄的儿童中采集急性腹泻时和 14 天后的直肠拭子，并通过针对多种病原体的实时聚合酶链反应进行分析。
在基线时，检测到的每种病原体的检出率均超过 20%，包括肠毒性大肠杆菌、志贺菌、弯曲菌、隐孢子虫、诺如病毒 GII 和腺病毒。在随访时，大部分感染已经清除（34-100%）或病原体载量降低，这也发生在与腹泻无关的病原体中。尽管如此，由于新的感染已经获得，大多数病原体在随访时的检测频率仍与基线时一样高。既没有清除也没有再次感染与中度营养不良有关，21%的儿童存在中度营养不良。
生活在贫困社会经济条件下的儿童，如桑给巴尔的儿童，大量接触肠道病原体，但能够迅速清除病原体和合并感染的病原体。
