Recent trend in malaria. Global Distribution of Malaria Accessed October 17, 2004 CDC. Available at...
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Transcript of Recent trend in malaria. Global Distribution of Malaria Accessed October 17, 2004 CDC. Available at...
Recent trend in malaria
Global Distribution of Malaria
Accessed October 17, 2004
CDC. Available at http://www.cdc.gov/malaria/distribution_epi/distribution.htm.
Malaria is a global disease.
40% world pop. lives in malarious areas.
300-500m malaria cases annually.
2– 3m death an average of one person every 12 seconds. Mostly children (<5 yrs).
India contribute 23% of clinical cases of Pf.
1.2 billion PAR P. vivax which is 42% of the global PAR.
Global BurdenGlobal Burden
Contd…
Hay et al., 2010. Lancet. 7(6):e1000290
2.4m malaria cases reported from South Asia.
Of which 75% are in India alone.
Five states responsible >60% malaria.
Orissa, CG, MP, Jharkhand & WB.
Malaria infect human at conception till adult.
Patients survive if they timely access to medicines.
Malaria present a diagnostic challenge.
Burden in Asia and IndiaBurden in Asia and India
World Malaria Report 2009. World Health Organization
Burden
Dhingra et al., Oct 2010 Lancet
MALARIA PROFILE OF INDIAMALARIA PROFILE OF INDIA (1961-2010)(1961-2010)
Malaria Cases PF
Deaths
State wise malaria contribution in India
DiagnosisDiagnosis
Clinical: Grossly inaccurate
Microscopy: Thick and thin blood smear
Fluorescent Microscopy
Polymerase Chain Reaction (PCR)
Rapid Diagnostic Tests (RDT)
Blood SmearBlood Smear
! The quantity of blood is very important for the thick smear! The quantity of blood is very important for the thick smear
! Not enough blood may lead to a WRONG NEGATIVE RESULT.! Not enough blood may lead to a WRONG NEGATIVE RESULT.
Too much blood cannot be stained properly and CANNOT BE Too much blood cannot be stained properly and CANNOT BE EXAMINED EXAMINED
FLUORESCENCE MICROSCOPY
Fluorescent dyes have an affinity for nuclic acid in the parasite nucleus.
They attach to the nuclei.
Under UV light, the nucleus fluorecence strongly (490nm).
Two fluorochromes used,
Acridine Orange (AO) Benzothio Carboxypurine (BCP)
Green/Yellow fluorescence
Quantitative Buffy Coat (QBC)(Becton Dickingson Franklin Lakes N.J.)
QBC combines an AO coated
capillary tube.
Centrifuged Parasite concentrate
below layer of cells.
In the upper layer of RBC
Between layers of Platelets and
WBC.
Parasite can be viewed through
the capillary tube using focal
length objective (Paralens)
LimitationsLimitationsQBC, BCP and AO are rapid and easy when parasitaemia >100 parasites/l.
Inability to differentiate between Plasmodium species (AO/BCP)
AO hazardous has special disposal requirements
QBC/BCP more demanding technically than AO
QBC requires a particular centrifuge and its tubes. This increase costs to about US$1.7/sample.
PCRPCRNested PCR and reverse transcription PCR enable all four species to be identified.
Lane 2-12 :Samples, Lane 1 & 13: positive & negative control, Lane 14:
100 bp DNA ladder
P.vivax
Lane 1-11 :Samples, Lane 12 & 13: positive & negative control, Lane 14:
100 bp DNA ladder
P.falciparum
AdvantagesAdvantages
• Ability to detect low level parasitaemia
• 5 parasites/µl can be detected (100% Sen/Sp.)
• Strain variations, mutations and drug resistance
• Mixed infection
LimitationsLimitations
•Expensive, extensive
technical expertise
•Labour intensive
involved multiple steps
•High cost of the
enzymes and primers
Why use RDT?
• Early diagnosis and prompt treatment.
