Any juvenile adjudged to be under subdivision (7) of section 43-247 shall remain in the custody of the Department of Health and Human Services or the licensed child placement agency to whom the juvenile has been relinquished unless the court finds by clear and convincing evidence that the best interests of the juvenile require that an alternative disposition be made. If the court makes such finding, then alternative disposition may be made as provided under section 43-284. Such alternative disposition shall relieve the department or licensed child placement agency of all responsibility with regard to such juvenile.