Agent factors of dengue- topic for 15 min pedagogy

It is short compact topic for pedagogy for community medicine PG students

1. Pedagogy 1 Dr. Shaikh B .M . By

2. Agent Factors of Dengue 2

3. Agent Factor of Dengue POINTS TO BE Learnt ; Introduction Agent Vector Transmission 3

4. Agent Factors of Dengue Introduction : Dengue fever is self limiting viral fever if not severe form it dengue hemorrhagic fever / dengue shock syndrome. most rapidly spreading mosquito-borne viral disease in the world incidence : 30-fold increase increasing geographic expansion to new countries, and from urban to rural settings 50 million dengue infections annually India : presently 31 states endemic , first epidemic 1812 ,1963-64 kolkatta peak cases in post monsoon Still 11 th s eptember 2016 total 36110 cases, deaths 70 Highest west B engal 6650 cases and 24 deaths Maharashtra 2572 cases 2 deaths 4

5. Agent Factors of Dengue Agent Arbovirus , flavirus Single stranded RNA 50 nm diameter with multiple copies of 3 structural proteins ( membrane bilayer and single-stranded RNA) 5

6. Agent Factors of Dengue Agent 4 Serotypes DENV1 , DENV2 , DENV3 & DEN 4 All four associated for Dengue epidemics . India : DENV 1 ,DEN2 Predominant 6

7. Agent Factors of Dengue Agent IMMUNITY : One serotype infection provides lifelong Immunity for that serotype But Few months cross immunity for other Serotypes SECONDARY INFECTION IMMUNOLOGICAL CATASTROPHY : Secondary infection with different serotype leads to severe dengue i.e. DHF dengue hemorrhagic fever DSS dengue shock syndrome 7

8. Agent Factors of Dengue Pathogenesis of Secondary infection : First virus produced non neutralizing antibodies acts with second virus and this complex increases/ makes easy entry i nto monocytes This infected monocytes releases cytokines TF IL which triggers the vasoactive mechanism and coagulation resulting disseminated intravascular coagulation . Activated platelets utilized in DIC and also act on capillary endothelium . This leads to increased vascular permeability Bone marrow suppression by virus complexes Thrombocytopenia hemorrhage 8

9. Agent Factor of Dengue Reservoir : Man and mosquito It replicates in both and infect each other by mosquito bite . 9

10. Agent Factor of Dengue VECTOR Aedes mosquitoes A . aegypti A. albopictus A . polynesiensis Tropical and subtropical species Urban places and now in rural too Various life stages are found in BREEDING PLACES In India mostly aegypti but at some places albopictus (south india , south asia ) , polnesiensis australia pacific region Grey to dark body and wings , white stripes/spots on body and legs … tiger mosquito . 10

11. Agent Factor of Dengue VECTOR common breeding places of aedes mosquitos 11

12. Agent Factor of Dengue VECTOR common breeding places of aedes mosquitos 12

13. Agent Factor of Dengue VECTOR Life Cycle : 7-10 days 13

14. Agent Factor of Dengue VECTOR Life Cycle : 7-10 days 14

15. Agent Factor of Dengue VECTOR FEMALE aedes mosquito is restless feeder it bites multiple human to complete its feed . Its day biter. Indoor dweller . Can fly 0.5-1km , lives for 1 to 2 weeks Sex Differentiaton : 15

16. Agent Factor of Dengue 16 Difference between Anopheles , Aedes and Culex

17. Agent Factor of Dengue Mosquito bites infected human , virus gets in midgut from there ovary , nervous tissue ,fat cells and salivary glands ..replicates ..bites second human virus . In circulation , target organs replicates .. viraemia . Transovarian / vertical transmission : virus is transmitted from ovary to eggs and larvae ,next generation mosquito 17 Transmission

18. Agent Factor of Dengue RECAP … Introduction Agent Vector Transmission 18

19. Agent Factor of Dengue QUICK TEST 1. Which serotype of dengue virus is predominant in india ? DEN1 & DEN 2 2. One tim e infection of dengue virus provides life long immunity for that particular serotype . True or False True 3. Cross infection by different serotypes of dengue virus may cause …… .. Dengue Hemorrhagic fever / Dengue Shock SYNDROME 4. Name the stages of life cycle of aedes mosquito EGG .. LARVA … PUPA .. ADULT 5. Aedes mosquitoes breeds in dirty stagnant water mostly . True or false False 6. Can aedes mosquito transmit dengue virus to its next generation ? yes 19

20. Agent Factor of Dengue References K ..Park . Park`s Textbook Of Preventive and Social Medicine. 23rd edition , Bhanot jabalpur 2015 , Antropod -borne infections, page no.246. NVBCP , Dengue cases and deaths in country since 2010 , Ministry of public health and family welfare , govt of india . Date 11/9/2016 report http :// nvbdcp.gov.in/den-cd.html accessed on 18/9/2016. 3. WHO , National Institute Of communicable disease . Guidelines for control and prevention of dengue. Govt .of India ; 2006. 4. The   University of Florida  /  Institute of Food and Agricultural Sciences .   Asian tiger mosquito Featured Creatures  website 20

21. THANKS 21