This essay Parasites has a total of 962 words and 6 pages.
Ever wonder what kind of parasites are in your water, or how they can enter in to your body to make you very sick? Well it is most definite that no on want to get sick. The information found in this paper was collected over the past month, either by going to the library or by accessing information off the Internet at home, almost every night. The point that will be given to you is a little in information about the infectious disease called Schistosomiasis. The points the main points will be the causative agents, symptoms, hosts, methods of transmission and history of the disease. So lets see what Schistosomiasis is.
Schistosomiasis is a parasite. This parasite is a worm that you get through contaminated water. Urine and feces usually contaminate the water. The worm goes in to your body and migrates to the bladder, rectum, liver, lungs, spleen, intestines and some veins. After the worm migrates to these places this is where it matures and lays its eggs. The disease has the ability to lay two thousand to three thousand eggs per day and can live for twenty years. There are five different kind of Schistosomiasis that effect humans, these different kinds are; S. mansoni, S. Heamatobium, S. japonicum, S. intercalatum and S. mekongi. There are also other kinds of Schistosomiasis that occasionally infect humans, there are; S. bovis, S. mathei, and some avian schistosomes. In some cases the eggs will get flushed out of the host. When this happens it releases miracidia that penetrate in to the snail. The snail is the intermediate host. When in the snail the organism uses asexual reproduction then development of cercariae. The cercariae can survive in fresh water for seventy-two hours. During penetration into the skin of a human the cercariae lose their tails changing into schistosomula. The next thing that happens is the worm migrates to the lungs and in 6 weeks matures in to an adult worm. It causes severe pulmonary vascular obstruction and pulmonary hypertension via both anatomic obstructive by the organism it self an inflammatory vasculitic response to the organism. It is a common cause of cor pulmonale. The liver is involved usually quite extensively before pulmonary involvement. It can cause seizures, abnormal neuralgic function, and increased pressure on the brain. It infects the kidneys, urethras, and bladder. Schistosomiasis is s a common cause of kidney failure, and bladder infections that lead to cancer. The eggs that are laid start developing after four to six weeks. The parasite migrates to the bladder or urethras depending on the animal. They can be one to two cm in length.
Some of the symptoms of Schistosomiasis are pain in organs and body, blockage and damage to the infected organ, and anemia. Most of the symptoms disappear within a few weeks but death may occur. In some of the endemic areas the disease would go unnoticed. There are a couple of reasons why it would go unnoticed. The first reason for this is because of the age they were at the time of exposure. The second reason would be the manner of exposure. The final reason would be the transfer of antigens, antibodies and anti-idiotypes from the mother. Immediately after exposure the person will have intense transient itching. You will find eggs in stool or rectal biopsy. Two to six weeks after exposure the following symptoms may develop:
*Hives or angioedema
*Loss of weight
Schistosomiasis is an infection that is contacted through contaminated water. The water is fouled with human waste (feces). It can also be transmitted through animal reservoirs. There have been some cases of dogs, cows, rodents, monkeys and baboons infected in nature. The host becomes sensitized to the egg proteins by a T-cell mediated mechanism that includes a larger granuloma. The infection granuloma decreases in size due to the recruitment of suppressor T-cell. The anti bodies have no effect on the granuloma. Eggs and granulomas release factors that induce fibroblast proliferation in vitro. The early cellular response induced by granulomas is followed by fibrosis in vivo, however liver fibroses in humans probably involves more then simple tusion of fibro tic granulomas. The disease is held in two hosts. In the adult stage it is in mammals usually humans. It spends its
None Provided49 None Provided49 Parasites and their Virulence By: Terry ABSTRACT Why do some parasites kill the host they depend upon while others coexist with their host? Two prime factors determine parasitic virulence: the manner in which the parasite is transmitted, and the evolutionary history of the parasite and its host. Parasites which have colonized a new host species tend to be more virulent than parasites which have coevolved with their hosts. Parasites which are transmitted horizontally tend to be m
Parasites and their Virulence Parasites and their Virulence ABSTRACT Why do some parasites kill the host they depend upon while others coexist with their host? Two prime factors determine parasitic virulence: the manner in which the parasite is transmitted, and the evolutionary history of the parasite and its host. Parasites which have colonized a new host species tend to be more virulent than parasites which have coevolved with their hosts. Parasites which are transmitted horizontally tend to be more virulent than those tr