Dengue Vector Surveillance provides fundamental information for application of an appropriate vector control intervention. Vector surveillance and control are strongly interlinked, and vector surveillance loses its worth without utilization of information for appropriate vector control. In Pakistan dengue is endemic in all parts of the country. First epidemic of the disease was reported in 1994 from karachi, thereafter, regular outbreaks are being observed after every 3-5 years.
1. Muhammad Asif Mahmood
Sr. Entomologist,
Institute of Public Health
Lahore
Dengue Vector Surveillance & Control
In Context of Punjab Province
2. Activities Comparison between 2019 and 2020
KEY FACTS
• Vector Born Viral Disease: 4 serotypes of Dengue virus
• Aedes aegypti & Ae. albopictus are known vectors
• 2.5 Billion people (about half of worlds population) is at risk of
dengue
• 1.8 Billion Resides in Asian pacific region
• Outbreaks usually occur every 3-5 years
• Pregnant woman, children and elderly people are at high risk of
complicated Dengue (DHF/DSS)
• No specific treatment for dengue, but early detection and
access to proper medical care lowers fatality rates below 1%.
• Dengue prevention and control HIGHLY depends on effective
vector management.
4. District Wise Comparison of Dengue Cases 1st Jan to 29th Dec, 2021
Activities Comparison between 2019 and 2020
5. Institutional Arrangements : Monitoring & Decision Making
Committee Chaired By
Central Emergency Response Committee (CERC) CM
Cabinet Committee on Dengue (CCD) by Minister P&SHCD
Provincial Implementation Committee (PIC) Chief Secretary
Technical Advisory Committee (TAC)
Chair: Secretary SHCMED
Co-Chair: Secretary P&SHD
Dengue Experts Advisory Group (DEAG) Chairman DEAG
District Emergency Response Committee (DERC) DCO
Town/ Tehsil Emergency
Response Committee (TERC)
Assistant Commissioner
6. CD & EPC Program Activities 2021-22
Name of the Activity 2021 2022
Vector
Surveillance
No. Of Positive Containers Detected from houses 204,697 172
No. Of Positive Containers Detected from outdoor spots 14,350 44
Awareness
No. of community Awareness Session 194,221 1780
No. of Print Media ( Newspaper) advertisement 4,890 241
Monitoring
Central Emergency Response Committee Meetings 2 0
Cabinet Committee Meetings 17 1
District Emergency Response Committee Meetings 2,454 186
Tehsil/ Town Emergency Response Committee Meetings 8,781 654
8. Vector Surveillance: District to Union Council
• CEO Health
• DOH (PS)
• DPC
• Entomologist
• CDCO
DCO • DDOH
• Entomol
ogist
• Inspector
ENV
• CDCS
• Surveillance
Teams
District Level Tehsil/ Town Level
9. Vector Surveillance
• Vector surveillance is systematic monitoring of the seasonality
and abundance of vector populations for application of vector
control measures
It also provides information about
• species composition
• vector behavior
• Vectorial capacity and competence
• susceptibility to insecticides.
10. Functions of Vector Surveillance
Direct links b/w vector surveillance and vector control is of
utmost important, otherwise, it loses its function
• Identification of hotspots, Stratification of the area and
application of appropriated vector control intervention
• Monitoring of efficacy of vector control interventions
11. Indoor Vector Surveillance
• The routine vector (larval) surveillance and control activity
continued round the year.
• Indoor Teams ensure proper surveillance of the houses
including the roof top and other breading spots for the
presence of larva or adult dengue mosquito along with
complete preventive activity (mechanical, chemical or
biological control and health education).
• Every activity is entered on specified forms and also
uploaded directly through mobile application.
12. Outdoor Vector Surveillance
• All premises/areas except family residences such as offices, schools, hotels, factories
and under construction buildings, marriage Halls, hospitals, religious places etc are
classified as outdoor hotspots.
Inter Sectoral Collaboration
• Every department need to notify its dengue focal person
• Every department is responsible for house keeping activities to avoid mosquito
breeding in their premises.
• All outdoor Hot-spots be registered on PITB Dashboard
• Outdoor surveillance teams of DDHO Office will also cross checking outdoor
surveillance activities on regular basis.
15. Surveillance at Immature stages (Larvae & Pupae)
• Dipping
• Pipetting
• Netting
• Whirl Pool etc.
• Ovitrap surveillance.
The selection of appropriate methods depends on
surveillance objectives, levels of infestation, and
availability of resources.
16. Larval surveys (LS)
• LS are more practical in case of Aedes.
• Sampling unit is the house or premise, which is
systematically searched for water-storage containers.
• Containers are examined for the presence of larvae or
pupae.
• The collection of specimens for laboratory examination
is necessary to confirm the species present.
17. Stratification / color coding
For the purpose of effective vector surveillance and control, all areas/UCs
are divided into three color coded clusters.
• Red: The areas in radius of 200 meters around confirm case will be
labeled as Red and house to house surveillance will be conducted
within 7 days.
