By now dengue is
a known name to majority of Pakistanis, thanks to 2011 outbreak. After winters
each year we start hearing buzzing of little mosquitoes. Annoying as they may
seem, these tiny creatures stir a sense of fear in us. It is November and we
are still getting cases of dengue infection mainly from Karachi
and Rawalpindi .
Dengue infection is caused by dengue virus which has four different types
circulating in blood of humans (serotypes 1-4). Serotype-5 of dengue infects
non-human primates only. Dengue infection has three manifestations, namely,
dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome
(DSS). World Health Organization (WHO) has updated case definitions for dengue
infection to classical dengue and severe dengue cases. Dengue fever is febrile
acute infection where the patient may or may not experience symptoms. Almost
97% of dengue infections are asymptomatic i.e., no visible symptoms appear to
identify the infection. Patient may feel lethargy and fever which are vague
signs to characterize this infection. Dengue hemorrhagic fever is the severe
form of infection where plasma leakage occurs that can cause failure of organs
and may lead to dengue shock syndrome.