Infection Model Flashcards
Outline the infection model
Patient + pathogen (mechanism of action) -> infection -> management -> outcome
What are the different pathogens
Virus, bacteria, fungus (yeast, moult), parasite (protozoa, helminth/worms)
What factors affect patient
Person - age, gender, physiological state, pathological state, social state
Time - calendar time - infections that occur in certain times of the year
Respiratory infections more common in winter in northern hemisphere
Relative time - diseases have specific incubation periods
Incubation period of chicken pox means it spreads at certain times
Place - respiratory infection - flu spreading very quickly in city
Places been to recently - Ebola in west Africa, West Nile fever
What are some mechanisms of infection
Direct spread - contact
Inoculation - needle injury
Haematogenous - zits when squeezed may spread substance into local tissue
Ingestion - food borne diseases - diarrhoea, GI upset, salmonella, hand contamination
Inhalation - breathing in aerosols - common viral infections but some in bacterial infections including tuberculosis
Vector - intermediates including insects, pets - malaria
Vertical transmission - from mother to child - during pregnancy, at birth, breast feeding
What factors affect infection
Once attached, can produce toxins or interact with host defenses
Leads to host damage and possible inflammation
What factors are in management
Diagnosis - history, examination, investigations, treatment
What are the 2 types of treamtent
Specific - giving specific antimicrobial
Could also do surgery to remove infected tissue and organism - cataract surgery infection where visceral is removed
Removed infected bone and tissue around bone - creates dead space which could lead to fluid build up and leads to infection
Supportive - symptom relief - cold - paracetamol and sleep
eg. giving chemicals such as noradrenaline to give more energy to heart, dialysis to remove excess fluid
What factors are in outcome
Range of outcomes from cure to death