• Yellow: The area positive for Dengue larva but no confirmed case will
be labeled as Yellow and surveillance will be conducted within 15 days.
• Green: The area with no Dengue larva or confirmed case will be
labeled as Green and surveillance will be conducted in 30 days.
• If no vector found in two consecutive rounds, the red area will be
converted into Yellow and yellow to green.
18. Daily Team Meeting
• UC Incharge ensure daily meeting at the end of day’s work to
• analyze the data of every cluster calculating BI/HI/CI locally to generate local
response and thus maintain record of every such activity in a file maintained for
every team.
• For any unusual matter, inform DDHO for support.
• Record of insecticide consumption will be maintained at the CEO(DHA)/ DDHO / UC
Supervisor
• Reports of chemicals used will be uploaded on the Dashboard on daily basis
23. Spray sheet collection
Equipments :White cotton sheets (sizes 2m x 1m, 2m x 2m and 2m x
3m); hand sprayers; pyrethrin solution; kerosene; small Petri dishes;
paper cups; hand lens; forceps; a container (or preferably a picnic box)
for transporting mosquitoes; cotton wool; filter paper; a torch.
M.Asif Entomologist
24. Alert Generation
• The data uploaded on the PITB Dashboard is used to calculate
various indices like
• Breateau, House & Container Index for alert generation and
preventive action.
• Alerts regarding vector indices are generated by the “Alert
Generation Team” notified by TWG.
• Breateau Index value of 3 or above is considered BI alert
25. Smart Trap for Mosquito Surveillance
Smart Trap:
A rough definition could be a trap containing some sort of
electronic device with magical software that collects and
evaluates data and then transfers this data to a place where it
can be easily accessed with another “smart” device.
U N-U
26. BG COUNTER
BG Counter: fixed on top of BG-Sentinel Trap
• An electronic device with software
• Differentiate mosquitoes from other insects
• Counts mosquitoes
• Transmits the results wirelessly to a cloud server
• Data received can be used to develop
• Mosquito activity pattern
• Adult density indices
• Population dynamics
• Prediction models
• Historical analyses of infested areas
• Biogents AG, Germany U N-U
27. John Hopkins University’s company VecTech
Smart System developed by
John Hopkins University spinoff company VecTech
• High resolution camera – installed within specific type of trap
• Mosquitoes caught by sticky paper
• Camera lens photographs trap’s mosquitoes
• Images are transmitted to remotely located lab
• These images are analyzed by staff members
• Images are so detailed that easily can identify Aedes aegypti
• Trap could be used for 4 weeks before its papers filled by mosquito catch
U N-U
28. Microsoft’s Jackson Trap
Smart System developed by
• Microsoft's broader Project Premonition
• Aim -- learning how to spot early signs of outbreaks.
• Named as Jackson’s Trap after Ethan Jackson, lead Entomologist
at Microsoft
• The trap consists of 64 "smart cells," compartments outfitted with an
infrared light beam
• When an insect crosses the beam, its shadow changes the light intensity
in a way that forms almost a fingerprint for that species
• Trap is programmed for the desired species—e.g. Aedes aegypti
• When one flies into a cell, its door snaps closed
• In pilot testing -- more than 90 % accuracy
• On each mosquito’s captured, sensors record the time, temperature,
humidity and other factors
• Show what environmental conditions have different species buzzing
• The information is to be used to schedule pesticide spraying
U N-U
29. Benefits of using Smart Gadgets
• More efficient
• No need of man power – less risk to get diseases
• Mosquito maps are prepared by location, gender and species
• Early identification of mosquito species
• No chance of human error
• More accurate data received
• Quick decision to take action like spraying
• Data can be recorded at lab / office
U N-U
31. Activities Comparison between 2019 and 2020
Integrated Vector Management (IVM)
• IVM is defined as a 'rational decision-making process for the optimal use
of resources for vector control’.
• IVM recommends application of evidence based vector control
interventions in best possible combination to improve
• Efficacy
• cost effectiveness
• ecological soundness
• sustainability.
33. Vector Control Methods
• Environment Management
• Source Reduction
• Personal Protection: Repellants/Screening/LLINs/Cloths
• Biological Control : Use of larvi-vorous fish, Bti, release of Wobachia
infected males, GM
• Chemical Control
• Use of chemical pesticides for vector control
34. Environmental Manipulation
• Draining water supply installations
• Covering domestic water-storage containers
• Cleaning flowerpots/vases
• Managing discarded receptacles
• Managing glass bottles and cans : Reuse, recycle or bury in landfills.
• Tire management
• Filling up of cavities / tree holes or bamboo holes
• Regular Street cleaning
35. Personal protection
• Protective clothing
Sufficiently thick or loosely fitting cloths. long sleeves and trousers
• Mats, coils and aerosols
Mosquito coils and aerosols. Electric vaporizer mats and liquid
vaporizers are more effective.
• Repellents
Natural: Citronella oil, lemon grass oil, rose bary and neem oil etc.
