Malaria - Epidemiology

8/18/2019 Malaria - Epidemiology

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MALARIA -

EPIDEMIOLOGY


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PROTOZOAL DS. – GENUS PLASMODIUM

TRANSMITTED TO MAN BY INFECTED FEMALE

ANOPHELINE MOSQUITO

3 STAGES - COLD STAGE

HOT STAGE

SWEATING STAGE


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PROBLEM STATEMENT

IN 2008 – 243 MILLION CASES OFMALARIA

CASES

AFRICAN

SOUTH - EAST ASIA

EAST

MEDITERRANEAN


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2008 – CAUSE SPECIFIC MORTALITY RATE

•WORLDWIDE – "# PER LAC POP.

•AFRICAN REGION – "04 PER LAC POP.

•EASTERN MEDITERRANEAN – 3 PER LACPOP.

•SOUTH – EAST ASIA – " PER LAC POP.


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8$ OF TOTAL UNDER – % YEARMORTALITY

•MA&. FROM AFRICAN REGION '"!$(

•3$ FROM EASTERN MEDITERRANEAN

•"$ FROM SEAR


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CHILDHOOD DEATHS FROM CEREBRAL MALARIA )

ANAEMIA

FATALITY RATE OF "0 -30$ - CHILDREN REFERRED TO HOSPITAL WITH SE*ERE MALARIA

HIGHER IN RURAL ) REMOTE AREAS – RESTRICTED

ACCESS TO ADEQUATE TREATMENT

ALSO CONTRIBUTES INDIRECTLY TO ILLNESS )

DEATHS FROM RESP. I+N DIARRHOEAL DS. )

MALNUTRITION

DEATHS OUTSIDE SUB – SAHARAN AFRICA –

NONIMMUNE PEOPLE INFECTED WITH

PLASMODIUM FALCIPARUM


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AFFECTS MAINLY POOR UNDERSER*ED )

MARGINALISED POP. IN REMOTE RURAL AREAS

CHARACTERISED BY INADEQUATE CONTROL

MEASURES ) LIMITED ACCESS TO HEALTH CARE

HIGHER MALARIA PRE*ALENCE AMONG ETHNIC ) TRIBAL GRPS. LI*ING IN REMOTE FORESTED )

BORDER AREAS AS WELL AS AMONG MOBILE )

MIGRANT POP.

UNDER – REPORTING – MA,OR CHALLENGE


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DRUG – RESISTANT PARASITES


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RESISTANCE OF P. FALCIPARUM TO

4 – AMINOQUINOLINES

SEAR SULFADO&INE – PYRIMETHAMINE

RESISTANCE TO MEFLOQUINE – MYANMAR

THAILANDQUININE – REDUCED SUSCEPITIBILITY INTHAILAND

ARTEMISININ – BASED COMB. THERAPY


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CHLOROQUINE – RESISTANT PLASMODIUM*I*A&

•INDIA

•INDONESIA

•MYANMAR

CURRENT TREATMENT RECOMMENDATIONS OF

THREE DAY CHLOROQUINE ) FOURTEEN DAY

PRIMAQUINE AGAINST *I*A& MALARIA AREINADEQUATE IN THESE AREAS

HIGH DOSE OF PRIMAQUINE REQUIRED


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LOW

COVERA

GE


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MALARIA IN INDIA

MA,OR PUBLIC HEALTH THREAT

P.FALCIPARUM PRONE TO COMPLICN.

HIGH TRANSMISSION AREAS – 2#$

LOW TRANSMISSION AREAS – %8$


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88$ CASES ) #$ DEATHS

•NORTH – EASTERN STATES

•

CHHATTISGARH• ,HAR/HAND

•MP

•

ORISSA•ANDHRA PRADESH

•MAHARASHTRA

•GU,ARAT•RA,ASTHAN

•WEST BENGAL

•/ARNATA/A


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API DECLINED FROM 3.2 IN "% TO ".40 IN 2008

SPR DECLINED FROM 3.%" IN "% TO ".!0 IN 2008

PF CASES DECLINED FROM "."4 MILLION IN "% TO

0.#! MILLION IN 2008

PF$ INCREASED FROM 38.8$ IN "% TO %0$ IN

2008 INCREASING CHLOROQUINE

RESIST.

