## Vectors of Medical Importance.pptx: Dive into the World of Disease Carriers Introduction: * Defining vectors and their significance in public health. * Highlighting the global burden of vector-borne diseases. Major Vector Groups: Arthropods: * Mosquitoes - major players in malaria, dengue, yellow fever, Zika. * Ticks - vectors of Lyme disease, Rocky Mountain spotted fever, encephalitis. * Flies - tsetse flies (sleeping sickness), sandflies (leishmaniasis). * Fleas - plague, murine typhus. Non-arthropods: * Snails - schistosomiasis. * Rodents - plague, hantavirus. Disease Transmission Mechanisms: * Different mechanisms for each vector-disease combination. * Role of vector biology and behavior in transmission. Impacts of Vector-Borne Diseases: * Global health burden - morbidity, mortality, economic impact. * Social and economic disparities in disease prevalence. Vector Control Strategies: * Insecticides and repellents. * Bed nets and other protective measures. * Vaccination and treatment programs. * Environmental modification and community engagement. Emerging Challenges: * Climate change and its impact on vector distribution and abundance. * Antibiotic resistance in vector-borne pathogens. * Need for innovative control strategies. Conclusion * Importance of continued research and collaboration in vector control. * Emphasizing the potential for disease prevention and improved public health. Additional elements: * Compelling visuals like images of vectors, disease transmission cycles, and maps. * Data and statistics highlighting the global impact of vector-borne diseases. * Case studies of specific vector-borne diseases and their control efforts. * Audience-specific tailoring depending on the intended audience (medical professionals, general public, policymakers).

1. Identifying features and
life cycle of vectors of public
health importance
Dr. Saurabh Kashyap
Associate Professor
Dr. Purnoor Kaur
Junior Resident
Dept of Community Medicine & Public Health
KGMU UP

2. What is a VECTOR in Disease Epidemiology?
• An insect or any living carrier that
transports an infectious agent from an
infected individual or its wastes to a
susceptible individual, its food or its
surroundings.*
* Oxford Dictionary of Epidemiology, sixth edition

3. Types of Vectors
Vectors
Invertebrate Vertebrate

4. • Diptera –Mosquitoes
Diseases transmitted:
-Malaria
-Filaria
- Viral Encephalitis
- Dengue
- West-Nile fever
- Yellow fever
Invertebrate Vectors- seven orders

5. • Diptera –Flies
Diseases transmitted by
Houseflies: Typhoid, paratyphoid fever, diarrhoea,
dysentery, cholera, polio, trachoma, anthrax, yaws
Sandfly: Kala-azar, oriental sore, sandfly fever,
Oraya fever
Tsetse fly: Sleeping sickness
Black fly: Onchocerciasis
Invertebrate Vectors

6. • Orthoptera- cockroaches
Transmits enteric pathogens
Invertebrate Vectors

7. • Siphonaptera- fleas
• Diseases transmitted:
Rat flea: Bubonic plague, endemic
typhus, chiggerosis, hymenolepsis
diminuta
Invertebrate Vectors

8. • Anoplura- Lice
Diseases transmitted:
Epidemic typhus, relapsing fever,
trench fever, pediculosis
Invertebrate Vectors

9. • Hemiptera- bugs
• Reduviid Bug: Chagas
disease
Invertebrate Vectors

10. Invertebrate Vectors
• Acarina- ticks and mites
• Hard tick: Tick typhus, viral
encephalitis, KFD, Tularemia, tick
paralysis, human babesiosis
• Soft tick: Q fever, relapsing fever
• Trombiculid mite: Scrub typhus,
Rickettsial-pox
• Itch-mite: Scabies

11. Invertebrate Vectors
• Copepoda- cyclops
• Guinea worm disease, fish
tapeworm

12. Vertebrate Vectors
• Mice, rodents, bats
• Leptospirosis
• Salmonelloisis
• Nipah virus disease

13. Transmission by vectors
Mechanical Transmission
• It is a type of disease transmission in
which the vector is no more than a
carrier that
• transmit pathogens without any
change either on the number or
• form of disease pathogens.
Biological Transmission
• In this type of disease transmission
certain developmental pattern exists
either in the vector or host or in both
cases. It is sub-divided in to
• Propagative- plague bacilli in rat fleas
• Cyclo-propagative- malaria in
mosquitoes
• Cyclo-developmental- microfilaria in
mosquitoes, guinea worm in cyclops
• Transovarian- infected female to her
progeny; tick-borne encephalitis

15. Anopheles Female
• Identification: Proboscis & palpi are equal in length, palpi are pointed,
proboscis straight in line with body, wings are spotted, antennae are not
hairy.
• Habits: Prefers human blood for oviposition, bites in the evening & at
night, rests inside the house, remains in dark, cool & shady corners, life
span is 1 week to one month.
• Breeding places: clean water e. g. well, roof tanks, flood waters, dams,
etc.
• Disease transmitted: Malaria- plasmodium species.
• Control: Environmental- source reduction, Chemical- Insecticide spray,
Genetic- gene & sex distortion, Personal protection- mosquito nets,
coils,reppellent creams etc.
• National programme: National Vector Borne Disease Control Programme.

