Dengue fever presentation by varsha BAMS

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1. DENGUE FEVER

2. INTRODUCTION Dengue fever, also known as breakbone fever , is an infectious tropical disease caused by the dengue virus.

3. Dengue fever virus (DENV) is an RNA virus of the family Flaviviridae and the genus Flavivirus . Most are transmitted by arthropods (mosquitoes or ticks ) and are therefore also referred to as arboviruses (arthropod-borne viruses).

4. There are four types of the virus, which are called serotypes, and these are referred to as DENV-1, DENV-2, DENV-3, and DENV-4. All four serotypes can cause the full spectrum of disease. Infection with one serotype is believed to produce lifelong immunity to that serotype but only short-term protection against the others.

5. TRANSMISSION Dengue is transmitted by several species of mosquito within the genus Aedes , principally A. aegypti. Other Aedes species that transmit the disease include A. albopictus, A. polynesiensis , and A. scutellaris . Humans are the primary host of the virus, but it also circulates in non-human primates.

6. An infection can be acquired via a single bite. A female mosquito that takes a blood meal from a person infected with dengue fever becomes infected with the virus in the cells lining its gut. About 8-10 days later, the virus spreads to other tissues, including the mosquito's salivary glands , and is subsequently released into its saliva.

7. MECHANISM When a mosquito carrying dengue virus bites a person, the virus enters the skin together with the mosquito's saliva. It binds to and enters white blood cells and reproduces inside the cells while they move throughout the body.

8. In severe infection, the virus production inside the body is greatly increased, and many more organs (such as the liver and the bone marrow) can be affected. Fluid from the bloodstream leaks through the walls of small blood vessels into body cavities. About 8-10 days later, the virus spreads to other tissues, including the mosquito's salivary glands, and is subsequently released into its saliva.

9. Furthermore, dysfunction of the bone marrow leads to reduced numbers of platelets , which are necessary for effective blood clotting ; this increases the risk of bleeding , the other major complication of dengue fever

10. SIGNS AND SYMPTOMS Incubation period : 2-7 day Prodrome : 2 days of malaise and headache Fever : Continuous or saddle-back, with break on 4 th or15 th day and then recrudescence, usually lasts 7-8 days.

11. Acute onset * Fever * Backache * Arthralgia * Headache * Generalised pains (break-bone fever) * Pain on eye movement * Lacrimation * Anorexia * Nausea * Vomiting * Pharyngitis * Upper respiratory tract symptoms * Relative bradycardia * Depression * Hyperaesthesia * Lymphadenopathy

12. Convalescence : Slow and may be associated with prolonged fatique syndrome, arthralgia or depression. Complications : * Dengue haemorrhagic fever * Disseminated intravascular coagulation. * Dengue shock syndrome. * Severe organ involvement. * Vertical transmission if infection within 5 weeks of delivery.

13. WARNING SIGNS *Abdominal pain *Ongoing vomiting *Liver enlargement *Mucosal bleeding *High hematocrit with low platelets *Lethargy

14. The course of infection is divided into three phases: Febrile phase Critical phase Recovery phase

15. FEBRILE PHASE high fever, often over 40 °C (104 °F), biphasic in nature breaking and then returning for one or two days generalized pain headache; usually lasts two to seven days. Rash occurs in the first or second day of symptoms as flushed skin, or later in the course of illness (days 4-7), as a measles-like rash .

16. Some petechiae (small red spots that do not disappear when the skin is pressed, which are caused by broken capillaries ) can appear at this point.

17. CRITICAL PHASE a critical phase, which follows the resolution of the high fever and typically lasts one to two days. During this phase there may be significant fluid accumulation in the chest and abdominal cavity due to increased capillary permeability and leakage. This leads to depletion of fluid for the circulation and decreased blood supply to vital organs .

18. organ dysfunction and severe bleeding , typically from the GIT. Shock (dengue shock syndrome) and hemorrhage (dengue hemorrhagic fever) occur in less than 5% of all cases of dengue, however those who have previously been infected with other serotypes of dengue virus (" secondary infection ") are at an increased risk.

19. RECOVERY PHASE This usually lasts two to three days. reabsorption of the leaked fluid into the bloodstream. severe itching and a slow heart rate. During this stage, a fluid overload state may occur; if it affects the brain, it may cause a reduced level of consciousness or seizures.

20. Classification The World Health Organization's 2009 classification divides dengue fever into two groups: Uncomplicated 2. Severe Dengue hemorrhagic fever was subdivided further into grades I-IV. Grade I is the presence only of easy bruising or a positive tourniquet test in someone with fever,

21. grade II is the presence of spontaneous bleeding into the skin and elsewhere. grade III is the clinical evidence of shock. grade IV is shock so severe that blood pressure and pulse cannot be detected. Grades III and IV are referred to as "dengue shock syndrome

22. DIAGNOSIS PCR NAAT(Nucleic acid detection) ELISA Tourniquet test Blood test (platelets count >1,50,000) CBC

23. DIFFERENTIAL DIAGNOSIS Chikungunya Malaria Leptospirosis Typhoid fever

24. MANAGEMENT * No specific treatment. * Mainly supportive therapy. * Analgesic and antipyretic for pain and fever such as Paracetamol. * Bed rest * Oral rehydration. * IV hydration if required is typically needed for one to two days. * NSAID such as aspirin and ibuprofen are contraindicated.

25. * Management of dengue hemorrhagic fever and dengue shock syndrome include; * Immediate evaluations of vital signs and degrees of hemoconcentration, dehydration, and electrolyte imbalance. * 02 should be given in a cyanotic patient . * Rapid replacement of fluid and electrolyte. * Transfusion of fresh blood or platelets may require to control bleeding.

26. PREVENTION The only method for controlling or preventing the dengue is to combat the vector mosquitoes . Mosquito control; * Vector control is implemented by using environmental management and chemical methods. * Proper solid waste disposal and improved water storage practices including covering the containers to prevent mosquito breeding.

27. Prevent mosquito bites; Screen home with mesh Wear full clothing Apply mosquito repellent Keep dengue fever patient under mosquito net And Etc.

28. VACCINATION

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