16th lecture (general pathology of infectious diseases, AIDS) Flashcards
How many people die from infectious diseases every year?
10,000,000 death/year
Sepsis, pneumonia are between the 10 most frequent cause of death in US.
what are some of the categories that have an affect on the infection?
Hygienic conditions
Quality of health care
- vacciation
- antibiotic treatment
- supportive therapy
New diseases and infecive agents (mutations) can develop
Medical treatment that suppresses the immune system can assist opportunistic diseases.
What is the definition of infectious?
Note that in medicine we make a distinction between infection and infectious diseases.
- presence of organisms in a normally sterile site
- where it was not previously member of the normal flora
Prions, viruses, bacteria, fungi, protozoa, parasitic worms, arthropods.
What is the definition of infectious disease?
Note that in medicine we make a distinction between infection and infectious diseases.
- infection accompanied by an inflammatory host response
- or tissue damage
how can an infection cause a disease?
it depends on the microorganism nature, 2 factors:
- Pathogenecity: how sever the disease that the it can cause
- transmissibility: how many microorganisms do you need to get an infection?
the 2 factors together are called Virulence
Define epidemy?
a widespread occurrence of an infectious disease in a community at a particular time.
It really depends on how infectious the disease is. Since sometime about 100 cases of Ebola could be considered an epidemic do to the nature of the disease.
Define the roots of infections and the method of causing disease or tissue damage?
- direct cell damage caused by the microorganism (apoptosis)
- Endo or Exotoxin (enzymes-like molecules that cause tissue damage
- it can go through the innate immunity PMN and macrophages are activated by the microorganism and the enzymes that are released cause tissue damage.
- through the adaptive immunity which can also active the macrophages and produce antibodies. The result is inflammation and tissue damage.
types of tissue damage?
- exodative purulent: Dilation of the small vessels causes macrophages and granulocytes and blood element leave the vessel through its wall and from an “exudatum” made of cell debris macrophages, inflammatory cells.
- Apoptotic necrosis: the cell individually die
- Necrosis: Infraction-like necrosis caused by filamentous fungus: since this affects the vessel wall necrosis occurs.
- Necrotic haemorrhagic: in the brain
- mononuclear/granulomatous damage (late hypersensitive reaction)
- Scarring reactions (chronic infection)
what are the different types of granulomas?
- Caseosus (mycobacterium tuberculosis) necrosis occurs in the center of the granuloma surrounded by epithelial cells and giant cells.
- Abscedent granuloma: in the center of the granulomas neurtophils are present: (cat scratch disease, tularaemia, lymphogranloma venereum)
- Foamy histiocyter:
what are the different types of stains used in detection.
- Stains: HE,
- Special stains:
- electron microscopy
Define sepsis?
is a potentially life-threatening condition caused by the body’s response to an infection.
Primary: we don’t know how the pathogen got into the body?
Secondary: when there is a primary site of infection. (pneumonia for example) we know where the infection is coming from and is associated with organ damage.
what are the risk factors for sepsis?
anything that compromises the immune reaction of the host.
- weaken/breach host defences
- surgical conditions
- type of hospitalization (duration of stay)
- urinary catheter
what kindof bacteria can produce sepsis?
all can cause sepsis
Endotoxins can make it worse.
what is the process of organ failure in sepsis?
peripheral vascular effects (vasodilation etc.) AND direct myocardial effects, Causes microvascular insufficiency and tissue hypoxia
This causes multiogran failure
what do we look for in the diagnosis of the sepsis?
acute-phase proteins; CRP is the most important
