Dr R.N.Roy
Associate Professor
Department of Community Medicine
Malaria
 A febrile illness caused by asexual plasmodium
parasite transmitted by infected female anopheles
mosquito
 Plasmodium genus of parasite infect RBC in human
 Occasional infections of monkey with P. knowlesi,
Magnitude of problems
 About half the world’s population (3.3 billion) in live in
areas(109 countries & territories) endemic for malaria
 Estimated 247 million malaria cases in 2006, of which
91% were due to Pf
 Around 40% of the global population at risk of malaria
resides in SEA Region
AFRO: African Region
SEARO: South-East Asia Region
EMRO: Eastern Mediterranean
AMRO: Region of the Americas
WPRO: Western Pacific region
Malaria Burden in India
 During Pre- control era(1953) Annual Incidence was
75 mil / (22% of population) and 0.8mil death/ yr
 During 2008 incidence was 1.53 million & half of
these were Pf & 1055 deaths reported
 About 88% of malaria cases & 97% of deaths
reported from
Northeastern (NE) States, Chhattisgarh, Jharkhand,
MP,
 Orissa,  AP
 Maharashtra
Gujarat  Rajasthan,
W B Karnataka
Problem in India
Major epidemiological types in India
1. Tribal malaria
2. Urban malaria
3. Malaria in project area
4. Border malaria
Serious problem in NE states
 Perennial malaria transmission
 Predominance of falciparum
 Drug resistance
EPIDEMIOLOGY OF MALARIA :Agent factors
 Four species :
(1)P. Vivax – causes BTM
(2) P.Falciparum-causes MTM
(3) P.Malariae-causes quartan malaria
(4) P.Ovale (not in India)
Host factors
 Age: Parasitemia is low during infancy due to
maternal antibody
 During first few weeks show resistance to Pf infection
due to fetal Hb
 Pregnancy: increase risk in pregnancy :anemia , LBW
delivery.
Epidemiology
Reservoir of infection: Human
 (Exception- chimpanzee in Africa may carry P. malariae)
Conditions for a successful reservoir:
 Must harbor viable & mature gametocyte of both
sexes in sufficient density
Route of transmission
 By bite of infected female anopheles mosquito
 Blood transfusion, needle stick injury, sharing
needles, organ transplantation
 Congenital malaria- mother to foetus
Genetic factors
 HbF and Thalassaemia protect against malaria
 Sickle cell trait (AS Hb) have higher immunity against
P. falciparum
 Person with ‘Duffy negative ‘ RBC are resistant to vivax
infection
Environmental conditions
 Urbanization,
 Industrialization and construction projects
 Consequent migration,
 Deficient water and solid waste management
 Indiscriminate disposal of articles (tyres, containers,
junk materials, cups, etc
LIFE CYCLE OF PLASMODIUM MOSQUITO
 Mosquito is definitive host (sexual
multiplication takes place)
 Mosquito picks up gametocytes from
infected person  in gut converted
into gamete, zygote, ookinets, oocist,
sporozoites finally sporozoites reach
the salivary gland (takes about 8- 25
days)
Other factors:
 Poor socioeconomic and housing conditions,
 population mobility
 some human habits like
 sleeping out of door
 Nomadism
 refusal of spray activities etc contribute to causation of
malaria .
LIFE CYCLE OF PLASMODIUM IN HUMAN
 Man -intermediate host (undergo asexual reprodn.)
 Hepatic phase : Mosquito bite  inoculate sporozoites reaches hepatocyte by 30mts  multiply to form hepatic
schizonts  mature to daughter merozoites and released
in sinusoids
 Erythrocytic phase: Merozoites reach blood stream 
invade RBC  in RBC multiply & develops schzoints 
RBC ruptures 48 or 72 hourly releasing cytokinin, TNF
pirogens 
 Some merozoites convert & develop into
gametocyte
Pathophysiology
 Incubation period: infective mosquito bite to onset of sign
and symptoms = 9-30 days
 IP depend upon species of parasite, host immune status,
infecting doses and use of antimalarial treatment
 Only erythrocytic parasitic stage causes clinical disease
 Relapse: after primary attack with out subsequent
mosquito bite.
 Recrudescence: Reappearance of clinical malaria or
M.P in blood, which remain dormant in RBC.
VECTOR
Only female Anopheles mosquito
carry parasite and infect human
Vector factors for transmission
 Vector density
 Man biting rate & frequency of blood meal
 Time and place of man - mosquito contact
 Man - cattle ratio
 Flight range
 Vector’s susceptibility to infection
IMPORTANT VECTORS OF MALARIA IN INDIA
Species
Distribution
An. culicifacies Commonest,
particularly in rural
An. stephensi Urban & industrial
areas
Breeding
Fresh water, in rice field etc
domestic a & peri-domestic artificial
water collection ( e.g tanks, wells,
cisterns etc.)
Forest pools and fringes.
An. dirus
N.E region
An. fluviatilis
Foot heal region
An. minimus
N.E Region, and
adjacent WB
Moving water, irrigation channels, rice
fields, shallow wells etc
Shaded slow flowing streams with
grassy margins
An. sundaicus
Costal region
Brackish water
Secondary
vectors
Annularis ,Varuna , Philippinensis
Critical density for transmission
Critical density
(Catch PMH)
A culicifacies/ Stephensi
3.3
A. Fluviatilis
0.4
A. Sundicus / philippinensis
1.3
ENTOMOLOGICAL INDICES
 Vector density (Man Hour Hand Captures ): Nos




