Infectious Diseases

Bacterial Diseases

A bacterium is a type of single-celled organism without a nucleus. Bacteria are among the oldest and most numerous living beings and are found in soil, water and inside many multi-cellular organisms. They are small, typically in the range of a few micrometers.

Typical bacteria include:

Bacillus anthracis  Escherichia coli  Helicobacter pylori  Mycobacterium tuberculosis  Neisseria gonorrhoea  Neisseria meningitis  Rickettsiae  Salmonella typhimurium  Staphylococcus aureus  Streptococcus pyogenes  Treponema pallidum  Thiomargarita namibiensis  Yersinia pestis

Bacterial infectious diseases include:

Anthrax -- Bacterial Meningitis -- Brucellosis -- Bubonic plague -- Campylobacteriosis -- Cholera -- Diphtheria -- Epidemic Typhus -- Gonorrhoea -- Hansen's Disease -- Legionellosis -- Leprosy -- Leptospirosis -- Listeriosis -- Lyme Disease -- MRSA infection -- Nocardiosis -- Pertussis -- Pneumococcal pneumonia -- Psittacosis -- Q fever -- Rocky Mountain Spotted Fever or RMSF -- Salmonellosis -- Scarlet Fever -- Shigellosis -- Syphilis -- Tetanus -- Trachoma -- Tuberculosis -- Tularemia -- Typhoid Fever -- Typhus

Viral Diseases

Viruses are the smallest of parasites, and are completely dependent on cells (bacterial, plant, or animal) to reproduce. Viruses are composed of an outer cover of protein and sometimes lipid, and a nucleic acid core of RNA or DNA. In many cases, this core penetrates susceptible cells and initiates the infection.

Viruses range from 0.02 to 0.3 microns in size; too small for light microscopy but visible using electron microscopy.

Several hundred different viruses infect humans. Because many have only recently been recognized, their clinical effects are not fully understood. Many viruses infect hosts without producing symptoms. However, because of their wide and sometimes universal prevalence, they create significant medical and public health problems.

Viruses that primarily infect humans are primarily spread through respiratory and enteric excretions. These viruses are found worldwide, but their spread is limited by inborn resistance, prior immunizing infections or vaccines, sanitary and other public health control measures and prophylactic antiviral drugs. Zoonotic viruses primarily pursue their biologic cycles in animals; humans are secondary or accidental hosts. These viruses are limited to areas and environments able to support their nonhuman natural cycles of infection (vertebrates or arthropods or both).

Viral disease include:

AIDS -- AIDS Related Complex -- Chickenpox or Varicella -- Common cold -- Cytomegalovirus Infection -- Colorado tick fever -- Dengue fever -- Ebola haemorrhagic fever -- Epidemical parotitis -- Flu -- Hand, Foot and Mouth Disease -- Hepatitis -- Herpes zoster -- Influenza -- Lassa fever -- Measles -- Marburg haemorrhagic fever -- Mononucleosis -- Mumps -- Poliomyelitis -- Progressive multifocal leukencephalopathy -- Rabies -- Rubella -- SARS -- Smallpox or variola -- Viral meningitis -- West Nile disease -- Yellow fever