dengue.pptx

COMMUNICABLE DISEASE

1. D E N G U E

2. Learning Objectives Epidemiological Triad Classification Management

3. 1.Introduction AR BO

4. 2. PROBLEM STATEMENT GLOBAL SEAR INDIA

5. Distribution   Endemic in more than 1 41 tropical and subtropical countries Pandemic began in South East Asia after WW II with subsequent global spread  Several epidemics since 1980s  Distribution is comparable to malaria

6. Epidemiology In India first outbreak of dengue was recorded in 1812 A double peak hemorrhagic fever epidemic occurred in India for the first time in Calcutta between July 1963 & March 1964 In New Delhi, outbreaks of dengue fever reported in 1967,1970,1982, &1996

7. Burden of disease in S.E. Asia CATEGORY-A (INDONESIA,MYANMAR & THAILAND) (INDIA,BANGALADESH,MALDIVES & SRILANKA) CATEGORY- B (BHUTAN, NEPAL) CTEGORY- C (DPR KOREA)

8. Dengue Endemic Areas (1996 to 201 5 = 2 5 States/UTs) Risk factors: C o n s t r u c t i on activities • W a t e r s t o r a ge practice P o pula ti on movement Heavy rainfall • Vector abundance

9. Dengue Fever Dengue endemic in 2 8+ 8 States/UTs, upsurge observed in 2010 & till date 2023 States reported higher numbers of cases in 2010 (as on Dec 31)  Dengue being reported from newer area s (A ssam, Meghalaya, Chhattisgarh, Jharkhand, Manipur, Nagalan d , Uttarakhand ,A&N Islands)

10. 3.Epidemiological triad

11. A. AGENT FACTORS The dengue viruses are the members of the genus flavivirus. These small (50nm)viruses contain single stranded RNA. There are four virus serotypes, which are designated as DEN V -1 , DEN V -2 , DEN V -3 and DEN V -4 . Although all four serotypes are antigenicaly similar, they are different enough to elicit cross-protection only for a few months after infection by any one of them. Infection with any one serotype confers lifelong immunity to the virus serotype. Man and mosquito are reservoirs of infection. Transovarian transmission (infection carried over to next progeny of mosquitoes through eggs) has made the control more complicated. At present DEN1 and DEN2 serotyp es are widespread in India

12. B. VECTOR OF DENGUE Dengue is transmitted by the bite of female Aedes mosquito In India Ae. aegypti is the main vector in most urban areas; however, Ae albopictus is also found as vector in few areas of southern India . The eggs can survive one year without water. At low temperature, however, it may take several weeks to emerge. Ae. aegypti has an average adult survival of fifteen days. During the rainy season, when survival is longer, the risk of virus transmission is greater. It is a day time feeder and can fly up to a limited distance of 400 m eters. To get one full blood meal the mosquito has to feed on several pe rsons, infecting all of them.

13. Few common and favoured breeding places/sites of Ae. aegypti

14. TRANSMISSION CYCLE OF DENGUE ##There is evidence that vertical transmission of dengue virus from infected female mosquitoes to the next generation occurs throu g h eggs, which is known as transovarian transmission.

15. The virus localizes and replicates in various target organs, for example, local lymph nodes and the liver. The virus is then released from these tissues and spreads through the blood to infect white blood cells and other lymphatic tissues. The virus is then released from these tissues and circulates in the blood. The mosquito ingests blood containing the virus. The virus replicates in the mosquito midgut, the ovaries, nerve tissue and fat body. It then escapes into the body cavity, and later infects the salivary glands. The virus replicates in the salivary glands and when the mosquito bites another human, the cycle continues. TRANSMISSION CYCLE OF DENGUE 1 . The v i r u s i s i n ocu l a t ed i nto h u m a n s w i t h t h e mosquito saliva.

16. C. HOST FACTORS HIGH RISK PERSONS: 1.Infants; 2.obesity; 3. pregnancy; 4. peptic ulcer disease; 5. women who are in menstruation or have abnormal bleeding; 6. haemolytic disease such as G—6PD, thalassaemia and other haemoglobinopathies ; 7. congenital heart disease; 8. chronic diseases such as diabetes mellitus, hypertension, asthma, ischaemic heart disease, chronic renal failure, liver cirrhosis; 9. patients on steroid or NSAID treatment.

17. 4.Clinical features

18. WHAT IS DEN GU E ? Dengue is a viral disease It is transmitted by the infective bite of female Aedes Aegypti mosquito Man develops disease after 5-6 days of being bitten by an infective mosquito It occurs in two forms: Dengue Fever and Dengue Haemorrhagic Fever(DHF) Dengue Fever is a severe, flu-like illness (Influenza) Dengue Haemorrhagic Fever (DHF) is a more severe form of disease, which may cause death Person suspected of having dengue fever or DHF mu s t see a doctor at once

19. T h er e a r e ac t u a lly f o u r d e n g u e c li n i cal syndromes: Undifferentiated fever; Classic dengue fever; Dengue hemorrhagic fever, or DHF; and Dengue shock syndrome, or DSS. D en g u e s ho c k s y n dr o m e is actu a lly a severe form of DHF. Dengue clinical syndrome

