infective pathology Flashcards
infection
infection is the invasion of disease causing agents into the body, their multiplication, the hosts reaction to the infectious agents and the toxins they produce
communicable disease
agent has been transferred from one person to another
clinical illness
when patient is aware of symptoms
subclinical/occult disease
symptoms are not apparent
examples of infection types
- virus
- bacterium
- fungi
- protozoan
- helmith
- prion
what is skin and how does it slow bacterial growth?
keratinised layer, low pH and fatty acids slow bacterial growth
diseases due to broken skin
- superficial pricks - fungus
- wounds - staphylococci
- burns - pseudomonas
diseases due to needle stick injuries
- HBV
- HCV
- HIV
diseases due to insect bites
- dogs - rabies
- mosquitos - malaria
- sand flies - leishmaniasis
- fleas - plague
- ticks - lyme disease
natural openings have mucosal linings. how do they help prevent infection? give examples
- low pH in stomach
- pancreatic enzymes are lytic
- bile is a detergent
- resident flora
- lysozyme in tears and mucus
some organisms invade mucosa?
- cholera - enters gut epithelium + release exotoxin
- salmonella - damage lamina propria - inflammation, ulceration
what are some organisms impairing ciliary function?
- H.influenza release toxins that cause ciliary paralysis
- mycoplasma pneumonia produce ciliostatic substance
- chronic damage to ciliary apparatus caused by CF and smoking
types of transmission : person to person
- airborne aerosols ( most viruses and bacteria )
- saliva ( EBV, mumps )
- faeco-oral ( hookworm )
- blood ( HBV, HCV, HIV )
- sexual ( STIs )
likelihood and severity of illness depends on …
- virulence of microbe
- host immune response
- number of causative agents
- whether host is immune compromised
what is nosocomial infection?
- hospital acquired infection
- develops 48 hours after entry to hospital or 48 hours after release from hospital
