Disease List C

Disease List C Chapter 13 correlates with specific viral diseases covered in multiple chapters. Due to time constraints, we cannot cover all possible microbial diseases, however, I have chosen diseases that are particularly common and/or problematic to study (I will do the same for the next unit). Please see specific diseases and pages listed at the end of this document. The diagram below illustrates some of the most common viral diseases currently know to infect humans. This diagram is by no means a complete list of viral diseases, however, it does illustrate the ability of virus to infect all different parts of the human body.

Further information: Table of clinically important viruses

Examples of common human diseases caused by viruses include the common cold, influenza, chickenpox and cold sores. Many serious diseases such as ebola, AIDS, avian and swine flue and SARS are caused by viruses. The relative ability of viruses to cause disease is described in terms of virulence. Other diseases are under investigation as to whether they too have a virus as the causative agent, such as the possible connection between human herpes virus six (HHV6) and neurological diseases such as multiple sclerosis and chronic fatigue syndrome.

As you know, viruses have different mechanisms by which they produce disease in an organism, which largely depends on the viral species. Mechanisms at the cellular level primarily include cell lysis, the breaking open and subsequent death of the cell. In multicellular organisms, if enough cells die the whole organism will start to suffer the effects. Although viruses cause disruption of healthy homeostasis, resulting in disease, they may exist relatively harmlessly within an organism. An example would include the ability of the herpes simplex virus, which cause cold sores, to remain in a dormant state within the human body. This is called latency and is a characteristic of the all herpes viruses including the Epstein-Barr virus, which causes glandular fever, and the varicella zoster virus, which causes chicken pox. Latent chickenpox infections return in later life as the disease called shingles. Some viruses can cause life-long or chronic infections, where the viruses continue to replicate in the body despite the hosts' defence mechanisms. This is common in hepatitis B virus and hepatitis C virus infections. People chronically infected are known as carriers, as they serve as reservoirs of infectious virus. In populations with a high proportion of carriers, the disease is said to be endemic. In contrast to acute lytic viral infections this persistence implies compatible interactions with the host organism. Persistent viruses may even broaden the evolutionary potential of host species. For the following diseases, you will need to know the causative agent, the mode of transmission, the mechanism of pathogenicity, signs, symptoms, treatment, and current relevant information (general info about the disease – ie is it an STD, is this disease problematic for certain regional areas, ethnic populations, etc. NOTE: The page numbers correlate directly with the custom edition book (the 9th edition pages should be similar, however, I don’t have a hard copy of that edition). CHICKEN POX/SHINGLES: PAGES 596-597 HERPES SIMPLEX: PAGES 597-598 POLIO: PAGES 620-622 INFECTIOUS MONONUCLEOSIS: PAGES 656 - 657 INFLUENZA: PAGES 692-695 (plus chapter 13 – Crossing the species barrier page 370-371) HEPATITIS: PAGES 712-728 GENITAL HERPES (HSV – 2): PAGES 757 - 758 GENETIAL WARTS: PAGE 758 – 758 EMERGING VIRAL HEMORRHAGIC FEVERS: 659 -660