Dengue control measures

National Vector Borne Disease
Control Programme
Madhya Pradesh
Training of Medical Officers
At Bhopal
14th August 2019
Dr JC Paliwal

Vector Borne Diseases
 Small Creatures
Big Threat

7 Vector Borne Diseases
Malaria
Dengue
Chikungunya
Filaria
Japanese Encephalitis
Kala-azar
Zika

Small Creatures Big Threat
Plasmodium
Den Virus
Woucheria
Anopheles
Aedes
Culex
Malaria
Dengue/
Chikungunya
Filaria
Chik Virus

 To reduce the disease burden
of Dengue and Chikungunya
 To reduce the case fatality rate
(CFR) due to Dengue
The objectives and Strategies

Dengue is a self limiting, acute
disease
Dengue is caused by an arbovirus
& transmitted by Aedes
mosquitoes.
Both Aedes aegypti and Aedes
albopictus can transmit the
disease.
Dengue

SIGNS & SYMPTOMS
OF DENGUE &
CHIKUNGUNYA

DENGUE
Fever
Headache
Joint & muscle pain
Nausea, Vomiting
Bleeding from nose
Excessive thirst
Difficulty in breathing
Skin rashes

CHIKUNGUNYA
Fever
Chills
Minor joints pain & Swelling
Skin rashes
Nausea

AGENT
Flavivirus
Single stranded RNA virus , 50 nanometers
Four sero types DEN- 1 to 4
DEN -1 and DEN -2, more prevalent in India.
Although all four serotypes are antigenicaly similar,
they are different enough to elicit cross-protection
only for few months after infection by any one of
them
Infection with any one serotype confers lifelong
immunity to the virus serotype.
Man and mosquito are reservoirs of infection.
Zoonotic virus , Man is accidentally infected

Some infections result in DHF (Dengue
Haemorrhagic Fever)
Severe form – DSS (Dengue Shock
Syndrome) can be lethal –because of
increased vascular permeability & shock.
Over past two decades, global increase in
frequency of DF, DHF and its epidemics,
with a concomitant increase in disease
incidence.
Dengue

Status
Dengue & Chikungunya
in INDIA &M.P.

Dengue/ Chikungunya Cases in India
Year Dengue Deaths Chikungunya
2010 28,292 110 48,176
2011 18,860 169 20,402
2012 50,222 242 15,977
2013 75,808 193 18,840
2014 40,571 137 16,049
2015 99,913 220 27,553
2016 1,29,166 245 64,057
2017 1,88,401 325 67,769
2018(Nov) 89,974 01 47,208

Dengue & Chikungunya Cases in M.P.
Sentinel sites established for diagnosis
Year Dengue Deaths Chikungunya
2009 1,467 92 05
2010 192 01 113
2011 50 00 280
2012 239 09 20
2013 1,255 13 139
2014 2,176 08 161
2015 2,108 14 67
2016 3,150 12 2,280
2017 2,666 06 2,257
2018(Nov) 4,265 00 3,131

Aedes aegypti (Vector)
Tiger Mosquito
Virus is transmitted by Female Aedes
Dengue
Yellow Fever
Chikungunya

Life Cycle Aedes Mosquito,
7 – 9 Days & Life 3 Weeks
2 Days
5 Days
1 - 2 Days
3 Weeks
Adult Mosquito

Breeding Habit
It breeds in fresh water inside & around
houses
Lays eggs preferentially in water jars,
discarded containers, coconut shells, old
tyres etc.
Year round breeding 250 N to 250 S
Tropics and sub-tropics are its favorite zones.
It is generally an urban/ semi urban vector
Can survive up to 3 weeks under normal
temperature & humidity

Silvery-white ‘sickle -
shaped“ pattern of scales
on its scutum
White stripe down the
center beginning at the
dorsal surface of the
head and continuing
along the thorax.
Identification of
Aedes aegypti
Identification of
Aedes albopictus

Vectorial Capacity of Aedes
Propagative type of Transmission
After feeding on viremic host, mosquito takes
8 to 11 days for virus to propogate, to levels
sufficient to transmit
Once infected, remains infected for life
160 C to 400 C temperature is suitable for
transmission of disease
Aedes ceases to bite below 160 C temperature
Transovarian Transmission

Biting Habit
Day biter
Late Morning
Early Evening
Repeated bite
Bites when normally coils,
repellents, nets etc are not used
Feeding Habit
Anthroponotic

Resting Habit
Rests Indoors in closet & dark places
Rests Outdoors in cool & shady places
Difficult to catch adult mosquito
Risky to catch infected mosquito
Flight Range
Limited
About 400 Mtr.