INTERPRETATION OF API ANNUAL BLOOD

E&AMIN. RATE

AT LOW LE*ELS OF SUR*EILLANCE SLIDE POSITI*ITY

RATE IS A BETTER INDICATOR


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UNSTABLE MALARIA TRANSMISSION

SEASONAL WITH INCREASED INTENSITY RELATED TO RAINS

UNSTABLE ) LOW TRANSMISSION DYNAMICS

MOST OF POP. HAS LITTLE+NO IMMUNITY

TOWARDS MALARIA

FORESTED AREAS INTENSE TRANSMISSION

CHILDREN


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SI& PRIMARY *ECTORS OF MALARIA

ANOPHELES C U L I C I F A C I E S

DIRUS T

EPIROTICUS E FLU*IATILIS P

H

E N

MINIMUS

I


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EPIDEMIOLOGICAL TYPESOF MALARIA

TRIBAL MALARIA

URBAN MALARIA

RURAL MALARIABORDER MALARIA

MALARIA IN PRO,ECT AREAS


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MALAR

IA

PRIORI

TY

AREAS


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TRIBAL MALARIA

TRIBAL AREAS OF AP MP CHATTISGARH GU,ARAT

MAHARASHTRA BIHAR ,HAR/HAND RA,ASTHAN

ORISSA ) NORTH – EASTERN STATES

%0$ OF P.FALCIPARUM CASES OF THE COUNTRY

MALARIA HIGH RIS/ GRPS. – INFANTS

YOUNG CHILDREN

PREGNANT WOMEN

TRIBAL POPULATION

HIGH MORBIDITY ) MORTALITY –

• LIMITED HEALTH INFRASTRUCTURE

• LAC/ OF DRUGS AT THE *ILLAGE LE*EL


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RURAL MALARIA

IRRIGATED AREAS OF ARID ) SEMI – ARID PLAINS

OF HARYANA PUN,AB WESTERN UP PARTS OF

RA,ASTHAN ) MP PLAIN DESERT AREAS ) PLAIN

COASTAL AREAS OF ORISSA AP ) TN

MODERATE TO LOW ENDEMICITY

MAIN *ECTOR – AN. CULICIFACIES

PREDOMINANCE – P.*I*A& – LEAN PERIOD

P.FALCIPARUM – PERIODIC E&ACERBATION

HEALTH INFRASTRUCTURE – MODERATELY DE*ELOPED


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URBAN MALARIA"% MA,OR CITIES INCLUDING 4 METROPOLITANS

DELHI MUMBAI CHENNAI/OL/ATA HYDERABAD

BANGALORE AHMEDABAD BHOPAL ,AIPUR

LUC/NOW CHANDIGARH *ADODARA*ISHA/APATANAM *I,AYAWADA ) /ANPUR

MODERATE TO LOW ENDEMICITY

P.*I*A& PREDOMINANCE ) FOCAL P. FALCIPARUM

TRANSMISSION

MAIN *ECTOR – ANOPHELES STEPHENSI


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MALARIA IN PRO,ECTAREAS

PRO,ECT AREAS – CONSTRUCTION )

DE*ELOPMENTAL ACTI*ITIES TA/EN UP )

TEMPORARY TROPICAL AGGREGATION OF

LABOURERS TA/E PLACE BRINGING DIFFERENT STRAINS OF MALARIA PARASITE ) NONIMMUNE

POP.