16. Anopheles Female
• Anopheles mosquitoes generally don’t fly more than a
1.2 miles (2 km) from their larval habitats.
• Anopheles mosquitoes are attracted to dark, sheltered
areas for resting during the daytime.

17. Anopheles

18. • Eggs float on the surface
• 50–200 eggs at a time
• Eggs do not tolerate drying
out

19. Larva Pupa

20. Larva
• Pupae live in water. Pupae do not have
external mouthparts, so they do not
eat during this stage.
• An adult mosquito emerges from a
pupa and flies away
Pupa
• Larvae live in the water. They hatch from
mosquito eggs.
• Anopheles larvae breath by using special
using special organs (called spiracles)
located on their abdomen.
• Larvae shed their skin (molt) four times
during this stage before becoming pupa

21. Adult
It usually takes
10–14 days for an
egg to develop
into an adult
mosquito

22. Culex Female
• Identification: Palpi are smaller than proboscis, proboscis make an acute
angle with body, wings are unspotted.
• Habits: Domestic, prefers human& animal blood, bites in mid night,
prefers legs below knee, rests inside the house.
• Breeding places: Remain in dark, cool, shady corners, breeds in dirty
water- stagnant & blocked drains, sullage & sewage water.
• Disease transmitted: Filariasis- Wuchereria bancrofti, Japanese
encephalitis- Arboviruses.
• Control: Environmental- source reduction, Chemical- insecticide spray,
Genetic- gene & sex distortion, Personal protection- mosquito nets, coils
& repellent creams etc.
• National programme: NVDCP

23. •Adult, female mosquitoes lay eggs on the surface of fresh
or stagnant water. Water sources can include barrels, horse
troughs, ornamental ponds, unmaintained swimming pools,
puddles, creeks, ditches, and marshy areas.
•A female Culex mosquito lays eggs one at a time. Eggs
stick together to form a raft of 100 to 300 eggs. The raft
floats on the water

24. Larva
• Larvae hatch from mosquito eggs and
live in water.
• Larvae can be seen in the water. They
are very active and are often called
“wigglers.”
• They feed on a variety of things found in
the water.
• Larvae shed their skin (molt) several
times during this stage.

25. Pupa
• Pupae live in water. Pupae do not have external mouthparts and do
not feed during this stage.
• An adult mosquito emerges from a pupa and flies away

26. • Adult female mosquitoes bite people and animals. Mosquitoes need blood to
produce eggs.
• After blood feeding, female mosquitoes look for water sources to lay eggs.
Several days pass between feeding and looking for a place to lay eggs.

27. Culex

28. Aedes Female
• Identification: Palpi are smaller than proboscis, wings- not spotted,
white stripes on black body, broad flat scales.
• Habits: Peri- domestic, rests in dark quite rooms, hanging articles, bites
throughout the day.
• Breeding places: Artificially collected water- discarded tin, bottle, tyers,
flower pots etc.
• Disease transmitted: Dengue & DHF-Arboviruses B, Chikungunya,
Yellow fever.
• Control: Environmental- Removal of artificially water collection
receptacles, Chemicals- insecticide spray, Genetic- gene & sex distortion,
Personal protection- mosquito net, coils & repellents.
• National programme: NVDBCP.

29. Aedes

30. •Adult, female mosquitoes lay eggs on the inner walls of containers
with water, above the waterline.
•Eggs stick to container walls like glue. They can survive drying out
for up to 8 months. Mosquito eggs can even survive a winter in the
southern United States.
•Mosquitoes only need a small amount of water to lay eggs. Bowls,
cups, fountains, tires, barrels, vases, and any other container storing
water make a great “nursery.”

31. Larva
• Larvae live in the water. They
hatch from mosquito eggs. This
happens when water (from rain
or a sprinkler) covers the eggs.
• Larvae can be seen in the water.
They are very active and are
often called “wigglers.”

32. Pupae
• Pupae live in the water. An adult
mosquito emerges from the pupa and
flies away.

33. • Adult female mosquitoes bite people and animals. Mosquitoes need
blood to produce eggs.
• After feeding, female mosquitoes look for water sources to lay eggs.
• Ae. aegypti and Ae. albopictus don’t fly long distances. In its lifetime,
these mosquitoes will only fly within a few blocks.
• Ae. aegypti mosquitoes prefer to live near and bite people.
• Because Ae. albopictus mosquitoes bite people and animals, they can live
in or near homes or in neighboring woods.
• Ae. aegypti mosquitoes live indoors and outdoors, while Ae.
albopictus live outdoors.

