The nature of DISEASE CAUSING ORGANISMS and the mechanisms employed by man to combat these organisms.
What is disease? A disease is a disturbance in the normal structure or function of an organism, group of organisms or the entire body. Diseases affect different organisms in different ways, they may be temporary, they may be chronic, or they may be terminal. They may even be localized or widespread through an entire body. Many diseases have been eradicated, but, some have no cure. Humans and other vertebrates have a system of specific immunity to combat disease. Some disease causing organisms invade body tissues and then destroy them, while others setup a symbiotic relationship with the cells. Most communicable diseases are caused by microorganisms or larger parasites that are commonly called germs, most scientists call them pathogens.
What kinds of disease are there, that are caused by organisms?
-Infectious disease- caused by living organisms, can be passed by contact.
-Viral disease- caused by viruses, difficult to treat because viruses are non-living
-Fungal disease- usually cause mild infections, difficult to treat
-Protozoan disease- the "tropical diseases" caused by protozoa
-Worm infections- mostly in the tropics, worms inside body causing damage
-Diseases can be caused by a wide variety of bacteria, viruses, fungi, protozoans, and parasitic worms. Some sferre some disease causing organisms, and how do they affect plants? Plant diseases can be caused by microorganisms, parasitic flowering plants, nematodes, viruses, or adverse environmental conditions. Bacterial diseases are marked by symptoms such as soft rot, leaf spot, wilt of leaves and roots, cankers, leaf and twig blight, and gall formation. Most plant diseases are caused by fungi. Fungal diseases have been documented on since biblical times. Fungal diseases are characterized by leaf spots, ulcerous lesions, blights, powdery mildew, cankers, root rots, wilts, and club root. Viral diseases are infectious and spread largely by insects. All economic plants suffer from one or more viral diseases. Symptoms include mosaic patterns, yellowing of foliage, vein clearing, ring spots, stunting and premature death, malformations and overgrowth. Nematodes, or roundworms, are a large cause of disease in plants. They live in and cause damage to the roots, stems, leaves, and bulbs of plants.
Thomas disccuseed thr “paranoid delusions on a societal scale,” that we have against human diseases or our “enemies.” The book contiuniuously uses anaphora by saying that diseases result from “inconclusive negoitions for symbiosis” and misinterpretation of biology” The fact that bacteria can only be harmful from practiacally harming themselves is an interesting point to point out. That shows the reader that the only way they could be harmed from bacteria, wouls be if the bacteria had gotten itself “sick” first. Thomas talks about certain microorganisms that have “advantages in their ability to affect himan beinhg, but that there is nothing to be gained, in an evolutionary sense, by the capacity to caue illness or death.” Another reassuraing statement for readers is when he says, pathogenicy is a disadvantage for most microbes because they are carrying
“There is no real definition for disease. ” This is a claim that Melody Petersen makes in her book. Most would define disease as an abnormality in regards to health. This seems logical, but it leads to the following question : what is “normal” ? What is the definition of “healthy” ? Asking major pharmaceutical companies these questions will most likely lead to the following conclusion: disease is malleable. In other words, it is open to a certain level of interpretation. According to Petersen, giant drug manufacturers consider disease to be a business. Thus, they create a market out of people’s physical or emotional shortcomings. In 1998, Pharmacia, a large American manufacturer of prescription drugs,
Disease: any abnormal functioning of the body, organs, tissues, or cells that create the inability to function normally
The main objectives of the pathogen are to gain entry inside the host, once inside grow and reproduce, and avoid host defenses. There are three possible routes of infection: respiratory, alimentary, and traumatic. The respiratory route is the easiest and most direct means of entry. Under crowded conditions, the rate of infection is even more rapid. The diseases brought over to America were mainly spread by the respiratory method. The alimentary pathway of infection is through the ingestion of contaminated food and water. Throughout Europe during the 15th century, food and water were contaminated with fecal matter and by unsanitary habits ( i.e. the lack of bathing). The traumatic route of infection is through insect and animal bites.
