A nationwide Dengue Prevention Week begins today (15) and will continue until 20 June amid concerns over the spread of dengue fever.Public places, including cities, drainage systems, commercial centres, religious sites and bus stations, will be cleaned until 17 June.Schools, pre-schools and tuition classes are scheduled for cleaning on 18 June, while public and private institutions and factories will be cleaned on 19 June.The program will conclude with the cleaning of homes and surrounding areas on 20 June.