WORLD HEALTH DAY-2014 THEME - “Vector Borne Diseases”

Small Bite , Big Threat

World Health Organization (WHO)

Dr Priya BansalAssistant Professor

Department of Community MedicineDayanand Medical College & Hospital,

Ludhiana

Why this theme was chosen

• 17% of all infectious diseases

• 1 million deaths annually.

• 2.5 billion people in over 100 countries are at risk

• Malaria causes more than 6,00,000 deaths every year glob

ally.

• Other VBDs diseases such as Chagas disease, leishmanias

is & schistosomiasis

Who are affected?• These diseases affect urban, peri-urban & rural communiti

es - Poor living conditions - Safe drinking water - Sanitation.

• Malnourished people are especially vulnerable.

Economic Effect

• Vector-borne diseases play a major role in economic downgrowth

• Countries with intensive malaria have income levels of only one third of those that do not have it

Definition

• Vector-borne disease (VBD) : an illness caus

ed by an infectious microorganism (pathogen)

that is transmitted to humans by a vector, usual

ly arthropods

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Common Vectors

– Mosquitoes (Aedes, Anopheles, Culex, Mansonia)– Fly (Sandfly, Housefly, Tsetse Fly, Black Fly )– Flea (Rat Flea, Sand Flea )– Ticks (Hard Tick & Soft Tick)– Lice / Bugs/ Mites/ Cyclops

Major Vector Borne Diseases in World

• Malaria

• Filaria

• Kala-azar

• Japanese Encephalitis

• Dengue / Dengue Hemorrhagic fevers

• Chikungunya

• Chagas Diseases (American Trypanosomiasis)

• Yellow Fever• Leishmaniases• Onchocerciasis (River

Blindness)• CCHF (Crimean Congo

Haemorrhagic Fever)• Lyme Disease• Tick Borne Encephalitis• Schistosomiasis

(Bilharzia)04/12/23

Major Vector Borne Diseases in India

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Malaria• Life-threatening disease

• Caused by plasmodium species

• Transmitted through bite of female anopheles

• Plasmodium - four parasite species

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Malaria- Burden

Globally-2012

• Approx 207 million cases & 6,27,000 deaths

• 97 countries- 3.4 billion people at ris

k

Malaria-Burden

India-2011• 1.31 million cases, inclu

ding 6,50,000 Pf cases & 463 deaths

• 27% of population resides in Malaria High Transmission areas

• 58% in Low Transmission areas

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PUNJAB

Year Cases

2011 2660

2012 1689

2013 1764

LUDHIANA

Year Cases

2011 381

2012 197

2013 210

Malaria-Burden

Malaria Kills More People than AIDS

• Malaria kills in one year ,what AIDS kills in 15 years

• For every death due to HIV/AIDS, there are about 50 deaths due to malaria

WHO are at High Risk?

• Young children

• Pregnant women

• People living with HIV

• Natural disasters

• Non-immune travellers movin

g into Endemic areas

Malaria

• Early diagnosis & treatment is key

• If left untreated, disease can lea

d to severe illness & death • Artemisinin -based combinati

on therapy (ACT)

Vaccine

• No commercially available vaccine

• Vaccine against P. Falciparum is currently under trial.

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Dengue fever

• Most rapidly spreading viral disease in the world

• In past 50 years, incidence has increased 30-fold

• Pattern changing from urban to rural settings

Dengue

• There are four known serotypes of dengue virus (DEN 1 to 4).

• Recovery from infection by one provides lifelong immunity

Dengue-Burden

Globally

• Estimated 5,00,000 people with severe dengue require hospitalization each year

• About 2.5% of those affected die

Dengue-Burden

Dengue-Burden

India-2011

• Endemic in 31 states/UTs.

• About 18059 cases were reported with 109 deaths.

• Case Fatality rate was 0.65%

• Highest Number of cases were reported from Punjab, followed by TamilNadu, Gujarat, Kerala & Andhra Pradesh.

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PUNJAB

Year Cases Deaths

2011 3921 33

2012 770 ----

2013 4117 -----

LUDHIANA

Year Cases Deaths

2011 1662 23

2012 269 2

2013 1033 7

Dengue-Burden

Dengue

• No effective antiviral medications exist

• No commercial vaccine available

Japanese Encephalitis

• Transmitted to humans through infected Culex mosquitoes.

