M12

• The relationship between the host and the normal microbiota

  • Symbiosis
• This period is characterized by mild aches, malaise and it follows the period of incubation of the disease

  • Prodromal stage
• The number of cases of Filipino with AIDS has increased tremendously over the past few years. This described as:

  • Epidemic
• Microorganism do not invade the bladder because they are easily flushed out by acidic urine. The distal urethra is sterile

  • First statement is correct. Second statement is incorrect
• Capsulated microorganism can pass through the stomach and may cause a disease. Flagellated microorganism can pass through slightly acidic stomach and may colonize other areas of GIT

  • Both of the statement are incorrect
• Anaerobes normal flora of the skin can be found in epidermis. Propionibacterium genus can be found in dermis

  • First statement is correct. Second statement is incorrect
• Influenza develops rapidly and lasts only for a short time. This is describes as

  • Acute
• It is an indication of the ability of a bacterium to produce pathologic changes or disease in the host

  • Pathogenicity
• Includes all the microbes that reside on and within that person

  • Indigenous Microflora
• They may be washed from external areas by bathing

  • Transient Microflora
• They ordinarily do not cause disease in their normal habitat in a healthy person but may do so in a different environment

  • Opportunistic Pathogens
• Acute: develop rapidly

  Chronic: develops slowly

  Subacute: symptoms between acute and chronic

  Latent: disease with a period of no symptoms
• Syndrome: a specific group of symptoms or signs may always accompany a particular disease

  Communicable disease: any disease that spreads from one host to another, either directly or indirectly

  Contagious disease: easily spread from one person to another (direct or indirectly or droplet)

  Non-communicable disease: not spread from one host to another
• Incidence: the number of people in a population who develop a disease during a particular time period

  Prevalence: develops a disease at a specified time, regardless of when it first appeared

  Sporadic: occurs only OCCASIONALLY in given population

  Endemic: constantly present in population

  Epidemic: an outbreak or higher than the normal number of cases

  Pandemic: spread of an epidemic across the continent
• Form of immunity that occurs when the vaccination of a significant portion of a population (or herd)

  • Herd Immunity
• Local infection: invading microorganism are limited to a relatively small area of the body

  Systemic infection: microorganism or their products are spread throughout the body by the blood or lymph

  Primary infection: an acute infection that causes the initial illness

  Secondary infection: caused by an opportunistic microbe after a primary infection has weakened the host's defense

  Subclinical (inapparent) infection: does not cause a noticeable illness
• Incubation period: time interval between the initial infection and the first appearance of any signs and symptoms

  Prodromal period: the time during which the patients feels "OUT OF SORTS", but is not yet experience actual symptoms of the disease

  Period of illness: this is the time wherein patient feels or experiences the typical symptoms associated with that particular disease

  Period of decline: time during which the patient recovers

  Period of convalescence: the person regains strength and the body return to its pre-diseased state. Recovery has occurred
• Principal living reservoir of human disease. This people are called carriers

  • Human reservoir
• Are infected, but they show no symptoms

  • Asymptomatic

  Spread the infectious agent during incubation period

  • Incubation carriers

  When they continue to shed microbes and convey the infection to others

  • Convalescent carriers

  An individual who shelters the infectious agent for a longer period time

  • Chronic carriers
• Zoonoses: disease that occur primarily in wild and domestic animals and can be transmitted to human

  • Animal reservoir
• Soil and water are two major nonliving reservoir of infectious disease

  • Non-living reservoir
• CONTACT TRANSMISSION

  Person to person transmission by physical contact between its source and susceptible

  • Direct contact transmission

  Spread of (disease) pathogen by fomites (non-living objects)

  • Indirect contact transmission

  Small liquid droplets carrying microorganisms

  • Droplet transmission
• VEHICLE TRANSMISSION

  Contaminated water

  • Waterborne transmission

  Contaminated food, incompletely cooked, poorly refrigerated or prepared under unsanitary conditions

  • Foodborne transmission

  spread of agents of infections by droplet nuclei in dust

  • Airborne transmission
• VECTOR

  The passive transport of the pathogens on the insect's feet or other body

  • Mechanical transmission

  Pathogens are within the vector and transmission to the host i sthrough a bite

  • Biological transmission
• Entails collecting all date that describe the occurrence of the disease under study

  • Descriptive epidemiology
• Analyzes a particular disease to determine its probable cause

  • Analytical epidemiology
• Begins with a hypothesis about a particular disease; experiment to test the hypothesis are then conducted

  • Experimental epidemiology
• the number of new cases of a particular disease that occurred during a specified time period

  • Morbidity rate
• The ratio of the number of people who dies of a particular disease during a specified period

  • Mortality rate
• infection dose for 50% of the test population, indication of virulence of microbe

  • ID50
• Lethal dose (of a toxin) for 50% of the test population, potency of a toxin

  • LD50
• Bacterial enzyme that clot the fibrinogen in blood

  • Coagulases
• bacterial enzymes that breaks down fibrin and thus dissolve clots formed by the body to isolate the infection

  • Kinase
• Hydrolyzes hyaluronic acid (glue that holds together connective tissues and epithelium barriers) allowing deeper invasion

  • Hyaluronidase
• breakdown the protein collagen, which forms the connective tissues of muscles and other body organs and tissues

  • Collagenases
• some microbes vary expression of antigens, thus avoiding the host's antibodies

  • Antigenic variation
• surface proteins produced by bacteria to control actin

  • Invasin
• allows penetration between cells at intercellular junction

  • Cadherin
• provide attachment and resistance to antimicrobial agents

  • Biofilms