Leishmania species — MCQs

A 32-year-old woman presents to your office with abdominal pain and bloating over the last month. She also complains of intermittent, copious, non-bloody diarrhea over the same time. Last month, she had a cough that has since improved but has not completely resolved. She has no sick contacts and has not left the country recently. She denies any myalgias, itching, or rashes. Physical and laboratory evaluations are unremarkable. Examination of her stool reveals the causative organism. This organism is most likely transmitted to the human host through which of the following routes?

A 48-year-old man comes to the physician because of a hypopigmented skin lesion on his finger. He first noticed it 4 weeks ago after cutting his finger with a knife while preparing food. He did not feel the cut. For the past week, he has also had fever, fatigue, and malaise. He has not traveled outside the country since he immigrated from India to join his family in the United States 2 years ago. His temperature is 38.7°C (101.7°F). Physical examination shows a small, healing laceration on the dorsal aspect of the left index finger and an overlying well-defined, hypopigmented macule with raised borders. Sensation to pinprick and light touch is decreased over this area. Which of the following is the most likely causal pathogen of this patient's condition?

A 28-year-old woman comes to the emergency department for a rash that began 3 days ago. She has low-grade fever and muscle aches. She has no history of serious illness and takes no medications. She has had 5 male sexual partners over the past year and uses condoms inconsistently. Her temperature is 38.1°C (100.6° F), pulse is 85/min, and blood pressure is 126/89 mm Hg. Examination shows a diffuse maculopapular rash that includes the palms and soles. The remainder of the examination shows no abnormalities. A venereal disease research laboratory (VDRL) test is positive. Which of the following is the next appropriate step in management?

During a humanitarian medical mission in rural Vietnam, a medical resident encounters a 50-year-old man with a year-long history of a pruritic rash on his upper body and face, along with numbness and tingling sensation of both of his palms. He mostly works on his family’s rice farm, where he also takes care of livestock. A physical examination revealed multiple erythematous macules and papules on the face, arms, chest, and back, as well as thinning of the eyebrows and loss of some eyelashes. Additional findings include hypopigmented macules around the elbows, which are insensitive to light touch, temperature, and pinprick. The grip strength is slightly diminished bilaterally with the conservation of both bicipital reflexes. What is the most likely diagnosis?

An investigator is studying human genetics and cell division. A molecule is used to inhibit the exchange of genetic material between homologous chromosomes. Which of the following phases of the cell cycle does the molecule target?

A 47-year-old woman comes to the physician because of a 3-day history of fever, fatigue, loss of appetite, cough, and chest pain. Physical examination shows diffuse inspiratory crackles over the left lung field. An x-ray of the chest shows hilar lymphadenopathy and well-defined nodules with central calcifications. Urine studies show the presence of a polysaccharide antigen. A biopsy specimen of the lung shows cells with basophilic, crescent-shaped nuclei and pericellular halos located within macrophages. This patient's history is most likely to show which of the following?

A 30-year-old woman who is 24-weeks pregnant presents to the emergency department with fever, painful urination, and headache. The patient's blood pressure is 111/67 mm Hg, the pulse is 95/min, the respiratory rate is 16/min, and the temperature is 38.3°C (101.1°F). Physical examination reveals bilateral tender inguinal lymphadenopathy and painful genital lesions. On closer inspection, the patient’s genital lesions contain clear fluid and measure 5–6 mm in diameter. What is the appropriate description of these lesions?

A 24-year-old female comes to the physician because of flu-like symptoms and a new rash for 2 days. She denies contacts with sick individuals or recent travel abroad, but recently went camping in Vermont. Vital signs are within normal limits. Examination of the lateral right thigh shows a circular red ring with central clearing. Which of the following is the natural reservoir of the pathogen responsible for this patient's symptoms?

A 27-year-old dental radiographer presented to a clinic with red lesions on his palate, right lower and mid-upper lip, as well as one of his fingers. These lesions were accompanied by slight pain, and the patient had a low-grade fever 1 week before the appearance of the lesions. The patient touched the affected area repeatedly, which resulted in bleeding. Two days prior to his visit, he observed a small vesicular eruption on his right index finger, which merged with other eruptions and became cloudy on the day of the visit. He has not had similar symptoms previously. He did not report drug usage. A Tzanck smear was prepared from scrapings of the aforementioned lesions by the attending physician, and multinucleated epithelial giant cells were observed microscopically. According to the clinical presentation and histologic finding, which viral infection should be suspected in this case?

A 27-year-old male who works on an organic farm is diagnosed with infection by N. americanus, a helminthic parasite. Eosinophils require which antibody isotype to destroy these parasites via antibody-dependent cellular cytotoxicity?