DISTURBANCE IN ECOSYSTEM PROLIFIC INCREASE

IN *ECTOR BREEDING PLACES ) INCREASED MAN

MOSQUITO CONTACT FA*OURING HIGH MALARIA

TRANSMISSION

POC/ETS LARGE NO OF CASES


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POC/ETS – LARGE NO. OF CASES

SMALL POP. GRPS INHABITING THE

AREA

ONE+MORE MA,OR *ECTORS IN*OL*ED IN

MALARIA TRANSMISSION

LIMITED HEALTH FACILITIES FOR PROMPT

TREATMENT ASSOCIATED WITH CHLOROQUINE

RESISTANT MALARIA PARASITE

SPECIFIC CONTROL STRATEGY REQUIRED FOR

SUCH

AREAS


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BORDER MALARIA

HIGH MALARIA TRANSMISSION BELTSALONG THE

INTERNATIONAL BORDERS ) STATEBORDERS

PROBLEMS IN REGARD TO MALARIACONTROL


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DEFINITIONS

MALARIA CONTROL REDUCING THE MALARIA DS.

BURDEN TO A LE*EL AT WHICH IT IS NO LONGER

A PUBLIC HEALTH PROBLEM

MALARIA ELIMINATION INTERRUPTION OF LOCAL

MOSQUITO – BORNE MALARIA TRANSMISSION

REDUCTION TO ZERO OF THE INCIDENCE OF I+N

CAUSED BY HUMAN MALARIA PARASITES IN A DEFINED GEOGRAPHICAL AREA AS A RESULT OF

DELIBERATE EFFORTS CONTINUED MEASURES

TO PRE*ENT RE – ESTABLISHMENT OF TRANSMISSION

ARE REQUIRED

CERTIFICATION OF MALARIA ELIMINATION


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CERTIFICATION OF MALARIA ELIMINATION

PRO*EN BEYOND REASONABLE DOUBT THAT THE

CHAIN OF LOCAL MALARIA TRANSMISSION BY

AN. MOSQUITOES HAS BEEN FULLY INTERRUPTED IN AN ENTIRE COUNTRY FOR ATLEAST 3 CON. YEARS

MALARIA ERADICATION

PERMANENT RED. TO ZERO OF THE WORLDWIDE

INCIDENCE OF INFECTION CAUSED BY A SPECIFIC

AGENT APPLIES TO A PARTICULAR MALARIA

PARASITE SPECIES INTER*ENTION MEASURES NO LONGER NEEDED

EPIDEMIOLOGICAL


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EPIDEMIOLOGICALDETERMINANTS

AGENT FACTORS

AGENT

•

4 DISTINCT SPECIES – * F M O•*I*A& - WIDEST GEOGRAPHIC DISTRBN.

THROUGHOUT THE WORLD

•INDIA – %0$ - P. FALCIPARUM - 4 – 8$ DUE TO MI&ED I+N

- REST – P. *I*A&

- 1 "$ - P. MALARIA


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LIFE HISTORY

2 CYCLES OF DE*ELOPMENT

•ASE&UAL CYCLE – HUMANS

•SE&UAL CYCLE – MOSQUITO


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ASE&UAL CYCLE

HEPATIC PHASE

ERYTHROCYTIC PHASE

GAMETOGENY


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SE&UAL CYCLEMALE ) FEMALE GAMETOCYTE

EIP – 10 – 20

DAYS

RESER*OIR OF I+N


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RESER*OIR OF I+N

•NO ANIMAL RESER*OIR /NOWN TO E&IST

•HUMAN RESER*OIR – HARBOURS THE SE&UAL

FORMS OF THE PARASITE

•PT. – CARRIER OF SE*ERAL P. SPECIES AT THE SAME

TIME

•

CHILDREN MORE LI/ELY TO BE GAMETOCYTE CARRIERS

•CHILD EPIDEMIOLOGICALLY A BETTER RESER*OIR


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CONDN. FOR A PERSON

TO ACT AS A RESER*OIRHARBOUR BOTH MALE ) FEMALEGAMETOCYTES

MATURE GAMETOCYTES

*IABLE GAMETOCYTES

SUFFICIENT DENSITY OF GAMETOCYTES'"2+CUMM(

PERIOD OF COMMUNICABILITY


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PERIOD OF COMMUNICABILITY

•

EARLY STAGES OF I+N – GAMETOCYTESABUNDANT

•

OCCUR IN WA*ES IN PERIPHERAL BLOOD

RELAPSE

•

* O – RELAPSE THAN 3YRS AFTER "ST

ATTAC/

•F – DISAPPEAR WITHIN "-2 YRS

•

M – PROLONGED LOW LE*EL

HOST FACTORS


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HOST FACTORS

AGE AFFECTS ALL AGES

NEWBORN - RESISTANCE TO I+N WITH P.FAL.

