DENGUE-A GLOBAL CONCERN

MODERATOR DR. RAUF –UR-RASHID KAUL ADDITIONAL PROFESSOR S.R. INCHARGE DR. FEROZ AH. WANI SENIOR RESIDENT

PRESENTED BY DR. UROOSA FAROOQ POST GRADUATE STUDENT

Table of contents1. INTRODUCTION

2. HISTORY3. MAGNITUDE :GLOBALLY , SEAR AND INDIA4. EPIDEMIOLOGY5. MANIFESTATIONS OF DENGUE VIRUS INFECTION6. WHO CLASSIFICATION OF DENGUE7. CLINICAL SIGN/SYMPTOMS AND TREATMENT8. GLOBAL STRATEGY FOR PREVENTION AND CONTROL

2012-2020

Introduction - What is Dengue?

• Dengue is a mosquito-borne, viral infection.• The infection causes flu-like

illness, and occasionally develops into a potentially lethal complication called severe dengue.• Common name of the disease is

‘break-bone fever’

(WHO 2011)

History

• The first epidemic of dengue was recorded in 1635 in the French West Indies, although a disease outbreak compatible with dengue had been reported in China as early as 992 AD.

• Epidemics of an illness resembling dengue occurred in 1779, 1780 in three continents-Asia, Africa and North America.• First epidemic of DHF occurred in Manila,

Philippines 1950.• In India dengue virus was first isolated in

Calcutta in 1945.• Epidemic of DHF first occurred in Calcutta

in 1963. (WHO 2011)

MAGNITUDE

GLOBALLY

SEAR

INDIA

( W H O 2 0 1 1 )

GLOBALLY:

The global incidence of dengue has grown dramatically in recent decades.

–The incidence of dengue has increased 30-fold over the last 50 years.

–Up to 50-100 million infections are now estimated to occur annually in

over 100 (only 9 counties in 1955) endemic countries.

–Almost half of the world’s population at risk.

(Who2011)

Average number of dengue and severe dengue cases reported to WHO annuallyin 1955–2007 and number of cases reported in recent years, 2008–2010

SEAR:• Some 2.5 billion people – two fifths of the world's

population in tropical and subtropical countries – are at risk.• An estimated 50 million dengue infections occur

worldwide annually.• About 500 000 people with DHF require

hospitalization each year. A very large proportion (approximately 90%) of them are children aged less than five years, and about 2.5% of those affected die. ( W H O 2 0 1 1 )

Variable endemicity for DF/DHF in countries of the SEA Region

Category A

• Bangladesh, India, Indonesia, Maldives, Myanmar, SriLanka, Thailand and Timor-Leste

• Major public health problem.• Leading cause of hospitalization and death among children.• Hyperendemicity with all four serotypes circulating in urban • areas.• Spreading to rural areas.

Category B

• Bhutan, Nepal• Endemicity uncertain.• Bhutan: First outbreak reported in 2004.• Nepal: Reported first indigenous dengue case in 2004.

Category C

• DPR Korea• No evidence of endemicity.

(Who2011)

STATE CASES DEATHSAndhra pradesh 990 1

Assam 4526 2Delhi 5574 6

Chandigarh 7132 6Goa 1255 9

Gujarat 6170 15Haryana 1751 4

Karnataka 6408 12Kerela 7911 25

Maharashtra 5432 48Punjab 4114 11

Rajhasthan 3160 8Tamil nadu 6122 0

Uttar pradesh 1409 5West bengal 5920 6

TOTAL 74168 168

( N A T I O N A L H E A L T H P R O F I L E 2 0 1 3 )

INDIA

What causes dengue?

