I personally found Chapter 5 to be very fascianitng; I love learning about host manipulation. Organisms, regardless of size or other classifcations, aim to survive and reproduce. Organisms that cause diseases are no exception. These organisms will manipualte their host so that the disease spreads to new victims, helping the disease-causing organisms survive and reproduce. An example of host manipualtion is the interaction between humans and the Guine worm. Intially, a human drinks water contaminated with water fleas, which have eaten the Guinea worm larvae. The human digestive system destroys the fleas, but the Guinea worm larvae survive. A year after infection, the larvae are fully grown and females make their way to the surface of the skin. …show more content…
The last example is T. gondii is a parasite that is only able to sexually reproduce in cats. When the parasite reproduces, it creates oocysts, which are removed from the cat when it passes feces. Animals, such as rodents and birds, will in time eat the oocysts and become infected. The parasite can also infect humans when we eat undercooked meat and unclean vegetables or do work with cat litter. This is why pregnant women should not empty a cat litter box. Although the infection is mostly benign in humans (those with weak immune systems can face complications), if a pregnant women becomes infected with the parasite, then the fetus is at a risk for severe complications. However, if a women is infected before fertilization, then the risk is nonexistent. Despite its lackluster effect in humans, the parasite greatly affects mice and rats. Once infected, rodents become heavy, lazy, and lose the concept of fear of predators. Furthermore, the rodents are attracted to the smell of cat urine. Clearly, the rodents are now slow, appetizing, and in the presence of a cat, which leads to a nice and tasty meal for the cat. Once in the cat, the parasite is able to sexually reproduce, ensuring its survival.
Ultimately, host manipulation is a very interesting topic. Although the organism causing the disease does not take full control of the host, it does cause the host to act in certain ways that will benefit the organism survive and reproduce--the goals for all living
TASK 2 Infectious diseases are the invasion of host organisms, (microbes) which can be invisible to the eyes. The microbes are also known as pathogens. A microbe infects an organism (which is known as the host of the microbe). In a human host, the microorganism causes a disease by either disrupting an important body process or by stimulating the immune system to mount a defensive reaction. The pathogen, interferes with the normal functioning of the host and can lead to chronic wounds, gangrene, loss of an infected limb, and even death.
These pets would then bite or scratch or perhaps carry the infected fleas and pass the infection
They were not interested in mice that showed malaria symptoms. But they were attracted to mice that were recovering from the disease. The researchers knew that this stage of malaria is when the parasite is at high levels. Somehow, the parasite was altering the mouse's odor, making the mosquitoes want to bite it. The researchers were able to extract the body scent from the mice.
The bacillus infects people through the bite of infected fleas and rats (“BLACK DEATH”). This was especially prominent in urban and over populated areas (“Ecology and Transmission“). When Plagues strike people and animals alike die horrifically, in turn fleas need to find other sources of food. The people living in poor conditions often get forayed by flea bites, thus infecting them (“Ecology and Transmission“). It was seldom for the Black Death to be spread from person to person.
Because there was no system of drains or sewers, a dirty environment was formed and bacteria began to grow on fleas. The fleas would attach themselves to rats, and the rats would
This specific bacteria attacks the lymph system causing the infection to spread throughout the body. The reservoirs of this bacteria and disease are mice, rats, squirrels and other small animals. A reservoir is a host of an infection. The vector, meaning carrier, is insects such as fleas and
During the Trench Warfare, fleas carried typhus, which was a deadly disease which could poison soldiers. Fleas were also on rats, so diseases could get transferred on air or
Merchant boats with stow-away rats infested with fleas carried the illness from port to port. When the boats docked, the fleas bit the townspeople on shore giving them the sickness. These people would then in turn spread the sickness to their friends and family. Soon, whole villages were infected. After several years, the plague came to an end, but the results of this disease left many farms, villages, and cities barren and empty.
There are many healthcare disparities involving parasitic infection. One disparity, for example, is that any one can get parasitic infection, it is so easy to be infected by a parasitic infection. Also, to really prevent one from getting a parasitic infection, they would have to be extremely cautious on the food they are eating and the water they are drinking. It is more common in regions of tropical or subtropical to avoid getting infected. We can also get infected through our pets and the disparity in this is that its hard to keep up with everything to avoid getting infected with parasitic
Basically, all the placenta waste from hundreds of eggs will flow out through the host’s gills. That has to be fun for the host. In the juvenile stage the young lice will have large eyes, spiny appendages, will have fine bristles on most appendages to aid in swimming. After the new offspring leave the original host they will search for and attach to any convenient fish for short periods of time. Because the juveniles only temporarily attach to a host they can be referred to as facultative parasites, which is an organism that may rely on parasitism but does not depend on it to complete its lifecycle.
Survival of the Sickest, by Dr. Sharon Moalem, is a book that reveals the origins of some modern diseases that beset us today. It explains how these sicknesses have been passed on for so many generations, and the impacts they have had on humanity, thus shedding a new light on them. By reading this book, much can be learned from the many different infections the author wrote about. However, hemochromatosis, diabetes, and progeria most exemplify how such terrible diseases worldwide could have provided evolutionary advantages for our ancestors. Hemochromatosis, an inherited disease, is a condition in which the body produces excess iron thinking there isn’t enough iron in the intestines, even though there is.
“Panleukopenia” comes from low white blood concentration that all affected animals show. Affected cats loose much water, experience severe dehydration. The virus moves from place to another on contaminated objects and substances. Hands, shoes, bearing saliva or pieces of stool are among the most common means of transfer.
All except the dwarf tapeworm are acquired by eating raw or undercooked meat from the meat source that the name indicates (fish, beef or pork). You get dwarf tapeworm by eating or ingesting the Hymenolepis eggs on or in any food contaminated by stool from another infected person. All except pork tapeworm infections never travel outside of the bowel in humans. People who ingest human stool or feces contaminated with pork tapeworm eggs can develop a disease called cysticercosis. Infected persons have multiple cysts in many parts of
The guinea worm is the largest of the parasites that can affect humans. The adult female can carry around 3 million eggs and can get up to 600-800 mm in length, as well as 2 mm in diameter. It can cause the parasitic infection, dracunculiasis, which is most commonly known as Guinea worm disease. The parasite moves through the subcutaneous tissues of the infected victim and up to the surface of the skin. About a year after initial infection, the guinea worm produces a blister on the skin, typically the feet, and then
This reckless type of hunting leaves hunters susceptible to injuries, which increase the chances of an infected animal’s blood entering a human’s blood stream. This would allow more chances for the disease to mutate as more humans become exposed to infected animal