ISLAMABAD: Health experts have advised the citizens of twin cities of Rawalpindi and Islamabad to take special preventive measures to protect them from carrying dengue virus. According to them, citizens should properly dispose of solid waste and stop water storage practices at their residences to prevent any access to egg-laying female mosquitoes. They said mosquitoes breed primarily in 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 from Pakistan Institute of Medical Sciences (PIMS) said that dengue was a mosquito-borne infection, which in recent years has become a major public health concern. He said that dengue fever was a severe, flu-like illness that affects infants, young children and adults. He added the spread of dengue was attributed to expanding geographic distribution of the four dengue viruses and of their mosquito vectors, the most important of which was the predominantly urban species Aedesa egypti. He said that the rapid growth of urban population was bringing ever greater numbers of people into contact with this vector, especially in areas that are favourable for mosquito breeding like in places where household water storage was common and where solid waste disposal services are inadequate. He said that dengue viruses were 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. He said that after virus incubation for eight to ten days, an infected mosquito was capable, during probing and blood feeding, of transmitting the virus to susceptible individuals for the rest of its life. He said that the virus circulates in the blood of infected humans for two to seven days, at approximately the same time as they suffer from fever. He added the clinical features of dengue fever vary according to the age of the patient. Dr Sharif Astori from Federal Government Poly Clinic (FGPC) said that infants and young children may have a non-specific febrile illness with rash as older children and adults may have either a mild febrile syndrome or the classical incapacitating disease with abrupt onset and high fever, severe headache, pain behind the eyes, muscle and joint pains and rash. He said that dengue haemorrhagic fever was a potentially deadly complication that was characterised by high fever, haemorrhagic phenomena.