anopheles collected per man hr. catch
Mosquito infection rate
Man biting rate
Human Blood Index-indicate anthrophilism
Av. nos of larva per dip
ENTOMOLOGICAL INDICES ….
PER MAN HOUR DENSITY:
No. of mosquitoes collected
=--- ---------------------------------------X100
No. of man hours spent in search
 High vector density indicates high potential for transmission
SPOROZOITE RATE
(%):
No. of females positive for sporozoites
= --------------------------------------------------x 100
Nos. dissected
Suspected case of malaria
A patient with fever but without any other obvious cause of fever
 Cough and other signs of respiratory infection
 Running nose and other signs of cold
 Pelvic inflammation indicated by severe low backache,
vaginal discharge , urinary symptoms
 Skin rash suggestive of eruptive illness
 Burning micturition
 Skin infections e.g. boils, abscess, infected wounds
 Painful swelling of joints
 Diarrhoea
 Ear discharge
Lab diagnosis:
All suspected fever cases be investigated
1. Blood smear examination/Microscopy
2. Rapid diagnostic test (RDT)
How & when to use RDT / Smear Exam
Where microscopy
result is available
within 24 hrs.

(Only microscopy
done)

Treatment based
on
slide-result
Where microscopy result is
not available within 24hrs
(Pf RDT + Slide taken)
RDT –Ve

