Medical experts have advised citizens of the 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) while talking to media on Thursday 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 said 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 i.e. in places where household water storage is common and where solid waste disposal services are inadequate.
He said that 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.
He said after virus incubation for eight to ten days, an infected mosquito is capable, during probing and blood feeding, of transmitting the virus to susceptible individuals for the rest of its life.
He said 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 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 dengue haemorrhagic fever is a potentially deadly complication that is characterized by high fever, haemorrhagic phenomena.