Dengue - SEMINAR BY DR SHAMIN EABENSON -

DENGUE - SEMINAR BY DR SHAMIN EABENSON

1. DENGUE PRESENTER: DR. SHAMIN . E MODERATOR: DR. SANDEEP. Y

2. CONTENTS History Introduction Disease burden Epidemiological factors Clinical features Lab diagnosis Treatment Indices Aedes aegypti Vector control measures National vector-borne disease control program References 1

3. First historical record of a case of dengue fever is in a Chinese medical encyclopedia (266 -420 AD) where it is referred to as a "water poison" associated with flying insects. Marked spread of dengue during and after the Second World War. As novel serotypes were introduced to regions already endemic with dengue, outbreaks of severe disease followed. The severe hemorrhagic form of the disease was first reported in the Philippines in 1953. HISTORY 1

4. HISTORY…….. In India dengue virus was isolated for the first time in 1945. The first evidence of occurrence of dengue fever was reported in 1956 from Vellore district in TN. The first Dengue hemorrhagic fever outbreak occurred in Calcutta in 1963. Dengue has continued to increase in prevalence during the 21st century, as the mosquito vector continues to expand its range. This is attributed partly to continuing urbanisation , and partly to the impact of a warmer climate. 1 1 1 2

5. INTRODUCTION Dengue is the most rapidly spreading mosquito borne viral disease of mankind. There has been a 30- fold increase in global incidence over the last five decades. It is a major public health concern throughout tropical and subtropical regions of the world. Almost half of the world’s population lives in countries where dengue is endemic. Dengue has been identified as one of the 17 neglected tropical diseases by World Health Organization (WHO). At present, except Ladakh all the States and Union Territories are reporting Dengue cases . 1 3

6. DISEASE BURDEN Global dengue surveillance [Internet]. Shinyapps.io. [cited 2024 Aug 28]. Available from: https://worldhealthorg.shinyapps.io/dengue_global/ 4

7. Outbreak Calender  :: Integrated Disease Surveillance Programme(IDSP), NCDC [Internet]. Gov.in. [cited 2024 Aug 28]. Available from: https://www.idsp.mohfw.gov.in/outbreak_d/Home.html 5

8. Ministry of Health, Family Welfare-Government of India. Dengue situation in India [Internet]. Gov.in. [cited 2024 Aug 28]. Available from: https://ncvbdc.mohfw.gov.in/index4.php?lang=1&level=0&linkid=431&lid=3715 6

9. Ministry of Health, Family Welfare-Government of India. Dengue situation in India [Internet]. Gov.in. [cited 2024 Aug 28]. Available from: https://ncvbdc.mohfw.gov.in/index4.php?lang=1&level=0&linkid=431&lid=3715 7

10. EPIDEMIOLOGICAL FACTORS AGENT FACTOR: A) AGENT : Belongs to group B arbovirus; genus Flavivirus of family - Flaviviridae a single-stranded virus and serotypes include 1, 2, 3 and 4 (DEN-1, DEN-2, DEN-3, and DEN-4). Although all 4 serotypes are antigenically similar, the cross protection is only for a short time. However, infection with one serotype confers life-long immunity to that serotype. Also the second infection later by another serotype increases the likelihood of suffering from DHF. DEN-1 and DEN-2 serotypes are widespread in India. 8

11. EPIDEMIOLOGICAL FACTORS…….. B) VECTOR : Aedes aegypti and Aedes albopictus are the most important vectors of dengue. They have high vectorial competency for dengue virus, i.e., high susceptibility to infecting virus, ability to replicate the virus and ability to transmit the virus to another host. AEDES AEGYPTI Highly domesticated, Strongly anthropophilic, Nervous feeder (it bites more than one host to complete one blood meal). Discordant species (it needs more than one feed for the completion of the gonotropic cycle). AEDES ALBOPICTUS Invades peripheral areas of urban cities. Aggressive feeder. Concordant species (it can complete its blood meal in one go on one person and also does not require a second blood meal for the completion of the gonotropic  cycle). 9

12. HOST FACTOR : Affects people from all walks of society but the poor, living in water scarcity and in inadequate waste disposal infrastructure provides a more favorable environment for breeding of Aedes aegypti. All ages and both sexes are susceptible to infection. Vulnerable population mainly includes infants, young children (less able than adults to compensate for capillary leakage) and young adults (more exposed to day biter). 10