Slide microscopy

Treatment
RDT +Ve

Treat Pf

Discard slide
EPIDEMIOLOGICAL
SURVEILLANCE
ASSESSMENT OF PROBLEM
(MALARIOMETRIC MEASUREMENT)
EPIDEMIOLOGICAL SURVEY

1. Proportional case rate
2. Spleen rate
3. Infant parasite rate
4. Children parasite rate-(% of 2-10 yr children ē MP
in blood)
5. Annual Parasite Incidence (API)
6. Annual Blood Examination Rate (ABER)
7. Slide Positivity Rate (SPR)
8. Slide falciparum Rate (SFR)
9. Annual falciparum rate (AFR)
Child Spleen Rate(CSR)
 % of 2-10 yr children ē enlarged spleen
Significance :
25-40%= Endemic
>40%=Hyper endemic
Infant parasite rate(IPR)
Most sensitive index for recent transmission
of malaria.
# Positive for MP
IPR= -----------------------------------------X100
# Blood slide examined from infants
Annual Blood Examination Rate (ABER)
Nos of smears examined & (RDTs +Ve) in a Yr.
ABER = ----------------------------------------------------------X100
Total Population under surveillance
 Index of operational efficiency of surveillance
 ABER should be equal to fever rate in the locality
 ABER should be > 10% of population
 Monthly Blood Examination Rate should be >1% of
population during the transmission season
Annual Parasite Incidence (API)
# of +Ve smears & +Ve RDTs in a year
API=------------------------------------------------ X 1000
# Population under surveillance
 Used to stratify malarious areas
 Disease burden in community
Slide Positivity Rate : % of slide positive for parasite
Slide Falciparum Rate : % of slide positive for Pf
SFR pinpoints areas of Pf preponderance for
prioritizing control measures
P.falciparum percentage (Pf %)
Surveillance in malaria
 Passive Case Detection- Collection of blood
slides in Clinic/ institution & treatment.
 Active Case Detection- system of detecting
malaria cases (blood slide collection ) by HW
through domiciliary visits
 Mass blood survey- Examination of blood from
all persons in a community (during
epidemiological investigation around positive
cases)
DRUG SCHEDULE FOR MALARIA
Diagnosis
P.Vivax
Treatment
Chloroquine: 10mg/kg on D1, 10mg/kg on D2 & 5mg/kg on D3)
Primaquine: 0.25 mg/kg daily for 14 days.
Artemisinin based Combination Therapy (ACT)
Artesunate 4 mg/kg daily for 3 days plus
Uncomplic
Sulfadoxine (25 mg/kg) & Pyrimethamine (1.25 mg/kg) on
ated Pf
Day 1 single dose
Primaquine(0.75mg/Kg) preferably on day 2
Pregnant & 1st Trimester: Quinine salt 10mg/kg 3 TDS X 7 days
uncomplica 2nd & 3rd Trimester: ACT as per dosage given above.
ted Pf
(Pv + Pf)
Full course ACT + Primaquine 0.25 mg / kg daily for 14 days
Clinical
Suspected malaria cases :Full course of chloroquine
malaria
When parasitological diagnosis available -specific treatment
Age-specific drug schedules
Age
(years)
<1
1-4
5-8
9-14
15+
Chloroquine (150mg base)
Day 1
Day 2
Day 3
½
½
¼
1
1
½
2
2
1
3
3
1½
4
4
2
Chemoprophylaxis
Short term chemoprophylaxis (up to 6 wks)
(e.g. travelers from non-malarious areas)
 Doxycycline 100 mg daily in adults or (1.5mg / kg
OD)above in children , started 2 days before reaching
endemic area continued for 4 weeks after leaving
 Contraindication : Pregnancy & children < 8 years.
Chemoprophylaxis for longer stay (> 6 wks)
(e.g Military & paramilitary troops in malarious areas duty )
 Mefloquine 250 mg weekly for adults
 Mefloquine 5 mg/kg for children
 Contraindication of Mefloquine : H/O convulsions, &
neuropsychiatric problems
MALARIA CONTROL ACTIVITIES & PROGRAMME IN INDIA
Problem status &
initiative
Salient features
Before 1953 there was
75 mil cases and 0.8
million deaths →
Introduced NMCP
(1953)
‘National
Malaria
Control
Programme’ Objectives: ↓ malaria
transmission, cease to be a public health
problem Strategies: 1) Anti-malarial
treatment(
institutional
cases)
2)
Residual insecticide spray with DDT
Encouraged
by
success of NMCP (2
million cases per year
in 1958) eradication
programme was takeup in 1958
National
Malaria
Eradication
Programme’ To stop transmission by
destroying entire vectors & elimination of
reservoir Strategies: 1) Two round of
DDT spray in all area 2) Active & passive
surveillance 3) Presumptive & Radical
treatment
Contd….
Continued..
NMEP↓cases to 0.1
mil. in 1966, but set
back resulted due to
technical,
operational
administrative
failures
→Resurgence
of
malaria cases &
deaths
→Eradication
attempt discarded &
introduced MPO in
1997.
‘Modified Plan of Operation’ Vertical approach
was
replaced
by
horizontal
approach.