Chemical: DEET (N, N-Diethyl-m-Toluamide), Picardin
36. Insecticide Treated Nets and other Materials
• Mosquito nets Protects infants and
night workers who sleep during day
• LLIN- three years of recommended
efficacy under field conditions
• Insecticide treated nets and curtains
reduce mosquito longevity on contact.
37. Biological Control
In 2019 researchers reported having nearly eradicated A.
albopictus on two islands in Guangzhou, China. Populations of the
species dropped by 94 percent between 2016 and 2019 following
the introduction into the wild of female mosquitoes that had been
sterilized by radiation in a laboratory and males that had been
infected with a strain of the bacterium Wolbachia pipientis, which
impeded the males’ ability to reproduce and
38. Chemical Control
Application of insecticides for
vector control
• Chemical Larviciding
• Residual Spray (IRS/PRS)
• Space Spray
39. Safe use of Chemical Insecticides
• Pesticides are toxic to both pests and humans.
However, they need not be hazardous to humans and
non-target animal species if suitable precautions
are taken.
• Causes of adverse effects of insecticides
• Ingestion: intentionally or accidentally
• Direct Contact with the skin for a long time
• Inhaled during spraying or mixing
• Special precautions must be taken during transport,
storage and handling.
• Regular cleaning and repair of spray equipment
• proper training of spray-men.
40. Larvicides used in Punjab, Pakistan
• Temephos 1 % Granules
• 1 g / 10 L of water container
• 1-2 g/ 0.1m3
• Temephos 50% EC :
• Mix 16ml in 10 L water (in spray pump)
• Uniformly spray 400 m2 area
• 2ml/ 1000L container
41. Indoor Residual Spray
• Application of
– residual insecticides at the interior surfaces (walls, ceiling and other structures)
– Where vector mosquitoes known to rest
– IRS interrupts the cycle before the female mosquito can further transmit the
infection by killing or reducing the longevity of the vectors.
42. Insecticides in Use & Dose
Alphacypermethrin 10% SC
A. Indoor Residual Spray (IRS)
• Properly Mix 75 ml chemical /10L water in spray
tank
• Spray 3-4 rooms (250m2 Area)
B. Peri-focal Residual Spray (PRS)
• Internal & External walls of all containers (dry /
wet)
• All walls/ objects within 60 cm of container
43. Space/Fogging Spray
• Recommended During Emergencies only
• Indoor space spray
• by hand carry machine
• Outdoor space spray
• by vehicle mounted machine
45. Wind Speed
• 3.5–15 km/hour
• Wind speed can be measured using a
handheld anemometer.
• Apply early morning or afternoon
46. Monitoring insecticide resistance
• All disease vector control programs highly
depends upon use insecticides
• Regular monitoring of insecticide
susceptibility/ resistance is vital to make
decisions about selection of an insecticide
for vector control and/or shift to
alternatives
• District Administration should establish
entomological labs and facilitate
entomologists to carry out bio-assay tests
on regular basis.
48. Activities Comparison between 2019 and 2020
Identification of Dengue Vectors
• Aedes: > 950 species (order Diptera)
• A. aegypti Primary vector
• A. albopictus Secondary vector
• Narrow black bodied insects
• Light and dark scales on the abdomen and thorax
• Alternating light and dark bands on the legs.
• Single white median scale on the scutum (Ae.albopictus)
• Two central lines of white scale and lyre shaped pattern
of scales on sides
49. Difference between Eggs
Aedes – Ovi-position
• Eggs are cigar/ rice grain shaped
• Eggs are laid Singly in a pile, on moist substrates
above water surface
• 30–150 eggs / batch
• Hatching in 1-2days when dipped in water
• All eggs do not hatch at a time
• Need drying and wetting
• Resistant to dryness 6-12 months
50. Difference between Larvae
Aedes Larvae
• Siphon tube short, thick and dark colored.
• One tuft of hairs at siphon tube
Culex
• Siphon tube long, thin and light colored
• More than One tuft of hairs at siphon tube
Anopheles
• Parallel to water surface
• Siphon tube absent
• Make angle with
water surface
51. Difference between Pupae
Pupae does not feed
• Breathing trumpet present on head
• Adult structures are formed in the pupal case
Aedes & Culex
• Breathing trumpet long with narrow opening
Anopheles
• Breathing trumpet short with wide opening
53. Activities Comparison between 2019 and 2020
Vector Biology and Bionomics
• Food: Plant juices & flower nectars. (Females need blood meal for development of eggs). Males do
not bite. Larvae feed on micro-organisms.
• Breeding sites: Preferably container breeder, inside or around the premises (houses, offices etc)
• Biting habits : Diurnal, Anthropophagic. Equally endo-phagic & Exo-phagic
• Bites multiple people during each feeding period.
• Resting Behaviour: after blood meal: indoor under furniture, curtains, cabinets etc
after emergence on the container walls and nearby surfaces.
• Flight range : short 50-100 meters
• Longevity : female mosquito is 2 to 3 weeks. The male lives 1 to 7 days.
• Optimum Temperature: 27+2oc , Humidity: 70 + 5
• Max die below 10 degrees and above 44 degrees Celsius.