WORLD MALARIA DAY(25th April)an update Dr.T.V.Rao MD
World Malaria Day - April 25 • Malaria remains a killer disease with nearly 1 million people losing their lives every year. Eighty five per cent of deaths are children under 5 years of age. • Most malaria cases occur in Africa but it nevertheless remains a global problem also affecting countries in large parts of Asia and Latin America.
Importance of World Malaria Day • It was first celebrated in 2008 following a resolution of the World Health Assembly in 2007. It aims to build greater awareness and understanding of malaria, its prevention, treatment, and control. • Malaria can cause severe illness and is often fatal but it is curable when diagnosed and treated promptly with effective medicines. Based on the World Health Organization data as of 2009, there are about 3.3 billion people who are at risk of malaria which leads to about 250 million malaria cases and a mortality of nearly one million people.
Malaria – Early History • The symptoms of malaria were described in ancient Chinese medical writings. In 2700 BC, several characteristic symptoms of what would later be named malaria were described in the Nei Ching,
Hippocrates and Malaria • Hippocrates, a physician born in ancient Greece, today regarded as the "Father of Medicine", was the first to describe the manifestations of the disease, and relate them to the time of year and to where the patients lived.
Malaria • Name is derived from Italian Mal’ aria or bad air Malaria continues to be most important cause of fever and morbidity in the Tropical world Malaria has been eradicated from Europe, Most of North America, USA South America Korea and Japan,
Why it is important in Medicine • Malaria remains the world's most devastating human parasitic infection. Malaria affects over 40% of the world'spopulation.WHO, estimates that there are 350 - 500 million cases of malaria worldwide, of which 270 - 400 million are Falciparum malaria, the most severe form of the disease.
Malaria Kills more people than AIDS • Malaria kills in one year what AIDS kills in 15 years. For every death due to HIV/AIDS there are about 50 deaths due to malaria. To add to the problem is the increasing drug resistance to the established drug.
History – Events on Malaria • 1880- Charles Louis Alphose Lavern discovered malarial parasite in wet mount • 1883 - Methylene blue stain - Marchafava • 1891 - Polychrome stain- Romanowsky • 1898 -Roland Ross - Life cycle of parasite transmission, wins Nobel Prize in 1902 • 1948 - Site of Exoerythrocytic development in Liver by Shortt and Garnham
Major Developments in 20th Century • 1955 - WHO starts world wide malaria eradication programme using DDT • 1970 – Mosquitos develop resistance to DDT Programme fails • 1976 – Trager and Jensen in vitro cultivation of parasite • 1948 - Site of E1948 - Site of Exoerythrocytic dev in Liver by Shortt and Garnham • xoerythrocytic dev in Liver by Shortt and Garnham
Charles Louis Alphonse Laveran, • Charles Louis Alphonse Laveran, a French army surgeon stationed in Constantine, Algeria, was the first to notice parasites in the blood of a patient suffering from malaria. This occurred on the 6th of November 1880. For his discovery, Laveran was awarded the Nobel Prize in 1907.
Ronald Ross • In August 20th, 1897, Ronald Ross, a British officer in the Indian Medical Service, was the first to demonstrate that malaria parasites could be transmitted from infected patients to mosquitoes For his discovery, Ross was awarded the Nobel Prize in 1902. • Doctortvrao’s ‘e’ learning series
Nobel Prizes in Malaria • The discovery of this parasite in mosquitoes earned the British scientist Ronald Ross the Nobel Prize in Physiology or Medicine in 1902. In 1907, Alphonse Lavern received the Nobel prize for his findings that the parasite was present in human blood.
Chloroquine (Resochin) (1934, 1946) • Chloroquine was discovered by a German, Hans Andersag, in 1934 at Bayer I.G. Farbenindustrie A.G. laboratories in Eberfeld, Germany. He named his compound resochin. Through a series of lapses and confusion brought about during the war, chloroquine was finally recognized and established as an effective and safe antimalarial in 1946 by British and U.S. • Doctortvrao’s ‘e’ learning series
Malaria a vector borne Disease • Malaria is a vector-borne infectious disease caused by protozoan parasites. It is widespread in tropicl and subtropical regions, including parts of the Americas, Asia, and Africa.