Need to control Aedes in Larval stage

Vector,
Aedes aegypti Breeding Sites

Cement Cistern Attached to Wall
Activities

Pot for drinking water for Animals/ Birds

Earthen Pot on Roof during Rains
Activities

Earthen Pots on Ground
Activities

Tires, Waste latrine Sheet, Plastic
container

ePNjksads iztuu LFky
Tyres
Tree Hole

An. stephensi & Aedes aegypti
Construction Site Cement Tank

Key Eight Elements of
Control Plan

(i) Surveillance -
• Disease Surveillance
• Entomological Surveillance
(ii) Case management
• Laboratory diagnosis
• Clinical management
(iii) Vector management
• Environmental management for Source
Reduction
• Chemical control
• Personal protection
• Legislation
Keyeight elements of Control Plan

Key eight elements of Plan are as under
(iv) Outbreak response
• Epidemic preparedness
• Media management
(v) Capacity building
• Training
• Infrastructure development
• Operational research
(vi) Behaviour Change Communication
• Social mobilization,
• IEC
(vii) Inter-sectoral coordination
• Health & non health sector
(viii) Monitoring & Supervision
• Review, field visit , feedback
• Analysis of reports

ELISA based antigen detection test (NS1 - nonstructural
protein 1) Fever from day 1 to day 5
Antibody detection test IgM Capture ELISA (MAC
ELISA) after 5th day of onset of fever
MAC-ELISA is based on detecting the dengue-specific
IgM antibodies in the test serum by capturing them out
of solution using anti-human IgM
Rapid Diagnostic tests -not recommended
under the programme
Rapid Diagnostic Test (RDT) kits for IgM/IgG
antibodies and NS1 are available
Accuracy of these tests is not known since they have not
yet been properly validated.
Laboratory Diagnosis –GoI Recommended
Elisa Based Tests For confirmation of Dengue infection

Samples should be collected soon after the onset of
illness or admission (acute serum, S1)
Shortly before discharge from the hospital or,
In the event of death (convalescent serum, S2).
Collect a third specimen- after subsidence of fever
-late convalescent serum, S3, (i.e.7-21 days after
the acute serum S1)
Transport in cold chain (40 C to 80 C temperature )
 Lab Testing- Mention day of onset of fever and day
of sample collection to perform :-
NS1, fever day 1 to 5 and
IgM, fever after day 5.
Collection of Specimens

WHICH LARVICIDES USED
Larvicide's
which are safe,
without any odour or colour,
having residual effect with low mammalian
toxicity and
do not pose any health hazard
These are:-
Temophos (Abate)/ Bacillus thuriengensis
Mosquito Larvicidal Oil (MLO)
Paris green

2.5cc dissolved in 10 litres water.
20 cc sprayed over one Sq. meter areas.
1 litre Solution for 50 Linear meters.
200 litres for one Hectare area.
Equipment- Knapsack sprayer.
Can apply in all water bodies.
Weekly application.
1 ppm (1 mg per liter of water).
Temophos
Larvicide - Doses Applied

Adulticides Used
Adulticides
 Pyrethrum Ext 2%
 Malathion Technical 95%
 Synthetic Pyrethroid

Space Spray- Indoors
1 litre Pyrethrum mixed in 19 litres
kerosene/Diesel.
Space spray, 15-30cc solution sprayed
over 30 Cubic meter space at a
concentration of 0.1% - 0.2%.
Time- Morning or Evening.
Equipment- Hand operated fogging
machine/ Flit pump/ Ganesh pump/
SP Bolo machine.
Close doors and windows for 1 hour.
Pyrethrum Extract 2%

Pumps Used
Ganesh Pumps
Aspeebolo Machine

Space Spray Outdoors
5 parts Malathion Technical mixed
in 95 parts diesel.
Time- Morning or Evening.
Equipment- Thermal fogging
machine mounted on vehicle.
Vehicle speed 6 Km per hour.
Fogging outdoors on roads.
Outside air flow should be normal.
Malathion Technical 95%

59
Epidemiological Interpretation of
Various Entomological Indices
Breteau Index >10 (High risk of Transmission)
Breteau Index <5 (Low risk of transmission)
House Index >5% (High risk of Transmission)
House Index <1% (Low risk of Transmission)

60
Entomological Surveillance
Aedes aegypti is the main vector
VECTOR SURVEILLANCE
1 Larval surveys:
i) House index (Hl):
percentage of houses infested with larvae and/or pupae
HI = Number of Houses infested X100
Number of Houses inspected
HI = 15 X 100 = 15
100
> 5 HI indicates high risk of transmission
The house index has been most widely used for
monitoring infestation levels, but it does not take into
account the number of positive containers nor the
productivity of those containers.

