Dengue fever is caused by a virus transmitted through the bites of infected Aedes aegypti mosquitoes. The mosquitoes breed in artificial water containers and their bites can transmit four types of dengue virus. Dengue fever causes high fever, headaches, and joint pains. In severe cases it can lead to dengue hemorrhagic fever with bleeding and low platelet counts. There is no vaccine or specific treatment, so prevention focuses on eliminating mosquito breeding sites and protecting against bites.

1. Dengue Fever Ahmed Siyah Maldivian Red Crescent

3. Life cycle completed in about 7 days

4. Life span of 4 – 8 weeks

6. Bites during day time, especially at dawn and dusk

7. Prefers to lay its eggs in artificial water containers, and does not fly far from breeding sites

8. Only female mosquitoes feed on blood

9. One female mosquito may lay 100 to 300 eggs at a time and may average 1,000 to 3,000 offspring during her life span.

11. Dengue Fever contd... Can be transmitted via infected blood products and through organ donation. Vertical transmission (from mother to child) during pregnancy or at birth has been reported. 80% people infected with dengue virus are asymptomatic or only have mild symptoms such as an uncomplicated fever Severe disease is more common in babies and young children, and it is more common in children that are relatively well nourished

12. Symptoms of Dengue Fever Sudden-onset high grade fever (over 40 °C) Headache (typically located behind the eyes) Muscle and joint pains (break bone fever) Nausea and vomiting Rash Mild bleeding from mouth (gums) and nose Low white blood cell count

13. Dengue Hemorrhagic Fever Complication of Dengue Fever occur in less than 5% of all cases of dengue. Stomach pains, lethargy, bleeding from mouth and gums Organ damage due to fluid accumulation in chest and abdominal cavity Dysfunction of the bone marrow leads to reduced numbers of platelets

14. Diagnosis Symptoms are similar to viral fevers Serological tests are expensive and time consuming Diagnosis is mainly by history and clinical examination DHF diagnosed by dropping platelet counts

15. Treatment No specific treatment. No vaccine. Fever usually runs it’s natural course and subsides Oral rehydration therapy at home with close follow-up Intravenous fluids at hospital Paracetamol for fever and discomfort Blood transfusion to replenish platelets Aspirin SHOULD NOT be given

16. Prevention – integrated approach WHO recommends an Integrated Vector Control program consisting of five elements: (1) Advocacy, social mobilization and legislation to ensure that public health bodies and communities are strengthened, (2) collaboration between the health and other sectors (public and private), (3) an integrated approach to disease control to maximize use of resources, (4) evidence-based decision making to ensure any interventions are targeted appropriately and (5) capacity-building to ensure an adequate response to the local situation.

17. Prevention – Fog Sprays Expensive Effective for only 2 to 4 hours Indiscriminate - they kill every insect, even butterflies Mosquitoes that survive come back stronger than ever Does not involve the community in taking responsibility for prevention

18. Actions Prevent mosquito bites Wear long sleeved clothes Use mosquito repellants Close house doors and windows at dawn and dusk Take extra care to protect people already having dengue fever from mosquitoes Do not send children with viral fever to schools or other classes as it might infect other children Eliminate mosquito breeding places Change water in plant pots every 2 – 3 days Put fish into wells and other water containers Upend any container that can collect water Dispose of rubbish that can collect water Cover water containers