Respiratory Tract Infections Flashcards
Name 5 LRTIs.
- Influenza virus
- RSV
- Varicella (adults)
- Measles
- SARS
- Cytomegalovirus
Describe two features of SARS.
CXR shoes pneumonia and SARS does not respond to antimicrobial medicine.
RSV re-infection occurs throughout life due to what?
Antigenic drift.
RSV in the elderly causes what?
Flu-like symptoms.
What are the 3 types of Influenza?
A,B and C.
What is special about A and C?
A has 2 subtypes - HA and NA (surface proteins).
C is not pathogenic to humans.
What are the two types of complications that can arise with influenza virus?
CNS complications - encephalitis.
Pneumonia - Primary viral and secondary bacterial.
Antigenic shift is specific for what type of influenza?
Influenza A. 20% of AA differ from each other. Genetic reassortment between human and non-human viruses leads to new genetic subtypes.
Influenza virus is lytic - what does this mean?
Strips off the lining off the respiratory epithelium - removes mucosa and cilia.
What production circulates in the blood?
Interferon production - virus doesn’t.
What production circulates in the blood?
Interferon production - virus doesn’t.
Antigenic Drift occurs in what types of influenza?
A and B. Random spontaneous mutation in viral genome encoding NA and HA.
Common cold can be caused by what? Name 5.
Enterovirus, Parainfluenza virus 1-4, Rhinovirus, Coronaviruses (can cause SARS), RSV, Adenovirus. All these may predispose a secondary bacterial infection eg: sinusitis/pneumonia.
URTI caused by what?
Virus - and very common.
List 4 URTIs.
Epiglottis, croup, pharyngitis/tonsillitis, glandular fever.
Glandular fever has what type of cells in blood?
Atypical mononuclear cells.
Glandular fever has what type of cells in blood?
Atypical mononuclear cells.
What are the two types of pneumonia?
HAP (Hospital acquired pneumonia) and CAP (Community acquired pneumonia).
What are the causes of CAP. What is the most common cause?
Most common cause is S. Pneumoniae - resistance to penicillin is common. Other causes are - H.Influenzae, C. pneumoniae, L. pneumophilia, M. pneumonia.
Bacteria, Atypical bacteria and Viruses cause what %/ of CAP.
Bacteria - 60-80%
Atypical bacteria - 10-20%
Viruses 10-20%.
What relevance does CURB65 have?
SEVERE CAP if you have 3 or more of the following symptoms.
C-confusion U-urea > 7mmol/l R-respiration rate > 30 per/min B-blood pressure - Systolic 65 - Are over the age of 65
What relevance does CURB65 have?
SEVERE CAP if you have 3 or more of the following symptoms.
C-confusion
U-urea > 7mmol/l
R-respiration rate > 30 per/min
B-blood pressure - Systolic
CAP is treated with what?
Amoxicillin prescribed if not severe.
If severe - co-amoxiclav and clarithromycin.
HAP occurs when?
More than 48 hours after admission to hospital.
