PPT presentation on integrated vector control approach in India people might find useful

1. Integrated vector control
approach
Dr. Kulrajat Bhasin
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2. Plan of presentation
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Introduction
Principles of vector control
Integrated vector control approach.
Selection criteria for vector control measures
Evolution of Integrated vector control approach.
Integrated vector control approach for mosquito.
Key elements of an IVC Strategy.
References.
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3. Introduction
• Vector - definition
• Common vectors and diseases
- Mosquito : Malaria, filaria, viral encephalitis e.g.., Japanese
encephalitis, viral fevers e.g.., Dengue, west Nile.
- Housefly : typhoid and Para typhoid fever, diarrhea, dysentery,
cholera, gastroenteritis, amoebiasis, helminthic infestations,
poliomyelitis, conjunctivitis, trachoma, anthrax, etc.
- Sand fly : Kala azar, oriental sore, sand fly fever, oraya fever
• Transmission of disease- Direct contact, mechanical, biological
(propagative, cyclopropagative, cyclodevelopmental).
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4. Principles of vector control
1. Environmental control: the best approach as
the results are likely to be permanent.
2. Chemical control
3. Biological control
4. Genetic control
5. Newer methods like insect growth regulators,
chemosterilents, pheromones
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5. Integrated vector control approach
• No single method is likely to provide a solution in all situations. The
present trend is to adapt a IVC approach.
• Vector control approach combining two or more methods with a
view to obtain maximum results with minimum efforts.
• “Integrated vector control approach is the present trend for vector
control defined as utilization of all appropriate technological and
management techniques to bring out an effective degree of vector
suppression in a cost effective manner and also to avoid the
overuse of one of the methods”.
• Selection of methods is not possible without detailed field
information on the ecology, bionomics of vectors, role in disease
transmission.
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6. Life cycle of Mosquito
4 Common stages in development namely : 1. Egg, 2.Larva ,
3.pupa and 4. adult
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7. Habits of vectors
A knowledge of these habits is essential from the point of view
of controlling them as well as the part they play in transmission
of disease
Mosquito
Housefly
1.
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Feeding habits:
males never bite and subsist on plant juices
females on the other hand are
hematophagus
2. Time of biting: generally evening (aedes
fearless females)
3. Resting habits: exophyllic . Vegetations, shrubs
, tree holes, cattle sheds.
4.Breeding habits: anopheles-prefer clean water
culicines - dirty polluted water.
aedes - artificial collections of water( rainy
season)
mansonia – aquatic plants( water hyacinth
5. Hibernation: in winters or when condns not
favorable in adult stage
6. Dispersal : not far unless swept away with air
currents( yellow fever)
7. Life span : normally varies from 8 – 34 days but
males as a rule are short lived
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Breeding habits : in order of importance are
Fresh horse manure
Human excreta
Manure of other animals
Garbage
Decaying fruits and vegs
Organic rubbish dumps
Liquid wastes scattered on ground
Feeding habits : does not bite, mechanical
transmission. Cannot eat solid food so vomits
and making a soln sucks in a liquid state
Restlessness : moves to and fro.
Vomit drop : fly vomits frequently which is a
culture of disease agents
Defecation : habit of defecating depositing
bacteria on exposed food
Resting habits : on vertical surfaces and
hanging objects and tendency to fly towards
light.
Dispersal : up to 4 miles or more from point of
origin
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8. Selection criteria for vector control measures
1. Effectiveness.
2. Safety.
3. Simplicity of use- indications, contraindications,
skills, difficulties in using.
4. Cost
5. Time and effort
6. Type of benefit.
7. Social acceptability- local context.
8. Support requirements.
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9. Evolution of the integrated vector control
• Vector control has been a part of malaria control activities
since the early 20th century.
• During the pre-DDT era, reduction of vector mosquitoes
largely relied on larviciding & environmental management of
breeding habitats.
• 1950s- DDT and other insecticides were extensively used.
• 1970s, development of insecticide resistance, poor human
acceptance and environmental concerns against the use of
insecticides.