Objectives: Elimination of deaths, reduction of
morbidity & maintenance of achievement
Strategies: 1) Stratification of rural area based on API
and differential vector control measures 2) Active &
passive surveillance 3) Presumptive & radical
treatment
Intervention in area with API ≥ 2
1. Residual spray with 2 round DDT/3 round Malathion
2. Surveillance/ Treatment of cases
3. Entomological assessment
Intervention in area with API<2
1.Focal spray around house with Falciparum
2. Surveillance/ Treatment of cases
3. Epidemiological investigation
4.Follow up
Continued …
Implementation of
MPO, UMS(‘71) &
Pf containment
progm. (’77)
incidence & death
↓but resurgence in
some area →MAP
Malaria Action Programme (MAP) 1995:
■ Areas divided in High risk & Low risk
area based on certain epidemiological
criteria
■ Priority spray operation and differential
treatment for high-risk area
Area with adverse ‘Enhanced
Malaria
Control
Project’
epidemiological
Strategies: Case detection, prompt treatment,
parameter→EMCP vector control and community participation
1997
1999
National Anti Malarial Programme
:Objectives and strategies same as MAP
&MPO
Continued ..
NAMP ↓ national API Intensified Malaria Control Project:
but some areas
Special inputs RDTs, ACT, Insecticide
register high API
Treated Bed nets (ITNs) and Health
→IMCP 2005
Systems Strengthening (HSS) were
provided.
2003-04
NVBDCP
Convergence of numbers of vector borne
programmes:Malaria, Filaria, JE and Dengue
under National Vector Born Disease Control
Programme
Strategies: Integrated vector control and
promotion of insecticide treated bed net
2006
ACT introduced in areas showing
Chloroquine resistant falciparum malaria.
NATIONAL ANTI-MALARIA PROGRAMME1999
Under NVBDCP
Objectives:
 Prevention of deaths due to malaria
 Prevention of morbidity due to malaria
 Maintenance of ongoing socioeconomic
development
Strategies
1. Surveillance and case management
 Case detection (passive and active)
 Early diagnosis and treatment
2. Integrated Vector Management (IVM)
3. Environmental Management
4. Stratification of the problem
 Area with API<2
 Area with API ≥2
5. Community Participation & BCC
6. Monitoring and Evaluation of the programme
Integrated Vector Management (IVM)
 Use of a range of biological, chemical and
physical interventions of proven efficacy,
separately or in combination, in order to
implement cost-effective control and reduce
reliance on any single intervention
IVM Includes:
 Rotation and & safe use of insecticides
including management of resistance
 Indoor Residual Spray (IRS)
 Insecticide Treated bed Nets (Tins) / Long
Lasting Insecticidal Nets (LLINs)
 Antilarval measures including source
reduction
Vector control methods
 Methods of reducing human-vector contact:
 Mosquito nets & insecticide treated nets (Synthetic pyrethroid)
 House protection with screening of windows, doors etc.
 Use of repellents
 Anti adult measures:
 Indoor residual spraying with DDT/
 Space spraying of insecticides
 Anti larval measures:
 Larviciding
 Biological Control
 Source reduction by environmental management
Anti adult measures
 Indoor residual spraying with
-Organo chlorine compound : DDT
- OP-compounds : Malathion, Fenitrothion
-Carbamate :Propoxur
-Synthetic pyrethroids: Deltamethrin
 Space spray: Pyrithrum
 Out door space spray :Malathion, Pyrethrum
Anti larval measures
 Larviciding with MLO, Temephos ( abate), Fenthion etc.
 Biological Control
 Use of larvivorous fish (Gambusia affinis & Poecilia reticulata)
 Use of biocides: bacillus thuringiensis
 Source reduction by environmental management
 Drainage /Filling /flushing/change of salinity
Community Perticipation & BCC
 Process of learning that empowers people to take rational
and informed decisions through appropriate knowledge
 Clear messages, communicated through different, credible
channels are most likely to bring about change. Ignorance,
prejudices must be replaced by knowledge Awareness
campaign programme-observe malaria week
 Legislative measures:
 Model civic bye-laws:
‘High risk areas’
 Recorded deaths due to malaria
 Doubling of SPR during last 3 yrs provided the SPR in
2nd / 3rd yr reaches ≥ 4%
 Average SPR of the last 3 yrs ≥ 5%
 P.falciparum proportion ≥ 30% provided SPR is ≥ 3%
during any of the last 3 yrs
 Any area with focus of CQ resistant P.f. cases
 Aggregation of labour in project area & new
settlements in endemic/receptive & vulnerable areas
Thank you