Although these principles for the staffing and design of newborn nurseries should be followed so as to ensure maximum safety, nothing can obviate the need for trained and conscientious personnel who are in constant attendance and give careful attention to proven and accepted techniques of cleanliness. If infected persons are permitted to come into contact with infants or if faulty techniques are used, no physical arrangement, however elaborate, will entirely prevent unfortunate accidents from occurring. All aspects of technique must be reviewed periodically and all mechanical aids such as ventilation checked frequently, if they are to provide maximum protection.