Best endeavours must be used to ensure that a detained person committed to a hospital unit does not see his or her detention rights being curtailed. This requires, on the hand, ensuring continuity regarding his or her administrative situation so as to avoid any interruption in care (external relations, nominative accounts, sentence adjustments, etc.) and, on the other, hospital units with the necessary logistics (exercise space, visiting rooms, activities, canteen, etc.). 4. The situation in detention facilities and centres for illegal immigrants Over 2016, the CGLPL's visits in facilities accommodating undocumented foreigners were mainly carried out in two atypical situations: the detention facilities and centre and the holding area of Mayotte on the one hand, and the measures taken by the Government to deal with the influx of migrants in Paris and the Calais region on the other. 4.1 In Mayotte – a territory under strong migratory pressures – there is a temptation to restrict migrants' rights. Mayotte is subject to strong migratory pressures, mainly from the Comoros and, to a much lesser extent, Madagascar. These flows are difficult to manage amid insufficient services and infrastructure, not least in terms of transport and health, as well as the recent development of a sense of insecurity that has gained media traction. The activity of the detention centre for illegal immigrants is marked by the sheer scale of these flows, since more than 18,000 people have been removed each year – including some 25% of minors – with passengers of boats intercepted out at sea forming half this figure. Their average length of stay in the centre is 17 hours. The centre must therefore organise removals in an almost industrial fashion, carrying them out in spite of no few linguistic difficulties. The accommodation conditions are acceptable and the procedures generally conducted correctly under the supervision of management staff who mostly show an attentive and respectful attitude towards the people concerned. In the event of a surge in migrants arriving, outstripping the detention centre's capacities, it is assisted by three newly opened administrative detention facilities. Two of these offer up particularly precarious accommodation conditions, with one being no more than a fenced holding area in portside installations. The wide range of different authorities managing and using suc h facilities undermines the consistency of the procedures implemented and respect of the rights of the persons detained within. The main difficulties concern the situation of minors and their entrusting to an adult – even when there is no legally established connection. In a context where relationships do not have the same significance as in mainland France and administrative documents are not always reliable – or available even, the situation is extremely complicated to manage. In practice, even if the law provides for referral to the Social Care Services for Children scheme (ASE), the most commonly adopted measure entails dispatching the children placed in detention back to their presumed homeland on the grounds that the poverty over there is preferable to the risk of not being properly cared for by one of the few foster families in Mayotte. Even more worryingly, serious doubts remain over the legitimacy of the claims made regarding the adult to whom children are entrusted for their removal. Whatever the ef forts undertaken by the association in charge of assisting families, the swiftness with which returns are 28