DENGUE Fever and other symptoms of dengue fever

Dengue fever

1. DENGUE FEVER

2. ALTERNATIVE NAMES Hemorrhagic dengue Dengue shock syndrome Philippine hemorrhagic fever Thai hemorrhagic fever Singapore hemorrhagic fever 2

3. INTRODUCTION Dengue Hemorrhagic Fever is an acute infectious viral disease usually affecting infants and young children. This disease used to be called break-bone fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking. It is a severe, potentially deadly infection spread by certain species of mosquitoes ( Aedes aegypti ). Philippine Hemorrhagic Fever was first reported in 1953. In 1958, hemorrhagic fever became a notifiable disease in the country and was later reclassified as Dengue Hemorrhagic Fever. 3

4. FLAVI VIRUS 4

5. Global Status of Dengue Fever New infections annually -- 50 mn Death -- 24,000 annually People at risk -- 2.5 to 3 bn Hospitalized cases- 50,000 /yr (90% affected are children) Disease burden -- 4,65,000 Disability Adjusted Life Years (DALY) Half of the world lives in HOT ZONE 5

6. World distribution of Dengue Fever 6

7. Outbreak in Pakistan The first case of Dengue Fever was detected in Pakistan in the year 1994 in Karachi. The first outbreak of Dengue Fever was in the year 2006. Since then dengue cases detected per year are on the rise. 7

8. Characteristics of Mosquito Aedes Mosquito One distinct physical feature – black and white stripes on its body and legs Bites during the day Lays its eggs in clean, stagnant water 8

9. Characteristics of Mosquito Only the female Aedes mosquito feeds on blood because they need the protein found in blood to produce eggs Male mosquitoes feed only on plant nectar On average, a female Aedes mosquito can lay about 300 eggs during her life span of 14 to 21 days 9

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11. Virus vector and transmission Causes dengue and dengue hemorrhagic fever Is an arbovirus Transmitted by mosquitoes Composed of single-stranded RNA Has 4 serotypes (DEN-1, 2, 3, 4) 11

12. Virus vector and transmission Each serotype provides specific lifetime immunity, and short-term cross-immunity. All serotypes can cause severe and fatal disease. Genetic variation within serotypes. Some genetic variants within each serotype appear to be more virulent or have greater epidemic potential. 12

13. Replication and Transmission of Dengue Virus 1. Virus transmitted to human in mosquito saliva 2. Virus replicates in target organs 3. Virus infects white blood cells and lymphatic tissues 4. Virus released and circulates in blood 5. Second mosquito ingests virus with blood 6. Virus replicates in mosquito midgut and other organs, infects salivary glands 7. Virus replicates in salivary glands 13

14. SIGNS AND SYMPTOMS An acute febrile infection of sudden onset with clinical manifestation of 3 stages: 14

15. FIRST 4DAYS- Febrile or Invasive Stage High fever Abdominal pain and headache Later flushing which may accompanied by vomiting, conjunctival infection and epistaxis 15

16. 4 th -7 th days-Toxic or Haemorrhagic Stage Lowering of temperature Severe abdominal pain Vomiting and frequent bleeding from gastrointestinal tract in the form of hematemesis or melena Unstable BP Narrow pulse pressure Shock 16

17. 7 th -10 th Days- Convalescent or Recovery Stage Generalized flushing with intervening areas of blanching appetite regained Blood pressure already stable 17

18. Manifestation of Dengue Fever  Dengue Fever (DF)  Dengue Hemorrhagic Fever (DHF)  Dengue Shock Syndrome (DSS) 18

19. CLASSIFICATION Severe, frank type – with flushing, sudden high fever, severe hemorrhage, followed by sudden drop of temperature, shock and terminating in recovery or death. Moderate – with high fever, but less hemorrhage, no shock Mild – with slight fever, with or without petechial hemorrhage but epidemiologically related to typical cases usually discovered in the course of investigation of typical cases. 19

20. Petechiae 20

21. Bruises 21

22. SOURCES OF INFECTION Vector mosquito Aedis Aegypti , Aedis albopictus , The infected person 22

23. 23 INCUBATION PERIOD UNCERTAIN. Probably 6 days to 1 week PERIOD OF COMMUNICABILITY Unknown. Presumed to be on the first week of illness when virus is still present in the blood.

24. SUSCEPTIBILITY, RESISTANCE AND OCCURRENCE All persons are susceptible. Both sexes are equally affected. Age groups predominantly affected are the preschool age and school age. Adults and infants are not exempted. Peak age affected 5-9 years. Occurrence is sporadic through out the year. Epidemic usually occur during the rainy seasons June – November. Peak months are September and October. Occurs wherever vector mosquito exists. Susceptibility is universal. Acquired immunity may be temporary but usually permanent. 24

25. EXAMS AND TESTS Physical Examination may reveal the following: Low BP A weak, rapid pulse Rash Red eyes Red throat Swollen glands Enlarged liver ( hepatomegaly ) 25

26. Test may include the following: Hematocrit Platelet count Electrolytes Coagulation studies Liver enzymes Blood gases Torniquet test (causes petechiae below the torniquet ) X-ray of the chest (may demonstrate pleural effusion) Serologic studies (demonstrate antibodies to Dengue viruses) Serum studies from samples taken during acute illness and convalescence (High in titer to Dengue antigen) 26

27. COMPLICATIONS Most people who develop DHF recover completely within 2 weeks. Some, however, may go through several weeks to months of feeling tired and/or depressed. Others develop severe bleeding problems. DHF is a serious illness which can lead to shock (very low BP) and is sometimes fatal especially to children and young adults. 27

28. Other complications are the following: Shock Encephalopathy Residual brain damage Seizures Liver damage 28

29. MANAGEMENT Supportive and symptomatic treatment should be provided For fever, give paracetamol for muscle pains. For headache, give analgesic. DON’T give ASPIRIN. Rapid replacement of body fluids is the most important treatment Includes intensive monitoring and follow-up. Give ORESOL to replace fluid as in moderate dehydration at 75 ml/kg in 4-6 hours or up to 2-3L in adults. Continue ORS intake until patient’s condition improves. 29

30. Chemeri Vax Dengue A tetravalent vaccine Uses Yellow Fever vaccine as base 20% sero conversion Still under research 30

31. METHODS OF PREVENTION AND CONTROL The infected individual, contacts and environment Recognition of the disease. Isolation of patient (screening o sleeping under the mosquito net) Epidemiological investigation Case finding and reporting Health Education 31

32. CONTROL MEASURES 1. Eliminate the vector by: Changing water and scrubbing sides of lower vases once a week. Destroy breeding places of mosquito by cleaning surroundings Proper disposal of rubber tires, empty bottles and cans. Keep water containers covered. 2. Avoid too many hanging clothes inside the house. 3. Residual spraying with insecticides 32

33. MANAGEMENT For hemorrhage – keep the patient at rest during bleeding episodes. For nose bleeding, maintain an elevated position of trunk and promote vasoconstriction in nasal mucosa membrane through an ice bag over the forehead. For melena , ice bag over the abdomen. Avoid unnecessary movement. If transfusion is given, support the patient during the therapy. Observe signs of deterioration (shock) such as low pulse, cold clammy perspiration, prostration. 33

34. For shock – prevention is the best treatment. Dorsal recumbent position facilitates circulation. Adequate preparation of the patient, mentally and physically prevents occurrence of shock. Provision of warmth-through lightweight covers (overheating causes vasodilation which aggravates bleeding). Diet – low fat, low fiber, non-irritating noncarbonated. Noodle soup may be given. 34