Infection Flashcards
Why is important to differentiate between hospital and community acquired infection?
Different infecting organisms
Different antibiotic resistance patterns
Marker for outbreaks/epidemiology
Marker of poor infection control in hospitals (hospitals can be fined if too much hospital-acquired infection)
What infections have more resistance hospital acquired or community, why?
Hospital infections have more resistance due to beta lactamases
Cell wall inhibitor antibiotics?
Beta lactams:
- Penicillins - amoxicillin, flucloxacillin
- cephalosporins - cefuroxime, ceftriaxone, ceftazidime
- Carbapenems - meropenem, ertapenem, imipenem
Glycopeptides:
- Vancomycin
Possible issues with using narrower spectrum antibiotics?
Can lead to C diff infection.
In hospital infections what antibiotic groups are not indicated due to beta lactamases?
Penecillins
Cephalosporins
Issues with vancomycin?
Has to be given IV
Risk of renal impairment
Therapeutic levels need to be monitored
What will vancomycin not work against?
Gram negatives
vanco-resistant enterococci
Protein inhibitor antibiotics
- Tetracyclines (bacteriostatic) – doxycycline, tetracycline
- Macrolides (bacteriocidal) – clarithromycin, erythromycin
- Aminoglycosides (bacteriostatic) - gentamicin
How can C diff progress?
- Mild diarrhoea
- Pseudomembranous colitis
- Toxic megacolon
- Colonic perforation
- death
How do you test for C diff infection?
Stool test
Most common causes of C diff infection?
- Cephalosporins
- Ciprofloxacin
- Clindamycin
- Co-amoxiclav
Risks associated with tetracyclines?
Risk of photosensitivity
Risk of teeth staining in
Risks associated with macrolides?
Risk of cardiac complications
Interact with statins
GI upset
Risks associated with aminoglycosides?
Renal toxicity
Ototoxicity
DNA synthesis inhibitor antibiotics?
- Quinolones (bacteriocidal) – ciprofloxacin, moxifloxacin, levofloxacin
- Nitroimidazoles (bacteriocidal at higher doses) – metronidazole
- Nitrofurans e.g. nitrofurontoin
Risks of Quinolones?
QT prolongation
reduced seizure threshold
achilles tendon rupture
C diff infection
Risks of metronidazole?
GI upset, peripheral neuropathy
Management of C diff infection?
- Stopping offending antibiotic
- Isolation
- Fluid rehydration
- Avoid anti-motility drugs e.g. loperamide
- Consider stopping PPIs
- Metronidazole/vancomycin
Norovirus diagnosis?
Stool PCR
Treatment of norovirus?
ORT, paracetamol antiemetics
Treatment of MRSA?
IV vancomycin
What groups should routine HIV testing be carried out in?
- MSM
- IVDU
- Pregnant women
- Anyone with another STI/a partner with an STI
- Anyone from a country with a high HIV prevalence
What is Pneumocystis pneumonia (PCP) how do you treat?
Most common Opportunistic infection in UK in immunosuppressed patients.
Treat with co-trimoxazole (&steroids)
What is toxoplasmosis, how is it treated?
protozoan parasite - uncooked food
Can cause SOL in brain, ost infection is fairly asymptomatic
Treated with sulfadiazine (antibiotoc) and pyrimethamine (anti protozaol)
What is Kaposi’s sarcoma? Treatment?
AIDS associated cancer
Dark/red pigmented lesion from a vascular tumour of spindle cells
Driven by co-infection with HHV-8
Treat with anti-retrovirals and chemo
Examples of antiretrovirals?
AZT/ zidovudine – a nucleotride reverse transcriptase inhibitor (NRTI)
Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) - Nevaripine
Protease inhibitors (PIs) Indinavir
Treatment regimens for HIV?
- 2 NRTIs and a NNRTI
- 2 NRTIs and a PI
- 2 NRTIs and an integrase inhibitor e.g. raltegravir
Four modes of action of antibiotics?
Cell wall inhibitor
Inhibit protein synthesis
Inhibit DNA synthesis
Inhibit RNA synthesis
RNA synthesis inhibitor antibiotics?
Rifamycins
Rifamycin limitations/SEs?
Stains bodily fluids orange
hepatotoxicity
Drug interactions
Common hospital acquired infections?
C. diff
MRSA
Norovirus
What types of antibiotics is MRSA resistant to?
Beta lactams
Major associated conditions with HIV?
Seroconversion illness Pneumocystis jirroveci pneumonia Toxoplasmosis Kaposis sarcoma Tuberculosis
Levels of CD4 associated with PCP?
Lower than 200
Predicted total life expectancy of HIV if caught early?
65 years+
Common cause of pneumonia and meningitis in the community?
Strep pneumonia
Use of monoclonal antibodies against C diff?
Reduce recurrence