Environment

Mosquito

Virus

VIRUS The cause

MOSQUITO transmitter of disease

ENVIRONMENT Helps transmission

Dengue Virus

1.Causes dengue and dengue hemorrhagic fever 2. It is an arbovirus 3.Transmitted by mosquitoes 4.Composed of single-stranded RNA 5.Has 4 serotypes (DEN-1, 2, 3, 4)

• Each serotype provides specific lifetime immunity, and short-term cross-immunity

• All serotypes can cause severe and fatal disease

• Genetic variation within serotypes

• Some genetic variants within each serotype appear to be more virulent or have greater epidemic potential

AEDES AEGYPTI

• Dengue transmitted by infected female mosquito

• Primarily a daytime feeder• Lives around human habitation• Lays eggs and produces larvae preferentially

in artificial containers

The most common epidemic vector of dengue in the world is the Aedes aegypti mosquito. It can be identified by the white bands or scale patterns on its legs and thorax.

AEDES ALBOPICTUS: is second most important vector of dengue

• AEDES AEGYPTI:• HIGHLY DOMESTICATED

• NERVOUS FEEDER

• DISCORDANT SPECIES

• AEDES ALBOPICTUS:• BREEDS IN PEREPHERAL

AREAS OF URBAN CITIES• AGGRESSIVE FEEDER

• CONCORDANT SPECIES

Egg

Larva

Pupa

Adult mosquito (7-12 days)

Life Cycle of a

Mosquito

ENVIRONMENTAL CONDITIONS HELP IN TRANSMISION

• Dengue transmission usually occurs during the rainy season when the temperature and humidity are conducive for build-up of the vector population breeding in secondary habitats as well as for longer mosquito survival.• In arid zones where rainfall is scanty during the

dry season, high vector population builds up in man-made storage containers. THEY GROW WELL AT A TEMP. OF 16 TO 30 DEGREE AND HUMIDITY OF 60-80%

1. The virus is inoculated into humans with the mosquito saliva.

2. The virus localizes and replicates in various target organs, for example, local lymph nodes and the liver.

3. The virus is then released from these tissues and spreads through the blood to infect white blood cells and other lymphatic tissues.

4. The virus is then released from these tissues and circulates in the blood.

5. The mosquito ingests blood containing the virus.

6. 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.

7. The virus replicates in the salivary glands and when the mosquito bites another human, the cycle continues.

HIGH RISK GROUP INCLUDES:• 1 INFANTS AND ELDERLY• 2 OBESITY• 3 PREGNANCY• 4 PEPTIC ULCER DISEASE• 5 MENSTRUATING WOMEN• 6 HAEMOLYTIC DISEASE• 7 CHD• 8 DIABETES, RENAL FAILURE, LIVER CIRRHOSIS AND

ASTHMA• 9 PATIENTS ON STEROIDS OR NSAID TREATMENT

Manifestation of dengue virus infection

Manifestation of dengue virus infection

Asymptomatic Symptomatic

Undifferentiated Dengue fever

Without hemorrh

age

With hemorrh

age

Dengue hemorrhagic

fever

No shock DSS

WHO CLASSIFICATION AND GRADING OF SEVERITY OF DENGUE INFECTION

Clinical characteristics

CLASSICAL

DENGUE FEVER

Fever

Headache

Arthralgia

MyalgiaRash

Retro Orbital

Pain

Hemorrhagic

manifestations

Hemorrhagic

Manifestations

Skin hemorrh

age Increased

menstrual flow

Hematuria

Gastrointestinal

bleeding

Nasal bleedi

ng

Gingival

bleeding

Dan

ger

Sign

s in

D

engu

e H

emor

rhag

ic

Feve

r

Abdominal pain

Persistent vomiting Abrupt change from

fever to hypothermia, with

sweating and prostration

Restlessness or somnolence

Signs and Symptoms of Encephalitis/Encephalopathy Associated with Acute Dengue Infection

