Infectious Diseases 2 Flashcards
A baby girl born 1 day ago born after a prolonged vaginal delivery, becomes drowsy. On examination, T: 38.9, HR: 170bpm, RR: 30. Which is the most likely causative agent?
A) Neisseria meningitis B) Streptococcus pneumonia C) Listeria monocytogenes D) Group B streptococcus E) E. Coli
D) Group B streptococcus
- meningitis (fever + drowsiness)
- prolonged vaginal birth (prolonged rupture of membranes) is more associated with Group B strep
A 21-year-old wild medical student presents with neck stiffness and photophobia. He has a non-blanching rash. Which of the following is the most likely finding from his LP?
A) Turbid colour, Increased polymorphs, normal monocytes, low glucose, high protein
B) Clear colour, normal polymorphs, high lymphocytes, normal glucose, high protein viral
C) Turbid colour, normal polymorphs, high lymphocytes, low glucose, normal protein
D) Cloudy colour, normal polymorphs, high lymphocytes, low glucose, high protein fungal
E) Clear colour, high polymorphs, normal lymphocytes, low glucose, high protein
A) Turbid colour, increased polymorphs, normal monocytes, low glucose, high protein
- meningococcal septicaemia (meningism + non-blanching rash) which is a BACTERIAL meningitis, therefore CSF findings should reflect bacterial infection
A 72-year-old patient with a new onset murmur, fever and clubbing presents with blood in his stools, diarrhoea and weight loss over the past 5 months. Which is the most likely causative agent?
A) Staph aureus B) Staph epidermis C) Streptococcus viridian D) Streptococcus bovis E) Enterococci
D) Streptococcus bovis
- picture of infective endocarditis (new onset murmur + fever) with colorectal carcinoma (clubbing + bloody diarrhoea + weight loss over 5 months)
- this is associated with S. bovis
A 15-year-old boy with DiGeorge syndrome had a dental tooth extraction 2 weeks ago, visits his GP who on auscultation finds a new murmur on the left sternal edge. Basic observations: BP 110/80, HR: 95, Temperature: 38.5, SaO2 98% on air. What is the most likely causative agent?
A) Staph aureus B) Staph epidermis C) Streptococcus viridian D) Streptococcus bovis E) Enterococci
C) Streptococcus viridian
- DiGeorge patients have congenital heart defects
- dental procedures can result in introduction of infection
- fever + new onset murmur = infective endocarditis
- IE + dental procedure = strep viridian
A 24 year old medical student comes back from their holiday and presents to A&E with profuse diarrhoea of rice water appearance. There is no blood. What is the most likely causative agent?
A) Entamoeba histolytica B) Staph aureus C) Bacillus cereus D) E. Coli E) Vibrio cholera
E) Vibrio cholera
- rice water appearance of profuse diarrhoea (not dysentery as no blood)
A 40 year old woman presents to A&E with bloody, foul smelling diarrhoea. She went to a barbeque yesterday where she suspects she ate undercooked chicken. She has a fever and severe abdominal pain. What is the most likely causative agent?
A) Campylobacter B) Shigella C) Bacillus cereus D) E. coli E) Salmonella
A) Campylobacter
- dysentery (bloody + foul-smelling diarrhoea) + undercooked poultry
(diarrhoea + undercooked poultry/eggs = salmonella, but mostly eggs)
A 67 year old male has been in hospital for the past two weeks for severe pneumonia. He develops bloody diarrhoea, colitis and reduced urine output. He has raised CRP, WCC and low albumin. What is the most likely causative organism?
A) Campylobacter B) C. Difficile C) Bacillus cereus D) E. Coli E) Vibrio cholera
B) C. Difficile
- associated with ABx suggested by hospitalisation + severe pneumonia
A 27-year-old promiscuous man returns from a trip to Thailand with a right upper quadrant pain, fever and raised ALP and AST. Which is the most likely causative agent?
A) Hepatitis A B) Hepatitis B C) Hepatitis C D) Hepatitis D E) Hepatitis E
B) Hepatitis B
- classic Hep symptoms (RUQ pain + raised ALP/AST + fever)
- Hep B most associated with sexual transmission
A 64-year-old male with thalassaemia is investigated under the two-week wait for jaundice, hepatomegaly and weight loss. His blood tests show a raised αFP. Which chronic infection is he most likely to have?
A. Hepatitis A B. Hepatitis B C. Hepatitis C D. Hepatitis D E. Hepatitis E
C. Hepatitis C
- jaundice + hepatomegaly + weight loss + RAISED aFP = hepatocellular carcinoma
- the 2-week wait (urgent referral for HCC) also points to this
- only HBV/HCV can cause HCC
- giveaway here is that HCV is more likely to cause chronic infection but also be transmitted by transfusions (before regulations were tighter and he is 64), which this man would be having for his thalassaemia
A 37-year-old bride-to-be returned from Jamaica 3 days ago, where she partied and explored the local cuisine with her best friends. She presents to her GP complaining of being jaundiced with right upper quadrant pain and fever. What is the most likely cause of her symptoms?
A) Alcoholic hepatitis B) Gall stones C) Cholecystitis D) Hepatitis A E) Hepatitis C
D) Hepatitis A
- Jamaica - endemic for Hep A
- faeco-oral transmission (explored local cuisine)
- classic hepatitis signs (RUQ pain + fever + jaundice)
A 35-year-old woman presenting to her GP with increased urinary frequency and lower back pain. On examination her BP is 130/90, HR: 83bpm, RR: 17bpm and T: 38.3. Which is the most likely finding on her urine dip stick and MC&S?
A) Positive nitrites and Gram-positive coccus
B) Positive nitrites and Gram-negative bacilli
C) Positive glucose, negative nitrites and negative culture.
D) Positive glucose, positive nitrites and negative culture
E) Positive nitrites and Gram-negative coccus
B) Positive nitrites and Gram-negative bacilli
- clinical picture of UTI (urinary frequency + lower back pain + fever)
- dipstick = positive nitrites + leukocytes
A 35-year-old woman presenting to her GP with increased urinary frequency and lower back pain. On examination her BP is 130/90, HR: 83bpm, RR: 17bpm and T: 38.3.
What is the most likely causative agent for the most likely diagnosis?
A) Proteus B) Klebsiella C) Staph aureus D) Enterococci E) E. Coli
E) E. Coli
- most common causative organism for UTI (classical clinical picture/urinalysis results)
- Gram-negative
A 45-year old man presented to his GP with cyclical fevers. He returned from Ethiopia 10 days ago. What is the most likely causative agent?
A) Salmonella typhi B) Yersinia pestis C) Leptospirosis D) Plasmodium falciparum E) Coxiella burnetii
D) Plasmodium falciparum
- man has malaria (cyclical fevers + travel to endemic country)
- most common cause of malaria = plasmodium sp. particularly falciparum
