MI9.1-6 | Zoonotic, Opportunistic & Emerging Infections — Graded Quiz

A 29-year-old veterinary assistant from Rajasthan presents with 3 weeks of undulant fever, profuse sweating, and bilateral sacroiliac joint pain. He regularly assists in calving and consumes unpasteurised camel milk. Blood culture is sent. Which selective medium is MOST appropriate for primary isolation of the suspected pathogen?

A public health officer investigating a plague outbreak in a rural district of Himachal Pradesh wants to rapidly confirm Yersinia pestis in lymph node aspirate from a dead rat. Which combination of tests best provides both presumptive identification AND species confirmation in the field laboratory?

A 55-year-old diabetic man undergoes emergency orchidectomy for Fournier's gangrene. Intraoperative cultures grow a mixed flora including Bacteroides fragilis, Escherichia coli, and Streptococcus anginosus. Histopathology shows thrombosis of subcutaneous vessels with widespread tissue necrosis. This infection pattern is BEST explained by which mechanism of opportunistic pathogenesis?

A 44-year-old woman with systemic lupus erythematosus on long-term prednisolone (40 mg/day) and mycophenolate develops 5 days of fever, pleuritic chest pain, and progressive dyspnoea. HRCT chest shows wedge-shaped peripheral consolidation with a central hypodense zone ('halo sign'). Bronchoscopy lavage reveals septate hyphae at 45° branching angles. Which diagnostic test will MOST reliably distinguish invasive aspergillosis from mucormycosis in this sample?

A 19-year-old male presents to an STI clinic with multiple soft, fleshy, exophytic warty growths around the anus and perianal region. HPV genotyping confirms HPV type 6 infection. He asks whether he is at increased risk of anal cancer. Which cellular mechanism BEST explains why HPV type 6 carries lower oncogenic risk compared to HPV type 16?

A 40-year-old HIV-positive patient (CD4 count: 75 cells/µL, not on ART) develops odynophagia. Endoscopy shows diffuse, creamy-white plaques covering the entire oesophagus that can be scraped off to reveal a bleeding base. Biopsy shows pseudohyphae invading the mucosa. He is started on systemic fluconazole. After 5 days, he has not improved. Which investigation is MOST appropriate next?

An epidemiologist investigates an outbreak of febrile illness with haemorrhagic manifestations and jaundice among slaughterhouse workers in Andhra Pradesh. Of 40 workers, 18 are affected. Serology confirms Q fever (Coxiella burnetii). The source is traced to parturient goats. Which property of Coxiella burnetii MOST explains why it is exceptionally hazardous in a slaughterhouse setting?

A 61-year-old male smoker with a 30-year history of H. pylori gastritis undergoes gastroscopy showing a 3 cm antral ulcer with rolled edges and central necrosis. Biopsy confirms intestinal-type gastric adenocarcinoma. Regarding H. pylori's carcinogenic mechanism, which pathway MOST directly drives intestinal metaplasia — the critical premalignant step?

A cluster of 8 patients with severe encephalitis and acute respiratory distress syndrome (ARDS) is reported in a pig-farming community in northern Kerala. All patients had direct contact with symptomatic pigs showing neurological signs. Fruit bats (Pteropus) are found roosting in mango trees over the pig pens. One healthcare worker who managed the patients without PPE develops similar illness. Based on these epidemiological features, which characteristic of this pathogen MOST concerns the outbreak response team regarding pandemic potential?

A state health department reviews its National TB Elimination Programme performance. Despite high GeneXpert coverage, smear conversion rates remain suboptimal in tribal district hospitals. The programme manager proposes integrating Digital Adherence Technologies (DATs) under the Ni-kshay 2.0 framework. Under the current National TB Elimination Programme (NTEP), which combination of interventions represents the COMPLETE standard package for a newly diagnosed drug-sensitive TB patient?

A clinician in an urban referral centre is evaluating a 37-year-old immunocompetent man who returned from Andaman & Nicobar Islands 2 weeks ago with a 10-day febrile illness. He reports daily fever spikes reaching 40°C, myalgia, and a painless eschar on the right ankle. Peripheral blood smear shows no malarial parasites. Widal test is negative. Which investigation algorithm BEST confirms the suspected diagnosis?

India launched the HPV vaccination programme including CERVAVAC (indigenous quadrivalent HPV vaccine) under the Universal Immunisation Programme in 2023. For a 15-year-old girl receiving her first dose today, which immunisation schedule AND rationale BEST reflects current Government of India recommendations?