SE& – MALES – OUTDOOR LIFE

BETTER CLOTHED FEMALES

RACE – AS HB. DUFFY NEGATI*E

PREGNANCY – INCREASES THE RIS/ OF MALARIA

INTRAUTERINE DEATH OF FETUS

PREMATURE LABOUR+ABORTION

SOCIO – ECONOMIC DE*ELOPMENT

HOUSING – ILL *ENTILATED ) ILL LIGHTED


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HOUSING – ILL *ENTILATED ) ILL LIGHTED

HOUSES

POP. MOBILITY – MIGRATION

LABOURERS NOMADSWANDERING TRIBES

IMPORTED MALARIA – PUBLIC HEALTH PROBLEM

IN EUROPE NA ) OTHER TEMPERATE PARTS OWING TO RISING TIDE OF AIR TRA*EL

TOURISM

) MIGRATION

OCCUPATION – AGRICULTURAL PRACTICES

HUMAN HABITS - INFLUENCE MAN – *ECTOR

CONTACT ) CHOICE OF CONTROL MEASURES

IMMUNITY

EN*IRONMENTAL FACTORS


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EN*IRONMENTAL FACTORS

•INDIAS GEOGRAPHIC POSITION )CLIMATIC CONDN.

SEASON – ,ULY TO NO*EMBER

TEMPERATURE – OPT. TEMP. IS 20 TO30C

HUMIDITY – OPT. RELATI*E HUMIDITY OF!0$

RAINFALL – OPPORTUNITIES FORBREEDING OF

MOSQUITOES ) GI*E RISETO EPIDEMIC

–


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*ECTORS OF MALARIA

AN. CULICIFACIESAN. STEPHENSI

AN. MINIMUS

AN. PHILIPPINENSISAN. SUNDAICUS

AN. MACULATUS

*ECTOR CNTRL MALARIA CNTRL


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*ECTOR CNTRL – MALARIA CNTRL.

FACTORS DETERMINING *ECTORIAL IMP.OF

MOSQUITOES

•DENSITY

BELOW CRITICAL DENSITY EFFECTI*E TRANSMISSION CANNOT BE MAINTAINED

•LIFE SPAN

ATLEAST LI*E FOR "0 -"2 DAYS AFTER

BLD. MEAL TO

BE INFECTI*E

•

CHOICE OF HOST –

•BREEDING HABITS – ANTILAR*AL


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•BREEDING HABITS – ANTILAR*ALOPERATIONS

• TIME OF BITING NOCTURNAL PERIODICITYB+W

DUS/ ) DAWN

•*ECTORIAL CAPACITY

COMBINED EFFECT OF THE DENSITY OFTHE *ECTOR

POP. ITS SUSCEPTIBILITY TO I+N LIFESPAN )

PROBABILITY OF FEEDING ON MAN

•RESISTANCE TO INSECTICIDES


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MODE OF TRANSMISSION

*ECTOR TRANSMISSIONDIRECT TRANSMISSION

CONGENITAL MALARIA


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INCUBATION PERIOD

LENGTH OF TIME B+W THE INFECTI*EMOSQUITO

BITE ) THE FIRST APPEARANCE OF

CLINICAL SIGNS OF WHICH FE*ER IS MOST COMMON

USUALLY NOT 1 "0DAYS


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CLINICAL FEATURESPRIMARY FE*ER MAR/ED BY PARO&YSMS

CORRESPONDING TO THE D*LPMNT. OF PARASITES

IN RBC

PEA/S OF FE*ER COINCIDE WITH RELEASE INTO THEBLD. STREAM OF SUCCESSI*E BROODS OF PARASITE

3 STAGES –

•COLD STAGE•HOT STAGE

•SWEATING STAGE


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COLD STAGE

ONSET WITH LASSITUDE HEAD ACHENAUSEA )