• This led to a rethinking in vector control strategies.
• 1980s, WHO proposed an Integrated Vector Control (IVC)
strategy based on the principles of Integrated Pest
Management in agriculture.
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10. Integrated vector control approach for mosquito
Mosquito Control Measures
Anti larval
measures
1.
Anti adult
measures
Environmental 1. Space sprays
control
2. Residual
2. Chemical
sprays
control
3. Genetic control
3. Biological control
Protection against
mosquito bites
Legislative
control
1. Mosquito nets
Civic laws
2. Screening
3. Repellents
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11. Anti-larval measures
Environmental control
The most important step in reducing the number of mosquitoes
1.Elimination of breeding places (source reduction) like,
 Filling and leveling
 Drainage of breeding places
 Water management
2.Proper disposal of refuse other wastes.
3.Cleanliness in and around the houses .
Community involvement & multisectoral
coordination
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12. Chemical Control
Larvicide
Formulation
Duration
Petroleum oil- Diesel oil and Larvicidal oil
Suspension
1-2 weeks
Paris green
Granules
2 weeks
Organophosphorus compounds
Abate
Malathion
Fenthion
Chlorpyrifos
Emulsifiable conc
Emulsifiable conc
Emulsifiable conc
EC, Suspension
2-11 weeks
1-3 weeks
1-2weeks
2-4 weeks
Insect growth regulators- Diflubenzuron,
Methoprene, Pyriproxyfen
Suspension/
Granules
4-8 weeks
Bacterial LarvicidesBacillus thuringiensis H-14
B. Sphaericus
EC/ Granules
1-2 weeks
2-8 weeks
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13. •
Highly toxic to insect larvae or pupae, interfering with
development into adults. Used in large scales in USA..
• Costly & have restricted availability -not used in India.
•
Particularly useful if insects have developed resistance to
insecticides or because of their environmental effect.
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Safe to human beings and environment.
1. Juvenile hormone analogues: prevent development of larvae
into pupa or pupae into adult. Ex. Methoprene
2. Chitin synthesis inhibitors: interfere with moulting process,
killing larvae when they moult. Act more rapidly.
Ex. Diflubenzuron and Triflumoron.
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14. • Expanded form of polystyrene granules - available commercially
with diameter ranging from 0.6 to 2.5 mm.
• Increased by boiling.
• They do not decay and remain floating for years.
• Spread on surface of water to form floating layer. A layer of 1-2
cm is sufficient if it covers the surface.
• Easily blown or washed away- only sites where water remains
confined -wells.
• Used safe in drinking water
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15. Biological Control
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Natural enemies into the environment-includes Insects,
Viruses, Bacteria, Protozoa, Fungi and Fish.
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Only two of them have become widely employed. They are
Larvivorous fish and Biolarvicides.
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16. 1.Larvivorous fish
• Feed on mosquito larvae.
• Easy, practical, cheap; they have no food value.
• They should have the following characteristics
– Preference for mosquito larvae over other types of food
– Small size
– High reproduction rate
– Tolerance to pollution, temperature fluctuation &
transportation.
• Two species are widely usedGambusia - clean water, tolerate wide range of temperature, pH
water salinities.
Guppy- Polluted water, cannot <10 degree C.
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17. • Useful in ornamental tanks, wells, Garden ponds, fountains,
swimming pools, large water collection.
• Approximately 5 fish per sq.m of water surface.
Advantages
a. Long term effective control measure.
b. Cost effective.
c. Environmentally safe.
d. Controls variety of mosquito species.
Disadvantages
a. Effective when large numbers eventually establish themselves.
b. takes 1-2 months; not suitable - quick anti larval measures are
needed.
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c. less effective in waters with much vegetation or floating garbage.

18. •
Bacteria for the control of mosquito larvae. Bacillus
thuringiensis H 14 and Bacillus sphaericus.
• Available as wettable powder and granules which contain
bacteria, spores and toxic crystals.
• Safe to environment , human being and animals but are
expensive.