34. MANSONIA
• The mosquitoes of this genus are big, black or brown mosquitoes with
speckling on their wings and legs.
• The common Indian species are: M. annulifera, M. uniformis, M. indiana and
M. longipalpis.
• They breed in ponds and lakes containing certain aquatic plants, especially the
floating types like Pistia stratiotes and water hyacinth.
• The eggs are laid in star shaped clusters on the under-surface of the leaves of
these aquatic plants.
• The larvae and pupae are found attached to the rootlets of these plants by
their siphon tubes; they obtain their air supply from these rootlets.
• When about to become adults, the pupae come to the surface of water and
the fully formed adults emerge and escape.
• The control of mansonoides mosquitoes is easy by the removal or destruction
of the aquatic host plants by herbicides.

36. Compact egg mass glued to the
undersurface of floating
vegetation.

37. BEHAVIOR
It is an endophilic species, prefer to rest indoor places. Adults
normally active in one after midnight and before dawn.
MEDICAL IMPORTANCE
It shows high affinity for human biting and is a potent vector
of Brugia malayi to cause Malayan filariasis. In 1980, Japanese
encephalitis virus was isolated from M. annulifera from India,
which was the first isolation of the virus from this mosquito.

38. • ADULT (illustrated):
Head: Palpus (MPlp) with apical white scales. Thorax: Scutum without well-
defined round spots or greenish stripes; pleuron not contrasting with
scutum or coxae (C-I–III); postpronotum with appressed white scales.
Wing: Wing scales mixed dark and pale, broad and asymmetrical.
Leg: Fe-III with c. 5 bands of pale scales; pale bands incomplete on all
tarsomeres.
Abdomen: III–VII-S mostly pale-scaled; VIII-Te with strong chitinized hooks.
• LARVA (not illustrated): Head: Larval antenna with dark rings at base and at
origin of antennal shaft. Abdominal segments: Seta 6-III,IV single. Terminal
segments: Seta 3-VIII double; comb with 2 robust blunt comb scales;
modified spiracular apparatus for piercing plants; saddle 2 times longer than
wide; precratal setae present.

39. TYPE OF
MOSQUITO
DISEASE
ANOPHELES Malaria, Filaria (not in India)
CULEX Bancroftian filariasis
Japanese encephalitis
West Nile fever
Viral arthritis
(epidemic/polyarthritis)
AEDES Yellow fever (not in India)
Dengue
Dengue haemorrhagic fever
Chikungunya fever
Chikungunya haemorrhagic fever
Rift valley fever
Filaria (not in India)
MANSONOIDES Malayan (Brugian) filariasis
Chikungunya fever

40. DIFFERENCES BETWEEN ANOPHELINI AND
CULICINI
ANOPHELINI ANOPHELES CULICINI CULEX, AEDES, MANSONIA
EGG 1) Laid singly (1) Laid in clusters or Rafts, each raft
containing 100-250 eggs (except-Aedes)
2) Eggs are boat-shaped, &
provided with lateral floats
(2) Eggs are oval-shaped, and not provided
with lateral floats
LARVAE (1) Rest parallel to water
surface
(1) Suspended with head downwards at an
angle to water surface
(2) No siphon tube (2) Siphon tube present
(3) Palmate hairs present
on abdominal segments
(3) No palmate hairs

41. ANOPHELINI ANOPHELES CULICINI CULEX, AEDES,
MANSONIA
PUPAE Siphon tube is broad and
short
Siphon tube is long and
narrow.
ADULT (1) When at rest, inclined at
an angle to the surface
(1) When at rest, the body
exhibits a hunch back
(2) Wings spotted (2) Wings unspotted
(3) Palpi long in both sexes (3) Palpi short in female

46. Binomics
• The study of the habit and habitats of mosquitoes is called
binomics.
• It provides effective ways for controlling the mosquitoes.

47. HABITS OF MOSQUITOES
(1) FEEDING HABITS: The males never bite: they subsist on plant juices.
• The females on the contrary are haematophagous.
• They require a blood meal, once in 2-3 days for the development of eggs.
• The females differ in their feeding habits.
– Some species (anthrophilic) prefer human blood,
– some (zoophillic) prefer animal blood,
– some indifferent in their choice and feed on both man and animals.
(2) TIME OF BITING: In general mosquitoes bite in the evening or in the early
part of the night, but there are great variations among the Species

48. (3)RESTING HABITS
– Mosquitoes obscure themselves during the day in dark and cool corners.
– Some rest indoors (endophilia), and some outdoors (exophilia).
– The indoor resting places are usually the dark corners of houses, upper
part of walls, behind pictures and under furniture.
– The outdoor resting places are usually the vegetation, shrubs tree holes.
cattle sheds and wells
(4) BREEDING HABITS : In general,
– the anophelines prefer clean water for breeding;
– the culicines prefer dirty and polluted water: the aedes prefer artificial
collections of water.
– The mansonia breed in water containing certain types of aquatic
vegetation.

