MALARIA Dr Biplob Kumar Modak 19 May21 Dr

MALARIA Dr. Biplob Kumar Modak 19 -May-21 Dr Biplob Kumar Modak 1

HIV, Malaria and TB • The most important infectious agents in the world. • There are no vaccines against them, and all have the same property of establishing chronic infection without an effective immune response. ” 19 -May-21 Dr Biplob Kumar Modak 2

Malaria is a vector-borne (mosquito) infectious disease caused by protozoan parasites. It is widespread in tropical and subtropical regions At risk for malaria: 40% of the world’s population More than 500 million are ill of malaria yearly If treated in the early stages, malaria can be cured 19 -May-21 Dr Biplob Kumar Modak 3

WHAT IS MALARIA? • Malaria is a protozoan parasite (Plasmodium spp) that enters the blood • 3 to 700 million people get malaria each year, and kills 1 to 2 million • 40% of the worlds population lives in malaria zones • Malaria zones are: Africa, India, Middle East, Southeast Asia, Central and South America, Eastern Europe, and the South Pacific (slide 13). 19 -May-21 Dr Biplob Kumar Modak 4

WHAT DETERMINES THE SPREAD OF MALARIA? Malaria spread depends on: • Rainfall pattern (How does this affect ? mosquito breeding? ) • Types of mosquitoes in the area • How close are people to the breeding sites? • Some areas constantly have a high rate of malaria. • Other areas have “malaria seasons” or occasional 19 -May-21 Dr Biplob Kumar Modak 5

How does Infection occur A bite from an infective female Anopheles mosquito. Anopheles must be infected through a previous blood meal taken on an infected person to transmit malaria 19 -May-21 Dr Biplob Kumar Modak 6

falciparum Plasmodiu m common Most and deadly of malaria type infection - can lead to cerebral malaria P. vivax - most common causes relapse if treatment was not completed. P. ovale. 19 -May-21 Dr Biplob Kumar Modak 7

Female Anopheles are: Anthropophilic : Zoophilic Endophagic Exophagic 19 -May-21 : : : from humans from animals prefer to bite indoors prefer outdoor biting Dr Biplob Kumar Modak 8

MALARIA PARASITE (Plasmodium) • Pathogen of malaria P. vivax ; P. falciparum ; P. malariae ; P. ovale • P. vivax ; P. falciparum are more common • Plasmodium is a wide distribution in many tropical or subtropical 19 -May-21 Dr Biplob Kumar Modak regions of the world 9

MALARIA – VECTORS Anopheles balabacensis A. freeborni 19 -May-21 A. gambiae A. stephensi Dr Biplob Kumar Modak 10

CHARACTERISTIC OF LIFE CYCLE • Intermediate host : human • Final host : mosquito • Infective stage : sporozoite • Infective way : mosquito bite skin of human • Parasitic position : liver and red blood cells • Transmitted stage : gametocytes • Schizogonic cycle in red cells : 48 hrs/P. v 19 -May-21 Dr Biplob Kumar Modak 11

Life Cycle • sporozoites injected during mosquito feeding • invade liver cells • exoerythrocytic schizogony (merozoites) • merozoites invade RBCs • repeated erythrocytic schizogony cycles • gametocytes infective for mosquito • fusion of gametes in gut • sporogony on gut wall in hemocoel • sporozoites invade salivary glands of mosquito 19 -May-21 Dr Biplob Kumar Modak 12

INCUBATION PERIOD Following the infective bite by the Anopheles mosquito a period of time (the "incubation period") goes by before the first symptoms appear. The incubation period in most cases varies from 7 to 30 days. The shorter periods are observed most frequently with P. falciparum and the longer ones with P. malariae. 19 -May-21 Dr Biplob Kumar Modak 13

Clinical Features • Characterized by acute febrile attacks (malaria paroxysms) • periodic episodes of fever alternating with symptomfree periods • Manifestations and severity depend on species and host status • immunity, general health, nutritional state, genetics • Recrudescences and relapses can occur over months or years • Can develop severe complications (especially P. falciparum) 19 -May-21 Dr Biplob Kumar Modak 14

