Pneumocystis jirovecii — MCQs

A 26-year-old man comes to the physician for a follow-up examination. He was diagnosed with HIV infection 2 weeks ago. His CD4+ T-lymphocyte count is 162/mm3 (N ≥ 500). An interferon-gamma release assay is negative. Prophylactic treatment against which of the following pathogens is most appropriate at this time?

A 50-year-old man with a remote history of intravenous drug use and a past medical history of AIDS presents to his primary care provider with several weeks of productive cough and a mild fever. He was in his normal state of health and slowly started to develop these symptoms. He is hoping to be prescribed an antibiotic so he can get back to “normal”. Family history is significant for cardiovascular disease and diabetes. He takes antiviral medication and a multivitamin daily. His heart rate is 90/min, respiratory rate is 19/min, blood pressure is 135/85 mm Hg, and temperature is 38.3°C (100.9°F). On physical examination, he looks uncomfortable. A chest examination reveals consolidation in the right lower lung. Chest radiography confirms right lower lobe pneumonia. Of the following options, which is the most likely cause of the patient’s pneumonia?

A 33-year-old HIV-positive male is seen in clinic for follow-up care. When asked if he has been adhering to his HIV medications, the patient exclaims that he has been depressed, thus causing him to not take his medication for six months. His CD4+ count is now 33 cells/mm3. What medication(s) should he take in addition to his anti-retroviral therapy?

A 26-year-old man is undergoing a bone marrow transplantation for treatment of a non-Hodgkin lymphoma that has been refractory to several rounds of chemotherapy and radiation over the past 2 years. He has been undergoing a regimen of cyclophosphamide and total body irradiation for the past several weeks in anticipation of his future transplant. This morning, he reports developing a productive cough and is concerned because he noted some blood in his sputum this morning. The patient also reports pain with inspiration. His temperature is 101°F (38.3°C), blood pressure is 115/74 mmHg, pulse is 120/min, respirations are 19/min, and oxygen saturation is 98% on room air. A chest radiograph and CT are obtained and shown in Figures A and B respectively. Which of the following is the most likely diagnosis?

A 10-year-old boy is brought to the physician by his mother because of a 2-day history of fever and productive cough. He has had similar episodes sporadically in the past with frequent episodes of thick, discolored nasal discharge. Physical examination shows diffuse crackles and rhonchi. The most likely cause of recurrent infections in this patient is a dysfunction of which of the following cell types?

A 35-year-old man comes to the emergency department with fever, chills, dyspnea, and a productive cough. His symptoms began suddenly 2 days ago. He was diagnosed with HIV 4 years ago and has been on triple antiretroviral therapy since then. He smokes one pack of cigarettes daily. He is 181 cm (5 ft 11 in) tall and weighs 70 kg (154 lb); BMI is 21.4 kg/m2. He lives in Illinois and works as a carpenter. His temperature is 38.8°C (101.8°F), pulse is 110/min, respirations are 24/min, and blood pressure is 105/74 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 92%. Examinations reveals crackles over the right lower lung base. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 11.5 g/dL Leukocyte count 12,800/mm3 Segmented neutrophils 80% Eosinophils 1% Lymphocytes 17% Monocytes 2% CD4+ T-lymphocytes 520/mm3(N ≥ 500) Platelet count 258,000/mm3 Serum Na+ 137 mEq/L Cl- 102 mEq/L K+ 5.0 mEq/L HCO3- 22 mEq/L Glucose 92 mg/dL An x-ray of the chest shows a right lower-lobe infiltrate of the lung. Which of the following is the most likely causal organism?

A 26-year-old man with HIV and a recent CD4+ count of 800 presents to his PCP with fever, cough, and dyspnea. He notes that he recently lost his job as a construction worker and has not been able to afford his HAART medication. His temperature is 102.6°F (39.2°C), pulse is 75/min, respirations are 24/min, and blood pressure is 135/92 mmHg. Physical exam reveals a tachypneic patient with scattered crackles in both lungs, and labs show a CD4+ count of 145 and an elevated LDH. The chest radiography is notable for bilateral diffuse interstitial infiltrates. For definitive diagnosis, the physician obtains a sputum sample. Which stain should he use to visualize the most likely responsible organism?

A 41-year-old male with a history of Pneumocystis jirovecii pneumonia is found to have multiple ring-enhancing lesions on brain CT. Which of the following is most likely responsible for this patient's abnormal scan?

A 3-month-old girl is brought to the emergency department because of a 2-day history of progressive difficulty breathing and a dry cough. Five weeks ago, she was diagnosed with diffuse hemangiomas involving the intrathoracic cavity and started treatment with prednisolone. She appears uncomfortable and in moderate respiratory distress. Her temperature is 38°C (100.4°F), pulse is 150/min, respirations are 50/min, and blood pressure is 88/50 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 87%. Oral examination shows a white plaque covering the tongue that bleeds when scraped. Chest examination shows subcostal and intercostal retractions. Scattered fine crackles and rhonchi are heard throughout both lung fields. Laboratory studies show a leukocyte count of 21,000/mm3 and an increased serum beta-D-glucan concentration. An x-ray of the chest shows symmetrical, diffuse interstitial infiltrates. Which of the following is most likely to confirm the diagnosis?

A 44-year-old man comes to the physician because of a 3-week history of productive cough, fever, and lethargy. He also has several skin lesions over his body. His symptoms began 3 weeks after he returned from a camping trip in Kentucky. Three years ago, he underwent kidney transplantation for polycystic kidney disease. Current medications include sirolimus and prednisone. His temperature is 38°C (100.4°F). Diffuse crackles are heard over the lung fields. There are 4 white, verrucous skin patches over his chest and upper limbs. A photomicrograph of a skin biopsy specimen from one of the lesions is shown. Which of the following is the most likely diagnosis?