49. (5) HIBERNATION : Mosquitoes are known to hibernate in the adult stage
when the environmental conditions are not favourable. Severe winters are
tided over by hibernation.
(6) DISPERSAL :
• Do not generally fly far from the place where they breed unless swept
by currents of wind. The range of flight :may range up to 11 kms.
• Aircrafts and ships have increased the possibility of the dispersal of
mosquitoes from country to country and have created fresh problems of
public health.
• The danger of introduction of mosquitoes infected with yellow fever
into India where the population have no past experience of the disease
is well recognised.

50. (7) LIFE SPAN :
• The life of a mosquito is influenced by temperature and
humidity.
• Both high and low temperatures are fatal.
• The normal life span of mosquitoes varies from 8 to 34 days.
• The males, as a rule, are short-lived.

51. Habits Anopheles Culex Aedes Mansonia
Feed on Anthropophilic
and zoophilic
Anthropophilic Anthropophilic Anthropophilic
Biting
time
Evening or early
part of night
Midnight Day biters Night
Resting
place
Indoor rester-
cattle sheds and
human
dwellings
Outdoors Dark and quiet
places,
bedrooms and
kitchens
Outdoors

52. Habits Anopheles Culex Aedes Mansonia
Breeding
place
Cleanwater,
ponds, pools,
lakes, spring,
overhead
tanks
Dirty water
collections,
stagnant
drains,
Cesspools,
septic tanks,
burrow pits
Artificial
accumulation
of water,
tyres, broken
glass
Aquatic plants
Flight 0.75-1km 11 km <100m -
Control
measures
IRS, biological
control
measures
Environmental
control
measures,
outdoor
spraying
Prevent
artificial
collection of
water
Biological
control
measures,
deweeding
aquatic plants

53. • Dengue is cluster disease because the flight
• VIP syndrome in dengue because in clean water
• Eggs are resistant to water
• Mobil oil/ natural repellants

54. House Fly
• Identification: Mouse grey in color, body is covered with sticky hair,
large compound eyes, retractile proboscis, dark & light marking on
abdomen, leg has hair pads.
• Habits: Lives close to breeding places, Restlessly moves from filth to
food, vomits & defecates feeds frequently,, not lives more than 48
hours without water.
• Breeding places: Human & animal excreta, dumps garbage.
• Disease Transmitted: By mechanical transmission- typhoid,
cholera,gastroentritis, Amoebiasis, polio, trachoma, etc.
• Control: Improvement of environmental & general sanitation,
hygienic disposal of refuse, human & animal excreta, insecticide- DDT-
5%, poisons-Fly baits, larvicides- Diazinon-2% in breeding places.

55. House Fly

57. Rat Flea
• Identification: Dark brown in colour, bilaterally compressed wingless body,
head is conical, attached directly to thorax, 3 pairs of spiny strong limbs.
• Habits: Lives on rats, in rat burrows, store house, cracks etc.
• Disease transmitted: Bubonic plague, by bite of blocked flea, Endemic
typhus- is transmitted by contamination of skin with faeces of fleas.
• Control: Both rat & rat flea should be destroyed together. Insecticide: DDT
10% (dust) where rodent moves & in burrows. Rat destruction- poisonous
bait, trapping.

58. Rat Flea

59. Head Louse
• Identification: Dark grayish in colour, 1 mm in size having head, thorax &
abodmen, 3 pairs of legs without wings.
• Habits: Ectoparasite of man, infestation is called pediculosis, head louse
lives in hair of scalp, body louse lives in hair of body, both sexes lives on
host. Dissemination: Directly by contact with lousy person, indirectly by
using clothes, bedroom of lousy person.
• Disease transmitted: Epidemic typhus, relapsing fever, trench fever, heavy
infestation cause dermatitis, insomnia due to irritation.
• Delousing: Head louse- 0.5% malathion is applied to head after hot bath,
12-24 hours later second application is done. Body louse- 50 gm /person is
dusted on body & clothing., Anti lice shampoos- 0.2 to 0.4% Phenothrin.

60. Head Louse

61. Sand Fly
• Identification: Dark brown hairy body, antenna are long & filamented,
second vein of the wing divides twice,3 pairs of slender legs, pair of large
compound eyes.
• Habits: Lives in cervices, holes, stone, rock in hills, tables, store room etc.
Organic matter, shady place & loose soil are essential for breeding, avoids
lights, bites mainly at night- bites the wrist & ankle, hops , female are
blood suckers.
• Disease transmitted: Kala Azar- L donovani(bite),Sand fly fever-
Virus(wound contamination with saliva), Oriental Sore- L tropica.
• Control: Insecticide- DDT- 1-2 gm/meter square, Source reduction-
clearing, filling of cervices, Personal protection: sand fly nets impregnated
with permethrin, not walking bare foot, repellent to legs.