Many of these diseases originate from animal populations. Humans’ interaction with the environment, and animals contribute to the rate and prevalence of disease. All three areas are interconnected. One Health is a concept that views human, animal, and environmental health as one area of health. The three entities, when separated can hinder each other and delay progress. The opposite is also true. When public health officials recognize the correlation between human, animal, and environmental health, advancements and innovation can occur. Other public health issues are present in relation to spread of infectious disease between humans and animals. People must know how to cook animal products in order to kill pathogens. Many diseases are also transferred when humans disrupt ecosystems. These are areas where public health has the opportunity to make progress. The issues that infectious diseases cause occur across the globe. In addition, One Health concepts can be applied to populations all over the
Schumann, Gail L., and Cleora J. D'Arcy. Hungry Planet: Stories of Plant Diseases. St. Paul: American Phytopathological Society, 2012. Print.
The known cause of this disease is bacterial though there are 5 main forms of Meningococcal some of which are both viral and bacterial. Bacteria and Viruses are very different. Bacteria can survive without a host while a virus needs a cell to survive. Most viruses cause diseases and target specific cells or bacteria. Unlike a virus only 1% of Bacteria actually cause diseases.
The major wide spread of disease is trade route because people were sometime trading illegally and their product was not tested before being sold and fleas that were in animal fur containing the virus of different disease would easily spread. Colonization/imperialism created fear to the indigenous people because they were separated from families and their culture was demolished. The missionary found the opportunity to spread Christianity by feeding lies of their God and how the disease is spread because of his wrath of wickedness and sins of the people. The spread of disease was involved in warm climate that will help the development of the virus to grow and attack the immune
Illness has been a major part of humankind’s lives almost since the beginning of time. Throughout history, illnesses caused fatal epidemics that caused deaths between young and old, and brought fear upon all for the absence of a cure. Having an illness throughout most of history was considered an inevitable death sentence, as the majority of causes of death (Offit). Vaccinations have been experimented in China and Turkey in the 15th century, with methods such as inhaling or rubbing grounded up smallpox scabs against open cuts (Clem). Then in 1700s, the first form of modern vaccination was invented by Edward Jenner with the cowpox virus acting against smallpox, giving immunity against it (Offit).
1) Sickness is different from disease as sickness refers to a social or cultural concept of a disease/illness while disease is the biological definition of it. An example of an sickness is “Qaug dab peg” a Hmong sickness that occurs when the soul leaves the body resulting in seizures. An example of a disease is epilepsy a neurological condition that causes the body to have random seizures. Both examples are of the same disease, but one is how the culture views it while the other is how biology views it.
The human population has a high susceptibility to the contraction of new diseases and outbreaks of these diseases are of high risk. Diseases in recent times that have broken out into the human population are the H7N9 flu strain and SARS. Despite the risk, outbreaks like H7N9 and SARS have been controlled due to epidemiology and other disease control methods. Outbreaks of disease are not uncommon to the human population as they move to new areas around the world with foreign diseases that the native residents would have developed a resistance to.
Throughout history many different diseases have infected the world. Such diseases consist of measles, mumps, malaria, typhus and yellow fever. Many of these diseases are caused by different things and originated in different countries.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
What does it mean to be healthy? Health is a state of complete physical , mental, and social well-being and not merely the absence of disease, illness or infirmity. It is important to distinguish between disease and health. Disease is the prognosis of a particular disorder with a specific cause and characteristic symptoms. On the other hand, illness is the existence of disease
This also requires the person to be socially and economically productive in order to be seen as healthy. According to Mildred Blaxter (1990), there are different ways of defining health. Furthermore, disease can be seen as the presence of an abnormality in part of the body or where there is a harmful physical change in the body such as broken bones. So, illness is the physical state of disease, that is to say, the symptoms that a person feels because of the disease. However, there is some limitation of these definitions which is not merely an absence of disease but a state of physical, mental, spiritual and social wellbeing.