13. ENVIRONMENTAL FACTOR : Temp: 16-30°C ; Relative humidity : 60-80%. Post-monsoon period when vector density is pretty high. Urban areas, having high population density, poor sanitation. Rural areas - friendly for mosquito breeding like storage water for cattle feeding and drinking. Breeding areas are found in and around households, construction sites and factories. Natural larval habitats are tree holes, leaf axils and coconut shells which are water receptacles. During hot and dry seasons, overhead tanks and ground water storage tanks are the usual breeding grounds. Some most common breeding sites are flower pots, coolers and unused tyres . 11

14. RESERVOIR OF INFECTION : Man and mosquito. TRANSMISSION OF DISEASE : The Aedes mosquito becomes infective by feeding on a patient from the day before onset to the 5th day (viraemia stage) of illness. After an extrinsic incubation period of 8 to 10 days, the mosquito becomes infective, and is able to transmit the infection. Once the mosquito becomes infective. it remains so for life. The genital tract of the mosquito gets infected and transovarian transmission of dengue virus occurs when virus enters fully developed eggs at the time of oviposition. INCUBATION PERIOD : Ranges for 5-6 days but may vary from 3 to 10 days. 12

15. 13 Sketchbubble.com. [cited 2024 Aug 29]. Available from: https://www.sketchbubble.com/en/presentation-dengue.html

16. 14 [cited 2024 Aug 28]. Available from: http://National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf

17. 15 KADRI A. IAPSMS Textbook of Community Medicine. 2nd ed. S.l. : JAYPEE BROTHERS MEDICAL P; 2024.

18. HIGH-RISK FACTORS FOR SEVERE DISEASE : • Infants and the elderly (age 65 years). • Obesity. • Pregnant women. • Female who have menstruation or abnormal vaginal bleeding. • Hemolytic diseases such as glucose-6-phosphatase dehydrogenase deficiency, thalassemia and other haemoglobinopathies. • Peptic ulcer disease. • Congenital heart disease. • Chronic diseases such as diabetes mellitus, hypertension, obstructive lung diseases cardiovascular diseases, chronic renal failure, and chronic liver disease. • Patients on long term steroid or NSAID treatment. 16

19. CLINICAL PHASES OF DENGUE INFECTION FEBRILE PHASE : High- grade fever (≥38.5°C) and may be biphasic. Lasts for 2-7 days, associated with headache, flushing, vomiting, myalgia, arthralgia, and macular rash. Rash is primarily maculopapular or rubelliform . It usually appears after the 3rd to 4th day of fever and occurs over the face, neck, chest, and abdomen. It usually fades away as the fever progresses. Bleeding manifestations may be observed in this phase, depending on the severity of the disease. Most of the cases may present with skin and mucosal bleeding (including gastrointestinal or vaginal) and less commonly with hematemesis, melena, heavy menstrual bleeding, epistaxis, or hematuria. 17

20. CLINICAL PHASES OF DENGUE INFECTION………….. CRITICAL PHASE (LEAKAGE PHASE): This phase usually begins after 3rd or 4th day of fever and may last about 24 to 48 hours. Characterized by vasculopathy and coagulopathy, leading to plasma leakage, excessive hemoconcentration, bleeding, eventually leading to shock and organ dysfunction. Warning symptoms and signs:- • Syncope or giddiness. • Enlarged Liver(>2cm). • Clinical fluid accumulation (ascites and pleural effusion). • Laboratory: Progressive increase in haematocrit with a rapid decrease in platelet count. • Persistent vomiting. • Abdominal pain and tenderness. • Lethargy and/or restlessness, sudden behavioral changes. • Bleeding manifestations like epistaxis, melena, haematemesis , excessive menstrual bleeding, and haematuria . 18

21. CONVALESCENT PHASE (RECOVERY PHASE): In this phase the extracellular fluid loss owing to capillary leakage returns to the circulatory system during the recovery phase, and signs and symptoms improve. Lasts for 2-3 days. The patient develops a convalescent rash characterized by confluent erythematous eruption with sparing areas of normal skin. It is often pruritic. CLINICAL PHASES OF DENGUE INFECTION………….. 19 Sketchbubble.com. [cited 2024 Aug 29]. Available from: https://www.sketchbubble.com/en/presentation-dengue.html

22. 20 [cited 2024 Aug 28]. Available from: http://National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf

