dengue Etiology , Pathogenesis clinical features and management

A complete ppt on Dengue fever it's Etiology , mode of transmission , Pathogenesis , clinical features and management of Dengue.

1. DENGUE FEVER TOPIC PRESENTATION BY DR. VISHUDHA S 1 ST YEAR PG

2. ETIOLOGY Dengue virus (DENV) is a single-stranded, positive-sense RNA virus in the Flaviviridae family. The genome is made up of three structural protein molecules (C, prM , and E) and seven nonstructural proteins (NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NS5). The five strains of the virus (DENV-1, DENV-2, DENV-3, DENV-4, and DENV-5) Current circulating strain DENV2 Most virulent strain DENV4

3. VECTOR Aedes aegypti mosquitoes>> Aedes albopictus .

4. COURSE OF INFECTION EARLY EVENTS : DENV is injected to skin by bite of mosquito. During the first 24 hours, virus could only be isolated from the injection site. The major cell type infected was Langerhans cells, myeloid dendritic cells, mast cells, and dermal fibroblasts. DISSEMINATION : Viremia begins 2 to 4 days later and lasts for 3 to 6 days. The detection of dengue viral antigen in a very high percentage of circulating monocytes and in the CD20+ B lymphocytes. IMMUNE RESPONSE AND CLEARANCE: Both innate and adaptive immunity involved in clearing. Interferon alpha has antiviral activity.Neutralization of virus by antibody. ANTIBODY DEPENDENT ENHANCEMENT

5. REINFECTION: HALSTED ‘S THEORY HOSKINS EFFECT

6. COAGULOPATHY IN DENGUE:

7. COMPLICATIONS FEBRILE PHASE DEHYDRATION NEUROLOGICAL COMPLICATIONS WITH SEIZURES CRITICAL PHASE PLASMA LEAKAGE SHOCK HEMORRHAGE ORGAN IMPAIRMENT RECOVERY PHASE VOLUME OVERLOAD STATUS ACUTE PULMONARY EDEMA

8. EXPANDED DENGUE SYNDROME

9. NEUROLOGICAL:

10. Department of Neurology and 1Radiology, Postgraduate Institute of Medical Education and Research, Chandigarh DOUBLE DOUGHNUT SIGN

11. GIT: Sangita Kamath *1, Tauheed Ahmed 2 1Specialist, Department of Medicine, Tata Main Hospital, Jamshedpur, India; [email protected] 2 3rd Year DNB Student, Department of General Medicine, Tata Main Hospital, Tata Steel, Jamshedpur; [email protected] elevated AST more than the ALT may give a clue to the possibility of dengue fever. Peak rise occurs between fifth to ninth day of illne ss The peak levels of liver enzymes were found from 5th to 9th day. On average, peak liver enzymes levels were found on 6.6(±2.4) days. The peak average (±SD) of ALT and AST levels were 272(±589) and 519(±1360) respectively while the maximum peak values of ALT and AST seen were 4300.5U/L and 12,270U/L respectively.Levels then declined after 10th day of illness.

12. Internal Medicine, Benazir Bhutto Hospital, Rawalpindi, PAK Corresponding author. Benish Adil   moc.liamg@1991lidahsineb Accepted 2020 Nov 4. Copyright  © 2020, Adil et al. Gall bladder wall edema is strongly correlated with dengue hemorrhagic fever. Hence it should be assessed in all patients with dengue fever. The mean gall bladder wall thickness for dengue hemorrhagic fever was 6.4mm ± 2.5 mm. A GBWT value of 3.5mm was found to have 94.6% specificity and 91.2% sensitivity.

13. RENAL T hese include electrolyte imbalance, acute kidney injury (AKI), proteinuria, glomerulonephritis, alanine aminotransferase (IgA) nephropathy,hemolytic uremic syndrome, and acute tubular necrosis. Hyponatremia is the most common electrolyte abnormality in DF. The mechanism f or AKI is multifactorial, which includes direct viral action on renal tissue, hypoperfusion secondary to shock , and rhabdomyolysis. CARDIAC Cardiac involvement of varying degrees has been described ranging from arrhythmias to myocardial depression, pericarditis, and myocarditis. A variety of rhythm abnormalities were reported in DF, which ranges from sinus tachycardia, second-degree heart block, third-degree heart block, atrial fibrillation to paroxysmal supraventricular tachycardia. RESPIRATORY R anging from pleural effusion, pneumonitis, non-cardiogenic pulmonary edema to hemoptysis . In DF, pleural effusion is the most frequent cause of dyspnea ; usually, it is bilateral and seen in the context of plasma leakage. Lung parenchymal involvements are less common, including ground glass abnormalities, the varying patterns of consolidation, interlobular septal thickening, and pulmonary hemorrhage .