Malaria Paroxysm • Paroxysms associated with synchrony of merozoite release • Between paroxysms temper - ature is normal and patient feels well • P. falciparum may not exhibit classic paroxysms (continuous fever) tertian malaria quartan malaria D T. V. R O MD 19 -May-21 Dr Biplob Kumar Modak 4 0 15

CLINICAL MANIFESTATIONS 1. Anemia 2. Splenomegaly 3. Cerebral malaria 4. Malaria nephropathy 5. Congenital malaria usually fatal 19 -May-21 6. Black water Dr Biplob Kumar Modak 16

What Are The Signs And Symptoms Of Malaria? Symptoms of malaria include fever and flulike illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells. Infection with one type of malaria, Plasmodium falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and 17 19 -May-21 Dr Biplob Kumar Modak

TREATMENT Falciparum? Yes Fansidar or Artemeter/Lumefantrine No Vivax or Ovale Chloroquine Check G 6 PD Primaquine 19 -May-21 Dr Biplob Kumar Modak Malariae Chloroquine 18

Uncomplicated P. falciparum Artemisinis combination are the best. ◦ MOA: ◦ production of free radicals that kill the parasite. ◦ Active against all human malaria parasites. ◦ Does not affect the hepatic stage. ◦ Artesunate 100 mg + amodiaquine 270 mg BID for 3 days. ◦ Artemether + lumefantrine (Riamet®): 4 tabs/12 h for 6 doses. 19 -May-21 Dr Biplob Kumar Modak 19

Sever malaria • Atresunate 2. 4 mg/kg IV or IM given on admission then after 12 h and 24 h, then once daily. i. e 12 hr 24 hr • Fluid therapy for rehydration. • Blood transfusion: usually used in children, because anemia is sever (Hb < 5 g/dl) 19 -May-21 Dr Biplob Kumar Modak 20

P. vivax, P. ovale and P. malariae Chloroquine For radical cure of P. vivax and P. ovale: ◦ Primaquine 15 mg daily for 14 days. ◦ It destroys the hypnozoite phase in the liver. ◦ It may cause hemolysis with G 6 PD deficient patients. 19 -May-21 Dr Biplob Kumar Modak 21

TREATMENT • HALOFANTRINE • MALARONE • ATOVAQUONE/PROGUANIL • TAFENOQUINE • QUININE based regimens • CHLOROQUINE/PROGUANIL IS AN INFERIOR REGIMEN AND SHOULD NOT BE USED 19 -May-21 Dr Biplob Kumar Modak 22

WHAT ARE WAYS TO PREVENT MOSQUITO BITES? • Use mosquito repellants. • Wear long pants and long sleeves. • Wear lightcolored clothes. 19 -May-21 Dr Biplob Kumar Modak 23

INSECTICIDE-TREATED NETS (ITNS) • What is happening here? • What needs to happen within six Source: HEPFDC, 2009. months? • Can you think of any practical challenges? 19 -May-21 Dr Biplob Kumar Modak 24

ORIGINAL ERADICATION PLANS • Interruption of transmission of main species infecting humans by DDT spraying • Malaria disappears spontaneously in under 3 years DSRo. T. u. V. rc. Re. AO: 19 -May-21 GMDabaldon Dr Biplob Kumar Modak 5 6 25

OTHER WAYS TO PREVENT MALARIA Who is at the highest risk of malaria? • Travelers to an area high in malaria • Travelers often take prophylactic (preventive) medicines to prevent malaria. • Pregnant women (especially those with HIV) • Pregnant women are given intermittent preventive treatment. They are given at least 2 doses of a malaria drug during their pregnancy. • Young children 19 -May-21 Dr Biplob Kumar Modak 26

Thank you! 19 -May-21 Dr Biplob Kumar Modak 27