Bacillus thuringiensis H 14
• Gram positive, spore forming bacteria which is specifically
acts against mosquito larvae.
• Produces endotoxin which after ingestion causes gut
paralysis & leakage of contents into body cavity leading to
death.
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19. •
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It is applied at 0.5 gm/sq.m
250gm of B. thuringiensis is mixed with 10 L of water to make
2.5% suspension & sprayed at 1L over 50 sq.m every 2 weeks.
Bacillus sphaericus
• It also produces toxin.
• It is more effective in polluted water - suitable for treatment
of breeding sites of Culex.
• 500gm of B. sphaericus with 10 L of water to make 5%
suspension & it is sprayed at 1 L over 50 sq.m. every 3 weeks.
Others BiolarvicidesFungi- Coelomyces, Culicinomyces,
Nematodes – Romanomermis cluicivorax and R. iyengari.
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20. Space sprays
– Space sprays are those where the insecticidal
formulations is sprayed into the atmosphere in the form
of mist or fog.
1. Thermal fog.
2. ULV cold aerosols.
– Done where immediate results are needed like during
outbreak of disease to bring down mosquito population
drastically.
– Exophillic vector species.
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21. Space sprays (contd)
Sl.
no
Name of
Insecticide
Formulation
Preparation of
formulation
Equipment used
Remarks
1
Pyrethrum
extract
2.0% extract
1:19 i.e., 1 part of
20% pyrethrum
extract in 19 parts
of kerosene
Flit pump or hand
operated fogging
machine
Used for
indoor
spray
2.
Technical
Malathion
5 parts of
tech.
Malathion in
95 parts of
Diesel oil
Vehicle mounted
thermal fogging
machine
Speed of vehicle 6
km/hour
Outdoor thermal
fogging
Used for
outdoor
spray
3
Deltamethrin 1 litre in 199
litre Diesel
1.25ULV
Thermal fogging
machine
Outdoor thermal
fogging
Used for
outdoor
spray
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22. Advantages of space sprays
• Immediate effect - suitable for control of disease outbreak.
• Less insecticide is required for one application.
• Kills exophillic species of mosquito.
Disadvantages of Space sprays
• Effect lasts for shorter period- repeated at least once a week.
• The cost of equipment, operational and maintenance - high;
• Needs specially trained staff for maintenance and repair.
• May cause pollution.
• Problems with acceptability.
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23. Indoor Residual Sprays
• Application of insecticides to surfaces so that the insecticide
particles remain on the surface in the form, size and quantity
suitable for insects to pick up on contact and sufficient to
exert a lethal effect over a long period.
• Endophillic species.
Knapsack sprayer
Compression pneumatic sprayer
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24. Indoor Residual Sprays
Sl. Name of the insecticide
No.
Dosage
Residual effect in weeks
1
DDT 50% wp
1 gm
10 -12
2
3
4
BHC 50% wp
Malathion 25% wp
Deltamethrin 2.5% wp
200 mg
2 gm
20 mg
6–8
6–8
10 -12
5
6
7
Alpha Cyperthrin 5.0% wp
Cyfluthrin 10% wp
Lamdadcyhalothrin 10% wp
25 mg
25 mg
25 mg
10 -12
10 -12
10 -12
8
9
Fenitrothion 40% wp
Primiphs-methyl 25% wp
1 gm
2 gm
6–8
6-8
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25. 1. May leave visible deposits on walls .
2. Non acceptability.
3. Painting or re-plastering of walls after application reduces or
eliminates efficacy of insecticides.
4. People may be reluctant to allow stranger into their houses.
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26. • Methods such as
1.
sterile male technique
2.
Cytoplasmic incompatability
3.
Chromosomal translocations
4.
Sex distortion
5.
Gene replacement
Limitations:
1. Lack of mating competitiveness released males.
2. Immigration of fertile females from regions close to the release
sites.
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27. •
Reallocation or introduction of cattle or domestic animals
between settlements and mosquito breeding i.e. ring of
cattle sheds on the outskirts of a village with houses in the
center.