62. Sand Fly

63. Soft Tick
• Identification: Oval shaped leathery body, head lies ventrally, not visible
from above, no antenna4 pairs of legs, no wings.
• Habits: Ectoparasite on multiple hosts, lives in cracks, cervices, bedding,
cattle sheds.
• Disease transmitted: Q fever, Relapsing fever, Kyasanur forest
disease(KFD)
• Control: Environment- filling up cracks & cervices, Chemical- Indane,
malathion, DDT, Personal protection- Insecticide repellents,(benzyl
benzoate),wearing full clothing

64. Soft Tick

65. Hard Tick
• Identification: Body is oval, grey white in color, rectangular head, head,
thorax & abdomen are fused, 4 pairs of legs, no antenna, no wings,
dorsum is covered by Chitinous shield.
• Habits: Both sexes bite & transmit the disease, blood sucking
Ectoparasite having 3 hosts- monkeys, dog & cattle.
• Disease transmitted: KFD, Typhus, Spotted fever, Encephalitis & tick
paralysis.
• Control: Insecticide- Malathion. Lindane, DDT, are dusted on animals,
vegetations & premises, Personal protection- Repellent(benzyle
benzoate)

66. Hard Tick

67. Itch Mite(Sarcoptes scabiei)
• Identification: Dirty white colored, tortoise(oval) shaped insect, 4 short
stumpy legs, no wings, no demarcation of body segments, body is
wrinkled covered with bristles.
• Habits: Burrows in epidermis of skin, spread by close contact.
• Disease: scabies.
• Treatment: Benzyl benzoate 25%, HCH(Linden) 0.5%, applied to the body
below chin after scrub bath, repeated after 12 hours, 12 hour after the
second application bath is given, all infested & close contacts are treated
simultaneously, Post treatment- laundering of clothes.

68. Itch Mite

69. Cyclops
• Identification: Pear shaped, semitransparent body,, forked tail, one small
pigmented eye, just visible to naked eye-1 mm in size, 2 pairs of antenna & 5
pairs of legs.
• Habits: Lives in fresh water & act as intermediate host.
• Disease transmitted: Guinea worm dracunculosis, fish tape worm.
• Control: Physical- straining in muslin/nylon strainer, boiling the drinking
water up to 6o deg.C, Chemical- Chlorination- 5 ppm, Permanent- conversion
of step well, providing safe drinking water & health education.

70. Cyclopes

71. Integrated Vector
Management
Environmental
Control Chemical
Control
Biological
Control
Mechanical and
physical control
Legislative
control

72. Control of Mosquito
• Environmental: Source reduction.
• Chemical Dose gm/m square Effectiveness
DDT 1-2 6-12 months.
Lindane 0.5 3 months
Malathion 2 do
Pyrethrum 0.1% short time
• Genetic: Sterile male technique, chromosomal translocation, sex
distortion, gene replacement.
• Biological : Using larvicidal fish- Gambusia, fungi, etc.
• Personal protection: Mosquito nets & coils, repellents.
• Antilarvidial: Crude oil10-15 gallons/ acre to breeding water, Paris
Green- 2%, one pound/ acre (for anopheles), Abate- once in 15
days(for Culex)

73. House fly Control Measures
1. Environmental Control
2. Control of Adult Flies:
Residual spray: Pyrethrum 0.1% is useful for
destruction of adult flies.
Light traps (electrocutors)
3. Fly proofing: With mesh

74. Sand fly Control Measures
1. Source control: Seals cracks, crevices,
holes
-Remove animal dung from stables and
cattle sheds.
-Maintain proper sanitation.
2. Anti-adult measures: Residual spraying
with DDT
- Lindane spraying once in three months
3. Personal Protection

75. Flea Control Measures
1. Insecticide Control:
- 10% dust of DDT- on rodents
- Indoor residual spray: At the
lower one metre of walls with
malathion
- Dusting of pets
2. Repellents: DEET, benzyl benzoate
3. Rodent control measures

76. Lice Control Measures
1. Good personal hygiene
2. Dusting: 10% DDT powder or 0.5%
permethrin dust and 1% propoxur dust
can be used for dusting garments.
3. Anti-lice shampoo: Permethrin (1%),
Fenitrothion (0.2-0.4%)

77. Tick Control Measures
1. Insecticidal control: DDT,
chlordane, dieldrin, lindane,
malathion
2. Environmental control
3. Personal protection measures:
Clothes impregnated with insect
repellent

78. Rodent Control Measures
1. Trapping
2. Rodenticides: Zinc phosphide, Barium
carbonate, Bromadiolone

79. Integrated Vector
Management
Environmental
Control Chemical
Control
Biological
Control
Mechanical and
physical control
Legislative
control

80. • The vector control is implemented under strategy of Integrated Vector
Management (IVM) which includes implementation of all feasible
strategies safely with or without insecticides to manage vector
population in such a way so that disease transmission is kept under
check. It also includes management of insecticide resistance either by
rotation within the same group or different group. Effective vector
control strategies are based on four facts:
• (i) Knowledge and understanding of vector biology
• (ii) Surveillance of vector species
• (iii) Incrimination of vector species
• (iv) Public education and implementation of effective control measures.

