4. Vectors of Public Health Importance
Class
Insecta
Mosquitoes
Flies
Human lice
Fleas
Reduviid bugs
Arachnida
Ticks
Hard Tick
Soft Tick
Mites
Leptotrobidium
Trombiculid mite
Itch mite
Crustacea
Cyclops
5. Vectors of Public Health Importance
Mosquito
• Anopheles
• Aedes
• Culex
Flies
• House flies
• Sand flies
• Tsetse flies
• Black flies
Human
lice
• Head &
body lice
• Crab lies
Fleas
• Rat fleas
• Sand fleas Reduviid
bugs
6. Vectors of Public Health Importance
Ticks
Hard tick
Soft tick
Mites
Leptotrobidium & Trombiculid mite
Itch mite
7. How do you differentiate them?
Insecta Arachnida Crustasea
Body division Head, neck, thorax,
abdomen
Cephalothorax ,
abdomen (no division)
in some cases
Cephalothorax,
abdomen
Legs 3 pairs 4 pairs 5 pairs
Antennae 1 pair None 2 pairs
Wings 1 or 2 pairs, some
are wingless
None None
Where found On land On land On water
15. Mode of Transmission
• Direct contact – man to man (close contact)
• Mechanical – Agent transmitted mechanically
• Biological – Disease agent either multiply or undergoes some
developmental change
16. Biological Transmission
• Propagative – Multiplies in the body of vector no cyclical
change (Plague)
• Cyclo - propagative – Undergoes cyclical change & multiplies
(Malaria)
• Cyclo - developmental – Undergoes cyclical change but no
multiplication (Filariasis)
17. Terminologies
Vector:
• An arthropod or other invertebrate which transmits infection by
inoculation through the skin or mucous membrane by biting or by
deposit of infective materials on the skin or on food or other objects.
Extrinsic incubation period:
• The period of time necessary fir the development of the disease
agent in the arthropod host.|
18. Terminologies
Definitive host
• The host in which the sexual cycle of the agent occurs
Indeterminate host
• The host in which the asexual cycle of the agent occurs
Infestation
• The lodgement, development and reproduction of arthropod on the
surface of the body or in the clothing
19. Habits of mosquitoes
• Feeding habits
• Females are haematophagous (for development of eggs),
Anthrophilic , Zoophilic or both
• Time of biting
• Evening or early night or Day biters
20. Habits of mosquitoes
• Resting habits
• Endophilic – Dark corners, Upper wall, behind pictures, under
furnitures
• Exophilic – Vegetation, shrubs, tree holes, cattle sheds , wells
21. Habits of mosquitoes
• Breeding habits
• Anopheles – Clean water
• Culex – Dirty & polluted water
• Aedes – Artificially collected water
• Mansonia – Water containing aquatic vegetation
23. Anopheles mosquito
• Usually breeds in fresh, unpolluted and oxygenated water.
• An. subpictus breeds in polluted water.
• It lays 150 eggs once in 3 days.
• Its life span is up to 2-3 weeks.
• Identification:
• It has spotted wings.
25. Culex mosquito
• Light brown in colour.
• Body segments having white bands but none on the legs.
• It breeds in polluted water.
• Common breeding sites:
• wet pit latrines, septic tanks, burrow pits, cess pools, drains, disused
wells and paddy fields.
26. Culex mosquito
• Bites maximum during mid night.
• Host: wild birds, cows, horses and man.
• These are weak fliers it can fly up to 2 miles.
• A single female can lay over 200 eggs at a time.
• These eggs can survive for more than five years.
• Wings are unspotted.
• The life span is 8 to 34 days.
27. Aedes mosquito
• The thorax and abdomen of the mosquitoes having black, white or
silvery scales. So it is also called as Indian Tiger mosquito.
• The legs having black and white rings.
• It is a day biting mosquito.
28. Integrated Vector Control
Mosquito control measures
Anti larval
Environmental
Chemical
Biological
Anti-adult
Residual spray
Space spray
Genetic control
Protection against bite
Net
Screening
Repellents
Mineral oil
Crude oil ,MLO
Paris green
Cu acetoarsenite , stomach poison
Synthetic insecticides
Fenthion , Malathion, Chlorpyrifos
& Abate
Larvivorous Fishes -
Gambusia affinis
Lebister reticulatus
Burrow pits, sewage oxidation
pond, cisterns, farm ponds
Source reduction
Elimination of breeding places
Filling , leveling & drainage of
breeding places
Changing salinity of water
Depends upon breeding habits of
mosquito
Pyrethrum extract
Nerve poison
For Ultra volume
fogging Malathion &
Phentrothion
Research phase
Sterile male
technique,
Chromosomal
translocation,
Sex destortion,
Gene replacement
DDT
Lindane
Malathion
Propoxur
16 meshes to
1 inch
0.0475 inch
size
Diethyltoluamide
Indalone
Dimethyl
phthalate
Dimethyl carbate
Ethyl hexanediol
Mosquito nets
0.475 inch size
hole
150 holes per
1 sq. inch
29. Mosquito borne diseases in India
S.No Type of mosquito Disease
1. Anopheles Malaria, Filaria (Not in India)
2. Culex Bancroftian filariasis, JE, West nile fever, Viral arthritis
3. Aedes Yellow fever, Filaria (Not in India)
Dengue, DHF, Chikungunya fever, Chikungunya HF, Rift
valley fever
4. Mansonoides Malayan (Brugian) filariasis, Chikungunya fever
30. Disease Vector Causal organism Reservoir
Malaria Anopheles Plasmodium sp. Man
Filaria Anopheles Micro filaria Man
Wuchereria bancrofti : Africa, Southern Asia, New guinea
Brugia malayi : Southern Asia
Brancroftian
Filariasis
Culex
quinquefasciatus
Wuchereria
bancrofti
Man
Westnile virus Culex
quinquefasciatus
West nile virus Birds
(amplifying host)
Japnese
encephalitis
Culex
tritaeniorhynchus
Japanese
encephalitis virus
Domestic pigs,
wild birds
Viral arthritis Virus
35. Anophelini Culicini
Eggs
1) Laid singly
2) Boat shaped with lateral floats
1) Clusters or rafts
2) Oval shaped & without lateral floats
Larvae
1) Rest parallel to water surface
2) Siphon tube absent
1) Head down, angle to water surface
2) Siphon tube absent
Pupae ST : Broad & Short ST : Long & Narrow
Adults
1) At rest, inclined to surface.
