Lecture 8- Activity of a pathogen 1 Flashcards
Pathogen
Microbe capable of causing disease
Infection
Microbe established on/in host, (doesn’t have to result in disease).
Colonisation
When another species comes and invades
-20% are colonised and therefore more likely to get diseases.
Endogenous infectious disease
Arise/ is cause by bacteria inside self
eg) UTI, appendicitis
Bulk of infectious diseases
Exogenous infectious disease
arises from elsewhere
eg) flu, zoonosis, environ, human transmission.
What a the risks for a non-infected, non-immune individual.
Immune senecescence (gradual deterioration of IS with age)
Risk behaviours
Other illness
Principle Pathogen
Causes disease in those w/ intact immune system
Opportunistic pathogen
Causes infection only when immune defenses are down. (illness/ underweight)
Primary pathogen
causes disease by direct interaction with host
eg) gonorrhea
settings in which infection can occur
Community accquired
Community onset
Hospital acquired
hospital onset
nosocomial
Prevention of Healthcare-associated infection
gloves/gowns decontamination of spills disposal of sharps/needles waste-management HAND HYGIENE
Transmission of infectious agents can be…
Direct: sexual transmission contact faecal-oral -droplet -airbourne
Indirect:vector borne (healthcare worker)
transfusion
airbourne
Structural Viral classification
- Nucleic Acid (+ or - )
- Capsid (viral protein shell)
- envelope (HIV is a - sense RNA retrovirus)
+ sense vs - sense
Positive-sense (5’ to 3’) viral RNA signifies that a particular viral RNA sequence may be directly translated into the desired viral proteins.
Negative-sense (3’ to 5’) viral RNA is complementary to the viral mRNA and thus must be converted to positive-sense RNA by an RNA polymerase prior to translation. Like DNA, this RNA cannot be translated into protein directly
Disease viral classification
Hepatitis: eg) HAV, HBV and HCV are not related BUT we put together as they all damage the LIVER cells.
Respiratory viruses
