MI3.1-9 | Bloodstream & Cardiovascular Infections — Graded Quiz

A 16-year-old girl is brought with fever, pleuritic chest pain, and a pericardial friction rub 3 weeks after an untreated sore throat. Echocardiography shows a small pericardial effusion. ASO titre is 320 IU/mL. Anti-DNase B is elevated. Which Jones criterion does the pericarditis satisfy?

A 40-year-old intravenous drug user presents with high fever, chills, and multiple small peripheral stigmata. Two of three blood cultures grow Staphylococcus aureus. Echocardiography shows vegetations on the tricuspid valve. Which classification of IE applies?

A patient with culture-confirmed IE is being managed medically. After 48 hours of antibiotics, blood cultures remain positive. Which characteristic of the pathogen MOST likely explains this persistence?

A clinical microbiologist receives a blood culture set from an ICU patient with suspected sepsis. The aerobic bottle turns positive at 18 hours and Gram stain shows Gram-negative rods. Subculture on MacConkey agar produces non-lactose-fermenting colonies. The organism is oxidase-negative, urease-negative, and produces hydrogen sulphide. Which organism is most likely?

A 22-year-old medical student performs a Widal test on herself after 8 days of fever. She received a TAB vaccination 2 years ago. Her TO titre is 1:160 and TH titre is 1:320. She has no other investigation results. Which interpretation is most accurate?

In a patient presenting on day 25 of untreated enteric fever, which specimen is MOST likely to yield Salmonella Typhi on culture?

A 55-year-old man with poorly controlled diabetes is admitted with fever of 39°C persisting for 3 weeks. Investigations: blood cultures (×3) negative, urine culture negative, chest X-ray clear, HIV negative, ANC 4,500/μL, no recent hospitalisation, malaria smear negative, LFTs mildly elevated, ANA negative. TB workup including CBNAAT on sputum is negative. Which investigation is most likely to identify the infective cause in the Indian context?

A 10-year-old boy with thalassaemia major presents with sudden severe anaemia (Hb drop from 7 to 2.5 g/dL) and reticulocyte count of 0.2%. He has been febrile for 3 days with no rash. Parvovirus B19 IgM is detected. Which pathological mechanism explains his anaemia?

A 35-year-old woman with systemic lupus erythematosus (SLE) on hydroxychloroquine develops fever 39°C 48 hours after elective cholecystectomy. She has a central venous catheter (CVC) in situ. Blood cultures drawn through the CVC grow coagulase-negative Staphylococci in 2 of 4 bottles (only from CVC sets, not peripheral sets). Which interpretation is correct?

A public health investigation identifies 12 cases of typhoid fever in a village tracing to a common water source. One household member has had no illness but a stool culture grows Salmonella Typhi. Widal Vi agglutinin titre is elevated. Which statement about this individual is correct?

A 30-year-old woman from Odisha returns from a pilgrimage with 7 days of fever, headache, and myalgia. Physical examination reveals splenomegaly and mild icterus. Peripheral blood smear shows ring forms with appliqué (accolé) pattern, banana-shaped gametocytes, and no enlarged RBCs. Which infective cause of anaemia is confirmed, and what is the immediate risk?

A haematology registrar evaluates a patient's iron studies to distinguish between iron-deficiency anaemia (IDA) and anaemia of chronic infection (ACI) due to suspected visceral leishmaniasis. Which combination of findings is characteristic of ACI?