23. LAB DIAGNOSIS ELISA based NS1 antigen tests : Dengue NS1 antigen, a highly conserved membrane glycoprotein, is abundant in the serum of patients. Detected upto 6 days from the onset of illness. IgM-capture enzyme-linked immunosorbent assay (MAC-ELISA) : detects the dengue-specific IgM antibodies. Detectable by day 5 of the illness; persist for 60 – 90 days. Isolation of Dengue Virus: Specimens used for this are acute phase serum, plasma or washed buffy coat from the patient, autopsy tissues from fatal cases (liver, spleen, lymph nodes, thymus) and mosquitoes collected in nature. Isolation of virus takes 7-10 days, hence not useful for starting the treatment. 21

24. IgG-ELISA: used to differentiate primary and secondary dengue infections. Other Serological Tests: Hemagglutination-Inhibition (HI), Complement fixation (CF), Neutralization test (NT). Rapid Diagnostic tests: A number of commercial Rapid Diagnostic Test (RDT) kits for anti-dengue IgM/IgG antibodies and NS1 antigen are available; gives results within 15 to 25 minutes. LAB DIAGNOSIS……. 22

25. COLLECTION OF SAMPLES: Day of onset of fever and day of sample collection should be mentioned to guide the laboratory for the type of test to be performed. (NS1 for samples collected from day 1 to 5 and IgM after 5 days). LABORATORY NETWORK : National Center for Vector Borne Diseases Control (NCVBDC), Government of India ( GoI ) has identified a network of laboratories for surveillance of Dengue fever cases across the country since 2007. Numbers were 110 in 2007 and 783 in 2022. Dengue IgM MAC ELISA test kits (1 Kit= 96 tests) are provided to the identified laboratories through the National Institute of Virology (NIV), Pune, since 2007. 23

26. 24 [cited 2024 Aug 28]. Available from: http://National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf

27. 25 [cited 2024 Aug 28]. Available from: http://National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf

28. 26 [cited 2024 Aug 28]. Available from: http://National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf

29. MANAGEMENT AT PHC LEVEL 27 [cited 2024 Aug 28]. Available from: http://Dengue/National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf

30. CRITERIA FOR DISCHARGING PATIENTS: • Absence of fever for at least 24 hours without the use of anti-pyretic agent. • Signs of recovery : return of appetite, visible clinical improvement, good urine output. • A minimum of 2–3 days have elapsed after recovery from shock. • No respiratory distress from pleural effusion/ascites. • Platelet count of more than 50,000/mm3. 28

31. INDICATIONS OF RED CELL TRANSFUSION: Blood loss - 10% or more of total blood volume. Refractory shock despite adequate fluid administration and declining haematocrit . Replacement volume should be 10 ml/kg body weight at a time and coagulogram should be done. If fluid overload is present packed cells are to be given. INDICATIONS OF PLATELET TRANSFUSION: Prophylactic platelet not given even at < 20,000/cu.mm. Prophylactic platelet transfusion is given at < 10,000/cu.mm. Prolonged shock; with coagulopathy and abnormal coagulogram . In case of systemic massive bleeding, platelet transfusion + red cell transfusion. 29

32. CONTAINER INDEX (CI): Number of water holding containers positive for Aedes aegypti larvae breeding per 100 wet containers. CI is mostly helpful in drawing vector control strategy. HOUSE INDEX (HI): Number of houses found positive for larvae of Aedes aegypti per 100 houses searched. BRETEAU INDEX (BI): Number of positive containers for Aedes aegypti per 100 houses inspected. INDICES Container Index X 100   Breteau Index X 100   House Index X 100   30

33. PUPA INDEX (PI): number of pupae per 100 houses inspected. ADULT LANDING: Number of mosquitoes landing on a bait in a given period of time. HUMAN BITING RATE: The average number of mosquito bites received by a human in a given unit of time. AEDES AEGYPTI INDEX : is the ratio expressed as percentage of the number of houses in a well-defined limited area in surrounding of which breeding places of aedes aegypti has been identified to the total number of houses surveyed in that area. House index <5 % and or Breteau index <20 indicate: Low larval index. House index >5% and or Breteau index >20: indicate: High larval index. Pupae Index X 100   31

34. LIFE CYCLE OF AEDES 32 [cited 2024 Aug 29]. Available from: http://Guidelines-Prevention-Control-of-Dengue-in-School-2019.pdf