14. Worsening hypovolemic shock Increasing tachycardia and peripheral vasoconstriction. By this stage the breathing becomes more rapid and increases in depth − a compensation for the metabolic acidosis ( Kussmaul’s breathing). One key clinical sign of this deterioration is a change in mental state as brain perfusion declines. The patient becomes restless, confused and extremely lethargic. Seizures may occur and agitation may occur. Finally, there is decompensation, both systolic and diastolic BPs disappear suddenly and dramatically, and the patient is said to have hypotensive or decompensated shock. OTHER TYPE OF SHOCK?

15. INCREASED HEMATOCRIT + UNSTABLE VITALS - Plasma leakage INCREASED HEMATOCRIT + STABLE VITALS - Maintenance fluids DECREASED HEMATOCRIT + STABLE VITALS- Reabsorption DECREASED HEMATOCRIT + UNSTABLE VITALS – Continued hemorrhage

16. DIAGNOSIS

17. TREATMENT APPROACH

18. PLATELET TRANSFUSION INOTROPES vasopressors maybe considered when MAP Persistently less than 60 mmhg despite adequate fluid therapy. While vasopressors increase the bloodpressure , tissue hypoxia may be further compromised by the vasoconstriction. INDICATIONS OF

19. CBC AS A PROGNOSTIC INDICATOR PROGNOSTIC INDICATORS Liver enzymes, interleukins 4 and 10, tumor necrosis factor α ( TNF α), some proteases, soluble adhesion molecules, the surface area of atypical lymphocytes, high fluorescent lymphocyte counts, immature granulocytes and immature platelet factor (IPF). The percentage of lymphocytes in the differential leukocyte count performed at the time of admission predicted the length of hospital stay. The higher the percentage of lymphocytes, the faster the recovery from dengue and shorter the duration of stay in the hospital. Ananda Rao A, U R R , Gosavi S, et al. (November 20, 2020) Dengue Fever: Prognostic Insights From a Complete Blood Count. Cureus 12(11): e11594. DOI 10.7759/cureus.11594

20. TREATMENTS TRIED Steroids IVIG Activated factor VII Pentoxifylline Statins Chloroquine Balapiravir [ Polymerase inhibitor ]

21. VACCINES: Dengvaxia  — In 2018 the Dengvaxia vaccine by WHO for persons aged 9 to 45 years with confirmed previous dengue infection who live in endemic areas. Formulation of four chimeric yellow fever and 17D-dengue vaccine viruses. TAK-003  — TAK-003 is tetravalent vaccine based on an attenuated laboratory-derived DENV-2 virus.

22. CHOICE OF IV FLUIDS CRYSTALLOIDS 0.9% saline is a suitable option for initial fluid resuscitation, but repeated large volumes of 0.9% saline may lead to hyperchloremic acidosis. Hyperchloremic acidosis may aggravate or be confused with lactic acidosis from prolonged shock. RINGER LACTATE It may not be suitable for resuscitation of patients with severe hyponatremia. However, it is a suitable solution after 0.9% saline has been given and the patient’s serum chloride level has exceeded the normal range. Ringer’s lactate should probably be avoided in liver failure a COLLOIDS Colloids may be the preferred choice if the BP has to be restored urgently, i.e. in those with pulse pressure less than 10 mmHg. Colloids have been shown to restore the cardiac index and reduce the level of haematocrit faster than crystalloids in patients with intractable shock. Impair coagulation and cause allergic reactions.

23. DISCHARGE CRITERIA NO FEVER FOR 24 HRS PLATELET COUNT >50000 3 DAYS AFTER RECOVERY FROM SHOCK GOOD CLINICAL IMPROVEMENT NORMAL VITALS GOOD APPETITE URINE OUTPUT STABLE HEMATOCRIT WITHOUT IV FLUIDS

24. DIFFERENTIALS:

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