1. Desiree R. Jaleco, RN
School Nurse II
Sagay National High School

2. Objective
• General
 Providethe scientific framework of the OL
Trap Program of Dengue vector control
QUITO OL-TRAP
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3. Dengue Fever
• Definition
 Also known as breakbone Fever
 An infectious tropical disease caused by the
Dengue Virus
QUITO OL-TRAP  Mosquito-borne viral disease
 Caused by one of four serotypes of
flaviviruses
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4. Four Strains of Serotypes Viruses
• DENV – I
• DENV – II
• DENV – III
QUITO OL-TRAP
• DENV - IV
All four types can cause full
spectrum of disease.
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5. Classification (WHO)
• DENGUE FEVER
• DENGUE HEMORRHAGIC FEVER
 GRADE 1 – presence of bruises
 GRADE 2 – presence of spontaneous bleeding
 GRADE 3 & 4 – referred as dengue shock
QUITO OL-TRAP
syndrome
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6. Signs and Symptoms
• Dengue Fever
 Fever
 Headache
 Muscle and joint pains
QUITO OL-TRAP
 Skin rashes
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7. DENGUE HEMORRHAGIC FEVER
QUITO OL-TRAP
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8. DENGUE SHOCK SYNDROME
QUITO OL-TRAP
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9. QUITO OL-TRAP
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10. Management
• No specific treatment
• Only symptomatic and supportive treatment
 Paracetamol (Acetaminophen)
 Oral Rehydration
 IV fluids
QUITO OL-TRAP
 Blood Transfusion (packed RBC or Whole Blood)
 Discontinue IV fluids during recovery phase to
prevent fluid overload
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11. The Vector
QUITO OL-TRAP
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12. Vector Biology
Aedes aegypti Aedes albopictus
- primary vector - secondary vector
- involve in cases of - maintains the virus in the
General characteristics epidemics environment
- urbanized areas - rural areas
- lives indoors - lives outdoors
QUITO OL-TRAP - confined to artificial - prefers to breed outdoor,
Breeding habitat containers indoors in natural containers
- rests in cool, dark corners - rests outdoors in
Resting habits of the house clearings and vegetations
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13. Morphology
Aedes aegypti Aedes albopictus
Size - 3-4 mm - same
Color - dark brown to black - same
- lyre-shaped white
Thorax marks or scales
- single white marks
QUITO OL-TRAP
- with white and dark
Abdomen - with white scales
marks
Legs - with white marks - same
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14. Vector Characteristics
• Biting Habits
 “daybiters” with two peaks of biting time:
 1 to 2 hours after sunrise
 1 to 2 hours before sunset
 only female mosquitoes bite because of the
requirement of blood for oviposition
QUITO OL-TRAP
 males do not bite but feed on plant juices and
nectar of flowers
 man is the preferred host but
in his absence, lower
vertebrates serve as substitute
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15. Vector Characteristics
• Flying Habit
 do not fly great distances
 farthest flight distance is within 200 to 400
meters radius from their breeding places
• Adults found around 50 meters from the
QUITO OL-TRAP
breeding sources
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16. Bionomics
• at temperatures <10oC and >40oC, no
developmental process takes place
• females mates with male only once
• Blood meal takes place after
QUITO OL-TRAP 48 hours from emergence and
after mating for egg
production
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17. Bionomics
• oviposition takes place about 2 to 5 days
from blood engorgement
• prefers dark-colored background for
oviposition
QUITO OL-TRAP
• lays egg 3 to 4 times in its lifetime
 60 to 100 eggs per batch
• Survival potential: 20-30 days
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18. Life Cycle (10-12 days)
Eggs:
- Black and oval in
Adult shape
-Maxillary pulps shorter - Laid singly above
than probosis water surfaces of
-Wings uniformly grayish containers
- Without float
black
- Viability: 6 months to
-Body and legs are black 1 year due to the
with distinctive white presence of chorion
patches throughout
-Thorax has markings
QUITO OL-TRAP
2 - 3 days
1 - 2 days
Larva:
Pupa - Feeding stage
6 - 8 days - Breeds in clean and
-Non-feeding stage
-Breeding trumpet is non-polluted water
long, slender with - Short and stout siphon
narrow opening with one pair of hair tuft
- Rests at an angle to the
water surface
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19. DOST-DOH Dep ED OL Trap
Ovicidal/Larvicidal Trap
• a method used to control the
reproductive capacity of dengue
carrying mosquitoes
QUITO OL-TRAP
• A project of DOST-DOH using a
natural/organic larvicide solution
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20. Usage of OL Trap
• Larvicide solution emits odor that attracts
female Aedes mosquitoes for oviposition
• The lawanit paddle submerge in solution
through capillary action serves as the
QUITO OL-TRAP breeding place
• The larvicide solution kills the eggs and larva
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21. Servicing the OL Trap
• OVITRAPS are installed and serviced
every six days in locations where
transmission of dengue is probable
 nursery schools
 pre-schools
QUITO OL-TRAP
 elementary schools
 Hospitals
 community with confirmed dengue cases
 Ovitrap Index = > 10%
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22. Setting the OL Trap
• Step 1
 Fill
the plastic tumbler with tap
water up to the lined mark just
above the DOST logo (~250 ml)
QUITO OL-TRAP
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23. Setting the OL Trap
• Step 2
 Pour one pack OL pellets
into the plastic cup
 Stir thoroughly to
ensure pellets are
QUITO OL-TRAP
dissolved
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24. Setting the OL Trap
• Step 3
 Placethe lawanit stick in the
solution with the rough
surface facing up
QUITO OL-TRAP
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25. Setting the OL Trap
• Step 4
 Place 1 cup each inside
and outside the classroom
in a low-lying and dark area
 If outside, protect from direct
QUITO OL-TRAP sunlight and rainfall
 Take care not to spill the
contents
 Keep out of reach of children
and animals
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26. Setting the OL Trap
• Step 5
 Collect trap and note for
the following on the sixth day
 Eggs on the paddle
 Live larva/pupa
QUITO OL-TRAP
 The presence of even one
larvae indicates a positive trap
 Recordin the OL Trap
Monitoring Sheet (3 copies)
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27. Setting the OL Trap
• Step 6
 Repeat steps 1-5 every 6 days
 Set the traps every Wednesday
 Collect traps every Tuesday
 Finalize report every Tuesday
QUITO OL-TRAP
 Submit a copy of the report to city dengue
coordinators every Wednesday
Note: If collection period falls on a holiday, please
collect traps a day before
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28. Cleaning the Trap
• Vigorously brush-off into
the solution eggs stuck
into the lawanit creases
• Kill the larva/eggs by
pouring hot water into
QUITO OL-TRAP
the black tumbler
• Dispose contents
properly by pouring
contents on dry ground
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29. Ovitrap Index
Total Number of positive traps
X 100%
Total Number of traps planted
QUITO OL-TRAP
If OI is >10%, the place is vulnerable to
dengue transmission.
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30. Remember:
• A positive trap means there is at least
one mosquito laying its eggs in the
sampling site (surveillance site)
QUITO OL-TRAP
• Aim is eliminate this one mosquito
laying its eggs
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31. THANK YOU!
QUITO OL-TRAP
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