Recent trend in malaria

Global Distribution of Malaria                                                                   Slide 6. Global Distribution of Malaria This slide shows the global distribution of malaria. Malaria is found in places where Anopheles mosquitoes can survive and the malaria parasites can complete their life cycle within the host. Climatic factors such as temperature, humidity, and rainfall are especially important, with the highest transmission rate found in Africa South of the Sahara. Economic development and public health measures have succeeded in eliminating malaria in many temperate areas, such as western Europe and the United States. Many of these areas have Anopheles mosquitoes that can transmit malaria, and reintroduction of the disease remains a risk. CDC. Available at http://www.cdc.gov/malaria/distribution_epi/distribution.htm. Accessed October 17, 2004. Accessed October 17, 2004 CDC. Available at http://www.cdc.gov/malaria/distribution_epi/distribution.htm.

Global Burden 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. Hay et al., 2010. Lancet. 7(6):e1000290 Contd…

Burden in Asia and India 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. World Malaria Report 2009. World Health Organization

Burden Dhingra et al., Oct 2010 Lancet

MALARIA PROFILE OF INDIA (1961-2010) 6

State wise malaria contribution in India PF Malaria Cases Deaths

Diagnosis Clinical: Grossly inaccurate Microscopy: Thick and thin blood smear Fluorescent Microscopy Polymerase Chain Reaction (PCR) Rapid Diagnostic Tests (RDT)

Blood Smear ! The quantity of blood is very important for the thick smear ! Not enough blood may lead to a WRONG NEGATIVE RESULT. Too much blood cannot be stained properly and CANNOT BE 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)

Limitations QBC, 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.

PCR Nested PCR and reverse transcription PCR enable all four species to be identified. P.falciparum P.vivax Lane 1-11 :Samples, Lane 12 & 13: positive & negative control, Lane 14: 100 bp DNA ladder Lane 2-12 :Samples, Lane 1 & 13: positive & negative control, Lane 14: 100 bp DNA ladder

Limitations Advantages Expensive, extensive technical expertise Labour intensive involved multiple steps High cost of the enzymes and primers Ability to detect low level parasitaemia 5 parasites/µl can be detected (100% Sen/Sp.) Strain variations, mutations and drug resistance Mixed infection

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

Principle Diagnosis is based on Detection of HRP-2 released from infected erythrocytes with P. falciparum monoclonal antibodies against HRP-2 fixed in the test strip that reacts with heamolyzed blood samples from positive patients. The antigen/antibody reaction is revealed by the addition of a detector reagent. A solid pink line on the strip indicates a positive test.

Advantages (RDTs) 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.

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

Molecular Diagnostics GENOMIX reader for Point-of-Care Diagnostics Molecular Diagnostics Portable Reader Handheld Reader A functional Genomics Company

Loop Mediated Isothermal Malaria Lamp Assay Loop Mediated Isothermal Amplication 900 grams weight

Major Vectors in India Anopheles fluviatilis Anopheles culicifacies Anopheles stephensi Anopheles sundaicus Anopheles minimus Anopheles dirus

Monitoring of insecticide resistance of An 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%

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 http://nvbdcp.gov.in/Doc/drug-policy-2010.pdf 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

National Drug Policy During Pregnancy Pregnant women with Pf (uncomplicated) 1st Trimester – Quinine 2nd & 3rd Trimester – ACT (Artesunate + Sulphadoxine-Pyrimethamine)

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