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Many mosquito prefer animal blood than human blood and
hence decreases biting of human and transmission of
disease.
• In Japan it is proved to be effective against Culex.
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28. a. Mosquito Nets
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Mosquito bite during sleep. They also protect against other
creatures like spiders, cockroaches, lizards and rats.
• Best pattern is rectangular net.
• Size of the openings in the net is should not exceed 0.0475
inch in any diameter. The number of holes in one square inch
is usually 150.
Disadvantages of Untreated Nets
1. Mosquito can feed when body makes contact with the net.
2. Hungry mosquito wait on or near the net until net is opened.
3. After failing to get through the net Mosquito are diverted to
unprotected people sleeping nearby.
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29. Insecticides Treated bed Nets
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Provide better and effective protection by not only
preventing mosquito bites & also killing them.
They are prepared by soaking the net in insecticidal solution
& dried.
Nylon nets are preferred - more durable, insecticide stays
longer duration and quicker in drying after impregnation.
Synthetic Pyrethroids
are used for impregnation.
Permethrin,Deltamethrin, Cyfluthrin and Lambdacyhalothrin
are used.
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30. b. Repellents
• Mainly used for application on exposed parts of skin.
• They act by preventing human-insect contact and do not
knock down or kill.
• Chief advantage is short duration of protection. Useful for
Plantation workers, Army people, Labors who work outdoor
at night and Travelers.
• N-N-Diethyl-3-toluamide (DEET),indalone, dimethyl pthalate,
dimethyl carbate.
• DEET is best available product; effect last for 4-6 hours. on
application.
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31. Personal Prophylaxis(contd)
c. Screening- Screening of buildings with zinc, aluminum, plastic or
bronze having 16 meshes to the inch is recommended.
d. Protective clothing.
d. Others- Mosquito hitting swatter, use of fan at high speed,
repellents.
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32. Personal Prophylaxis(contd)
Insecticide Vaporizers
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Protect against mosquito and biting flies by,
1. Irritating and disturbing them after contact and preventing
them from biting and also preventing them entering room.
2. Paralyzing or killing them.
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Coils, mats, liquid vaporizers and aerosols/spray- Transfluthrin,
Legislative control
• Use of laws to prevent / reduce propagation and spread of
vectors is an effective means of vector management, through
stringent approach.
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33. •Intermittent irrigation
•Water level management
•Land filling
•Channelling
•Draining
•Exotic natural enemies
•Larvivorous fish
•Microbial agents
Source
reduction
Biological
•Insect growth
regulators
•Adulticides
•Larvicides
Chemical
IVC
Health
Education
•Community
•School education
•TV
•Mass media
Personal
Protection
Bed nets and repellents
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34. Key elements of an IVC Strategy
1.
Advocacy, social mobilization and legislation
– Promotion and inclusion of IVC principles.
– Empowerment of communities for sustainability.
– Establishment or strengthening - regulatory & legislative
control for public health.
2. Collaboration within the health sector and other sectors:
– Agriculture and agriculture development projects.
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Urban sector;
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Industrial development;
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Infrastructure development projects;
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Water resources development projects;
–
Housing projects;
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35. 3. Integrated approach
• IRS in high risk areas and in epidemic situations based on
vector behavior and community acceptance.
• Use of insecticide-treated nets/long-lasting insecticidal nets
and other personal protection methods.
• Environmental management.
• Biological control.
4. Evidence-based decision making
• IVC strategy requires assessment of the vector control needs
based on the local factors.
• Demands efficient surveillance/ information management
system that highlights targets for vector control interventions.
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36. 5. Operational and implementation research
• Strong operational and implementation research support for
development of new and modified tools
6. Capacity building
• expertise at the central, as well as peripheral levels.
• developing tools and guidelines in local languages and training
of personnel for vector control.
7. Monitoring and evaluation
• indicators as per the local requirements and targets set.
• Inputs, costs & outcome of different interventions, when used
singly or in combination & simultaneously or consecutively in a
defined area, must be monitored.
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37. Thank you
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