20. CLASSIS DENGUE       Acute febrile illness with headache, retro-orbital pain, myalgia, arthralgia “Break-bone fever” High fever 5-7 days Second fever for 1-2 days in 5% patients Followed by marked fatigue days to weeks Classic dengue 15-60% of infections  Nausea, vomiting, diarrhea (30%)  Macular or maculopapular rash (50%)  Respiratory symptoms: cough, sore throat (30%)

21. SIGNS & SYMPTOMS OF DENGUE FEVER Abrupt onset of high fever Severe frontal headache Pain behind the eyes which worsens with eye movement Muscle and joint pains • Loss of sense of taste and appetite Measles-like rash over chest and upper limbs Nausea and vomiting

22. Dengue Hemorrhagic Fever WHO classification of DHF  Thrombocytopenia (platelet count <100,000)  Fever 2-7 days  Hemorrhagic manifestations with a positive tourniquet test  Hemoconcentration or evidence of plasma leakage t r e a t e d  Usually occurs in secondary infections after actively or passively (maternal) acquired immunity to a different viral serotype  Only 2-4% of secondary infections result in severe disease  Mortality is 10-20% if untreated, but decreases to <1% if adequately  Plasma leakage may progress to dengue shock syndrome

23. SIGNS & SYMPTOMS OF DENGUE HAEMORRHAGIC FEVER AND SHOCK SYNDROM Symptoms similar to dengue fever Severe continuous stomach pains Skin becomes pale, cold or clammy Bleeding from nose, mouth & gums and skin rashes Frequent vomiting with or without blood Sleepiness and restlessness Patient feels thirsty and mouth becomes dry Rapid weak pulse Difficulty in breathing

24. LABORATORY DIAGNOSIS OF DENGUE Haemagglutination inhibition (HI) test Compliment Fixation Test (CFT) Neutralization test (NT) IgM-capture Enzyme-Linked Immunosorbent Assay (MAC-ELISA) ndvbcp recommended IgG-ELISA Rapid Diagnostic tests (N S 1)

25. 5. Management of Dengue Fever (DF) No specific therapy, management of Dengue fever is symptomatic and supportive Bed rest is advisable during the acute phase. Use cold sponging to keep temperature below 39o C. Antipyretics may be used to lower the body temperature. Aspirin/NSAID like Ibuprofen etc should be avoided since it may cause gastritis, vomiting, acidosis and platelet disfunction. Paracetamol is preferable in the doses as follows: 1-2 years: 60 -120 mg/doses 3-6 years: 120 mg/dose 7-12 years: 240 mg/dose Adult : 500mg/dose In children the dose is calculated as per 10mg/KG Body Weight per dose which can be repeated at the interval of 6hrs Oral fluid and electrolyte therapy are recommended for patients with excessive sweating or vomiting. Patients should be monitored in DHF endemic area until they become afebrile for one day without the use of antipyretics and after platelet and haematocrit determinations are stable, platelet count is >50,000/ cumm.

26. Crystalloids- Indication of Blood Transfusion: PCV:

27. Discharge criteria Absence of fever for at least 24 hours without the use of anti-pyretic drugs. Return of appetite. Visible clinical improvement. Good urine output. Minimum of 2-3 days after recovery from shock. No respiratory distress from pleural effusion or ascites . Platelet count > 50,000/cu.mm.

28. Vaccination      No current dengue vaccine Estimated availability in 5-10 years Vaccine development is problematic as the vaccine must provide immunity to all 4 serotypes Lack of dengue animal model Live attenuated tetravalent vaccines under phase 2 t r i a l s  New approaches include infectious clone DNA and naked DNA vaccines

29. Prevention P e r s o n a l:     clothing to reduce exposed skin insect repellent especially in early morning, late afternoon. Bed netting important mosquito repellants(pyrethroid based) coils, sanitation measures Environmental:  reduced vector breeding sites  solid waste management  public education  empty water containers and cut weed/t a l l grass

30. Prevention Biological:   Target larval stage of Aedes in large water storage containers Larvivorous fish (Gambusia), endotoxin producing bacteria (Bacillus), copepod crustaceans (mesocyclops) Chemical: Thermal fogging-malathion,pyrethrum  Insecticide treatment of water containers  Space spraying (thermal fogs)  Indoor space spraying(2% pyrethrum), organophosphorus compounds

31. Although the goal of disease control is to prevent epidemic transmission, if an epidemic does occur, ways to minimize its impact include: Teaching the medical community how to diagnose and manage dengue and dengue hemorrhagic fever (DHF), so they are better prepared to effectively manage and treat large numbers of cases. Mortality from DHF will thus be minimized. Implementing an emergency contingency plan to anticipate the logistical issues of hospitalizing large numbers of patients and to outline measures for community-wide vector control activities. Such plans should be prepared with the participation of all parties and agencies involved, and should be ready for implementation prior to the emergence of an epidemic. Educating the general public to encourage a n d enable them to carry out vector control in their homes and neighborhoods. Social Issues

32. Public Health  Major and escalating global public health problem  Global demographic changes: urbanization and population growth with substandard housing, water, and waster management systems  Deteriorating public health infrastructure with limited resources resulting in “crisis management” not prevention  Increased travel  Lack of effective mosquito control

33. THANK YOU