Infectious Diseases - Cases Flashcards
(22 cards)
What are the common caustive organisms in
- Erysipelas
- Cellulitis
- beta haemolytic Group A Streptococci e.g. strep pyogenes
- Staph Aureus
What is first line antibiotic for mammal bites?
Co-amoxiclav
Which 2 anitibiotics could you use in MRSA?
Doxycycline (mild/mod) and Vancomycin (severe)
What is a worrying sign of deep soft tissue infection?
Pain that is out of proportion with clinical signs
What is necrotizing fasciitis?
- a medical emergency.
- In the media it is often referred to as “flesh eating disease”.
- The hall-mark of this disease is rapid progression and tissue necrosis, often following trauma or surgery.
- Infection has spread along the fascial planes and systemic illness is the norm.
- The patient will need emergency surgical debridement of all necrotic tissue and antibiotics to cover Gram negative, Gram positive and anearobic bacteria.
- Infection is often polymicrobial and the most commonly isolated bacteria are Group A Streptococcus, Staphylococcus aureus and anaerobes.
- Even with prompt therapy, mortality is around 10-30%.
What is the most common group A strep?
Strep pyogenes
This is caused by gas-forming bacteria especially Clostridium perfringens. It is an emergency
gas-gangrene
Who are at risk for cellulitis?
People with venous stasis or lymphoedema are at higher risk of cellulitis in the legs,
- for example patients who have pedal oedema secondary to congestive cardiac failure
- patients who are obese and have excess adipose tissue on their limbs and trunk.
- Diabetes is another common risk factor.
What looks like cellulitis but isn’t?
- deep vein thrombosis
- lymphedema
- venous insufficiency
- venous eczema
What is the difference between MSSA and MRSA?
MRSA is is more difficult to treat because of resistance to antibiotics
MRSA and MSSA have similar virulence, it is just that MRSA is resistant to all penillins, cephalosporins and many other antibiotics. It is particularly associated with hospital-acquired infection but does exist in the community.
What organism is gas gangrene caused by?
Clostridium perfringens
Why can you get sick from Flu twice in one year?
2 different strains - genetic drift
What is antigenic shift?
two or more strains combine to form a new subtype with surface antigens that humans have not encountered previously.
When are flu patients most infectious?
24-48hrs before they display symptoms
Which is the more serious strain of influenza virus?
Influenza A
What kind of drug is used as an antiviral against influenza?
Neuraminidase inhibitors - end in -amivir
How long can the “shedding” period after flu be?
Up to 14 days
What are the common causes of CAP in regular pts?
- Streptococcus pneumoniae,
- Haemophilus influenzae,
- Influenza,
- Legionella pneumophila,
- Mycoplasma pneumoniae
What are the contraindications to flu vaccination?
- immunocompromised
- aged < 2 years
- current febrile illness or blocked nose/rhinorrhoea
- current wheeze (e.g. ongoing viral-induced wheeze/asthma) or history of severe asthma (BTS step 4)
- egg allergy
- pregnancy/breastfeeding
- if the child is taking aspirin (e.g. for Kawasaki disease) due to a risk of Reye’s syndrome
What test is used to diagnose systemic mould (Aspergillus) infections?
Serum galactomannan (GM) test
Which viruses can cause diarrhoea?
- Rotavirus
- Norovirus
- In the immunocompromised, CMV
What is the treatment for CMV?
Ganciclovir