35. EGGS : Black in color and of cigar shaped. Lays eggs singly. LARVA: Suspended in water with head downwards. Much slower with snake like movement. Siphon tube is small and thick. Known as bottom feeder. AEDES AEGYPTI 33

36. PUPA Two small respiratory tubes or trumpets project from the upper surface of the thorax. Breathing trumpet is narrow with narrow opening. ADULT Wings are unspotted: There are white strips over the black body (tiger mosquito). Palpi are shorter than proboscis in female mosquito. It rests parallel to the surface. 34

37. BREEDING PLACE : Artificial collection of water - water in coolers, buckets, flowerpots, overhead tanks, discarded tins or tyres , etc. FLIGHT RANGE : 100m but it can fly up to 400m. FEEDING AND BITING HABIT :- Only female bites and mainly at daytime and highly anthropophilic. Preferred site of biting is below the knee. 35

38. VECTOR CONTROL MEASURES ANTI- LARVAL MEASURES: (a)Environmental Control: Source reduction: Elimination of mosquito breeding places. Filling of cesspools & open ditches, removal and disposal of sewage. Leveling & getting rid of water-holding containers such as discarded tins, empty pots, broken bottles, coconut shells, etc. Drainage of breeding places, and Water management ( e.g intermittent irrigation) & removal of aquatic plants or destruction by herbicides. Rendering the water unsuitable for breeding- changing salinity of the water. 36 [cited 2024 Aug 28]. Available from: http://Spotters%20in%20_Environment%20and%20Health_%20Mosquito%20control%20Measures_%20for%20CFM%20&%20MPH%20students.pdf .

39. (b) Chemical control : ( i ) Mineral Oils: (ii) Paris green/ Copper acetoarsenite : (iii) Synthetic insecticides: MOA: kill larvae & pupae by spreading over the water surface & forming a thin film that cuts off the air supply. The application rate is 40 to 90 liters per hectare once a week. Disadvantages: Renders water unfit for drinking & kill fishes. Emerald green, micro-crystalline powder, insoluble in water. MOA: Stomach poison. Kills mainly surface feeders. Applied as 2% dust prepared by 2 kg of Paris green & 98 kg of diluent (soapstone powder or soaked lime) in a 'rotary mixer’. Dose is 1 kg of actual paris green per hectare of water surface. It does not harm fishes, humans, or domestic animals. Fenthion, Chlorpyrifos, and Abate. MOA: organophosphorus poison Dosage: Abate 56-112 g/ha, Malathion 224-672 g/ha, Fenthion 22-112 g/ha, Chloropyrifos 11-16 g/ha. 37 [cited 2024 Aug 28]. Available from: http://Spotters%20in%20_Environment%20and%20Health_%20Mosquito%20control%20Measures_%20for%20CFM%20&%20MPH%20students.pdf .

40. (c) Biological control: Gambusia affinis & Lebister reticulatus (Barbados Millions) are fishes that feed readily on mosquito larvae. These can be used in burrow pits, sewage oxidation ponds, ornamental ponds, cisterns, and farm ponds. 2. ANTI- ADULT MEASURES: (a) Residual sprays: DDT is the insecticide of choice. In case of DDT resistance malathion, propoxur & lindane are recommended. Dosage: DDT 1-2 g/m2 for 6-12 months, Lindane 0.5 g/m2 for 3 months, Malathion 2 g/m2 for 3 months, OMS-33 2 g/m2 for 3 months. 38 [cited 2024 Aug 28]. Available from: http://Spotters%20in%20_Environment%20and%20Health_%20Mosquito%20control%20Measures_%20for%20CFM%20&%20MPH%20students.pdf .

41. (b) Space sprays: These formulations are sprayed into the atmosphere in the form of a mist or fog to kill insects. Pyrethrum extract: pyrethrin is a nerve poison. Dosage is 1 oz (0.1%) per 1000 C. ft. of space. Residual insecticides: fogging are malathion and fenitrothion. (c) Genetic control: Sterile male technique Cytoplasmic incompatibility Chromosomal translocation Sex distortion Gene replacement 39 [cited 2024 Aug 28]. Available from: http://Spotters%20in%20_Environment%20and%20Health_%20Mosquito%20control%20Measures_%20for%20CFM%20&%20MPH%20students.pdf .

