Introduction: Dengue is an arthropod borne disease caused by dengue virus. It is transmitted via bite of female Ades Aegypti mosquito. It is fresh water breeding mosquito with peak biting activity at dusk and dawn. Four serotypes of virus circulate in humans. It is estimated that over 390 million dengue virus (DENV) infections occur each year and approximately 96 million are clinically apparent. Pakistan is included in dengue endemic areas.
Incubation period: Symptoms appear in 4 -7 days after mosquito bite and last for 10 -14 days.
Clinical Manifestations: Dengue fever is also known as ‘Break Bone Fever’. It is characterized by sudden onset of high grade fever, headache, retro-ortbital pain, myalgias, arthralgias, nausea, vomiting, maculopapular rash, thrombocytopenia and haemorrhagic manifestations.
Course of Disease: Patients with primary dengue fever undergo uneventful recovery. The haemorrhagic manifestations in this case are positive tourniquet test, petechiae, purpura and gum bleeding etc. Complications i.e dengue haemorrhagic fever and dengue shock syndrome arise when a person had second episode of dengue fever with a different serotype of virus. Warning signs include > 20 rise in hematocrite, narrow pulsese pressure, weak and rapid pulse and hypotension leading to shock.
Treatment: No antiviral available. Treatment is supportive with maintenance of fluid and electrolyte balance. Avoid giving aspirin.
Immunization: WHO, recommends use of DENGVAXIA by Sanofi Pastuer in dengue endemic regions. Three doses should be given at 0, 1 and 6 months.
Prevention: Main preventive measures include:
1. Keep surroundings clean. Dispose off waste properly.
2. Empty vessels containing water or cover them.
3. Wear full clothing while going out.
4. Avoid outdoor activities at dusk and dawn.
5. Use mosquito repellents.
6. Fogging is recommended during periods of outbreak.