Infectious Diseases Flashcards
What is the most common causative organism for infective endocarditis?
Staphylococcus aureus
Which pathogen is associated with poor dental hygiene in infective endocarditis?
Streptococcus viridans
Which pathogen is associated with prosthetic valves in infective endocarditis?
Staphylococcus epidermidis
Which pathogen is associated with colorectal cancer in infective endocarditis?
Streptococcus bovis
What are the risk factors of infective endocarditis?
Rheumatic valve disease (30%)
Prosthetic valves
Congenital heart defects
Intravenous drug users (IVDUs)
Dental work
Which valve is most commonly affected by infective endocarditis?
Mitral valve
Aortic > tricuspid > pulmonary
What are the symptoms of infective endocarditis?
Fever/sweats/chills/rigors
Malaise, arthralgia, myalgia, confusion, weight loss
Pyrexia, tachycardia, signs of anaemia
Clubbing
New valvular mumur
Haematuria
Vasculitis lesions
Splenomeagaly
What are the specific signs of infective endocarditis?
Roth spots
Osler nodes
Janeway lesions
Splinter haemorrhages
Which valve is affected in IVDU infective endocarditis?
Tricuspid
What investigations are performed in infective endocarditis?
Bloods -FBC, ESR, CRP
3 blood cultures 1 hour apart within 24 hours
Urgent transoeophageal echocardiogram
Dukes Classification
How many blood cultures are performed in the investigation of infective endocarditis?
3 blood cultures 1 hour apart within 24 hours
Aerobic bottle first before anaerobic
What is the initial blind therapy for infective endocarditis?
Native valve
amoxicillin, consider adding low-dose gentamicin
If penicillin allergic, MRSA or severe sepsis
vancomycin + low-dose gentamicin
If prosthetic valve
vancomycin + rifampicin + low-dose gentamicin
In addition to antibiotics what is added to management for infective endocarditis in prosthetic valve?
Anticoagulation
What are the complications of infective endocarditis?
Stroke (left-side)
PE (Right side)
Congestive heart failure
What are the features of UTIs?
Features dysuria urinary frequency urinary urgency cloudy/offensive smelling urine lower abdominal pain fever: typically low-grade in lower UTI malaise
What is the most common cause of UTI?
E.coli
Which pathogen can cause struvite stones in UTIs?
Proteus mirabilis
What are the risk factors for UTIs?
Age >50 years
Urine outflow obstruction -BPH, stones, strictures
Catheters
DM
Pregnancy
Immunosuppression
What are the signs and symptoms of pyelonephritis?
Rigours Flank pain Pyrexia Nausea and vomiting Acute confusional state
What are the signs and symptoms of cystitis?
Frequency, urgency Dysuria Haematuria Foul-smelling + cloudy urine Suprapubic pain or loin pain
What is the first-line investigation for urinary tract infections?
Dipstick urinalysis - positive nitrites/leukocytes/blood
Urine MC&S - via Mid-stream urine - DIAGNOSTIC
What do White cell casts in urine suggest?
Pyelonephritis
What ABx is prescribed in UTIs?
Trimethoprim (Avoid in pregnancy)
Nitrofurantoin
What is Malaria?
Infection with the protozoan plasmodium
What is the most common type of malaria?
Falciparum malaria
What are the symptoms of malaria?
Headaches Weakness Myalgia/Arthralgia Anorexia Cyclical fevers - paroxysmal of severe cold rigors followed by severe sweating
Signs
- Pyrexia
- Splenomegaly
- Haemolytic anaemia - dark urine
What are the investigations to diagnostically confirm Malaria?
Giemsa-stained thick and thin blood smears
Thick -detects parasites present
Thin - identifies species
What is the management of malaria?
Complicated/severe
- Artensunate
- Quinine
What are the main signs and symptoms of hepatitis?
Raised AST/ALT
Fever
Jaundice
What is the prodromal phase of viral hepatitis?
General fatigue Malaise Joint/muscle pain Low-grade fever GI upset- RUQ pain
What are the symptoms associated with the icteric phase of viral hepatitis?
Jaundice Pale stools Dark urine Pruritus Hepatomegaly RUQ pain
Which hepatitis is associated with chronic hepatitis?
B,C,D
How is HepA-E transmitted?
Faeco-oral transmission
Shellfish and contaminated water.
How is Hep B and C transmitted?
Sexual contact Blood borne Vertical transmission Needle-stick injury Associated with HIV