2) Spotted wings
3) Palpi : Long in both sexes
1) At rest, Hunch back
2) Unspotted wings
3) Palpi : Short in females
Difference b/n
36. List of entomology spotters
1. Anopheles mosquito – adult
female
2. Culex mosquito – adult female
3. Aedes mosquito adult female
4. Anopheles (eggs)
5. Anopheles (pupa)
6. Head Louse / Pediculus
capitis Female
7. Hard Tick
8. Sandfly (F)
9. Ascaris eggs
10. Cyclops
22-Jul-17 SPOTTERS 36
37. List of entomology spotters
11. Ascaris lumbricoides
12. Hookworm
13. Culex Life History
14. Housefly Life history
15. Head louse
16. Ancylostoma
17. Taenia with scolex
18. Ascaris - Male
19. Ascaris - Female
22-Jul-17 SPOTTERS 37
38. Entomology spotter questions
1. Identify the specimen in the slide
2. Write the identification points.
3. Write the public health importance
4. Write the control measures.
43. 2. Culex mosquito - adult female
1. Identify giving reasons
• Culex mosquito female; mosquitoes with unspotted wings; palpi short in
female, Antennae are not bushy
2. Name two disease spread by it
• Bancrofitian filariasis ; Japanese encephalitis; west Nile fever
22-Jul-17 SPOTTERS 43
45. 3. Aedes mosquito – Adult Female
1. Identify giving reasons
• Female Aedes mosquito; mosquitoes with white stripes on a black body
with unspotted wings
2. Mention two viral diseases spread by it
• Dengue, Chikungunya fever, Yellow fever, Filariasis, Rift valley fever.
22-Jul-17 SPOTTERS 45
51. 6. Head louse / Pediculus capitis Female
1. Identify giving reasons
• Head louse; Insect with body flattened dorsoventrally and five jointed
antennae; legs with claws
2. Mention any one form of treatment
• 0.5% malathion lotion applied to the head
22-Jul-17 SPOTTERS 51
53. 7. Hard Tick
1. Identify giving reasons
• Hard tick; oval shaped arthropod, with 4 pairs of legs and no antennae;
dorsal surface covered with scutum
2. Mention two diseases spread by this
• Kyasanus forest disease (India), Rocky mountain spotted fever, Russian
spring-summer encephalitis, colarado tick fever, tularemia, tick
paralysis, human babesiosis.
22-Jul-17 SPOTTERS 53
55. 8. Sandfly
1. Identify giving reasons
• Sandfly; small insect with body and wings densely clothed with hair; wings
are lanceolate in shape.
2. Name a disease spread by it
• Kala azar, sandfly fever, oriental sore.
22-Jul-17 SPOTTERS 55
57. 9. Ascaris eggs
1. Identify.
• Round worm or Ascaris lumbricoides eggs.
2. Mention the portal of entry into human being.
• By ingestion of infective eggs with contaminated food & water.
59. 10. Cyclops
1. Identify giving reasons
• Pear shaped arthropod with 2 pairs of antennae, 5 pairs of legs, a small eye
and a forked tail
2. Mention the diseases spread by it
• Guinea worm disease (Dracunculiasis)& Fish Tapeworm
3. Name the chemical used to kill it
• Tempos (Abate) at a concentration of 1 ppm.
22-Jul-17 SPOTTERS 59
61. 11. Ascaris lumbricoides
1. Identify the worm
• Round worm or Ascaris lumbricoides
2. Mention the portal of entry into human being
• By ingestion of infective eggs with contaminated food & water
22-Jul-17 SPOTTERS 61
66. 13. Culex Life History
1. Identify the specimen.
• Life history of Culex mosquito.
2. Mention the breeding places for it.
• Dirty and polluted water collections e.g. open drains, cesspools,
leaking septic tanks etc.
68. Housefly Life history
1. Identify the specimen.
• Life history of housefly.
2. Name any 2 diseases transmitted by this vector.
• Cholera, Diarrhoea, Dysentery, Typhoid, Paratyphoid,
Amoebiasis, Anthrax, Polio, Trachoma (any 2)
70. Head louse
1. Identify the specimen.
• Head louse
2. Mention any 2 diseases transmitted by it.
• Epidemic typhus, Relapsing fever, Trench Fever, Dermatitis
74. Taenia with scolex
1. Identify the specimen.
• Taenia with scolex
2. Mention the 2 food items in which this parasite may be present.
• Undercooked or uncooked / raw pork and beef