Parasites Cause of Malaria • Malaria is caused by an infection by one of four single celled Plasmodia species, they are: falciparum, vivax,malariae, and ovale. Themost dangerous of the four is.P.falciparum
Newer species of Mosquito • A fifth species, Plasmodium knowlesi, causes malaria in macaques but can also infect humans. • Doctortvrao’s ‘e’ learning series
SPOROZOA • SPOROZOA belong to phylum Apicomplexa – contains two classes 1 Haematozoea 2 Coccidea Belong to class Haematozoea occur in the blood of the vertebrate hosts contain two orders Haemosporidia (genus Plasmodium – Malaria ) Piroplasmidia (containing genus Babesia) Doctortvrao’s ‘e’ learning series
Falciparum most Dangerous • Falciparum accounts for 90% of deaths due to malaria and vivax is the most widely spread species because it exists in both temperate and tropical climates (Encarta). The malaria life cycle is a complex system with both sexual and asexual aspects . • Doctortvrao’s ‘e’ learning series
Human Cycle 1Pre erythrocytic schizogony 2 Erythrocytic Schizogony 3 Gametogony 4 Exoerythrocytic schizogony Doctortvrao’s ‘e’ learning series
Events in Humans start with Bite of Mosquito • Man – Intermediate host. • Mosquito – Definitive host – Sporozoites are infective forms • Present in the salivary gland of female anopheles mosquito • After bite of infected mosquito sporozoites are introduced into blood circulation. • Doctortvrao’s ‘e’ learning series
Period of Pre erythrocytic cycle • 1 P.vivax 8 days • 2 P.falciparum – 6 days • 3 P.malariae - 13 – 16 days, • 4 P.ovale 9 days On maturation Liver cells ruputure Liberate Merozoites into blood stream Doctortvrao’s ‘e’ learning series
Pre erythrocytic cycle • Sprozoites undergo developemtnal phase in the liver cell • Sprozoites are elongated and spindle shaped become rounded inside the liver parenchyma • Multiple nuclear divisions develop to Schozonts • A Schizont contains 20,000 – 50,000 merozoites. • Doctortvrao’s ‘e’ learning series
Oocyst Sporozoites Mosquito Salivary Gland Zygote Hypnozoites (for P. vivax and P. ovale) Gametocytes Erythrocytic Cycle Malaria Life Cycle Life Cycle Sporogony Exo- erythrocytic (hepatic) cycle Schizogony
Exo-erythrocytic (tissue) phase • P. malariae or P. falciparum sporozoites do not form hypnotizes, develop directly into pre-erythrocytic schizonts in the liver • Pre-erythrocytic schizogeny takes 6-16 days post infection • Schizonts rupture, releasing merozoites which invade red blood cells (RBC) in liver
Affinity of Parasite to Erythrocytes • P.vivax • P.malariae Infectes only young or • P.ovale Old Erythocytes • P.falciparum Infects all ages of RBC Also adhere to the endothelial lining of Blood vessesl Causes the obstruction, Thrombosisand Local Ischemias
Erythrocyte cycle • Merozoites released invade red cells • P.vivax infects young erythrocytes • P.malariae Infects old erythrocytes • P.falciparum infects RBC of all ages • The Merozoites are pear shaped 1-5 microns in length • The receptors for Merozoites are on red cells in the glycoprotein • Doctortvrao’s ‘e’ learning series
Erythrocytic Schizogony • Liberated Merozoites penetrate RBC • Three stages occur 1 Trophozoites 2 Schizont 3 Merozoite
Erythrocytic cycle • Ruptured red cells release Merozoites which attack new red cells • Continue with Schizogony • Repeated cycles will continue • In P.falciparum - infected erythrocytes with Schizonts aggregate in the capillaries of brain and other internal organs • Only ring forms are seen in the blood smears
Trophozoites • After invasion grow and feed on hemoglobin • Blue cytoplasm and red nucleus, Called as Signet ring appearance • Hence called ring form
Schizont • When the Trophozoite is fully developed becomes compact. • Malarial pigments are scattered through the cytoplasm • The Nucleus is large and lies at the periphery starts dividing. • Becomes Schizont • Doctortvrao’s ‘e’ learning series
Plasmodium vivax • Number of merozoites 12 to 24 arranged in grape like clusters • RBC enlarged • Schuffner’s dots present • Yellowish brown fine granules • Schizont 9-10 microns fills and enlarged Red cell • Gametocytes – spherical or globular • Size much larger than red cell • Male 9 microns • Female 10 – 11 microns • Doctortvrao’s ‘e’ learning series
Plasmodium falciparum • RBC is normal size • Maurer’s dots 9 large red spots sometimes basophilic stippling • Dark brown or blackish one or two solid blocks • Gametocytes Crescentric, larger than a red cell 9 -10 microns, male and female 12- 14 microns
Plasmodium malaria • RBC Normal size • Contain Ziemann’s stippling • Contain dark brown coarse granules • Schizont – 6 – 7 microns almost fills a normal sized red cell. • Gametocytes Spherical or globular • Size much larger than a red cell
Plasmodium ovale • Infected RBC slightly larger • Contain Schuffner’s dots coarse granules • Schizont 6.2 microns fills three quarters • Merozoites 6 -12 fills three quarters • Gametocytes Spherical or globular, much larger than a red cell • Doctortvrao’s ‘e’ learning series