Dengue

Introduction• Potentially fatal disease caused by Dengue virus

transmitted by bite of infected Aedes aegypti

• Incubation period is 5-6 days.

• First confirmed case report by Benjamin Rush.

• Viral etiology and transmission by mosquitoes discovered by Sir John Burton Cleland.

• Pandemic of dengue began in Southeast Asia after World War II and spread around the globe since then.

History

Burden of Disease Worldwide

Burden of Disease in India

Source - http://nvbdcp.gov.in/dengue5.html

Magnitude of problem in India

Source - http://nvbdcp.gov.in/dengue6.html

In year 2009• Max no of cases were reported by Gujrat followed by

Maharashtra• Max no of deaths occurred in Maharashtra followed by

RajasthanIn this year till June 2010

• Max no of cases were reported by Kerela (1338) followed by Gujrat (544)

• Max no of deaths occurred in Kerela (4) followed by Maharashtra (2)

Symptoms and signs

• Fever

• Headache,

• Retro-orbital pain

• Myalgia

• Arthralgia

• Rash

• Haemorrhagic manifestations

• Thrombocytopenia (<100,000 cells per cumm)

DiagnosisDengue fever

Acute febrile illness of 2-7 days with two or more of the following

• Headache,

• retro-orbital pain

• Myalgia

• Arthralgia

• rash

• Haemorrhagic manifestations.

Dengue Haemorrhagic FeverA confirmed case of dengue

PLUSHaemorrhagic tendencies

• positive tourniquet test• Petechiae/Ecchymoses• bleeding from mucosa,GIT,

nasal bleeding or other sites• haematemesis or melaena

PLUSThrombocytopenia

PLUSEvidence ofplasma leakage due to increased vascular permeability.

Dengue Shock SyndromeDHF plusevidence of circulatory failurerapid and weak pulsenarrow pulse pressure (<20 mm Hg) or hypotension forage, cold and clammy skin and restlessness

TreatmentDengue Fever

Mainly symptomatic and supportive

• Bed rest.

• Cold sponging.

• Antipyretics-Paracetamol is preferable

• Oral fluid and electrolyte therapy in patients with

excessive sweating or vomiting.Dengue Haemorrhagic Fever

Treatment is same as above except:

• Need hospitalization

• IV fluid therapy if rise in haemoconcentration

• Observed for signs of shock

Dengue Shock Syndrome• Fresh whole blood in volumes of 10ml/kg/hour

• Oxygen therapy

Chikunguniya• Debilitating non-fatal illness caused

by Chikunguniya virus transmitted by bite of infected Aedes aegypti.

• Human beings are major reservoir.

History• Epidemic in 2006 after about three

decades• There were 1.39 million cases• There is no attributed deaths to

chikunguniya• During 2008 95,091 cases were

reported.• It was not part of NVBDCP till 2006

but after outbreak it was added to the programme

Sign and symptoms

It presents same as dengue except• Haemorrhagic

manifestations are rare• Shock is not observed

Diagnosis and Management

Diagnosis

• IgM ELISA

Management

• Bed rest.

• Cold sponging.

• Antipyretics-Paracetamol is preferable

• Oral fluid and electrolyte therapy in patients with excessive sweating or vomiting.

GOI initiatives for Dengue and Chikunguniya

1. National guidelines for clinical management of Dengue Fever, Dengue Hammorragic Fever, Dengue Shock Syndrome.

2. Long Term Action Plan for Prevention and Control of Dengue and chikunguniya.

3. Established 110 Sentinel Surveillance Hospital and all these are linked with 13 Apex Referral Laboratories.

4. To maintain the uniformity and standard of diagnostics.

5. Diagnosis of Dengue and Chikungunya is provided to the community at free of cost.

6. Since 2007, every year in the 1st quarter Directorate of NVBDCP prepare the tentative allocation of test kits.

7. Kits are supplied by NIV.

8. Buffer stocks maintainance.

9. State wise allocation of Dengue and Chikungunya test kits.

10.Ensuring the diagnostic facility and availability of kits is the responsibility of the respective State Programme Officers, NVBDCP.

Long Term Action Plan

The long term strategies for prevention and control of DF/DHF/DSS and Chikungunya in India is three-pronged and is as follows:

• Early Case reporting and management

• Integrated vector management (for transmission risk reduction)

• Supporting Interventions

Case Reporting and ManagementCase reporting• Fever alert surveillance

• Sentinel surveillance sites with lab support

• Strengthening of referral services

• Involving private sector

Case management• Case management

• Epidemic preparedness and rapid response

Integrated Vector

Management

Vector Surveillance

Anti-adult measures

Anti-larval measures

Vector Surveillance• Larval surveillance

• House Index = No of houses infected X 100 No of houses inspected

• Container Index = No of positive containers X 100

No of containers inspected

• Breteau Index = No of positive containers X 100 No of houses inspected

• Pupae Index = No of pupae X 100 No of houses inspected

• Adult surveys• Landing/Biting collection• Resting collection• Oviposition traps

Anti-larval measures• Source reduction• Chemical larvicide

• Temephos• Biological control

• Larvivorous fish• Bacillus thuringiensis serotype H-14 (Bt H-14)

• Environmental management• Environmental modification• Environmental manipulation• Changes in human habitations

Anti-adult measures• Indoor spraying

• Pyrethrum• Fogging

• Malathion• Personal protection measures

• Protective clothing• Repellents

• Insecticide treated bed nets limited role

Supporting Interventions• Capacity building

• BCC

• Legislative Measures• Model civic byelaws• Building Construction Regulation Act• Environmental Health Act• Health Impact Assessments

• Health education for community mobilization and inter-sectoral convergence• At Household Level• At Community Level• At Institutional Level

• Live attenuated vaccines• The Walter Reed US Army Institute of

Research (WRAIR) developed a tetravalent live attenuated vaccine.

• It is licensed to GSK, which is carrying Phase II trials.

• Live chimeric virus vaccines• The DEN-YF chimeras were developed by

Acambis and licensed to Sanofi Pasteur.• A Phase II trial is taking place in the USA

and Latin America and a Phase IIb pediatric trial has been launched by Sanofi Pasteur in early 2009 in Thailand.

• Live recombinant, DNA and subunit vaccines• A subunit dengue vaccine has been

developed by Hawaii Biotech Inc.• Clinical trials are envisaged in the near

future.

Vaccines

There are three types of vaccines

It is aimed to develop dengue vaccine by 2012