• Decreased level of consciousness: lethargy, confusion, coma

• Seizures • Nuchal rigidity • Paresis

LABORATORY DIAGNOSIS:• 1 VIRUS ISOLATION WITHIN FIRST 6 DAYS• 2 VIRAL NUCLEIC ACID DETECTION BY RT-PCR• 3 IMMUNOLOGICAL : NT, CFT, HIA AND IgM/IgG RATIO• 4 VIRAL ANTIGEN DETECTION BY ELISA• 5 RDT FOR IgM AND IgG ANTIBODY DETECTION• 6 PLATELET COUNT AND HAEMATOCRIT MUST BE

CLOSLY • MONITORED

Treatment of Dengue fever:• Fluids• Rest• Antipyretics (avoid aspirin and non-

steroidal anti-inflammatory drugs)• Monitor blood pressure, hematocrit,

platelet count, level of consciousness

Rx of DHF I & IIHemorrhagic tendencies ,

thrombocytopenia Initiate IV therapy-6ml/kg/hr crystalloid solution for 1-2

hrsImprovement IV therapy by

crystalloid successively reducing frm

6 to 3 ml/kg/hr

Further improvement

Discontinue IV after 24hrs

NO IMPROVEMENTIncrease IV-10 ml/kg/hr -2hrs

ImprovementReduce IV to 6 ml/kg/hr crystalloid with further reduction to 3ml/kg/hr

discontinue after 24-48hrs

No improvement Unstable vital

signs

Hematocrit risesIV colloid dextran

10ml/kg/hr duration 1hrImprovement

IV therapy by crystalloid successively reducing

the flow frm 10 to 6 and 6 to 3 ml/kg/hr

discontinue after 24-48hrs

Hematocrit fallsBlood transfusion

10ml/kg/hr duration 1hr

Rx of DHF III & IV UNSTABLE VITAL SIGNS

URINE OUT PUT FALLS, SIGNS OF SHOCK

IMMEDIATE RAPID VOLUME REPLACEMENT: INITIATE IV THERAPY 10-20ML/KG/HR

CRYSTALLOID SOLN FOR 1HR

IMPROVEMENTIV THERAPY BY CRYSTALLOID SUCCESSIVELY

REDUCING FROM 20 to 10, 10 to 6 AND 6 to

3

FURTHER IMPROVEMENT

DISCONTINUE IV AFTER 24HRS

NO IMPROVEMENTOXYGEN

HAEMATOCRIT RISESIV COLLOID DEXTRAN

OR PLASMA 10ML/KG/HR AS INTRAVENOUS

BOLUS(REPEAT IF NECESSARY) IMPROVEMENT

IV THERAPY BY CRYSTALLOID

SUCCESSIVELY REDUCING THE FLOW FROM 10 to 6

and 6 to 3ml/kg/hrDISCONTINUE AFTER 24-

48HRS

HAEMATOCRIT FALLSBLOOD

TRANSFUSION 10ML/KG/HR

Dengue vaccine

• No licensed vaccine at present• Recently Tetravalent Dengue Vaccine phase 3

trial completed in Asia.

Prevention & Control

Global strategy for dengue prevention & control 2012- 20

• To reduce dengue mortality by at least 50% by 2020• To reduce dengue morbidity by at least 25

% by 2020• To estimate the true burden of disease by

2015( W H O 2 0 1 2 )

(WHO 2013)

National Vector Born Disease Control Program

• Surveillance• Case management• Vector management• Outbreak response• Behavioral change communication• Inter-sectoral coordination• Monitoring & supervision

Disease Surveillance:Epidemiological and Entomological

Epidemiological surveillance Epidemiological surveillance is an ongoing systematic collection, recording, analysis, interpretation and dissemination of data for initiating suitable public health interventions for prevention and control.Objectives of surveillance The objectives of public health surveillance applicable to dengue are to detect epidemics early for timely intervention; • measure the disease burden; • monitor trends in the distribution and spread of dengue over time; • assess the social and economic impact of dengue on the affected community; • evaluate the effectiveness of prevention and control programmes; and • facilitate planning and resource allocation based on the lessons learnt from programme evaluation.