• Rapid, reliable and simple to perform-
• RDTs an alternative to microscopy.
• With New Expensive ACT, RDT is must.
RDTs Three type of Antigen detection tests common.
Histidine rich Protein 2 (HRP-2).
Plasmodium Lactate dehydrogenase (pLDH) test usually detects falciparum and non falciparum.
Combo test– HRP-2 + pLDH based - First Response– HRP-2 + Aldolase - ICT Combo
Diagnosis is based on Detection of HRP-2 Diagnosis is based on Detection of HRP-2 released from infected erythrocytes with released from infected erythrocytes with P. falciparumP. falciparum monoclonal antibodies against monoclonal antibodies against HRP-2 fixed in the test strip that reacts with HRP-2 fixed in the test strip that reacts with heamolyzed blood samples from positive heamolyzed blood samples from positive patients. The antigen/antibody reaction is patients. The antigen/antibody reaction is revealed by the addition of a detector revealed by the addition of a detector reagent. A solid pink line on the strip reagent. A solid pink line on the strip indicates a positive test.indicates a positive test.
PrinciplePrinciple
Do not require extensive training or good
infrastructure or electricity.
Simple to perform.
Easy to learn.
Ideal on the spot diagnosis and treatment.
No supervision required.
Simple to carry in the field.
Advantages (RDTs)
Limitations (RDTs)
Expensive
Low sensitivities in low parasitaemia
Persistent positivity upto 2 weeks after medication
May not be used for identification of drug resistance
False positives rheumatoid factor/ heterophile
antibody
It can not different between current/ recent
parasitaemia
Can not quantify the parasitaemia
Can not differentiate between sexual and asexual
Assisting staff fills consent form Collection of blood sample for RDT
Interpretation of Rapid Diagnostic Test Kit Medical Officer provides medicine
Portable Reader
Molecular Diagnostics
GENOMIX reader for Point-of-Care Diagnostics
HandheldReader
A functional Genomics Company
Malaria Lamp AssayMalaria Lamp Assay
900 grams weight
Loop Mediated IsothermalAmplication
Major Vectors in India
• Anopheles fluviatilis
• Anopheles culicifacies
• Anopheles stephensi
• Anopheles sundaicus
• Anopheles minimus
• Anopheles dirus
Monitoring of insecticide resistance of An. culicifacies, malaria vector in district Balaghat, Dindori, Mandla,
Sidhi, Jhabua and Shahdol of MP
Insecticide Mortality
DDT 4% 6.7 – 11.2%
Malathion 5% 77.3 – 83.5%
Deltamethrin 74.4 – 97.0%0.05%
Alphacypermethrin 50.0%
0
20
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120
Pe
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nta
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19
86
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00
20
01
Years
P.falciparum P.vivax
DYNAMICS OF P.vivax & P.falciparum RATIO IN STUDY AREA SHOWING SHIFTING TREND
Singh et al., 2004. Trop Med Int Hlth
Aims of National Drug Policy on Malaria (2010)
• Providing complete cure of malaria cases.
• Prevention of progression of uncomplicated malaria to severe malaria.
• Prevention of relapses by administration of radical treatment.
• Interruption of transmission by the use of gametocytocidal drugs.
• Preventing development of drug resistance by early treatment of malaria.
Treatment of Malaria
• All fever cases should be tested by microscopy/ RDT
• No presumptive treatment
• P. vivax - CQ (3 days) PQ for 14 days
• P. falciparum - ACT 3 days
- PQ single dose
• Cases not responding to ACT should be treated with oral quinine with Tetracycline/ Doxycycline
http://nvbdcp.gov.in/Doc/drug-policy-2010.pdf
National Drug PolicyDuring Pregnancy
• Pregnant women with Pf (uncomplicated)
• 1st Trimester – Quinine
• 2nd & 3rd Trimester – ACT
(Artesunate + Sulphadoxine-Pyrimethamine)
Thank you…Thank you…