42. 3. PROTECTION AGAINST MOSQUITO BITES: MOSQUITO NET SCREENING REPELLENTS Should be white to detect mosquitoes. The best pattern is a rectangular net. The size of openings in the net should not exceed 0.0475 inches in any diameter. The number of holes in one square inch is usually 150. Screening of buildings with copper & bronze gauze having 16 messes to the inch is recommended. The aperture should not be larger than 0.0475 inches. Used mainly for application on the skin. These are indalone , dimethyl phthalate, ethyl hexanediol, etc. The chief advantage is the short duration of protection. 40 [cited 2024 Aug 28]. Available from: http://Spotters%20in%20_Environment%20and%20Health_%20Mosquito%20control%20Measures_%20for%20CFM%20&%20MPH%20students.pdf .

43. NATIONAL VECTOR-BORNE DISEASE CONTROL PROGRAM (NVBDCP) NVBDCP is implemented in the State/UTs for prevention and control of vector borne disease namely Malaria, Filariasis, Kala-azar, JE, Dengue and Chikungunya. This program is under the Directorate General of Health Services, Ministry of Health and Family Welfare, Government of India. A) EARLY CASE REPORTING AND MANAGEMENT Done through fever alert surveillance where health workers at all levels are trained to report cases of fever directly to the District VBDC Officer. This is supplemented by a call center under Integrated Disease Surveillance Project (IDSP) to report outbreaks. 41

44. CASE DEFINITION: Probable DF/DHF : A case compatible with clinical description of dengue fever during outbreak OR non-ELISA based NSI antigen/IgM positive. Clinical description : Acute febrile illness of 2-7 days duration, with 2 or more of the following manifestations: Headache, retro-orbital pain, myalgia, arthralgia, rash, and hemorrhagic manifestations. Confirmed dengue fever : A case compatible with clinical description of dengue fever with at least one of the following: • Isolation of the dengue virus (virus culture positive) from serum, plasma, leukocytes. • Demonstration of IgM antibody titer by ELISA positive in single serum sample. • Demonstration of dengue virus antigen in serum sample by NS1-ELISA. • IgG seroconversion in paired sera after 2 weeks with four-fold increase of IgG titer. • Detection of viral nucleic acid by PCR. 42

45. B) INTEGRATED VECTOR MANAGEMENT: It includes entomological surveillance along with larval surveys, and vector control. Emergency vector control during outbreaks is done by immediate targeted source reduction program, along with periodic household spraying with pyrethrum and ultra-low volume (ULV) malathion fogging of the entire ward/village. C) SUPPORTIVE INTERVENTIONS: It includes capacity building and training of health personnel, behavior change communication for vector control, intersectoral collaboration and partnership between the health and non- health sectors-government, private and NGOs, and legislative support in the form of civic by-laws. 43

46. REFERENCES Park K. Park’s textbook of Preventive and Social Medicine. 27th ed. Jabalpur: M/S Banarsidas Bhanot ; 2023. KADRI A. IAPSMS Textbook of Community Medicine. 2nd ed. S.l. : JAYPEE BROTHERS MEDICAL P; 2024. Balwar R. Textbook of Community Medicine. 5th ed. Wolters Kluwer; 2023. [cited 2024 Aug 28]. Available from: http://National%20Guidelines%20for%20Clinical%20Management%20of%20Dengue%20Fever%202023.pdf [cited 2024 Aug 28]. Available from: http://Spotters%20in%20_Environment%20and%20Health_%20Mosquito%20control%20Measures_%20for%20CFM%20&%20MPH%20students.pdf . Global dengue surveillance [Internet]. Shinyapps.io. [cited 2024 Aug 28]. Available from: https://worldhealthorg.shinyapps.io/dengue_global/ Outbreak Calender  :: Integrated Disease Surveillance Programme(IDSP), NCDC [Internet]. Gov.in. [cited 2024 Aug 28]. Available from: https://www.idsp.mohfw.gov.in/outbreak_d/Home.html Ministry of Health, Family Welfare-Government of India. Dengue situation in India [Internet]. Gov.in. [cited 2024 Aug 28]. Available from: https://ncvbdc.mohfw.gov.in/index4.php?lang=1&level=0&linkid=431&lid=3715 [cited 2024 Aug 29]. Available from: http://Guidelines-Prevention-Control-of-Dengue-in-School-2019.pdf 44

47. THANK YOU

48. Karnataka sees 22 per cent rise in dengue cases this year  (newindianexpress.com)