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Chapter 3

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University of Toronto Scarborough
Health Studies
Rhan- Ju Song

September, 20 , 2012 Chapter 3: Six Plagues of Antiquity  Agriculture provided increased amounts of food for the people, but it also contributed to the conditions that would result in a decline in human health  It was agricultural revolution which led to the driving force of the growth of cities  Urban life also enhanced the transmission of certain diseased through the air and water by direct contact and by vectors such as snails, mosquitoes, and flies  The disease of antiquity were characterized by parasites with long- lived transmission stages as well as those involving person-to-person contact The Pharaoh’s Plague (1900 BC)  Hematuria: blood to appear in the urine  There is a hieroglyphic sign showing a penis dripping fluid, being blood o it was not considered to be a disease but a male child hitting puberty  Snail fever has occurred in tropical & subtropical parts of the world but especially in Egypt  Egypt’s people, had a very bad case of snail fever o They could not get rid of snail fever because they needed irrigation for the crops, and that was one of the main causes that transmitted snail fever  The cause of snail fever was unknown because the transmission stages of the parasite are microscopic, the adult worms are tiny and live within the small blood vessels, so they were unnoticed for thousands of years  Blood fluke disease aka snail fever involves feces or urine, water, snails, and flat worms  The first Europeans to experience the disease on any scale appear to have been the soldiers of the Napoleon’s army during the invasion of Egypt  The symptom of the disease – bloody urine- was rife among the soldiers  Connection between hematuria and a parasite was not recognized until 1851, an autopsy was happening on a young man and worms were found in his blood vessel  They assumed that humans got the infection by either eating infected snails or by drinking water containing the ciliated larvae called miracidia  Now there are three known species of human-infecting blood flukes o Schistosoma o Schistosoma japonicum o Schistosoma mansoni  After 65 years, the lifecycle of a snail fever was finally known: o On reaching fresh water, the discharged eggs release a swimming larva (miracidium) o Miracidia are short-lived but if they encounter a suitable snail change in form (sporocyst) for 6 to 7 weeks, by asexual reproduction, the #’s of the parasite increased o During this time, the snail sheds thousands of fork-tailed cercariae which can swim and directly penetrate human skin, and in 5 to 8 weeks they develop into adult worms  Granuloma: it is the passage of eggs through the bladder wall that results in bleeding and gives the telltale sign of hematuria  The earliest signs of infection occur within 1 to 2 months and are fever, chills, sweating, headaches, and cough 1 September, 20 , 2012  Schistosomiasis is an arithmetic disease: the severity of the symptoms and cumulative damage are directly related to the number of worms present, and the latter depends on the degree of exposure  In places where the disease is common (Africa) people have built immunity to it  Schistosomiasis has not been eliminated yet, there is around 200 million people that are still infected with the disease , it is one of Africa’s greatest tragedies  Schistosomiasis first originated in animals living in the rainforests and lakes of East Africa and then spread together with its vector snails. Along the Nile and out into the middle East and Asia via trade routes  Blood flukes occur in birds and mammals other than humans  Diagnosis of Schistosomiasis is made my examining stools and urine under the light microscope and finding eggs  Preventive measures include education of the population in means to prevent transmission, treatment of infected persons, and control of the snail vector using molluscicides  It wasn’t until the 1970s that a truly effective drug with low toxicity was developed: praziquantel o There is no preventive vaccine or drug for this disease  As long as infected individuals continue to urinate and poo in the same waters where the vector snail lives and to expose their bare skin, there will be blood fluke disease The Plague of Athens (430 BC)  There was war in Greece with Athens & Sparta o Athenians was defeated by Sparta due to the plague  An epidemic that started in Ethiopia moved into Eg
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