61
VECTOR SURVEILLANCE
1 Larval surveys:
ii) Container Index (Cl):
percentage of water holding containers infested with
larvae or pupae.
CI = Number of Positive Container X100
Number of Containers inspected
CI = 45 X 100 = 18 %
250
Container Index provides information only on the
proportion of water-holding containers that are
positive

62
VECTOR SURVEILLANCE
1 Larval surveys:
iii) Breteau Index (Bl):
Number of positive containers per 100 houses inspected
BI = Number of Positive Containers X100
BI = 45 X 100 = 45
100
> 10 BI indicates high risk of transmission
Breteau index establishes a relationship between
positive containers and houses, and is considered to be
the most informative, but again there is no reflection
of container productivity

63
VECTOR SURVEILLANCE
1 Larval surveys:
iv) Pupae Index (Pl):
Number of pupae per 100 houses
PI = Number of pupae X100
PI = 30 X 100 = 30
100
Pupal Index provides vital information, which needs
special attention for taking preventive measures.

64
Interpretation of Various
Entomological Indices
Date Total
House
s
House
s +ve
for
larva
Total
Container
s
Contai
ner +ve
for
larva
Aedes Larva Collection
(Index)
Result
Area
under
House Bruteau Contai
ner
6.6.14 20 12 18 12 60% 90 66%
High
risk
7.6.14 13 3 6 3 23% 46 50%
High
risk
8.6.14 33 0 0 0 0% 0 0%
Low
risk
Distt.-Sehore CHC-Ashta Village-Khajuriya Kasam

65
Interpretation of Various
Entomological Indices
Date Total
House
s
House
s +ve
for
larva
Total
Container
s
Contai
ner +ve
for
larva
Aedes Larva Collection
(Index)
Result
Area
under
House Bruteau Contai
ner
6.6.14 20 12 18 12 60% 90 66%
High
risk
7.6.14 13 3 6 3 23% 46 50%
High
risk
8.6.14 33 0 0 0 0% 0 0%
Low
risk
Distt.-Sehore CHC-Ashta Village-Khajuriya Kasam

First reported during 1956 from Vellore district in
Tamil Nadu.
First DHF outbreak occurred in Calcutta (West
Bengal) in 1963 with 30% haemorrhagic
manifestations
As Aedes aegypti breeding is more common in urban
areas, the disease was prevalent in urban areas.
Due to socio economic &man made ecological
changes Aedes aegypti mosquitoes found into rural
areas,
So chances of spread of disease in rural areas have
increased.
Dengue in India

Collection of Specimens
Laboratory diagnosis of dengue depends on proper
collection, processing, storage and shipment of the specimens.
 Samples could be collected as soon as possible after the
onset of illness, hospital admission or attendance at a clinic
(acute serum, S1)
 Shortly before discharge from the hospital or, in the event
of a fatality, at the time of death (convalescent serum, S2).
 In the event hospital discharge occurs within 1-2 days of
the subsidence of fever collect a third specimen 7-21 days
after the acute serum (S1) was drawn (late convalescent
serum, S3).
While sending the samples for lab confirmation the day of
onset of fever and day of sample collection should be
mentioned to guide the laboratory for the type of test to be
performed NS1 (nonstructural protein 1) for samples
collected from day 1 to 5 and IgM after day 5.

Laboratory Diagnosis -Recommended tests -
GoI recommends use of ELISA based antigen detection test
(NS1) for diagnosing the cases from 1st day to 5th day
Antibody detection test IgM Capture ELISA (MAC ELISA)
for diagnosing the cases after 5th day of onset of disease for
confirmation of Dengue infection.
MAC-ELISA is based on detecting the dengue-specific IgM
antibodies in the test serum by capturing them out of
solution using anti-human IgM
Rapid Diagnostic tests
A number of commercial Rapid Diagnostic Test (RDT) kits
for anti-dengue IgM/IgG antibodies and NS1 are available at
present which produces the results within 15 to 23 minutes.
However, the accuracy of most of these tests is not known
since they have not yet been properly validated. Hence
currently use of RDT is not envisaged under the programme.

Dengue control measures

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