Dengue is transmitted to humans by female Aedes mosquitoes. These mosquitoes carry the dengue virus (DEN), which comprises four distinct serotypes (DEN-1, DEN-2, DEN-3 and DEN-4) and belong to the Flaviviridae family. The dengue mosquito commonly bite during daytime or before dusk.
The patient infected with dengue virus starts showing symptoms within 3 to 14 days. The first symptom includes high-fever followed by body pain. Fever may be accompanied frequently with severe sweating and headaches. Some patients even experience pain behind the eyes, which is known as retro-orbital pain in medical terms. Nausea, vomiting, fatigue, rashes on face and limbs, mild bleeding and low blood pressure are other symptoms of dengue. In acute cases, decreased urine output and breathlessness may also trouble the patients.