Lactobacillary replacement of the flora of the adult

This preview shows page 8 - 9 out of 12 pages.

lactobacillary replacement of the flora of the adult colon does not take place so easily, there have been some successes with capsules containing lyophilized bacteria. In some studies, administration of preparations containing a particular strain of Lactobacillus ( L rhamnosus strain GG , LGG) has reduced the duration of rotavirus diarrhea in children and prevented relapses of antibiotic-associated diarrhea caused by C difficile . Infectious Disease Epidemiology Pathogenesis Immunity Clinical Aspects of Infectious Disease Manifestations Diagnosis Treatment Prevention Summary Of the thousands of species of viruses, bacteria, fungi, and parasites, only a tiny portion is involved in disease of any kind. These are called pathogens . There are plant pathogens, animal pathogens, and fish pathogens, as well as the subject of this book, human pathogens. Among pathogens, there are degrees of potency called virulence , which sometimes makes the dividing line between benign and virulent microorganisms difficult to draw. Other pathogens are virtually always associated with disease of varying severity. Yersinia pestis, the cause of plague, causes fulminant disease and death in 50% to 75% of persons who come in contact with it. It is highly virulent. Understanding the basis of these differences in virulence is a fundamental goal of this book. The better that students of medicine understand how a pathogen causes disease, the better they will be prepared to intervene and help their patients. For any pathogen the basic aspects of how it interacts with the host to produce disease can be expressed in terms of its epidemiology, pathogenesis, and immunity. Usually our knowledge of one or more of these topics is incomplete. It is the task of the physician to relate these topics to the clinical aspects of disease and be prepared for new developments which clarify, or in some cases, alter them. We do not know everything, and not all of what we believe we know is correct. Epidemiology Epidemiology is the "who, what, when, and where" of infectious diseases. The power of the science of epidemiology was first demonstrated by Semmelweis, who by careful data analysis alone determined how streptococcal puerperal fever is transmitted. He even devised a means to prevent transmission (ie, handwashing) decades before the organism itself was discovered. Since then, each organism has built its own profile of vital statistics. Some agents are transmitted by air, others by food, and others by insects; some spread by the person-to-person route. Figure 1–5 presents some of the variables in this regard. Some agents occur worldwide, and others only in certain geographic locations or ecologic circumstances. Knowing how an organism gains access to its victim and spreads is crucial to understanding the disease.
Image of page 8

Subscribe to view the full document.

Image of page 9

{[ snackBarMessage ]}

Get FREE access by uploading your study materials

Upload your study materials now and get free access to over 25 million documents.

Upload now for FREE access Or pay now for instant access
Christopher Reinemann
"Before using Course Hero my grade was at 78%. By the end of the semester my grade was at 90%. I could not have done it without all the class material I found."
— Christopher R., University of Rhode Island '15, Course Hero Intern

Ask a question for free

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern