The health authorities have been asked to take preventive measures to protect the citizens of federal capital from dengue virus. According to health experts, active monitoring and surveillance of natural mosquito is necessary during these days to check spread of the dengue virus. They urged the staff of departments concerned of the federal capital for proper solid waste disposal and improved water storage practices, including covering containers to prevent access by egg laying female mosquitoes. They said mosquitoes breed primarily in man-made containers like earthenware jars, metal drums and concrete cisterns used for domestic water storage, as well as discarded plastic food containers, used automobile tyres and other items that collect rain water. Dr Wasim Khawaja of Pakistan Institute of Medical Sciences (PIMS) said that dengue is a mosquito-borne infection which in recent years has become a major public health concern. He said dengue fever is a severe, flu-like illness that affects infants, young children and adults. He added the spread of dengue is attributed to expanding geographic distribution of the four dengue viruses and of their mosquito vectors, the most important of which is the predominantly urban species aedes aegypti. He warned the rapid growth of urban population is bringing ever greater numbers of people into contact with this vector, especially in areas that are favourable for mosquito breeding like where household water storage is common and where solid waste disposal services are inadequate. He pointed out dengue viruses are transmitted to humans through the bites of infective female aedes mosquitoes. He added mosquitoes generally acquire the virus while feeding on the blood of an infected person.