81. • Strategy -There are many tools available and recommended for
vector control. Some are used for personal protection and
some are their combination are used as public health
measures
• 1. Source reduction & Environmental management
• 2. Personal Protection
• 3. Biological (fish)
• 4. Chemical a. Larvicide b. Adulticide

82. Source reduction and Environmental
management
1. Improved water supply
2. Mosquito-proofing of overhead
tanks/ cisterns/ underground
reservoir/wells
3. Flowerpots/vases and ant traps
4. Desert water coolers, condensation
collection pans under refrigerators
5. The design of buildings
6. Mandatory water storage for
firefighting
7. Solid waste disposal
8. Filling of cavities of fences
9. Tyre management

83. Personal Protection
1. Protective clothing
2. Mats, coils and aerosols
3. Repellents
4. Insecticide-treated mosquito
nets and curtains

84. Biological Control:
1. Fish: Larvivorus fish (Gambusia affinis and Poecilia reticulata) have
been extensively used for the control of An. stephensi and/or Ae.
aegypti in large water bodies or large water containers in many parts of
countries.
2. Bacteria: Two species of endotoxin-producing bacteria are
recommended under programme which are Bacillus thuringiensis
serotype H-14 and Bacillus sphaericus. These are effective mosquito
control agents and do not affect nontarget species. Bt.H-14 has been
found to be most effective against An. stephensi and Ae. aegypti, while
Bs is the most effective against Culex quinquefasciatus which breeds in
polluted waters.

85. Chemical Control
Larviciding
• Larviciding has to be done at
weekly/fortnightly interval
• Its application is difficult and expensive
on a long-term basis
• Best used in situations where the
disease and vector surveillance
indicate the existence of certain
periods of high risk and in localities
where outbreaks might occur.
• Insect growth regulators: pyriproxifen
and diflubenzuron
Adulticiding
• Insecticidal Residual Spray (IRS):
Insecticidal Residual Spray is one of the
most cost-effective control measures
for Malaria and Kala-azar in India.
• The objective of IRS is to interrupt the
transmission by reducing numbers of
infective vectors

86. • Indoor Residual spray (IRS): Most of the insecticides having
residual effect are sprayed indoors, so that mosquitoes after
having bite on an infective person will rest in the house and
will pick up sufficient insecticide particles sprayed on the walls
and other indoor surfaces of the house and its longevity will be
reduced so much so that it does not survive to become
infective

87.  Sanchari Rog Niyantaran Abhiyan
July transmission session
October- end of transmission session
Entomological lab in aliganj

88. • https://blog.mygov.in/%E0%A4%B8%E0%A4%82%E0%A4%9A%
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91. Mark 2 - prevents JE

92. Temephos,
2.5ml/10 litres

93. Entomological terminology
• Arbovirus. Refers to viruses that are transmitted by arthropod vectors such as
mosquitoes, sandflies, or ticks.
• Invasive mosquito species. An invasive species is an exotic species that establishes
and proliferates within an ecosystem and whose introduction causes, or is likely to
cause, economic or environmental impact or harm to human health.
• Native or indigenous mosquito species. A native or indigenous species is a species
that occurs within its natural geographical range (past or present) and dispersal
potential (i.e. within the range it occupies naturally, or could occupy, without direct
or indirect introduction or other human intervention).
• Introduction of mosquito species. Introduction is the process of bringing a species
from its endemic range into a biogeographic area to which it is completely foreign.

94. • Establishment of mosquito species. Establishment is the perpetuation,
for the foreseeable future, of an invasive species within an area
following the species’ introduction.
• Susceptible host. In the context of vector-borne diseases, ‘susceptible
host’ is defined as an organism nonimmune to the pathogen that can be
infected by a pathogen through a vector-borne transmission mode. The
host can be symptomatic or not. Depending on the characteristics of the
disease, the susceptible host can become infectious to the vector and
act as the source of further transmission.
• Receptive area. A receptive area is an area where an abundant vector
population is present and where the ecological and climatic factors
favour the transmission of an arbovirus. To appraise receptivity one
needs to assess vector capacity and the environmental and climatic
suitability for transmission in that area.

95. • Vector competence. Vector competence is the ability of an arthropod to
transmit an infectious agent following exposure to that agent. In other
words, it refers to the ability of a vector to acquire an arbovirus from a
reservoir host and later transmit this arbovirus to a susceptible host during
the act of taking another blood meal. Vector competence can be assessed
under laboratory conditions using artificial feeding of the vector species
under study with blood meal infected with the pathogen (e.g. Zika virus). A
sequential analysis of blood-fed mosquito pools at successive times is
performed in order to identify the presence and quantity of the virus in the
salivary glands. If the virus is identified in the salivary glands, it is assumed
that the mosquitoes can transmit the disease to the susceptible host.
Competence depends on the characteristics of the pathogen (strain-specific
vector competence) and the origin of the mosquito species. Mosquito
populations originating from different areas but belonging to the same
species can have different level of vector competence.

