Semis public heath 2

• Public Health


  The prevention of spread of diseases within the population
• Categories of diseases


  • Communicable
  • Non-communicable
• Communicable Diseases


  Diseases that can be transmitted to humans either directly or through mediums, caused by microorganisms like bacteria, parasite, fungi, prion or virus

  
• Germ Theory


  The growth and reproduction of a micro-organism (germ) inside a human body can cause a specific disease
• Pathogen


  A disease-causing microorganism

  
• Susceptibility


  A person's susceptibility to the disease plus the pathogenicity of the micro-organism can increase the risk of having the disease

  
• Immune System


  The body's defense against pathogens
• Types of Immune Systems

  • Innate Immune System
  • Adaptive Immune System
• Innate Immune System


  • Nonspecific, does not confer long-term immunity, first line of defense, responds in a generic way, has humoral and cell-mediate immunity components
• Functions of Innate Immune System

  • Recruiting immune cells
  • Activation of complement cascade
  • Identification and removal of foreign substances
  • Activation of adaptive immune system
  • Acting as physical and chemical barrier
• Inflammation


  The first reaction of the body as a response to a pathogen or antigen, characterized by redness, increased heat, pain and swelling
• Cells involved in Innate Immune System

  • Neutrophil
  • Dendritic Cell
  • Basophil
  • Eosinophil
  • Mast Cell
  • Macrophage
  • Natural Killer Cell
• Adaptive Immune System


  • Highly specific, creates long-term memory of immunity, provides long-term protection, has humoral and cell-mediate immunity components
• Major Functions of Adaptive Immune System

  • Recognition of specific "non-self" antigens
  • Generation of tailored responses to eliminate pathogens
  • Development of immunological memory
• Types of T Lymphocytes


  • T Helper Cell
  • Cytotoxic T cell
  • Memory T Cell
  • Suppressor T Cell
  • Natural Killer T Cells
• Antibodies or Immunoglobulins


  • IgG
  • IgA
  • IgM
  • IgE
  • IgD
• B Cell Receptor (BCR)


  An immobilized antibody molecule that recognizes and binds to a particular antigen

  
• Plasma Cell


  Effector B cells that secrete antibodies

  
• Passive Immunity


  Short-term immunity acquired through transfer of antibodies, e.g. from mother to fetus, or breastmilk to infant

  
• Active Immunity


  Long-term immunity acquired through activation of B and T cells, e.g. through vaccination
• Immunization


  The process of making a person immune or resistant to an infectious disease, typically by administering a vaccine
• Types of Vaccines


  • Live attenuated
  • Inactivated
• Live Attenuated Vaccines


  Derived from "wild" viruses or bacteria that have been weakened in a lab, replicate but usually do not cause disease, produce immune response similar to natural infection
• Inactivated Vaccines


  Produced by growing the bacterium or virus in culture, then inactivating it, cannot replicate, require multiple doses to produce protective immunity, mostly induce humoral immunity
• Polysaccharide Vaccines


  Inactivated subunit vaccines composed of long chains of sugar molecules that make up the surface capsule of certain bacteria
• Recombinant Vaccines


  Vaccine antigens produced by genetic engineering technology

  
• Types of vaccines


  • Inactivated whole viral vaccines (polio, hepatitis A, and rabies)
  • Inactivated whole virus influenza vaccine
  • Whole inactivated bacterial vaccines (pertussis, typhoid, cholera, and plague)
  • Subunit vaccines (hepatitis B, influenza, acellular pertussis, human papillomavirus, anthrax)
  • Toxoid vaccines (diphtheria, tetanus)
• Polysaccharide vaccine


  A unique type of inactivated subunit vaccine composed of long chains of sugar molecules that make up the surface capsule of certain bacteria
• Diseases with polysaccharide vaccines

  • Pneumococcal disease
  • Meningococcal disease
  • Salmonella Typhi
  • Haemophilus influenzae type b (Hib)
• Recombinant vaccines


  • Hepatitis B vaccine
  • Human papillomavirus (HPV) vaccine
• Live attenuated vaccines


  Vaccines with pathogens genetically modified to not cause illness
• Live attenuated vaccines


  • Live typhoid vaccine (Ty2 la)
  • Live attenuated influenza vaccine
• It is important to know the type of pathogens that is causing the disease. Every pathogen has its own characteristics, life cycle and means of transmission which when identified can be anticipated.

  
• Bacterial pathogens and diseases

  • Clostridium botulinum - Botulism
  • Leptospira - Weil's Disease (Leptospirosis)
  • Clostridium tetani - Tetanus
  • Mycobacterium tuberculosis - Tuberculosis
  • Salmonella typhi - Typhoid fever
  • Corynebacterium diphtheria - Diphtheria
  • Staphylococcus aureus - Impetigo
  • Mycobacterium leprae - Hansen's Disease (Leprosy)
  • Neisseria gonorrheae - Gonorrhea
  • Streptococcus - Rheumatic Fever
  • Bordetella pertussis - Whooping cough (Pertussis)
  • Vibrio cholerae - Cholera

  
• Viral pathogens and diseases

  • Hepatitis virus - Hepatitis
  • Dengue (Flavivirus) virus - Dengue Hemorrhagic Fever
  • Rabies (Rhabdovirus) virus - Rabies
  • Human papillomavirus - Warts
  • Human Immunodeficiency virus - Acquired Immunodeficiency Syndrome
  • Measles (Paramyxovirus) Virus - Rubeola (Measles)
  • Mumps (genus Rubulavirus) virus - Epidemic parotitis (Mumps)
  • Polio (genus Enterovirus) virus - Poliomyelitis
  • Rotavirus - Severe diarrhea
  • Varicella zoster virus - Chickenpox, Shingles
  • Rubella (genus Rubivirus) Virus - German Measles
  • Epstein-Barr Virus - Infectious Mononucleosis
• Parasitic pathogens and diseases

  • Entamoeba histolytica - Amebiasis
  • Ascaris lumbricoides - Ascariasis
  • Diphyllobothrium latum - Diphyllobothriasis (Tapeworm infection)
  • Ancylostoma braziliense - Cutaneous Larva Migrans
  • Wuchereria bancrofti - Filariasis (Elephantiasis)
  • Plasmodium sp. - Malaria
  • Schistosoma sp. - Schistosomiasis (bilharzia)
  • Trichuris trichiura - Whipworm infection
  • Taenia sp. - Tapeworm infection, cystecircosis

  
• Fungal pathogens and diseases

  • Candida albicans - Candidiasis (thrush, genital, etc.)
  • Cryptococcus neoformans - Cryptococcosis
  • Dermatophytes - Ringworm
  • Trichophyton sp. - Tinea pedis (Athlete's foot)

  
• Bacteria


  • Prokaryotic microorganisms
  • Come in various shapes or morphologies: rod-shaped, spherical, curved, square or even star-shaped
  • Can form in chains or clusters or pairs
  • Often attach to surfaces and form dense aggregations called biofilms or bacterial mats
• Bacterial cell structure


  • Surrounded by a cell membrane (also known as a plasma membrane)
  • Do not usually have membrane-bound organelles in their cytoplasm, and thus contain few large intracellular structures
  • Lack a true nucleus, mitochondria, chloroplasts, and the other organelles present in eukaryotic cells
• Bacterial movement


  • Use flagella for swimming through fluids
  • Use bacterial gliding and twitching motility to move across surfaces
  • Change buoyancy to allow vertical motion
  • Have two distinct modes of movement: forward movement (swimming) and tumbling