Lecture 13- Pathogens 2 Flashcards
Why are doctors being advised to only prescribe AB when needed?
Antibiotic prescribing leads to development of resistance, due to the incredibly fast evolution of pathogens. This means AB become invalid and don’t work, and the patient can no longer be cured. MAJOR WORLD WIDE ISSUE
Indirect transmission
infectious disease spread from person to person, but they are not at the same place at the same time
- vector bourne (mozzi, healthcare worker)
- blood transfusion
- airbourne
Direct transmission
Person to person
- coughing
- sneezing
- faecal - oral
Universal precautions
gloves decontamination of spills disposal of sharps/needles waste management environmental cleaning HAND HYGIENE
Extra precautions that are done
Contact precautions:
Gloves for ALL patient contact
Gowns/eyeware
Droplet precautions: masks for close contact
Airbourne precautions: respirator mask for staff/patients
Viral tropism
viral target cell
eg) HIV and CD4 on helper T-cells
Steps of viral infection
1) Virus attachment and entry
2) nucleic acid released in host
3) + RNA formed
4) Protein synthesus
5) Genome replication
6) Assembly
7) release
Cause of viral infection symptoms?
symptoms due to damaged cells! Immune system reacts against these.
eg) damaged hepatocytes in Hep C
Rotavirus causes illness by
VP4 spikes o outer shell attach to colonic epithelium»_space; diarrhea
Serology
Study blood
measure viral antibodies against antigens.
Specific antibodies (for rare illnesses) OR how the numbers of ABs change
Seroconversion
change in type of immunoglobulin
-indicates infection
Virulence factors
genetic determinants that allow a pathogen to cause disease
- adherence
- invasion
- immune evasion
- toxins
levels of virulence
commensual, ‘never’ cause disease
» commensual, rarely cause disease»_space; requires some breech of host defences»_space; can cause disease in hosts with intact defences