Japanese Encephalitis

Japanese Encephalitis- Burden

Globally

• 50,000 cases &10,000 deaths every year

• Majority (85%) of cases occur in <15 years of age

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Distribution Of Japanese Encephalitis in IndiaDistribution Of Japanese Encephalitis in India // //

J E Cases And Deaths Reported in 2011 Case Death

U P 3490 579

Total 7838 1137

Japanese Encephalitis Endemic areas

Japanese Encephalitis

• No specific treatment

• Vaccine (SA 14-14-2) - most effective preventive measure

CHIKUNGUNYA

• Occurs in Africa, Asia & Indian subcontinent

• In recent decades, there

have been outbreaks of the disease in countries

Burden-Chikungunya• Earlier reported in 1965

with 3,00,000 cases in Kolkata & Chennai

• 2006- Reappeared in 16 states

• 17,472 cases were reported by the GOI in 2011

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CHIKUNGUNYA

• Shares same vectors, symptoms & geographical distribution as dengue, except for the presence of joint pains

• No specific treatment

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Prevention & Control

STRATEGIES

• Needs sound knowledge of the

Bionomics

Distribution

Seasonal prevalence

Vectorial capacity

Insecticide susceptibility status

Role of arthropods in disease transmission

" Integrated Approach"

Integrated Vector Management

• " the utilization of all appropriate technological & management techniques to bring about an effective degree of vector suppression in a cost effective manner"

• Best approach to strengthen vector control in a way that is compatible with national health systems

• Evidence-based decision-making

• Monitoring & Evaluation

• Advocacy & Social mobilization

• Intra & intersectoral Collaboration

• Capacity-building

• Legislation & Regulation

Key Elements of IVM

Methods of Control

Environmental Control

Chemical Control

Biological Control

Personal Protective measures

Genetic control

Methods of Control

Environment(Source reduction,Waste management)

HUMAN(PPM, Repellants)

Vector(Chemical Control, Biological Control,

Genetic Control)

Environmental Control• Eliminate their

breeding places

• Known as "source reduction"

• Results are generally permanent

Filling

Levelling & drainage of breeding places

Water management (intermittent irrigation)

Source Reduction

Chemical ControlOiling (diesel oil,fuel

oil, kerosene oil)

Paris green

Synthetic Insecticides (Fenthion, malathion, chlorpyrifos, abate)

Indoor residual spraying

• Most widely used method

• Effective way to reduce sandflies & bugs inside homes

• 80% of houses in targeted area need to be sprayed.

• Effective for 3–6 months, depending on the insecticide used & type of surface

Indoor residual spraying

Outdoor spraying• Spraying outer surface

s of - Domestic animal shel

ters, - Outdoor latrines & - Damp places

• Aerial spraying -- control mosquitoes during epidemics of dengue & yellow fever.

Biological Control

• Introduction of bacterial larvicides & larvivorous fish

• Target vector larvae without generating ecological impacts of chemical use

• Regular monitoring & restocking is important

GAMBUSIA FISHES

Genetic Control• "Use of any treatment

that reduce the reproductive potential by replacing the hereditary material"

Sterile male technique Hybrid male technique Sex distortion Gene replacement

Personal protection• First line of defence

• Prevent vectors from biting & feeding on host

• Acheived by wearing long sleeved, light-coloured shirts, trousers, socks, shoes & by the use of repellents like Benzyl benzoate, DEET (N,N-diethyl-m-tolumide)

Long-lasting Insecticidal Nets• Most efficient & cost-ef

fective method

• WHO recommends that everyone at risk of malaria sleeps under a net

Waste Management• Empty tins, plastic bot

tles, unused drums, coconut shells & used car tyres can serve as important breeding sites

Housing Modification• Door & window screens

• Plaster walls & concrete floors in good condition

• Cracks & entry points sealed up

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Challenges in the Control ofVector-Borne Diseases

Challenges in the Control ofVector-Borne Diseases

Emerging insecticide resistance Major threat Widespread use of synthetic insecticides

Lack of expertise in vector control Expertise of entomologists is critical ; an extreme sh

ortage

Lack of Surveillance In many high-burden settings, there is almost no dat

a

Entomological Skills

• WHO calls for countries to increase their investment in training people with entomological skills, as well as the corresponding infrastructure

Sanitation and Access toSafe Drinking Water

• Poor sanitation & lack of access to clean drinking water allows many vectors to thrive

Environmental Change

• Climate change is likely to exacerbate impact

Role of Health Education

• Active Community participation

• Strict enforcement of legislation for wastes disposal

• Unless man himself changes his behavior & becomes vector conscious & stops creating breeding places , no one can eliminate

Health Education Material on Dengue

Health Education Material on Malaria

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Conclusion

• VBDs - greatest contributors to human mortality & morbidity in tropical settings & beyond.

• Significant progress is being made in combating diseases such as Malaria, Filariasis & Chagas disease

• Dengue continue to spread at an alarming pace

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Conclusion• Resistance to insecticides threatens the gains

made through vector control & calls for concerted planning & collaboration across sectors

• Areas where VBDs overlap, integrated management of insecticide resistance is essential, supported by adequate capacity of trained personnel

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Thank You!Thank You!