CHILLY SENSN. FOLLOWED IN AN HOUR

OR SO BY RIGORS

TEMP. RISES RAPIDLY TO 3 – 4"C

EARLY PART – S/IN FEELS COLD LATER –HOT

PARASITEMIA ) WEA/ ) RAPID PULSE

DUR 5 - " HOUR


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HOT STAGE

PT. FEELS BURNING HOT ) CASTS OFF HISCLOTHES

S/IN HOT ) DRY TO TOUCH

INTENSE HEADACHE NAUSEADIMINISHED

PULSE FULL ) RESPIRATION RAPID

DURATION 2 – ! HOURS


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SWEATING STAGE

FE*ER COMES DOWN WITH PROFUSESWEATING

TEMP. DROPS TO N+L ) S/IN IS COOL )

MOISTPULSE RATE BECOMES SLOWER PT. FEELSRELIE*ED

FALLS ASLEEPDUR 2 – 4 HOURS


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COMPLICATIONS OF

FALCIPARUM MALARIAACUTE RENAL FAILURE

NAEMIA

BLAC/WATER FE*ERCEREBRAL MALARIA

OLLAPSE

DEHYDRATION

AMAGE TO LI*ER

GASTROINTESTINAL SYMPTOMS


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DIAGNOSIS

MICROSCOPY

• THIC/ ) THIN FILMS

•

HIGH SENSITI*ITY•DETECT MALARIAL PARASITE AT LOWDENSITIES

•

QUANTIFY PARASITE LOAD•DIFFERENTIATE *ARIOUS SPECIES ) THEIRSTAGES


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SEROLOGICAL TEST

•MALARIAL FLUORESCENT AB TEST 6*E2W/S + MORE

AFTER PRIMARY I+N

•GREATEST *ALUE IN EPIDEMIOLOGICAL

STUDIES )

DETERMINING WHETHER A PT. HADMALARIA IN THE

PAST


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RAPID DIAGNOSTIC TEST

•DETECTION OF CIRCULATING PARASITE

ANTIGENS

WITH A SIMPLE DIPSTIC/ FORMAT


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MEASUREMENT OFMALARIA

ERADICATION ERA – M+S DIAGNOSISCOMMONLY USED PARAMETERS – APIABERAFI

SPR SFR

API 7 CONFIRMED CASES DURING ONE YR

"000POP. UNDER SUR*EILLANCE

•MEASURE OF MALARIA INCIDENCE IN A

COMMUNITY

ABER 7 NO. OF SLIDES E&AMINED "00


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ABER NO. OF SLIDES E&AMINED "00

POPULATION

•INDE& OF OPERATIONAL EFFICIENCY

SPR - $ OF SLIDES FOUND 6*E FORMALARIA

PARASITE IRRESPECTI*E OF THE TYPE OFSPECIES

SFR - $ OF SLIDES POSITI*E FORP.FALCIPARUM


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*ECTOR INDICES

HUMAN BLD INDE&PROPORTION OF FRESHLY FED FEMALE

AN.

MOSQUITOES WHOSE STOMACHCONTAINS HUMAN

BLOOD

SPOROZOITE RATE

PERCENTAGE OF FEMALE ANOPHELINES

WITH

MOSQUITO DENSITY


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MOSQUITO DENSITY

•NO. OF MOSQUITOES PER MAN HOURCATCH

MAN BITING RATE

•A*G. INCIDENCE OF ANOPHELINE BITESPER DAY PER

PERSON

•DETERMINED BY STANDARDISED *ECTORCATCHES

ON HUMAN BAIT

INOCULATION RATE

•

MAN BITING RATE MULTIPLIED BY THE


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THAN/ U9999..

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Malaria - Epidemiology