96. • Vectorial capacity. The concept of vectorial capacity (or vector capacity)
was developed for transmission models of vector-borne parasitic
diseases but can also be applied to arboviral diseases such as Zika virus.
It is frequently used as a framework for disease transmission modelling.
Vector capacity is determined by a number of factors such as vector
competence, the mosquito population density, feeding host
preferences, biting rates and survival of the mosquito population. In
practice, the occurrence of an arbovirus outbreak is not only dependent
on the presence of a competent vector in a location. This is a necessary,
but not sufficient, condition. Mosquitoes may be competent, but if they
have low vector capacity, they are not effective vectors. For instance, a
competent vector with a zoophilic feeding behavior will not have with a
high vector capacity with regard to pathogen transmission to humans.

97. Entomological
surveillance
Compendium-Entomological-
Surveillance&Vector-Control-India

98. • In India, insecticides are introduced into
public health programmes based on
entomological parameters and their impact
on disease incidence/ prevalence.
• Anopheles and Culex generally nocturnal
and therefore are targeted with residual
insecticidal spray and/or Long lasting
insecticidal nets (LLINs). Aedes species
usually bite during day time and hence
personal protection, larval control and
changes in domestic environment are
considered as better option.

99. • The NVBDCP considers introduction of new insecticides and
amendment to the list of insecticides or deletion of
insecticides in usage on the basis of data on bio-efficacy, vector
susceptibility and epidemiological impact generated by state
health departments, National Centre for Disease Control
(NCDC), or Indian Council of Medical Research (ICMR)
institutes. The insecticides used under programme must have
the registration of Central Insecticide Board (CIB) as this is
mandatory clause

100. Indoor residual
spraying
• Indoor residual spraying (IRS) has
been in use since last 6 decades and
sown the impact if used appropriately.
It is useful mainly in areas of malaria
transmission with collateral benefit for
control of lymphatic filariasis
transmission. The areas with high
disease burden of malaria with
inadequate coverage of LLINs should
also be covered with IRS.

101. LLIN/ITN, curtain nets
• used by the community.
• maintain a barrier even if they have
some holes.
• The killing and contact repelling
effect of the insecticide improves
the efficacy of nets for both
individual prevention and area –
wide reduction in transmission.
These nets are one of the main tool
used to control malaria vectors and
are highly effective.
• LLINs provide a long-term solution,
as they last for about 3 years

102. Insecticide-treated
curtains or wall linings
• may be suitable in areas where the
predominant vectors for lymphatic filariasis are
Culex mosquitoes. Curtains should be adapted
to the type of house.
• Wall linings or curtains will require
reimpregnation with insecticides.

103. Space spraying
Space spraying is used
mainly during outbreaks,
as the effects are not
longlasting and the
procedure must be
repeated frequently. It is
usually applied in or
around houses, some
outdoor resting places
and dense vegetation or
salt marshes.

105. Mosquito Sprays
• To be clear, we mean mosquito
pesticide sprays – not mosquito
repelling sprays, i.e., bug spray.
Mosquito sprays are good if you have a
small infestation or if you need precise
targeting for certain areas. These
products typically contain a
concentrated pesticide. Sprays don’t
require premixing or filling like foggers
and misters. However, these products
are not typically reusable, so they can
become pricey if you have to treat your
Mosquito Foggers
• Thermal Foggers
• Foggers are designed so that a small
amount of pesticide can cover a large
area. It’s similar to an essential oil
diffuser you might have at home. A few
drops of concentrated scent are mixed
with water and turned into a mist to
waft around the room. Thermal
foggers are powered by propane or
gasoline. They have a heating element
that heats and vaporizes pesticides.
Depending on the size of your yard, it

106. House screening
Useful in the control of Anopheles
and Aedes mosquitoes which is a
physical barrier and should be
placed on all openings, including
windows, door and Eaves.
Householders should be
encouraged to improve the
conditions of their house (closing
holes, filling crevices in walls), as
this will also decrease the
opportunity for mosquitoes to
enter or rest

107. Household
insecticides
• Such as aerosol insecticide
sprays or flit guns are
commercially available for use by
individuals and households. The
spray should be applied within a
room with all exits closed.
• The method has limitations as
opening a window or door again
may re-introduce vectors. It also
has no residual killing effect.

