SUMMARYThe occurrence of Brachyspira species and Lawsonia intracellularis was investigated by PCR analyses of faeces from 60 children living on European pig farms. In addition, 60 other children were included as controls. Two samples were positive for B. aalborgi but B. pilosicoli and L. intracellularis were not demonstrated.Two species of the genus Brachyspira, B. aalborgi and B. pilosicoli, have been associated with human intestinal spirochaetosis (HIS) [1,2]. The clinical significance of HIS is largely unknown. In Western countries, B. aalborgi seems to be more common with reported prevalences of for example, 7 . 9 % [3] or 70 % of submitted cases of HIS [4]. Brachyspira pilosicoli is more frequent in developing countries with reported prevalences of 15-23 % [2,3,5]. Further, B. pilosicoli and the intracellular rod Lawsonia intracellularis are major causes of enteric disease in young, growing pigs with 32% and 48 %, respectively, of the herds being infected [6,7]. The infection causes similar clinical signs and the microbes often occur concomitantly. L. intracellularis have been isolated in a wide range of other animal species, e.g. pig, hamster, horse, guinea pig, dog, lamb, calf, ferret, fox, deer, rabbit, rat, mouse, ratites, wild boar, wolf, giraffe, hedgehog, and primates. The broad host range raises the question whether natural cross-species transmission might occur. L. intracellularis belongs to the Desulfovibrionaceae family and in patients with ulcerative colitis an increased carriage of closely related bacteria has been demonstrated. The microbe causes proliferative enteropathy, characterized by crypt hyperplasia of immature cells. The lesions are morphologically similar to those found in patients with coeliac disease and hypotheses regarding a similar aetiology have been proposed. However, the bacterium has never been reported in humans [8][9][10].The aim of the present study was to investigate the occurrence of Brachyspira species and L. intracellularis in faeces from children living on European pig farms and compare the findings to those in children not living on pig farms.