Protozoan Diseases and Helminth disease

•  Parasite - Living organism living in or on, and having some metabolic dependence on another organism known as host
• Parasitism - a relationship in which one of the participants, the parasite, either harms its host or in some sense lives at the expense of the host
• Parasitic disease, also known as parasitosis, is an infectious disease caused or transmitted by a parasite​
• • Infection- is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce.​
• Medical parasitology: “the study and medical implications of parasites that infect humans
• Host: “the organism in, or on, which the parasite lives and causes harm
• Protozoa: unicellular organisms, e.g. Plasmodium (malaria)
• • Metazoa: multicellular organisms, e.g. helminths (worms) and arthropods (ticks, lice)​
• • An endoparasite: “a parasite that lives within another living organism” e.g. malaria, Giardia​
• • An ectoparasite: “a parasite that lives on the external surface of another living organism” e.g. lice, ticks​
• Definitive host: “the organism in which the adult or sexually mature stage of  the parasite lives”
• Intermediate host: “the organism in which the parasite lives during a period of its development only
• Zoonosis: “a parasitic disease in which an animal is normally the host - but which also infects man
• • Vector: “a living carrier (e.g.an arthropod) that transports a pathogenic organism from an infected to a non-infected host”. A typical example is the female Anopheles mosquito that transmits malaria​
• Ebers papyrus-  refers to intestinal worms, and these records can be confirmed by the discovery of calcified helminth eggs in mummies dating from 1200 BC.​
• Hippocrate- knew about worms from fishes, domesticated animals, and humans
• • Hippocrates-Father of Medicine​
•  Celsus and Galen were familiar with the human roundworms Ascaris lumbricoides and Enterobius vermicularis and tapeworms belonging to the genus Taenia.​
• • Paulus Aegineta - clearly described Ascaris, Enterobius, and tapeworms and gave good clinical descriptions of the infections they caused ​
• Antonie van Leeuwenhoek observed and illustrated Giardia lamblia in 1681, and linked it to "his own loose stools". This was the first protozoan parasite of humans that he recorded, and the first to be seen under a microscope
• • Late 17th century that the detailed anatomy of the ​

     worm was described, first by Edward Tyson​
• • James Paget discovered the intestinal nematode ​

      Trichinella spiralis in humans in 1835
• • James Annersley described amoebiasis, protozoal infections of the intestines and the liver, though the pathogen  Entamoeba histolytica, was not discovered until 1873 by Friedrich Lösch​
• • Francesco Redi, considered to be the father of modern parasitology, was the first to recognize and correctly describe details of many important parasites.​
• German parasitologist Karl Georg Friedrich Rudolf Leuckart discovered the alternation of generations involving parasitic and free-living phases.
• • Patrick Manson discovered the life cycle of ​

      elephantiasis, caused by nematode worms ​

      transmitted by mosquitoes,
• • Giovanni Battista Grassi and others ​

     described the malaria parasite's life ​

       cycle stages in Anopheles mosquitoes​
• • Friedrich Zenker (1860) recognized the clinical significance of the adult worms infection and concluded that humans became infected by eating raw pork.​
• • Sir Ronald Ross

     was a British medical doctor who received the ​

     Nobel Prize for Physiology or Medicine in 1902 ​

     for his work on the transmission of malaria
• • The life cycle in humans, including the migration of the larval stages around the body was discovered only in 1922 by a Japanese pediatrician, Shimesu Koino​
• One of the deadliest parasites is the mosquito which can give you, Malaria.
• The world's largest flowering plant, called Rafflesia, is parasitic, living inside tropical trees.
• Helminths are one of the leading causes of morbidity in the developing world with over two billion people affected
• • Roundworm (Ascaris)​ - Pneumonitis, intestinal obstruction​
• • Whipworm (Trichuris)​ - Bloody diarrhea, rectal prolapse​
• • Hookworm (Ancylostoma and Necator)​ - Coughing, wheezing, abdominal pain and anaemia​
• Schistosoma​ - Renal tract and intestinal disease​
• Filariae​ - Lymphatic filariasis and elephantiasis​
• Trypanasoma cruzi​ -Chagas disease (cardiovascular)​
• African trypanosomes​ - African sleeping sickness​