108. Repellents, coils and
vaporizing mats
• popular, inexpensive method of vector
control. They burn slowly and steadily
release insecticide into the air over 6-8
hours. Vaporizing mats work on the same
principal but are powered by electricity, and
their advantage over coils is that they release
no visible smoke. The porous paper pad is
impregnated with an insecticide (usually a
pyrethroid), which both repels and kills
mosquitoes. Repellents are also available in
the form of creams, lotions, patches, wrist-
bands and sprays, which can be bought and
applied as required by individuals.

110. Natural methods
Natural methods include
certain fast-growing, densely
foliated plants that repel
mosquitoes. Production of the
plants is cheap and self –
sustaining, but botanical toxins
may have health effects, and
the efficacy of these methods
need to be explored and
documented.

111. Larvicides
Larvicides are used in
mainly in urban areas and
also in rural areas affected
with dengue or
chikungunya as per
programme guidelines.

112. • This preparedness planning guide focuses on the following
main components that should be considered when developing
preparedness plans:
• Identification of risk areas
• Organization and coordination
• Early detection
• Response
• Risk and crisis communication

114. Preparedness planning should consider the
following scenarios:
Scenario A. Areas receptive for arbovirus transmission:
• During the period of mosquito activity
• Outside the period of mosquito activity.
Scenario B. Areas not receptive for arbovirus transmission
• Both scenarios require the following measures:
• Early detection and reporting of human cases
• Response after detection of cases:
– case management (including safety measures related to substances
of human origin)
– determining the risk of further transmission.

115. For Scenario A, the following additional actions should be taken:
–Early detection and reporting of mosquito-borne infections in
humans
–Monitoring and reporting of mosquito activity
–Additional response actions after detection of cases:
• epidemiological investigation
• vector control
• measures to ensure the safety of substances of human origin

116. NVBDCP presentation for
orientation for PS/MDs

117. Introduction
 National Vector Borne Disease Control Program (NVBDCP) is
implemented in the States/UTs for prevention and control of vector
borne diseases (VBDs) namely Malaria, Dengue, Chikungunya, Filariasis,
Japanese Encephalitis (JE) and Kala-azar
 The Directorate of NVBDCP is the nodal agency for planning, policy
making, technical guidance and monitoring and evaluation of program
implementation in respect of prevention and control of these vector
borne diseases under the overall umbrella of NHM.
 Dengue, Chikungunya and JE are known as outbreak prone VBDs

118. Sr
No
Disease Caused by Target year for elimination
1 Malaria Anopheles
mosquito
2030 (in
phased
manner)
Cat-I(15 states/UTs) by 2020
Cat-II(11states/UTs) by 2022
Cat-III(10 states/UTs) by 2020
2 Lymphatic
Filariasis
Culex
quinquefasciatus
2021 (Mf rate <1)
3 Kala-azar Sandfly 2020 (< I case per 10,000 population)
4 Dengue Aedes mosquito
5 Chikunguny
a
Aedes mosquito
6 Japanese
Encephalitis
Culex
VBDs & its Elimination Target

119. Strategy for prevention & control of
Malaria:
 Early diagnosis and complete treatment
 Vector Control Strategies (Indoor Residual Spray (IRS), LLINs,
fish, chemical and bio- larvicide, source reduction)
 Supportive intervention including behaviour change
communication (BCC), public private partnership and inter-
sectoral convergence, human resource development through
capacity building, operational research

120. Strategies for prevention & control of
Dengue & Chikungunya
 Surveillance - Disease and Entomological Surveillance
 Case management - Laboratory diagnosis and Clinical management
 Vector management - Environmental management for Source Reduction,
Chemical control, Personal protection and Legislation
 Outbreak response - Epidemic preparedness and Media management
 Capacity building - Training, strengthening human resource and Operational
research
 Behaviour Change Communication - Social mobilization and Information
Education and Communication (IEC)
 Inter-sectoral coordination - Health, Urban Development, Rural
Development, Panchayati Raj, Surface Transport and Education sector
 Monitoring and Supervision - Analysis of reports, review, field visit and
feedback

121. Strategies for elimination of Kala-Azar
 Parasite elimination and disease management
• Early case detection and complete treatment.
• Strengthening of referral;
 Integrated vector control
• Indoor Residual Spraying (IRS),
• Environmental management by maintenance of sanitation and hygiene
and provision of pucca houses in Kala-azar affected villages PMAY-G.
 Supportive interventions
• Behaviour Change Communication for social mobilization,
• Inter-sectoral convergence,
• Capacity building by training and Monitoring and Evaluation.

122. Elimination Strategies for Lymphatic Filariasis
 Twin pillar strategy adopted for elimination.
 Annual Mass Drug Administration
 Morbidity Management & Disability Prevention (MMDP)
 Implementation of Triple Drug
Therapy(IDA(Ivermectin+DEC+Albendazole))

123. Strategies for prevention & control of Japanese Encephalitis
 JE Vaccination
 Disease and vector surveillance
 Laboratory diagnosis through sentinel sites in
government/private medical colleges and hospitals
 Case management
 Capacity building
 BCC/IEC