Components of a surveillance system

The surveillance system comprises passive surveillance, active surveillance and event-based surveillance.All three surveillance components require a good public health laboratory to provide diagnostic support in virology, bacteriology and parasitology . The laboratory need not be able to test for all agents but should know where to refer specimens for testing, for example, select samples for the WHO collaborating centers for reference and research. Individually, the three components are not sensitive enough to provide effective early warning. But when used collectively they can often accurately predict epidemic activity.

Indices used to assess the levels of Ae. aegypti infestations

Pupal Index: Number of pupae per house Pupal Index (PI) = Number of pupae/Number of houses inspected X 100 In order to compare the relative importance of larval habitats, the Pupal Index can be disaggregated by “useful”, “non-essential” and “natural” containers, or by specific habitat types such as tyres , flower vases, drums, clay pots, etc.

ANTI LARVAL MEASURES

•1.ENVIRONMENTAL CONTROL•2.CHEMICAL CONTROL•3.BIOLOGICAL CONTROL

ANTI ADULT MEASURES

•1.RESIDUAL SPRAY•2.SPACE SPRAY•3.GENETIC CONTROL

PROTECTION AGAINST MOSQUITO BITES

•1.MOSQUITO NETS•2.SECREENING•3.REPELLENTS

•Don’t allow water to remain stagnant in and around your house. Fill the ditches.

•Clean the blocked drains.

•Empty the room air coolers and flower vases completely at least once in seven days and then refill them.

•Tray below the fridge also to be cleaned.

Anti-larval measures-Environmental Control

• Dispose off old containers tins and tyres etc. Properly.

•Keep the water tanks and water containers tightly covered so that the mosquitoes can not enter them and start breeding.

•Keep the surroundings of your house clean.•Don’t litter garbage.•Don’t allow wild herbs etc.to grow around your house.

Do inform and take help from your local health Centre ,panchayat or municipality incase you notice abnormal density of mosquitoes or too many cases of fever are occurring in your area.

Anti-larval measures-chemical control

•TEMEPHOS an insecticide can be used to kill larva in water. or•Put about two tablespoons (30 ml) of petrol or kerosene oil into 100 liters of water.

Anti-larval measures-Biological control•Some types of small fish (Gambusia, Lebister) whicheat mosquito larva, can be obtained from local administrative bodies.

•These fish can be used in burrow pits , sewage oxidation pounds, ornamental pounds, Cisterns and farm ponds.

ANTI-ADULT MEASURES-Residual spray & Space spray•Don’tforgettospraybehindthephoto-frames,curtains,calendars,cornersofhouseandstores.•Useinsecticidalspraysinallareaswithinthehouseat-leastonceaweek.

Don’t turn away spray workers whenever they come to spray your house.

Protection Against Mosquito Bites

•Wear clothes which cover the body as much as possible.

•Use Wire mesh on windows and doors.

•Usemosquitorepellentsprays,creams,coils,matsorliquidstodriveaway/kill the mosquitoes..

It is advisable to always keep the patient of Dengue fever under a mosquito net in the first 5-6 days of the illness so that mosquitoes don’t have an access to him/her . The characteristics of net are it should be rectangular, the size of opening should not exceed 0.0475 inch and the no. of holes in 1sq inch is usually 150.

RECENT OUTBREAK OF DENGUE IN INDIA

IN THE YEAR 2014 NEAR ABOUT TEN THOUSAND CASES WHERE REPORTED AND 37 DEATHS HAD OCCURRED.

WHILE IN YEAR 2015 THE CASE LOAD UPTO NOVEMBER IS NINTEEN THOUSAND AND 41 DEATHS. AMOUNG THESE HIGHEST NO. OF CASES WHERE REPORTED FROM DELHI 1259 AND 25 DEATHS.

DENGUE FEVER CAN BE EASILY PREVENTED ITS YOUR ,MINE AND OUR RESPONSIBILITY

Thank You